LONG-TERM DEBT - LINE OF CREDIT (DETAILS) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 credit_facility
Line of Credit Facility [Line Items]
Line of Credit Facility, Number of Credit Facilities	2
Line of Credit Facility, minimum asset requirement	$ 500
Secured by aircraft [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	100
Secured by other [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 100