Income Taxes (Components of income tax expense and income before taxes, by jurisdiction) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Geographic sources of income (loss) before income taxes
United States									$ 5,535	$ 26,040	$ (10,880)
Foreign									180,280	281,456	240,575
Income before taxes									185,815	307,496	229,695
Current:
Federal									22,003	0	0
State									39	11	22
Foreign									47,318	81,969	49,577
Current income tax expense (benefit)									69,360	81,980	49,599
Deferred:
Federal									5,468	(34,787)	0
State									2,993	(4,072)	0
Foreign									(21,571)	(3,330)	1,443
Deferred income tax expense (benefit)									(13,110)	(42,189)	1,443
Income tax expense	$ 28,812	$ 14,326	$ 10,631	$ 2,481	$ (13,613)	$ 21,263	$ 33,466	$ (1,325)	$ 56,250	$ 39,791	$ 51,042