Defined Benefit Pension Plans Schedule of Net Periodic Pension Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4,572	$ 3,559	$ 4,205
Interest cost	2,380	3,476	3,355
Expected Return on Plan Assets	(502)	(619)	(635)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	59	138	70
Amortization of actuarial net (gains) loss	1,979	572	926
Defined Benefit Plan, Settlement and Other Benefit Costs	420	55	(493)
Net Periodic Benefit Cost	$ 8,908	$ 7,181	$ 7,428