Defined Benefit Pension Plans Change in Benefit Obligation and Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at January 1,	$ 98,767	$ 116,178
Service cost	3,472	4,572	$ 3,559
Interest cost	2,573	2,380	3,476
Actuarial (gain) loss	7,733	(5,211)
Benefits paid	(9,481)	(4,382)
Foreign currency exchange rate changes	(4,386)	(12,190)
Defined Benefit Plan, Curtailments	14	(1,683)
Defined Benefit Plan, Settlements, Benefit Obligation	(1,431)	0
Defined Benefit Plan, Other Changes	0	(897)
Benefit obligation at December 31,	97,261	98,767	116,178
Fair value of plan assets at January 1,	9,662	10,761
Actual return on plan assets	604	159
Company contributions	348	671
Foreign currency exchange rate changes	(29)	(1,621)
Fair value of plan assets at December 31,	10,215	9,662	$ 10,761
Net pension benefit obligation at fair value	87,046	89,105
Other Pension Plan, Postretirement or Supplemental Plans [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits paid	$ (370)	$ (308)