Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest income:
Interest and fees on loans	$ 2,162,145	$ 2,086,097	$ 2,111,160
Interest on investment securities available for sale	192,124	191,492	178,301
Interest on investment securities held to maturity	27,449	27,971	30,632
Interest on federal funds sold, securities purchased under agreements to resell and interest bearing deposits	5,608	702	192
Interest on trading account assets	50,935	7,723	2,971
Total interest income	2,438,261	2,313,985	2,323,256
Interest expense:
Interest on deposits	274,478	251,914	212,100
Interest on FHLB and other borrowings	89,988	68,957	66,275
Interest on federal funds purchased and securities sold under agreements to repurchase	8,390	2,302	2,082
Interest on other short-term borrowings	52,442	5,318	118
Total interest expense	425,298	328,491	280,575
Net interest income	2,012,963	1,985,494	2,042,681
Provision for loan losses	193,638	106,301	107,546
Net interest income after provision for loan losses	1,819,325	1,879,193	1,935,135
Noninterest income:
Service charges on deposit accounts	216,248	222,685	221,413
Card and merchant processing fees	112,818	107,891	102,189
Investment banking and advisory fees	105,235	87,454	47,604
Retail investment sales	101,614	108,477	97,276
Asset management fees	33,194	42,772	40,939
Corporate and correspondent investment sales	30,000	29,635	35,674
Mortgage banking income	27,258	24,551	35,399
Bank owned life insurance	18,662	18,616	17,747
Investment securities gains, net	81,656	53,042	31,371
Gain (loss) on prepayment of FHLB and other borrowings, net	(8,016)	(315)	21,775
Other	257,804	222,614	203,403
Total noninterest income	976,473	917,422	854,790
Noninterest expense:
Salaries, benefits and commissions	1,071,196	1,072,269	1,005,244
Equipment	230,960	223,963	208,059
Professional services	216,325	207,679	191,402
Net occupancy	160,309	158,379	157,737
FDIC insurance	64,072	64,260	41,421
FDIC indemnification expense	55,129	115,049	267,159
Marketing	41,770	35,991	37,352
Amortization of intangibles	39,208	50,856	60,691
Communications	21,980	24,608	25,965
Goodwill impairment	17,000	12,500	0
Securities impairment:
Other-than-temporary impairment	1,747	415	7,107
Less: non-credit portion recognized in other comprehensive income	87	235	3,243
Total securities impairment	1,660	180	3,864
Other	216,881	215,018	200,281
Total noninterest expense	2,136,490	2,180,752	2,199,175
Net income before income tax expense	659,308	615,863	590,750
Income tax expense	167,513	147,331	170,820
Net income	491,795	468,532	419,930
Less: net income attributable to noncontrolling interests	2,228	1,976	2,094
Net income attributable to shareholder	$ 489,567	$ 466,556	$ 417,836