LONG-TERM DEBT - LINE OF CREDIT (Details) - Jun. 30, 2015	USD ($) credit_facility
Line of Credit Facility [Line Items]
Line of Credit Facility, Number of Credit Facilities | credit_facility	2
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000,000
Line of Credit Facility, Asset Restrictions	500,000,000
Secured by aircraft [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000,000
Line of Credit Facility, Expiration Date	Sep. 30, 2017
Secured by other [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000,000
Line of Credit Facility, Expiration Date	Mar. 31, 2017