Income Taxes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net tax benefit from U.S. tax reform	$ 41,600	$ 0	$ (22,284)	$ 41,554
Tax benefit from income tax holiday		$ 14,700	$ 1,900	$ 6,200
Benefit from income tax holiday on diluted earnings per share (in dollars per share)		$ 0.06	$ 0.01	$ 0.03
Undistributed earnings of foreign subsidiaries				$ 1,100,000
Transition tax payable	$ 21,800		$ 21,800
Reductions from lapse of statutes of limitations		$ 6,400
Repatriation of earnings estimated tax impact			$ 89,800