Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

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

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 formula. There were no SARs issued during the six months ended June 30, 2016. For SARs issued in the six months ended June 30, 2017 the data and assumptions shown in the following table were used:

	Six Months Ended June 30, 2017
Weighted-average fair value of grants	$	27.81
Dividend yield		0	%
Average risk-free interest rate		2.01	%
Expected term (years)		5
Expected volatility		42.4	%

Summary of Stock-Based Compensation Grants

The following table summarizes the Company’s stock-based compensation grants for the six months ended June 30, 2017:

	Stock Awards Granted		Weighted-Average Grant Price Per Share
Time-based restricted stock units		19,516	$	70.05
Performance-based restricted stock units (a)		40,216	$	56.19
Stock appreciation rights		16,340	$	70.09

(a) Includes 22,895 of target performance-based restricted stock unit awards granted during the six months ended June 30, 2017, and adjustments of 1,071, 5,396 and 10,854 grants due to the actual performance level achieved for restricted stock and restricted stock units awarded in 2014, 2015, and 2016, respectively.

Summary of Stock-Based Compensation Expense

The following table summarizes the Company’s stock-based compensation expense (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
Stock appreciation rights	$	25	$	75	$	192	$	184
Time-based restricted stock		403		863		1,139		1,479
Performance-based restricted stock		468		720		1,507		1,230
Employee stock purchase plan		16		11		38		52
Total stock-based compensation	$	912	$	1,669	$	2,876	$	2,945