CERTAIN NONTRADITIONAL LONG-DURATION CONTRACTS (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Activity in the Company's deferred sales inducement asset
Deferred asset, beginning of period	$ 125,527	$ 112,147	$ 116,298
Amounts deferred	23,362	29,472	25,587
Amortization	(4,940)	(16,092)	(29,738)
Deferred asset, end of period	143,949	125,527	112,147
Annuity account balances
Certain Nontraditional Long-duration Contracts
Account balances of variable annuities with guarantees invested in variable annuity separate accounts	9,552,777	6,158,383
Equity mutual funds | Annuity account balances
Certain Nontraditional Long-duration Contracts
Account balances of variable annuities with guarantees invested in variable annuity separate accounts	6,171,196	3,972,729
Fixed income mutual funds | Annuity account balances
Certain Nontraditional Long-duration Contracts
Account balances of variable annuities with guarantees invested in variable annuity separate accounts	$ 3,381,581	$ 2,185,654