Fixed Assets (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Depreciation and leasehold amortization expense				$ 43,691	$ 47,664	$ 46,794
Impairment of fixed assets	$ 742	$ 12,420	$ 1,014	742	14,571	$ 4,569
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of fixed assets				$ 742	$ 14,571