Equity Compensation (Tables)
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12 Months Ended |
Dec. 31, 2015 |
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| Equity Compensation |
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| Summary of stock option activity |
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Weighted
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Weighted
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Average
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Shares Subject
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Average
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Weighted
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Remaining
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to Options
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Grant Date
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Average
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Contractual
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Outstanding
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Fair Value
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Exercise Price
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Life (Years)
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Balance at December 31, 2013
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4,905,214
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$
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6.31
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Granted
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1,592,268
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$
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9.99
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18.00
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Exercised
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(1,512,514)
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4.24
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Expired
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(136)
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7.40
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Forfeited
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(133,611)
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13.77
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Balance at December 31, 2014
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4,851,221
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10.57
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Granted
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238,516
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5.31
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10.52
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Exercised
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(285,387)
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4.87
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Expired
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(47,866)
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13.92
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Forfeited
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(183,812)
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14.76
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Balance at December 31, 2015
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4,572,672
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10.72
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Exercisable options at December 31, 2014
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2,494,711
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6.33
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5.6
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Vested and expected to vest at December 31, 2014
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4,615,485
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10.30
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7.0
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Exercisable options at December 31, 2015
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3,185,180
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8.76
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5.2
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Vested and expected to vest at December 31, 2015
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4,466,655
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10.61
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6.1
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| Summary of stock options outstanding and exercisable |
The following table summarizes information about stock options outstanding and exercisable at December 31, 2015:
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Options Outstanding
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Options Exercisable
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Weighted-
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Weighted-
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Weighted
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Average
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Average
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Average
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Number of
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Remaining
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Number of
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Remaining
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Exercise
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Underlying
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Contractual
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Underlying
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Contractual
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Range of Exercise Prices
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Price
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Shares
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Life (in years)
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Shares
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Life (in years)
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$
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1.96
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-
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3.38
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2.59
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222,051
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0.9
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222,051
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0.9
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$
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3.58
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-
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6.14
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5.66
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1,382,873
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4.4
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1,382,873
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4.4
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$
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6.34
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-
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9.94
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8.32
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1,006,242
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6.2
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810,505
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5.8
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$
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11.28
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-
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16.97
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13.74
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1,230,444
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8.1
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427,094
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7.2
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$
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17.66
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-
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22.92
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20.97
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731,062
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7.9
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342,657
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7.5
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4,572,672
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3,185,180
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| Summary of aggregate intrinsic-value of options exercised, exercisable, and vested and expected to vest |
The following table summarizes the aggregate intrinsic‑value of options exercised, outstanding and exercisable (in thousands):
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For the Years Ended
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and as of December 31,
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2013
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2014
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2015
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Options Exercised
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$
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1,315
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$
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22,668
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$
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1,432
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Options Exercisable
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42,116
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22,718
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3,496
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Options Vested and Expected to Vest
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55,099
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27,663
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3,499
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| Schedule of assumptions used to estimate fair value of option awards |
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Years Ended
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December 31,
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2013
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2014
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2015
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Expected volatility
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56
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-
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59
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%
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49
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-
|
60
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%
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51
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-
|
55
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%
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Expected dividends
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0
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%
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0
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%
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0
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%
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Expected terms (in years)
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3.3
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-
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7.2
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1.0
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-
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6.1
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5.3
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-
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6.1
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Risk-free rate
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0.8
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-
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1.7
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%
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0.3
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-
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2.0
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%
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1.3
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-
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1.8
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%
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| Summary of restricted stock unit activity |
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Number of
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Weighted Average
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Shares
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Grant Date Fair Value
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Non-vested balance at December 31, 2014
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—
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Awarded
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433,000
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$
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8.18
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Vested
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—
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Forfeited
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(8,000)
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Non-vested balance at December 31, 2015
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425,000
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| Schedule of total stock-based compensation expense classified in statements of operations |
Total stock‑based compensation expense has been classified as follows in the accompanying Consolidated Statements of Operations (in thousands):
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Years Ended
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December 31,
|
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2013
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2014
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2015
|
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Cost of revenue
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$
|
63
|
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$
|
105
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$
|
174
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Research and development
|
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1,414
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2,235
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2,885
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Sales and marketing
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743
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1,110
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1,783
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General and administrative
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1,540
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1,891
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2,192
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Total stock-based compensation expense
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$
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3,760
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$
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5,341
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$
|
7,034
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