STOCKHOLDERS' EQUITY (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Unrealized gain on investment securities available-for-sale:
Unrealized gains on holding gains arising during period, before-tax amount	$ 26,474	$ (41,405)	$ 63,150	$ (2,493)
Less: reclassification adjustment for losses/(gains) included in income, before-tax amount	(93)	(3,191)	(647)	(6,823)
Net unrealized gain (loss), before-tax amount	26,381	(44,596)	62,503	(9,316)
Less: Noncredit-related impairment loss recorded in other comprehensive income			(5,066)	(5,091)
Foreign currency translation adjustments, before-tax amount	(1,552)	98	(1,552)	(1,269)
Unrealized gain (loss) on other asset investment, before-tax amount	9	(374)	16	(153)
Other comprehensive income, before-tax amount	24,838	(44,872)	55,901	(15,829)
Unrealized gain on investment securities available-for-sale:
Unrealized gains on holding gains arising during period, tax (expense) or benefit	(11,119)	17,390	(26,523)	1,047
Less: reclassification adjustment for losses/(gains) included in income, tax (expense) or benefit	39	1,341	272	2,866
Net unrealized gain (loss), tax (expense) or benefit	(11,080)	18,731	(26,251)	3,913
Noncredit-related impairment loss on securities, tax effect			2,128	2,138
Foreign currency translation adjustments, tax (expense) or benefit	652	(41)	652	533
Unrealized gain (loss) on other asset investment, tax (expense) or benefit	(4)	157	(7)	64
Other comprehensive income, tax (expense) or benefit	(10,432)	18,847	(23,478)	6,648
Unrealized gain on investment securities available-for-sale:
Unrealized gains on holding gains arising during period, net of tax amount	15,355	(24,015)	36,627	(1,446)
Less: reclassification adjustment for losses/(gains) included in income	(54)	(1,850)	(375)	(3,957)
Net unrealized gains (loss), net of tax amount	15,301	(25,865)	36,252	(5,403)
Noncredit-related impairment loss on securities			(2,938)	(2,953)
Foreign currency translation adjustments, net of tax amount	(900)	57	(900)	(736)
Unrealized gain (loss) on other asset investment	5	(217)	9	(89)
Other comprehensive income (loss)	$ 14,406	$ (26,025)	$ 32,423	$ (9,181)