LINES OF CREDIT - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2011
Line of Credit Facility [Line Items]
Compensating balance requirments for our letters of credit	$ 40,000,000
Real Estate
Line of Credit Facility [Line Items]
Line of credit, amount available	50,000,000
Revolving credit facility, new
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	1,000,000,000
Line of credit, expiration date	6/2/2015
Revolving credit facility, old
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity	$ 1,000,000,000
Line of credit, expiration date	12/31/2011