Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Jan. 01, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excess tax benefit	$ 400		$ 4,800
Net cash provided by operating activities			340,986	$ 558,611
Decrease to financing activities			$ 99,583	301,601
Accounting Standards Update 2016-09, Excess Tax Benefit Component
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities				$ 3,900
Decrease to financing activities		$ 3,900
Accounting Standards Update 2016-16 | New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net long-term deferred tax asset					$ 479,700
Accounting Standards Update 2016-16 | New Accounting Pronouncement, Early Adoption, Effect | Prepaid Expenses and Other Current Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Current deferred charge						$ (24,100)
Accounting Standards Update 2016-16 | New Accounting Pronouncement, Early Adoption, Effect | Other Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Non-current deferred charge						$ (348,800)