MORTGAGE LOANS (Details 2) (Commercial mortgage loans, USD $)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2013 item	Sep. 30, 2013 item	Dec. 31, 2012
Commercial mortgage loans
Mortgage loans
Mortgage loans having participation feature	$ 714,500,000	$ 714,500,000	$ 817,300,000
Income recognized on participating mortgage loans	3,700,000	12,900,000
Nonperforming mortgage loans, foreclosed properties and restructured loans to invested assets (as a percent)	0.05%	0.05%
Nonperforming mortgage loans, foreclosed properties and restructured loans pursuant to pooling and servicing agreements	16,400,000	16,400,000
Number of mortgage loan transactions accounted for as troubled debt restructurings	2
Mortgage loans accounted for as troubled debt restructurings	3,200,000	3,200,000
Mortgage loans, associated reserve	0	0
Number of loan categories		2
Loans not subject to a pooling and servicing agreement which are either nonperforming or restructured	10,700,000	10,700,000
Number of nonperforming loans foreclosed		2
Loans subject to a pooling and servicing agreement which are either nonperforming or restructured	5,700,000	5,700,000
Number of nonperforming loans subject to a pooling and servicing agreement which have been restructured		0
Change in the allowance for credit losses
Beginning balance		2,875,000	6,475,000
Charge offs		(2,643,000)	(9,840,000)
Recoveries		(374,000)	(628,000)
Provision		8,112,000	6,868,000
Ending balance	$ 7,970,000	$ 7,970,000	$ 2,875,000