Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

Stock-Based Compensation [Abstract]

Summary of assumptions used to estimate fair value of each SAR

	Three Months Ended March 31,
	2013			2012
Weighted-average fair value of grants	$	23.34		$	14.01
Dividend yield		0	%		0	%
Average risk-free interest rate		0.7	%		0.8	%
Expected term (years)		5			5
Expected volatility		64	%		66	%

Summary of stock-based compensation grants

	Stock Awards Granted		Weighted-Average Grant  Price Per Share
Stock appreciation rights		60,176	$	43.87
Restricted stock		39,592	$	43.87

Summary of stock-based compensation expense

	Three Months Ended March 31,
	2013		2012
Stock appreciation rights	$	331	$	302
Restricted stock		537		403
Employee stock purchase plan		27		31
Total stock-based compensation	$	895	$	736