Income Taxes - Summary of Provision for Income Taxes and U.S. Federal Tax Rate (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount [Abstract]
Computed “expected” tax expense	$ 58,579	$ 54,919
Foreign income tax differential	(5,843)	(4,769)
Excess tax benefits related to stock-based compensation	(8,721)	(1,118)
State taxes net of federal benefits	1,607	1,832
Foreign-sourced nontaxable income	(603)	(2,178)
Domestic production activities deduction	0	0
Other	(1,344)	(2,864)
Provision for income taxes	$ 43,675	$ 45,822	[1]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Computed “expected” tax expense	35.00%	35.00%
Foreign income tax differential	(3.50%)	(3.00%)
Excess tax benefits related to stock-based compensation	(5.20%)	(0.70%)
State taxes net of federal benefits	1.00%	1.10%
Foreign-sourced nontaxable income	(0.40%)	(1.40%)
Domestic production activities deduction	(0.00%)	(0.00%)
Other	(0.80%)	(1.80%)
Provision for income taxes	26.10%	29.20%

[1] Reflects the impact of the Company's adoption of Accounting Standards Update 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, to simplify several aspects of the accounting for share-based compensation, including the income tax consequences.