PARENT COMPANY CONDENSED FINANCIAL STATEMENTS (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Statement of income
Interest expense	$ 23,536	$ 24,343	$ 27,953	$ 27,544	$ 27,647	$ 28,974	$ 27,992	$ 28,207	$ 103,376		$ 112,820		$ 112,492
Compensation and net occupancy reimbursement to subsidiary									61,292		63,815		56,641
Other expense									86,995		79,750		77,113
Income before income taxes	148,485	138,989	144,421	146,826	122,595	85,299	122,966	116,163	578,721	[1]	447,023	[1]	447,146	[1]
Income tax benefit	(56,680)	(44,892)	(45,673)	(46,799)	(27,093)	6,601	(38,661)	(41,992)	(194,044)	[1]	(101,145)	[1]	(153,822)	[1]
NET INCOME	$ 91,805	$ 94,097	$ 98,748	$ 100,027	$ 95,502	$ 91,900	$ 84,305	$ 74,171	384,677	[1]	345,878	[1]	293,324	[1]
Parent Company
Statement of income
Dividends from subsidiaries									88		111,701		319,085
Other income									625		7,414		821
Total income									713		119,115		319,906
Interest expense									4,636		4,823		3,436
Compensation and net occupancy reimbursement to subsidiary									5,386		4,039		3,662
Other expense									24,829		50,280		12,677
Total expense									34,851		59,142		19,775
Income before income taxes									(34,138)		59,973		300,131
Income tax benefit									30,849		80,674		22,885
Equity in undistributed income (loss) of subsidiaries									387,966		205,231		(29,692)
NET INCOME									$ 384,677		$ 345,878		$ 293,324

[1] Prior period was restated to reflect the retrospective application of adopting the new accounting guidance related to the Company’s investments in qualified affordable housing projects Accounting Standards Update (“ASU”) 2014-01. Please see Note 9 — Investments in Qualified Affordable Housing Partnerships, Tax Credit and Other Investments, Net to the Consolidated Financial Statements for additional information.