DEBT AND OTHER OBLIGATIONS (Details) (USD $)	3 Months Ended	12 Months Ended	0 Months Ended	3 Months Ended				3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Oct. 10, 2012 Golden Gate V and Red Mountain	Mar. 31, 2013 Golden Gate II Captive Insurance Company	Mar. 31, 2013 Golden Gate V Vermont Captive Insurance Company	Mar. 31, 2013 Red Mountain	Oct. 10, 2012 Red Mountain	Mar. 31, 2013 Repurchase Program Borrowings	Dec. 31, 2012 Repurchase Program Borrowings	Mar. 31, 2013 Repurchase Program Borrowings Maximum	Mar. 31, 2013 Credit Facility	Mar. 31, 2013 Credit Facility Federal Funds Rate	Mar. 31, 2013 Credit Facility LIBOR One-Month Rate
Debt and other obligations
Line of credit, current borrowing capacity											$ 750,000,000
Line of credit, maximum borrowing capacity to be granted upon entity's request											1,000,000,000
Base of floating rate interest rate payments											LIBOR	Federal Funds rate	one-month LIBOR
Interest rate added to the base rate (as a percent)											1.20%	0.50%	1.00%
Line of credit, amount outstanding											40,000,000
Outstanding non-recourse funding obligations of Golden Gate II Captive Insurance Company	575,000,000
Term of transaction			20 years
Maximum financing capacity under transaction			945,000,000				945,000,000
Principal amount of note issued						315,000,000	275,000,000
Non-recourse funding obligations	596,000,000	586,000,000		281,000,000	315,000,000
Non-recourse funding obligations held by affiliates	294,000,000
Year-to-date weighted-average interest rate of non-recourse funding obligations (as a percent)				1.03%	6.25%
Outstanding nonrecourse funding obligations repurchased at discount	5,000,000	121,800,000
Gain from repurchase of outstanding nonrecourse funding obligations	1,300,000	38,400,000
Fair value of securities pledged under the repurchase program								337,700,000
Repurchase program borrowings	300,000,000	150,000,000						300,000,000
Average borrowing rate (as a percent)								0.12%
Maximum balance outstanding								472,300,000	425,000,000
Average daily balance								372,700,000	266,300,000
Average borrowing rate (as a percent)								0.14%	0.14%
Outstanding balance									$ 150,000,000
Term of debt										90 days