STOCKHOLDERS' EQUITY AND EARNINGS PER SHARE (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Unrealized gains (losses) on investment securities available-for-sale:
Net unrealized gains (losses) arising during period, before-tax amount	$ 25,681		$ (42,707)		$ 52,271		$ (34,533)
Less: reclassification adjustment for gains included in net income, before-tax amount	(671)	[1]	(5,345)	[1]	(4,089)	[1]	(10,922)	[1]
Net unrealized gains (losses) , before-tax amount	25,010		(48,052)		48,182		(45,455)
Net unrealized (losses) gains arising during the period, before-tax amount	(7)		12		(36)		29
Other comprehensive income (loss), before-tax amount	25,003		(48,040)		48,146		(45,426)
Unrealized gains (losses) on investment securities available-for-sale:
Net unrealized gains (losses) arising during period, tax (expense) or benefit	(10,786)		17,937		(21,954)		14,504
Less: reclassification adjustment for gains included in net income, tax (expense) or benefit	282	[1]	2,245	[1]	1,717	[1]	4,587	[1]
Net unrealized gains (losses) , tax (expense) or benefit	(10,504)		20,182		(20,237)		19,091
Net unrealized (losses) gains arising during the period, tax (expense) or benefit	3		(5)		15		(12)
Other comprehensive income (loss), tax (expense) or benefit	(10,501)		20,177		(20,222)		19,079
Unrealized gains (losses) on investment securities available-for-sale:
Net unrealized gains (losses) arising during period, net of tax amount	14,895		(24,770)		30,317		(20,029)
Less: reclassification adjustment for gains included in net income, net of tax amount	(389)	[1]	(3,100)	[1]	(2,372)	[1]	(6,335)	[1]
Net unrealized gains (losses) , net of tax amount	14,506		(27,870)		27,945		(26,364)
Net unrealized (losses) gains arising during the period, net of tax amount	(4)		7		(21)		17
Other comprehensive income (loss)	$ 14,502		$ (27,863)		$ 27,924		$ (26,347)

[1] The pretax amount is reported in net gains on sales of investment securities in the consolidated statements of operations.