Employee Benefit Plans Defined Benefit Plan Change in Benefit Obligations and Plan Assets Table (Details) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	$ (37,640)	$ (38,240)
Service costs	(1,150)	(950)	$ (890)
Interest costs	(1,290)	(1,510)	(1,580)
Participant contributions	(60)	(60)
Actuarial gain (loss)	990	(4,080)
Benefit payments	1,320	1,250
Settlements and curtailments	710	2,360
Change in foreign currency	(1,910)	3,590
Defined Benefit Plan, Benefit Obligation	(39,030)	(37,640)	(38,240)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets	26,260	28,270
Actual return on plan assets	2,510	2,910
Employer contributions	3,170	1,890
Participant contributions	60	60
Benefit payments	(1,320)	(1,250)
Settlements	(710)	(2,530)
Change in foreign currency	1,790	(3,090)
Fair value of plan assets	31,760	26,260	$ 28,270
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Funded Status at December 31	$ (7,270)	$ (11,380)