Income Taxes - Summary of Provision for Income Taxes and U.S. Federal Tax Rate (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016		Jun. 30, 2017	Jun. 30, 2016	[1]
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount [Abstract]
Computed tax expense at the U.S. federal tax rate	$ 66,636	$ 56,822
Foreign income tax differential	(7,473)	(4,424)
Excess tax benefits related to stock-based compensation	(803)	(2,068)
State taxes net of federal benefits	2,361	1,909
Foreign-sourced nontaxable income	1,373	(2,020)
Other	(2,692)	(4,124)
Provision for income taxes	$ 59,402	$ 46,095	[1]	$ 103,077	$ 91,917
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Computed tax expense at the U.S. federal tax rate	35.00%	35.00%
Foreign income tax differential	(3.90%)	(2.70%)
Excess tax benefits related to stock-based compensation	(0.40%)	(1.30%)
State taxes net of federal benefits	1.20%	1.20%
Foreign-sourced nontaxable income	0.70%	(1.20%)
Other	(1.40%)	(2.60%)
Provision for income taxes	31.20%	28.40%

[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.