Income Taxes Income Tax Expense Components (Details) - 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
Current:
Current federal tax expense (benefit)									$ 5,181	$ 8,786	$ 13,198
Current foreign tax expense (benefit)									11,926	13,267	10,132
Current state and local tax expense (benefit)									618	(28)	1,548
Current income tax expense (benefit)									17,725	22,025	24,878
Deferred:
Deferred federal income tax expense (benefit)									(69)	(57,250)	(1,340)
Deferred foreign income tax expense (benefit)									(11,144)	23,558	1,909
Deferred state and local income tax expense (benefit)									(616)	(623)
Deferred income tax expense (benefit)									(11,829)	(34,315)	569
Income tax expense (benefit)	$ 6,540	$ 3,663	$ (261)	$ (4,046)	$ 7,177	$ 3,335	$ 4,808	$ (27,610)	$ 5,896	$ (12,290)	$ 25,447