Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2017

Stock-based Compensation

Summary of stock option activity

				Remaining	Aggregate
		Exercise		Contractual Term	Intrinsic Value
	Shares	Price		(in years)	(in thousands)(1)
Balance at December 31, 2016	3,308,158	$	20.40	3.50	$	46,086
Granted	—	$	—	—	$	—
Exercised	(97,500)	$	22.71	—	$	1,618
Forfeited/canceled	—	$	—	—	$	—
Balance at September 30, 2017	3,210,658	$	20.33	2.74	$	71,569
Vested and exercisable as of September 30, 2017	3,210,658	$	20.33	2.74	$	71,569

(1) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the closing stock price of our Class A common stock as of the respective date.

Summary of additional information regarding exercisable and vested stock options

	Stock Options Exercisable
	and Vested
		Weighted-
		Average
	Number of	Remaining Life
Range of exercise prices	Shares	(in years)
$20.00	3,090,658	2.71
$28.80	120,000	3.57
$20.00 - $28.80	3,210,658	2.74

Summary of activities for unvested RSUs

	UnvestedRestricted Stock Units
		Weighted-Average
		Grant-Date
	Number of Shares	Fair Value
Unvested at December 31, 2016	1,129,045	$	37.47
Granted	505,545	$	45.05
Vested	(311,259)	$	37.43
Forfeited/canceled	(103,364)	$	48.27
Unvested at September 30, 2017	1,219,967	$	39.71