INVESTMENTS IN DEBT AND EQUITY SECURITIES (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 265,306	$ 241,208
Available-for-sale Securities, Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses	(2,537)	(9,342)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	41,479	22,349
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer Aggregate Losses	(2,263)	(106)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	306,785	263,557
Available-for-sale Securities, Continuous Unrealized Loss Position Aggregate Losses	(4,800)	(9,448)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1,210
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(325)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	1,210
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Losses	(325)
United States Government Sponsored Enterprises Debt Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	153,553
Available-for-sale Securities, Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses	(880)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer Aggregate Losses	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	153,553
Available-for-sale Securities, Continuous Unrealized Loss Position Aggregate Losses	(880)
Residential Mortgage Backed Securitiess Debt Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	69,201	67,395
Available-for-sale Securities, Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses	(376)	(126)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	278	22,349
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer Aggregate Losses	(81)	(106)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	69,479	89,744
Available-for-sale Securities, Continuous Unrealized Loss Position Aggregate Losses	(457)	(232)
Us States and Political Subdivisions [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1,210
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(325)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	1,210
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Losses	(325)
Corporate Note Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	42,552	173,813
Available-for-sale Securities, Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses	(1,281)	(9,216)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	41,201	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer Aggregate Losses	(2,182)	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	83,753	173,813
Available-for-sale Securities, Continuous Unrealized Loss Position Aggregate Losses	$ (3,463)	$ (9,216)