Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest Income
Interest and fees on loans	$ 249,649	$ 196,972	$ 716,329	$ 554,867
Interest and dividends on investment securities:
Taxable	29,895	24,162	90,622	71,295
Tax-exempt	11,883	8,268	31,883	24,540
Other interest	4,036	2,492	9,366	5,581
Total interest income	295,464	231,894	848,201	656,283
Interest Expense
Interest on deposits	50,116	27,778	121,959	65,882
Interest on Federal funds purchased and securities sold under agreements to repurchase	504	768	1,564	2,107
Interest on other short-term funding	38	70	150	239
Interest on FHLB advances	19,318	8,612	53,720	20,209
Interest on long-term funding	6,095	4,544	15,183	13,632
Total interest expense	76,072	41,772	192,576	102,068
Net Interest Income	219,392	190,122	655,625	554,215
Provision for credit losses	(5,000)	5,000	(1,000)	26,000
Net interest income after provision for credit losses	224,392	185,122	656,625	528,215
Noninterest Income
Mortgage banking, net	4,012	6,585	16,640	16,191
Capital markets, net	5,099	4,610	15,189	12,535
Bank and corporate owned life insurance	3,540	6,580	10,705	13,094
Asset gains (losses), net(a)	(1,037)	(16)	1,353	(716)
Investment securities gains (losses), net	30	3	(1,985)	359
Other	2,802	2,254	7,529	6,746
Total noninterest income	88,300	85,895	271,522	248,136
Noninterest Expense
Personnel	124,476	108,098	366,141	321,946
Occupancy	14,519	12,294	44,947	40,345
Technology	17,563	15,233	54,730	45,126
Equipment	5,838	5,232	17,347	15,951
Business development and advertising	8,213	7,764	21,973	20,751
Legal and professional	5,476	6,248	17,173	16,125
Card issuance and loan costs	3,677	3,330	10,154	8,924
Foreclosure / OREO expense, net	950	906	2,694	3,593
FDIC assessment	7,750	7,800	24,250	23,800
Other intangible amortization	2,233	450	5,926	1,459
Acquisition related costs(b)		0		0
Other	11,445	10,072	33,318	29,413
Total noninterest expense	204,413	177,427	628,636	527,434
Income before income taxes	108,279	93,590	299,510	248,917
Income tax expense	22,349	28,589	54,932	69,663
Net income	85,929	65,001	244,578	179,254
Preferred stock dividends	2,409	2,339	7,077	7,008
Net income available to common equity	$ 83,521	$ 62,662	$ 237,501	$ 172,246
Earnings per common share:
Basic	$ 0.49	$ 0.41	$ 1.40	$ 1.13
Diluted	$ 0.48	$ 0.41	$ 1.38	$ 1.11
Average common shares outstanding:
Basic	170,516	150,565	168,249	150,983
Diluted	172,802	152,968	170,876	153,782
Insurance Commissions and Fees
Noninterest Income
Service charges on deposit account fees	$ 21,636	$ 19,815	$ 68,279	$ 62,288
Deposit Account
Noninterest Income
Service charges on deposit account fees	16,904	16,268	49,714	48,654
Card-Based and Loan Fees
Noninterest Income
Service charges on deposit account fees	14,090	12,619	41,899	38,848
Fiduciary and Trust
Noninterest Income
Service charges on deposit account fees	14,140	12,785	40,946	37,066
Brokerage Commission and Fees
Noninterest Income
Service charges on deposit account fees	7,084	4,392	21,253	13,071
Acquisition-related Costs [Member]
Noninterest Income
Asset gains (losses), net(a)	(1,000)		(2,000)
Operating Segments [Member] | Risk Management and Shared Serivies [Member]
Interest Expense
Net Interest Income	14,770	15,951	47,770	47,552
Provision for credit losses	(21,512)	(9,545)	(49,081)	(21,866)
Noninterest Income
Total noninterest income	2,183	5,750	8,257	12,822
Noninterest Expense
Acquisition related costs(b)	2,271		29,983
Total noninterest expense	22,932	17,505	100,445	49,276
Income before income taxes	6,599	4,604	(22,488)	(1,999)
Income tax expense	1,390	(2,217)	(10,416)	(15,500)
Net income	$ 5,209	$ 6,821	$ (12,072)	$ 13,501