Income Taxes (Income Tax Reconciliation) (Details 3) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
U.S. Federal taxes at statutory rate									$ 89,561	$ 67,937	$ 63,976
State and local taxes, net of U.S. Federal tax									(4,064)	(1,279)	6,949
Stock based compensation				$ (1,700)				$ 1,800	(1,743)	(1,731)	(6,023)
U.S. Federal Manufacturing Deduction tax benefits									0	0	(1,329)
Deferred tax impact of U.S. Federal tax rate reduction to 21%, net of state tax impact									0	0	(153,336)
Deferred tax benefit on unremitted non-U.S. subsidiary earnings related to the Tax Act									0	0	(28,324)
Other, net									2,012	1,618	1,268
Total provision for income tax	$ 39,100	$ 15,200	$ 16,700	$ 27,600	$ 12,400	$ 10,000	$ 16,100	$ 13,600	98,600	52,100	(119,700)
State [Member]
Income Taxes [Line Items]
Valuation allowance against tax benefits									11,632	(15,767)	(946)
non-U.S. [Member]
Income Taxes [Line Items]
Valuation allowance against tax benefits									$ 1,202	$ 1,322	$ (1,935)