Income Taxes (Pre-Tax Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
US	$ (13,355)	$ (80)	$ 1,384
Non US	116,715	96,011	85,255
Total	$ 103,360	$ 95,931	$ 86,639