Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other Commitments [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 7,289
Operating Leases, Future Minimum Payments, Due in Two Years	4,568
Operating Leases, Future Minimum Payments, Due in Three Years	2,376
Operating Leases, Future Minimum Payments, Due in Four Years	702
Operating Leases, Future Minimum Payments, Due in Five Years	349
Operating Leases, Future Minimum Payments, Due Thereafter	369
Operating Leases, Future Minimum Payments Due	15,653
Operating Leases, Rent Expense	$ 9,200	$ 9,200	$ 8,800