Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Summary of Stock-Based Compensation Expense

The following table summarizes the Company’s stock-based compensation expense for the years ended December 31, 2016, 2015 and 2014 (in thousands):

	Year Ended December 31,
	2016		2015		2014
Time-based restricted stock and time-based restricted stock units	$	2,281	$	2,704	$	2,974
Performance-based restricted stock and performance-based restricted stock units		2,210		1,562		727
Stock appreciation rights		184		525		1,035
Employee stock purchase plan		113		70		71
Total stock-based compensation	$	4,788	$	4,861	$	4,807

Summary of Assumptions Used to Estimate Fair Value of Each SAR

The fair value of each SAR is estimated on the date of grant using a Black-Scholes option-pricing model. There were no SARs issued in the year ended December 31, 2016. For SARs issued in the years ended December 31, 2015 and 2014, respectively, the assumptions shown in the following table were used:

	December 31,
	2015			2014
Dividend yield		0	%		0	%
Average risk-free interest rate		1.6	%		1.7	%
Expected term (years)		5			5
Expected volatility		42.9	%		52.6	%

SAR Activity

SAR activity under the Plan and all predecessor stock incentive plans is as follows:

	SARs			Weighted-Average Grant Price Per Share		Weighted- Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value as of December 31, 2016
Outstanding at December 31, 2013		739,194		$	12.93
Granted		3,866		$	37.88
Exercised		(218,826	)	$	10.96
Canceled		(8,404	)	$	4.74
Outstanding at December 31, 2014		515,830		$	13.98
Granted		15,585		$	41.19
Exercised		(263,626	)	$	13.86
Canceled		(5,712	)	$	21.94
Outstanding at December 31, 2015		262,077		$	13.13
Granted		—		$	—
Exercised		(124,352	)	$	11.09
Canceled		—		$	—
Outstanding at December 31, 2016		137,725		$	19.57		5.6	$	6,174,886
Vested at December 31, 2016		127,469		$	17.83		5.4	$	5,936,639
Exercisable at December 31, 2016		127,469		$	17.83		5.4	$	5,936,639

Stock Option Activity

Stock option activity under the Plan and all predecessor stock incentive plans is as follows:

	Options			Weighted-Average Exercise Price Per Share
Outstanding at December 31, 2013		42,288		$	20.05
Granted		—		$	—
Exercised		(27,942	)	$	35.73
Canceled		(1,188	)	$	17.92
Outstanding at December 31, 2014		13,158		$	23.36
Granted		—		$	—
Exercised		(13,158	)	$	50.37
Canceled		—		$	—
Outstanding at December 31, 2015		—		$	—

Time-Based Restricted Stock [Member]

Restricted Stock Activity

Time-based restricted stock activity under the Plan and all predecessor stock incentive plans is as follows:

	Time-based Restricted Stock			Weighted-Average Grant Price Per Share
Nonvested at December 31, 2013		382,974		$	13.78
Granted		66,511		$	32.70
Vested		(116,641	)	$	33.73
Forfeited		(3,282	)	$	16.61
Nonvested at December 31, 2014		329,562		$	18.89
Granted		57,598		$	43.81
Vested		(230,704	)	$	42.37
Forfeited		(48,549	)	$	20.20
Nonvested at December 31, 2015		107,907		$	29.43
Granted		57,874		$	37.64
Vested		(43,848	)	$	42.34
Forfeited		(133	)	$	43.89
Nonvested at December 31, 2016		121,800		$	31.59

Performance-Based Restricted Stock [Member]

Restricted Stock Activity

Performance-based restricted stock activity under the Plan is as follows:

	Performance-based Restricted Stock  and Performance-based Restricted Stock Units			Weighted-Average Grant Price Per Share
Nonvested at December 31, 2014		42,676		$	33.72
Granted		34,638		$	43.89
Vested		(35,679	)	$	41.91
Forfeited		(12,538	)	$	38.12
Nonvested at December 31, 2015		29,097		$	39.38
Granted		44,925		$	35.83
Vested		(14,949	)	$	35.71
Forfeited		(657	)	$	33.72
Nonvested at December 31, 2016		58,416		$	36.63