Income Taxes (Income from Operations) (Details 1) - 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 before Income Taxes [Abstract]
U.S.									$ 403,295	$ 390,144	$ 257,312
Non-U.S.									3,973	36,335	66,196
Income Before Income Taxes	$ 317,743	$ 108,054	$ 60,762	$ (79,291)	$ 185,117	$ 58,165	$ 73,895	$ 109,302	$ 407,268	$ 426,479	$ 323,508