Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

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, 2013	3,357,658	$	20.39	6.49		35,883
Granted	—		—	—		—
Exercised	(45,500)	$	20.00	—		814
Forfeited/canceled	—		—	—		—
Balance at December 31, 2014	3,312,158	$	20.40	5.49		46,077
Granted	—		—	—		—
Exercised	(3,000)	$	20.00	—		49
Forfeited/canceled	—		—	—		—
Balance at December 31, 2015	3,309,158	$	20.40	4.50		43,287
Granted	—		—	—		—
Exercised	(1,000)	$	20.00	—		14
Forfeited/canceled	—		—	—		—
Balance at December 31, 2016	3,308,158	$	20.40	3.50		46,086
Vested and exercisable as of December 31, 2016	3,308,158	$	20.40	3.50		46,086

(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

			Options Exercisable
	Options Outstanding		and Vested
		Weighted-		Weighted-
		Average		Average
	Number of	Remaining Life	Number of	Remaining Life
Range of exercise prices	Shares	(in years)	Shares	(in years)
$20.00	3,158,158	3.46	3,158,158	3.46
$28.80	150,000	4.32	150,000	4.32
$20.00 - $28.80	3,308,158	3.50	3,308,158	3.50

Summary of activities for unvested RSUs

	Unvested Restricted Stock Units
		Weighted-
		Average
	Number of	Grant-Date
	Shares	Fair Value
Unvested at December 31, 2015	993,092	$	41.62
Granted	612,635	$	29.54
Vested	(455,242)	$	35.80
Forfeited/canceled	(21,440)	$	38.48
Unvested at December 31, 2016	1,129,045	$	37.47
Expected to vest after December 31, 2016(1)	1,115,358	$	37.47

(1) RSUs expected to vest reflect an estimated forfeiture rate.