SECURITIES (Details) (USD $)	3 Months Ended			3 Months Ended			3 Months Ended		3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Corporate debt securities	Mar. 31, 2012 Corporate debt securities	Dec. 31, 2012 Corporate debt securities	Mar. 31, 2012 Common and preferred stock	Mar. 31, 2013 Common and preferred stock	Mar. 31, 2013 Other securities, at estimated fair value	Dec. 31, 2012 Other securities, at estimated fair value	Mar. 31, 2013 Residential mortgage-backed securities, at estimated fair value	Dec. 31, 2012 Residential mortgage-backed securities, at estimated fair value
Securities Available-for-Sale
Amortized Cost	$ 335,968,000		$ 394,821,000
Gross Unrealized Gains	25,039,000		27,281,000
Gross Unrealized Losses	(2,042,000)		(9,809,000)
Estimated Fair Value	358,965,000		412,293,000					0
Total Securities
Amortized Cost									41,436,000	27,991,000	162,483,000	171,385,000
Gross Unrealized Gains									15,456,000	9,768,000	4,423,000	3,762,000
Gross Unrealized Losses									(689,000)	(374,000)	(79,878,000)	(91,305,000)
Securities, at estimated fair value									56,203,000	37,385,000	87,028,000	83,842,000
Amortized Cost	539,887,000		594,197,000
Gross Unrealized Gains	44,918,000		40,811,000
Gross Unrealized Losses	(82,609,000)		(101,488,000)
Securities, at estimated fair value	502,196,000		533,520,000
Fair value on available for sale securities in a gross continuous unrealized loss position by the length of time
Less Than 12 months				33,970,000		45,900,000
12 Months or More				27,809,000		37,500,000
Total Estimated Fair Value				61,779,000		83,400,000
Unrealized losses on available for sale securities in a gross continuous unrealized loss position by the length of time
Less Than 12 months				(665,000)		(4,398,000)
12 months or More				(1,377,000)		(5,411,000)
Total Unrealized Losses				(2,042,000)		(9,809,000)
Other-than-temporarily impairment loss				5,900,000	700,000		0
Estimated fair value of corporate debt securities in default				0		0
Net realized gains and losses recognized on the sale of securities available for sale
Gross realized gains	2,150,000	7,581,000
Net realized gains	2,150,000	7,581,000
Net realized gains from paydowns and restructurings	1,600,000	16,200,000
Redemption premium	1,000,000	800,000
Impairment charge for investments which were determined to be other than temporarily impaired	$ 5,900,000	$ 700,000