MORTGAGE LOANS (Details 2) (Commercial mortgage loans, USD $)	12 Months Ended
	Dec. 31, 2012 item	Dec. 31, 2011
Commercial mortgage loans
Mortgage loans
Mortgage loans having participation feature	$ 817,300,000	$ 876,800,000
Maximum nonperforming mortgage loans, foreclosed properties and restructured loans to invested assets (as a percent)	0.06%
Maximum nonperforming mortgage loans, foreclosed properties and restructured loans pursuant to pooling and servicing agreement	23,900,000
Reduction in the entity's investment in mortgage loans, net of existing allowances for mortgage loan losses, due to transactions accounted for as troubled debt restructurings	7,800,000
Number of loan categories	2
Nonperforming loans not subject to a pooling and servicing agreement	12,600,000
Foreclosed property related to loans not subject to a pooling and servicing agreement	4,200,000
Loans subject to a pooling and servicing agreement which are either nonperforming or restructured	6,900,000
Foreclosed property related to loans subject to a pooling and servicing agreement	300,000
Change in the allowance for credit losses
Beginning balance	6,475,000	11,650,000
Charge offs	(9,840,000)	(16,278,000)
Recoveries	(628,000)	(2,471,000)
Provision	6,868,000	13,574,000
Ending balance	$ 2,875,000	$ 6,475,000