Income Taxes - Schedule of Net Deferred Tax Assets/(Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Net operating loss carryforwards	$ 106,128	$ 125,966
Tax credit carryforwards	156,242	130,782
Intangible assets	23,469	23,536
Share-based compensation	24,592	23,128
Accruals	57,575	45,088
Indirect effects of unrecognized tax benefits	34,349	29,733
Investment in subsidiaries	25,585	0
Other	51,175	63,235
Total deferred tax assets	479,115	441,468
Valuation allowance	(61,237)	(52,144)
Net deferred tax assets	417,878	389,324
Deferred tax liabilities:
Intangible assets	(595,746)	(655,347)
Other	(73,350)	(82,890)
Total deferred tax liabilities	(669,096)	(738,237)
Net deferred tax liabilities	$ (251,218)	$ (348,913)