Income Taxes (Schedule of Income Tax Expense and Effective Tax Rate) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income before income taxes	$ 206,367	$ 204,865	$ 624,635	$ 613,641
Income before incomes taxes, % change	1.00%		2.00%
Income tax expense	$ 34,951	$ 33,563	$ 138,815	$ 82,958
Income tax expense, % change	4.00%		67.00%
Effective tax rate (as a percent)	16.90%	16.40%	22.20%	13.50%