Income Taxes (Income Tax Expense Difference) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax expense at Federal statutory income tax rate	$ 23,161	$ 28,429	$ 17,403
International tax rate differential	(4,792)	(6,772)	(2,541)
Foreign source income, net of tax credits	2,449	5,195	(786)
State tax, net of federal	(416)	0	0
Unrecognized tax benefits	148	603	(2,197)
General business credits	(908)	(604)	(702)
Acquisition related expenses	453	590	0
Valuation allowance change	(1,489)	388	0
Other	1,247	(17)	342
Total	$ 19,853	$ 27,812	$ 11,519