Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2017

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Stock Option Activity and Weighted Average Exercise Prices

A summary of stock option activity and weighted-average exercise prices during the three months ended March 31, 2017 follows:

	Options		Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value as of March 31, 2017
Outstanding at January 1, 2017	1,090,160		$	48.02
Granted	262,372		34.81
Forfeited	(17,753	)	43.39
Exercised	(10,901	)	24.59
Unearned performance-based options	(19,362	)	59.97
Outstanding at March 31, 2017	1,304,516		$	45.44	4.8	$	1,022
Options exercisable at March 31, 2017	721,139		$	43.21	3.5	$	298

Schedule of Restricted Stock and Restricted Stock Units Activity and Weighted-Average Grant Date Fair Value

The following table summarizes the restricted stock and restricted stock unit activity and weighted average grant-date fair values for the three months ended March 31, 2017:

	Shares		Weighted-Average Grant Date Fair Value
Non-vested at January 1, 2017	150,682		$	33.39
Granted	129,146		35.54
Forfeited	(3,075	)	33.17
Vested	(483	)	41.70
Unearned performance-based awards	(604	)	52.83
Non-vested at March 31, 2017	275,666		$	34.34

Employee Stock Option

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Valuation Assumptions

For stock options granted during the three months ended March 31, 2017 and March 31, 2016 valued using the Black-Scholes option valuation model, we used the following assumptions:

	Three Months Ended
	March 31, 2017		March 31, 2016
Risk-free interest rate	2.02	%	1.1% - 1.21%
Expected dividend yield	—	%	—	%
Expected term of option	5 years		4 years
Expected volatility	45.2	%	46.7	%
Weighted-average expected volatility	45.2	%	46.7	%