PARENT COMPANY CONDENSED FINANCIAL STATEMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of income
Interest expense	$ 27,647	$ 28,974	$ 27,992	$ 28,207	$ 28,195	$ 27,456	$ 27,709	$ 29,132	$ 112,820	$ 112,492	$ 132,168
Compensation and net occupancy reimbursement to subsidiary									63,815	56,641	55,475
Other expense									92,359	77,576	80,582
Income before income taxes and equity in undistributed income of subsidiaries	113,047	75,112	115,606	111,690	98,564	108,906	111,870	106,510	415,455	425,850	425,592
Income tax benefit	(20,049)	13,644	(31,618)	(34,949)	(22,782)	(35,749)	(37,855)	(34,419)	(72,972)	(130,805)	(143,942)
NET INCOME	92,998	88,756	83,988	76,741	75,782	73,157	74,015	72,091	342,483	295,045	281,650
Parent Company
Statement of income
Dividends from subsidiaries									111,701	319,085	324,094
Other income									7,414	821	2
Total income									119,115	319,906	324,096
Interest expense									4,823	3,436	3,092
Compensation and net occupancy reimbursement to subsidiary									4,039	3,662	2,573
Other expense									50,280	12,677	1,309
Total expense									59,142	19,775	6,974
Income before income taxes and equity in undistributed income of subsidiaries									59,973	300,131	317,122
Income tax benefit									80,674	22,885	2,892
Equity in undistributed income (loss) of subsidiaries									201,836	(27,971)	(38,364)
NET INCOME									$ 342,483	$ 295,045	$ 281,650