Income Taxes - Effective Income Tax Rate Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Provision at statutory rate		$ 3,419	$ 3,940	$ (35,022)
Foreign provision in excess of federal statutory rate		205	37	32
State income taxes (benefit), net of federal benefit		(222)	2,189	(1,821)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount		887	1,561	2,131
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Meals and Entertainment, Amount		343	655	649
Permanent differences		27	54	483
Income Tax Reconciliation, Nondeductible Expense, Impairment Losses		0	2,905	0
Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount	(800)	(1,668)	0	(1,028)
Other		188	(374)	973
Change in valuation allowance		(396)	(2,153)	4,560
Income Tax Expense (Benefit), Total		$ 2,783	$ 8,814	$ (29,043)