MORTGAGE LOANS (Details) (USD $)			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Minimum	Mar. 31, 2013 Maximum
MORTGAGE LOANS
Mortgage loans holdings	$ 4,835,917,000	$ 4,950,201,000
Mortgage loans
Period for exercise of call options or interest rate reset options			3 years	10 years
Loan-to-value ratio with participating interest (as a percent)				85.00%
Amount that would become due in 2013, if loans are called at their next call dates	143,000,000
Amount that would become due in 2014 through 2018, if loans are called at their next call dates	1,300,000,000
Amount that would become due in 2019 through 2023, if loans are called at their next call dates	588,200,000
Amount that would become due after 2023, if loans are called at their next call dates	$ 178,300,000