Income Taxes (Provision for Income Taxes Components) (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. Federal, Current									$ 77,882	$ 16,500	$ 46,059
State and Local, Current									8,083	2,949	2,240
Non-U.S., Current									6,958	9,400	10,924
Total income tax, Current									92,923	28,849	59,223
U.S. Federal, Deferred									6,669	63,838	16,718
State and Local, Deferred									4,954	6,630	(23,809)
Non-U.S., Deferred									2,754	(717)	(32)
Total income tax, Deferred									14,377	69,751	(7,123)
U.S. Federal, Total									84,551	80,338	62,777
State and Local, Total									13,037	9,579	(21,569)
Non-U.S., Total									9,712	8,683	10,892
Total provision for income tax	$ 80,800	$ 30,000	$ 41,900	$ (45,400)	$ 39,100	$ 15,200	$ 16,700	$ 27,600	$ 107,300	$ 98,600	$ 52,100