Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income tax expense	$ 37,777	$ 56,702
Effective Income Tax Rate Reconciliation, Percent	25.00%	28.70%
U.S federal statutory rate, percent	21.00%	21.00%
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options	$ 2,000
Income tax benefit related to federal and state income tax filings for prior year	3,000
Charge related to certain income tax matters	$ 2,000
Write-off of unrealized deferred tax asset		$ 2,000