EMPLOYEE BENEFIT PLANS - PILOT LONG-TERM DISABILITY BENEFITS (DETAILS) (Pilot Long-term Disability Benefits [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2011
Pilot Long-term Disability Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
PBO associated with future disability payments removed from overall defined-benefit pension plan liability	$ 32.6
Defined-benefit plan liabilty removal recognized in AOCI	29.6
Total liability net of a prefunded trust account		8.1
Prefunded trust account		$ 0.9