LONG-TERM DEBT - LINE OF CREDIT (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) aircraft credit_facility
Line of Credit Facility [Line Items]
Number of credit facilities | credit_facility	3
Line of Credit Facility, minimum asset requirement	$ 500,000,000
Credit Facility 1 [Member] | Secured by aircraft [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	100,000,000
Credit Facility 2 [Member] | Secured by other [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	100,000,000
Credit Facility 3 [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 52,000,000
Number of aircrafts used as collateral | aircraft	2
Secured Debt [Member] | Credit Facility 1 [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 100,000,000
Secured Debt [Member] | Credit Facility 2 [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 100,000,000