MORTGAGE LOANS (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2012 item	Dec. 31, 2011
MORTGAGE LOANS
Mortgage loan holdings	$ 5,203,999,000	$ 5,351,902,000	[1]
Mortgage loans
Amount that would become due in the remainder of 2012, if loans are called at their next call dates	43,600,000
Amount that would become due in 2013 through 2017, if loans are called at their next call dates	1,400,000,000
Amount that would become due in 2018 through 2022, if loans are called at their next call dates	792,200,000
Amount that would become due after 2022, if loans are called at their next call dates	270,000,000
Allowance for loan and credit losses	8,800,000	6,500,000
Change in the allowance for credit losses
Ending balance	8,800,000	6,500,000
Commercial mortgage loans
Mortgage loans
Allowance for loan and credit losses	8,750,000	4,975,000
Mortgage loans having participation feature	860,400,000	876,800,000
Delinquent mortgage loans, foreclosed properties and restructured loans pursuant to pooling and servicing agreement	42,000,000
Delinquent mortgage loans, foreclosed properties and restructured loans to invested assets (as a percent)	0.12%
Number of loan categories	2
Nonperforming loans not subject to a pooling and servicing agreement	34,500,000
Loans subject to a pooling and servicing agreement which are either nonperforming or restructured	7,000,000
Foreclosed property related to loans subject to a pooling and servicing agreement	500,000
Period for average credit loss factor	10 years
Average credit loss factor for commercial mortgage loan portfolio over past ten years (as a percent)	0.02%
Change in the allowance for credit losses
Beginning balance	4,975,000	11,650,000
Charge offs	(986,000)	(16,278,000)
Recoveries	(122,000)	(2,471,000)
Provision	4,883,000	12,074,000
Ending balance	$ 8,750,000	$ 4,975,000
Commercial mortgage loans | Minimum
Mortgage loans
Period for exercise of call options or interest rate reset options	3 years
Commercial mortgage loans | Maximum
Mortgage loans
Period for exercise of call options or interest rate reset options	10 years
Loan-to-value ratio with participating interest (as a percent)	85.00%

[1] Recast from previously reported information