INVESTMENTS (Details 3) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Maximum	Dec. 31, 2012 Maximum	Dec. 31, 2012 U.S. Government	Mar. 31, 2013 Mortgage-backed	Mar. 31, 2013 ABS/CMO	Dec. 31, 2012 ABS/CMO	Mar. 31, 2013 Corporate	Dec. 31, 2012 Corporate	Mar. 31, 2013 Municipal	Dec. 31, 2012 Municipal	Mar. 31, 2013 Subtotal, debt securities	Dec. 31, 2012 Subtotal, debt securities	Mar. 31, 2013 Subtotal, debt securities Maximum	Sep. 30, 2012 Subtotal, debt securities Maximum	Mar. 31, 2013 Equity securities	Dec. 31, 2012 Equity securities
INVESTMENTS
Maximum unrealized losses relative to total invested assets (as a percent)	1.00%	1.00%
Fair value
Less than 12 months	$ 166,346	$ 88,007			$ 749	$ 28,234	$ 14,612	$ 18	$ 68,943	$ 35,969	$ 52,178	$ 35,064	$ 163,967	$ 71,800			$ 2,379	$ 16,207
12 Months and Greater	976	960							976	960			976	960
Total Fair value	167,322	88,967			749	28,234	14,612	18	69,919	36,929	52,178	35,064	164,943	72,760			2,379	16,207
Cost or amortized cost
Less than 12 months	167,894	89,232			749	28,411	14,805	18	69,558	36,162	52,451	35,221	165,225	72,150			2,669	17,082
12 Months and Greater	993	993							993	993			993	993
Total Cost or Amortized Cost	168,887	90,225			749	28,411	14,805	18	70,551	37,155	52,451	35,221	166,218	73,143			2,669	17,082
Unrealized Loss
Less than 12 months	(1,548)	(1,225)				(177)	(193)		(615)	(193)	(273)	(157)	(1,258)	(350)			(290)	(875)
12 Months and Greater	(17)	(33)							(17)	(33)			(17)	(33)	(100)	(100)
Total Unrealized Loss	(1,565)	(1,258)				(177)	(193)		(632)	(226)	(273)	(157)	(1,275)	(383)			(290)	(875)
Fair value of trading securities			$ 100	$ 100