Income Taxes - The Components of Net Deferred Income Tax Assets (Liabilities) (Details 4) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Net current deferred income tax assets:
Accrued expenses and reserves	$ 14,001	$ 10,221
Stock-based compensation	5,528	4,425
Total current deferred income tax assets	19,529	14,646
Less: valuation allowance	(1,394)	(1,442)
Net current deferred income tax assets	18,135	13,204
Net non-current deferred income tax assets:
Net operating loss carryforwards	15,688	18,527
Property and equipment	7,975	11,470
Deferred revenue	914	550
Facility abandonment	143	262
Other	877	305
Total non-current deferred income tax assets	23,095	26,671
Less: valuation allowance	(14,713)	(17,781)
Net non-current deferred income tax assets	8,382	8,890
Net non-current deferred income tax liabilities:
Software	190	211
Client contracts and related intangibles	835	3,127
Goodwill	(7,590)	(6,747)
Net operating loss carryforwards	23,038	23,298
Property and equipment	(15,219)	(15,048)
Convertible debt securities	(16,853)	(27,708)
Deferred revenue	3,354	961
Contingent payments	849	840
Facility abandonment	2,231	2,194
Other	1,235	(290)
Total non-current deferred income tax liabilities	(7,930)	(19,162)
Less: valuation allowance	(1,307)	(1,284)
Net non-current deferred income tax liabilities	(9,237)	(20,446)
Software
Net non-current deferred income tax assets:
Intangibles	412	809
Client contracts
Net non-current deferred income tax assets:
Intangibles	$ (2,914)	$ (5,252)