Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Components of Deferred Tax Assets
Deferred tax assets - current	$ 27,914	$ 25,884
Deferred tax liabilities - current	(47)	(12)
Deferred tax assets - non current	7,399	5,873
Deferred tax liabilities - non current	(11,471)	(10,068)
Total net deferred tax assets	23,795	21,677
Net operating losses	24,992	22,402
Accrued liabilities	26,524	23,720
Deferred compensation	12,362	11,531
Accrued compensation	5,920	5,554
Deferred revenue	5,692	5,861
Deferred rent	3,921	4,313
Tax credits	4,670	3,414
Equity awards	5,031	3,559
Valuation allowance	(17,069)	(13,368)
Total deferred tax assets	72,043	66,986
Intangible assets	(44,067)	(41,242)
Depreciation	(2,511)	(3,389)
Other	(1,670)	(678)
Total deferred tax liabilities	$ (48,248)	$ (45,309)