FAIR VALUE MEASUREMENTS (Details 9) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Mortgage and other loans receivable, Fair Value	$ 58,000,000	$ 134,000,000
Long-term debt, Fair Value	7,663,000,000	8,055,000,000
Fair Value Option
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Mortgage and other loans receivable, Fair Value	58,000,000	134,000,000
Mortgage and other loans receivable, Outstanding Principal Amount	58,000,000	141,000,000
Mortgage and other loans receivable, Difference		(7,000,000)
Long-term debt, Fair Value	7,663,000,000	8,055,000,000
Long-term debt, Outstanding Principal Amount	5,727,000,000	5,705,000,000
Long-term debt, Difference	1,936,000,000	2,350,000,000
Disclosure level, past due mortgage or other loans receivable for which the fair value option was elected, number of days past due threshold	90 days	90 days
Mortgage or other loans receivable for which the fair value option was elected which were 90 days or more past due	0	0
Mortgage or other loans receivable for which the fair value option was elected which were in non-accrual status	$ 0	$ 0