Income Taxes (Provision for Income Taxes Components) (Details 2) - 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 Tax Expense (Benefit), Continuing Operations [Abstract]
U.S. Federal, Current									$ 16,500	$ 46,059	$ 10,743
State and Local, Current									2,949	2,240	5,930
Non-U.S., Current									9,400	10,924	10,079
Total income tax, Current									28,849	59,223	26,752
U.S. Federal, Deferred									63,838	16,718	(153,217)
State and Local, Deferred									6,630	(23,809)	3,306
Non-U.S., Deferred									(717)	(32)	3,459
Total income tax, Deferred									69,751	(7,123)	(146,452)
U.S. Federal, Total									80,338	62,777	(142,474)
State and Local, Total									9,579	(21,569)	9,236
Non-U.S., Total									8,683	10,892	13,538
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)