Commitments and Contingencies Warranty Account Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Beginning balance	$ 43,302	$ 54,512
New product warranties	7,849	7,987
Other adjustments and expirations	(393)	5,933
Claims activity	(18,094)	(24,364)
Effect of change in exchange rates	2,198	(766)
Ending balance	34,862	43,302	$ 54,512
Less: current portion of warranty	21,150	24,874
Long-term warranty	13,712	18,428
Warranty Expense	$ (2,054)	$ 13,920	$ 45,984