Income Taxes Income Tax Expense Components (Details) - 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
Current:
Current federal tax expense (benefit)									$ 8,786	$ 13,198	$ 10,699
Current foreign tax expense (benefit)									13,267	10,132	9,147
Current state and local tax expense (benefit)									(28)	1,548	725
Current income tax expense (benefit)									22,025	24,878	20,571
Deferred:
Deferred federal income tax expense (benefit)									(57,250)	(1,340)	(2,948)
Deferred foreign income tax expense (benefit)									23,558	1,909	626
Deferred state and local income tax expense (benefit)									(623)
Deferred income tax expense (benefit)									(34,315)	569	(2,322)
Income tax expense (benefit)	$ 7,177	$ 3,335	$ 4,808	$ (27,610)	$ 5,750	$ 9,404	$ 5,020	$ 5,273	$ (12,290)	$ 25,447	$ 18,249