Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
TCJA, provision reduction to income tax expense	$ 38,400
Income taxes paid	86,900	$ 126,000	$ 144,100
Unrecognized tax benefits accrued interest	$ 315	$ 433