Stock-Based Compensation (Tables)
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12 Months Ended |
Dec. 31, 2015 |
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| Stock options |
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| Schedule of stock-based compensation expense included in the consolidated statements of operations |
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Year Ended December 31,
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2015
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2014
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2013
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(in thousands)
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Servicing and support
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$
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2,270
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$
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1,468
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$
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364
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Technology and content development
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1,548
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794
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159
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Program marketing and sales
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1,057
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676
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178
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General and administrative
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7,624
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4,589
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1,725
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Total stock-based compensation expense
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$
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12,499
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$
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7,527
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$
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2,426
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| Summary assumptions used for estimating the fair value of the stock options granted |
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Year Ended December 31,
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2015
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2014
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2013
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Risk-free interest rate
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1.5% - 1.9%
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1.7% - 2.1%
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0.9% - 2.0%
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Expected term (years)
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5.56 - 6.08
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5.11 - 6.25
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5.54 - 6.31
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Expected volatility
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50%
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50% - 55%
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55% - 58%
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Dividend yield
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0%
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0%
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0%
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Weighted average grant date fair value
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$12.54
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$5.71
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$4.58
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| Summary of stock option activity |
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Number of
Options
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Weighted-Average
Exercise Price per
Share
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Weighted-Average
Remaining
Contractual Term
(in years)
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Aggregate
Intrinsic
Value
(in thousands)
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Outstanding balance at December 31, 2014
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5,850,211
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$
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5.39
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7.33
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$
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83,487
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Granted
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692,814
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25.73
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9.04
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Exercised
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(1,141,731
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)
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4.67
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5.76
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Forfeited
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(96,441
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)
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12.34
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Expired
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(6,343
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)
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12.13
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Outstanding balance at December 31, 2015
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5,298,510
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8.07
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6.66
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105,595
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Exercisable at December 31, 2015
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3,426,496
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4.30
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5.77
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81,131
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Vested and expected to vest at December 31, 2015
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5,161,978
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7.82
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6.61
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104,132
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| Summary of the number of shares of common stock subject to stock options granted during the period, as well as the associated exercise price per share and the estimated fair value per share of the Company's common stock on the grant date. |
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Grant Date
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Number of
Shares
Underlying
Options
Granted
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Exercise Price
per Share
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Estimated
Grant Date Fair
Value per Share
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January 1, 2015
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3,518
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$
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19.66
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$
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19.66
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January 2, 2015
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14,888
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19.48
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19.48
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April 1, 2015
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608,746
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25.52
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25.52
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June 1, 2015
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28,770
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28.23
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28.23
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June 3, 2015
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10,629
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28.58
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28.58
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July 1, 2015
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19,743
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30.83
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30.83
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October 1, 2015
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6,520
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32.20
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32.20
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| Restricted Stock Units |
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| Summary of restricted stock unit activity |
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Number of
Restricted Stock
Units
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Weighted-Average
Grant Date Fair
Value
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Outstanding balance at December 31, 2014
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992,665
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$
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11.39
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Granted
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585,765
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25.74
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Vested
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(272,128
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)
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11.54
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Forfeited
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(86,294
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)
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15.20
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Outstanding balance at December 31, 2015
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1,220,008
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17.97
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