Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

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, 2012	3,358,408	$	20.39	7.49	$	4,813
Granted	—		—	—		—
Exercised	(500)	$	20.00	6.54	$	5
Forfeited/canceled	(250)	$	20.00	—	$	3
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
Vested and exercisable as of December 31, 2015	3,309,158	$	20.40	4.50	$	43,287

(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	3,159,158	4.46	3,159,158	4.46
$28.80	150,000	5.32	150,000	5.32
$20.00 - $28.80	3,309,158	4.50	3,309,158	4.50

Summary of activities for unvested RSUs

	Unvested Restricted Stock Units
		Weighted-
		Average
		Grant-Date
	Number of Shares	Fair Value
Unvested at December 31, 2014	969,225	$	33.51
Granted	427,194	$	44.95
Vested	(315,315)	$	27.98
Forfeited/canceled	(88,012)	$	25.58
Unvested at December 31, 2015	993,092	$	41.62
Expected to vest after December 31, 2015(1)	980,707	$	41.62

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