Income Taxes - Components of Income Tax Expense (Benefit) (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
Current expense (benefit):
Federal									$ (747)	$ 5,350	$ 5,662
State									333	1,014	1,001
Foreign									2,324	995	1,491
Total current expense									1,910	7,359	8,154
Deferred expense (benefit):
Federal									1,089	871	1,121
State									278	(343)	74
Foreign									(8)	21	482
Total deferred expense									1,359	549	1,677
Total	$ 1,642	$ 833	$ 1,253	$ (459)	$ 1,209	$ 1,811	$ 2,719	$ 2,169	$ 3,269	$ 7,908	$ 9,831