Defined Benefit Pension Plans Schedule of Net Periodic Pension Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,472	$ 4,572	$ 3,559
Interest cost	2,573	2,380	3,476
Expected Return on Plan Assets	(540)	(502)	(619)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	58	59	138
Amortization of actuarial net (gains) loss	1,351	1,979	572
Defined Benefit Plan, Settlement and Other Benefit Costs	1,340	420	55
Net Periodic Benefit Cost	$ 8,254	$ 8,908	$ 7,181