Accumulated Other Comprehensive Loss (Details textual) (Details) - Terminated Interest Rate Contract [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Interest Rate, Designated Derivatives, Deferred Gain or Loss Expected to be Amortized In Next Twelve Months	$ 9,056
Other Financings [Member]
Interest Rate, Designated Derivatives, Deferred Gain or Loss Expected to be Amortized In Next Twelve Months	1,334
Securitization Number One [Member]
Interest Rate, Designated Derivatives, Deferred Gain or Loss Expected to be Amortized In Next Twelve Months	4,855
Term Financing No.1 -- terminated 2012 [Member]
Interest Rate, Designated Derivatives, Deferred Gain or Loss Expected to be Amortized In Next Twelve Months	1,118
ECA Term Financings [Member]
Interest Rate, Designated Derivatives, Deferred Gain or Loss Expected to be Amortized In Next Twelve Months	$ 1,749