LONG-TERM DEBT - LINE OF CREDIT (DETAILS) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Line of Credit Facility [Line Items]
Line of Credit Facility, Minimum Asset Requirement Amount	$ 500
Secured by aircraft [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	100
Line of Credit Facility, Expiration Date	Mar. 29, 2013
Secured by other [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 100
Line of Credit Facility, Expiration Date	Mar. 31, 2016