Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income tax reconciliation, income tax expense (benefit), at federal statutory income tax rate									$ 132,832	$ 118,158	$ 101,843
Income tax rate reconciliation, foreign income tax rate differential amount									(6,668)	(5,665)	(5,531)
Income tax rate reconciliation, repatriation of foreign earnings - prior to the enactment of the Tax Reform Act									4,212	3,855	3,810
Income tax rate reconciliation, excess tax benefits recognized on share-based compensation									(6,051)
Income tax reconciliation, transition impact of the Tax Reform Act									(95,457)
Income tax rate reconciliation, recognition of foreign tax credits									(40,386)
Income tax rate reconciliation, change in valuation allowance on foreign tax credits									40,386
Income tax reconciliation, other reconciling items									397	1,833	988
Income tax expense (benefit)	$ (60,354)	$ 33,565	$ 33,282	$ 22,772	$ 30,191	$ 30,400	$ 32,554	$ 25,036	$ 29,265	$ 118,181	$ 101,110
Effective income tax rate reconciliation, at federal statutory income tax rate									35.00%	35.00%	35.00%
Effective income tax rate reconciliation, foreign income tax rate differential									(1.80%)	(1.70%)	(1.90%)
Effective income tax rate reconciliation, repatriation of foreign earnings - Prior to the enactment of the Tax Reform Act									1.10%	1.10%	1.30%
Effective income tax rate reconciliation, excess tax benefits recognized on share-based compensation									(1.60%)
Effective income tax rate reconciliation, transition impact of the Tax Reform Act									(25.10%)
Effective income tax rate reconciliation, recognition of foreign tax credits									(10.60%)
Effective income tax rate reconciliation, change in valuation allowance on foreign tax credits									10.60%
Effective income tax rate reconciliation, other adjustments									0.10%	0.60%	0.30%
Effective income tax rate									7.70%	35.00%	34.70%