Lease Obligations (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Capital Leases, Balance Sheet, Assets by Major Class, Net, Total	$ 5,000
Capital Lease Obligations, Current	1,085	$ 0
Capital Lease Obligations	4,900
Operating Leases, Rent Expense, Net	$ 44,900	$ 57,200	$ 41,100
Maximum [Member]
Operating Lease Remaining Term	5 years
Minimum [Member]
Operating Lease Remaining Term	1 year