Equity-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock option activity during 2015 and 2016 was as follows (aggregate intrinsic value in thousands):


	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Options outstanding at January 1, 2015		737,422		$	32.19		8.09	$	14,512
Options granted		204,700			63.07		9.21		1,724
Options exercised		(214,079	)		42.75		N/A		9,890
Options cancelled		(33,300	)		46.53		N/A		N/A

Options outstanding at December 31, 2015		694,743			42.87		7.70		20,717
Options granted		456,850			59.26		9.73		—
Options exercised		(12,700	)		30.98		N/A		478
Options cancelled		(39,875	)		57.30		N/A		N/A

Options outstanding at June 30, 2016		1,099,018		$	49.36		8.24	$	11,676

Options exercisable at December 31, 2015		106,330		$	36.41		5.83	$	4,968

Options exercisable at June 30, 2016		317,476		$	41.17		6.55	$	8,217

Restricted Stock Activity

Restricted stock activity during 2015 and 2016 was as follows:


	Number of Shares			Weighted Average Grant-Date Fair Value
Unvested at January 1, 2015		722,028		$	39.77
Granted		503,052			62.67
Cancelled		(44,900	)		49.55
Vested		(235,618	)		34.93

Unvested at December 31, 2015		944,562		$	52.74
Granted		299,047			59.07
Cancelled		(54,828	)		58.02
Vested		(243,669	)		46.79

Unvested at June 30, 2016		945,112		$	55.96

Restricted Stock Unit Activity

Restricted stock unit activity during 2015 and 2016 was as follows:


	Number of Units			Weighted Average Grant-Date Fair Value
Unvested at January 1, 2015		125,113		$	38.73
Granted		217,994			61.77
Cancelled		—			—
Vested		(125,023	)		32.38

Unvested at December 31, 2015		218,084		$	56.97
Granted		230,750			56.95
Cancelled		—			—
Vested		(175,235	)		52.71

Unvested at June 30, 2016		273,599		$	59.68

Schedule of Stock Options Valuation Assumptions

The grant-date fair value of the Company’s stock options is estimated using the Black-Scholes option pricing model. The following table summarizes the grant-date fair value of options and the assumptions used to develop the fair value estimates for options granted during the six months ended June 30, 2016 and year ended December 31, 2015:


	June 30, 2016			December 31, 2015
Weighted average grant-date fair value of options	$	19.57		$	21.78
Risk-free interest rate		1.4	%		1.5	%
Expected volatility		33	%		35	%
Expected life (in years)		5.5			5.5