Income Taxes (Deferred Tax Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Net operating loss carryforwards	$ 49,451	$ 23,501
Tax credits	13,279	13,581
Intangible assets	29,370	17,760
Stock based compensation	16,371	16,994
Other	16,174	10,386
Total deferred tax assets	124,645	82,222
Valuation allowance	(4,186)	(2,425)
Total deferred tax assets net of valuation allowance	120,459	79,797
Deferred tax liabilities:
Fixed assets	(4,044)	(1,192)
Indefinite lived intangible assets	(231,662)	(18,099)
Total deferred tax liabilities	(235,706)	(19,291)
Net deferred tax assets	$ (115,247)	$ 60,506