SECURITIES (Schedule of Unrealized Gross Losses and Estimated Fair values of Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Fair Value - Less Than 12 Months	$ 470,413	$ 115,880
Unrealized Losses - Less Than 12 Months	(13,246)	(199)
Fair Value - 12 Months of More	5,985	8,174
Unrealized Losses - 12 Months or More	(268)	(697)
Fair Value	476,398	124,054
Unrealized Losses	(13,514)	(896)
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value - Less Than 12 Months	171,566	42,782
Unrealized Losses - Less Than 12 Months	(5,401)	(79)
Fair Value	171,566	42,782
Unrealized Losses	(5,401)	(79)
Collateralized mortgage obligations
Schedule of Available-for-sale Securities [Line Items]
Fair Value - Less Than 12 Months	298,708	73,098
Unrealized Losses - Less Than 12 Months	(7,840)	(120)
Fair Value	298,708	73,098
Unrealized Losses	(7,840)	(120)
Private issue collateralized mortgage obligations
Schedule of Available-for-sale Securities [Line Items]
Fair Value - Less Than 12 Months	139
Unrealized Losses - Less Than 12 Months	(5)
Fair Value - 12 Months of More	5,985	8,174
Unrealized Losses - 12 Months or More	(268)	(697)
Fair Value	6,124	8,174
Unrealized Losses	$ (273)	$ (697)