Schedule of Operating Lease Rental Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Rent expense
Operating Leases, Rent Expense	$ 13,288	$ 13,566
Space Lease Agreements [Member]
Rent expense
Operating Leases, Rent Expense	9,527	10,137
Related Party Leases [Member]
Rent expense
Operating Leases, Rent Expense	576	702
Other Operating Leases [Member]
Rent expense
Operating Leases, Rent Expense	$ 3,185	$ 2,727