Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Components of income before taxes
United States									$ 21,365	$ (1,468)	$ 27,152
Foreign									2,221	222	1,024
Income (loss) before income taxes	10,229	6,913	6,289	155	(15,994)	4,773	6,958	3,017	23,586	(1,246)	28,176
Current provision:
U.S. federal									3,183	748	6,202
Foreign									734	233	292
State									2,162	(11,830)	1,678
Total current									6,079	(10,849)	8,172
Deferred provision:
U.S. federal									2,301	6,069	2,547
Foreign									(91)	(11)	5
State									532	1,171	(24)
Total deferred									2,742	7,229	2,528
Income tax expense (benefit)	$ 4,462	$ 2,448	$ 2,065	$ (154)	$ (10,140)	$ 2,504	$ 2,801	$ 1,215	$ 8,821	$ (3,620)	$ 10,700