Accrual for Loss Contracts Related to Service (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accrual For Loss Contract Related to Service
Beginning balance	$ 752	$ 10,050
Reduction for losses realized	$ (752)	(1,748)
Ending balance		$ 8,302