Equity Compensation (Tables)
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12 Months Ended |
Dec. 31, 2018 |
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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, 2015
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4,572,672
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$
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10.72
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Granted
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50,000
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$
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4.63
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8.16
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Exercised
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(685,798)
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5.01
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Expired
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(76,907)
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14.96
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Forfeited
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(83,562)
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14.81
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Balance at December 31, 2016
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3,776,405
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11.55
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Exercised
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(1,617,659)
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10.48
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Expired
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(60,275)
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17.51
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Forfeited
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(28,669)
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16.70
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Balance at December 31, 2017
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2,069,802
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12.13
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Exercised
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(979,586)
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11.20
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Expired
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(3,212)
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5.95
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Forfeited
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(5,792)
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13.30
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Balance at December 31, 2018
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1,081,212
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12.98
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Exercisable options at December 31, 2018
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1,031,239
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13.16
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4.6
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Vested and expected to vest at December 31, 2018
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1,081,212
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12.98
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4.6
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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, 2018:
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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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4.89
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-
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7.49
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6.18
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286,951
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2.6
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282,443
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2.5
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$
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8.16
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-
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12.93
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10.54
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280,219
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5.2
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234,876
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5.0
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$
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12.98
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-
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19.56
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15.60
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281,973
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5.8
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281,851
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5.8
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$
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20.91
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-
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22.92
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21.15
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232,069
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5.1
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232,069
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5.1
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1,081,212
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1,031,239
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| Summary of aggregate intrinsic-value of options exercised, outstanding and exercisable |
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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2018
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2017
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2016
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Options Exercised
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$
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18,616
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$
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19,966
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$
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3,312
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Options Exercisable
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5,420
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31,841
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6,089
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Options Vested and Expected to Vest
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5,836
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36,489
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6,280
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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, 2015
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425,000
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$
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8.18
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Awarded
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1,147,946
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7.40
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Vested
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(35,340)
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7.85
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Forfeited
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(141,219)
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7.66
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Non-vested balance at December 31, 2016
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1,396,387
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7.60
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Awarded
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783,060
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11.28
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Vested
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(823,620)
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7.62
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Forfeited
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(65,167)
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8.82
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Non-vested balance at December 31, 2017
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1,290,660
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9.75
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Awarded
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461,350
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28.46
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Vested
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(866,515)
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9.97
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Forfeited
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(61,130)
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12.71
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Non-vested balance at December 31, 2018
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824,365
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19.77
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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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2018
|
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2017
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2016
|
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Cost of revenue
|
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$
|
247
|
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$
|
251
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$
|
171
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|
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Research and development
|
|
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4,379
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4,242
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3,256
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Sales and marketing
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3,770
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3,662
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2,273
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General and administrative
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5,115
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3,950
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2,670
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Total stock-based compensation expense
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$
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13,511
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$
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12,105
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$
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8,370
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