Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest Income
Interest and fees on loans	$ 246,646	$ 184,246	$ 466,680	$ 357,895
Interest and dividends on investment securities:
Taxable	30,623	23,658	60,727	47,133
Tax-exempt	10,783	8,143	20,000	16,272
Other interest	3,153	1,553	5,330	3,089
Total interest income	291,205	217,600	552,737	424,389
Interest Expense
Interest on deposits	38,431	21,180	71,843	38,104
Interest on Federal funds purchased and securities sold under agreements to repurchase	538	824	1,060	1,339
Interest on other short-term funding	51	84	111	169
Interest on FHLB advances	21,279	7,149	34,402	11,596
Interest on long-term funding	4,544	4,544	9,088	9,088
Total interest expense	64,843	33,781	116,504	60,296
Net Interest Income	226,362	183,819	436,233	364,093
Provision for credit losses	4,000	12,000	4,000	21,000
Net interest income after provision for credit losses	222,362	171,819	432,233	343,093
Noninterest Income
Service charges on deposit account fees	72,825	65,014	145,553	129,896
Mortgage banking, net	6,258	5,027	12,628	9,606
Capital markets, net	4,783	4,042	10,089	7,925
Bank and corporate owned life insurance	3,978	3,899	7,165	6,514
Asset gains (losses), net	2,497	(466)	2,390	(700)
Investment securities gains (losses), net	(2,015)	356	(2,015)	356
Other	2,235	2,213	4,727	4,492
Total noninterest income	92,842	82,410	183,222	162,241
Noninterest Expense
Personnel	123,980	107,066	241,665	213,848
Occupancy	15,071	12,832	30,428	28,051
Technology	19,452	15,473	37,167	29,893
Equipment	5,953	5,234	11,509	10,719
Business development and advertising	7,067	7,152	13,760	12,987
Legal and professional	6,284	5,711	11,697	9,877
Card issuance and loan costs	3,173	2,974	6,477	5,594
Foreclosure / OREO expense, net	1,021	1,182	1,744	2,687
FDIC assessment	8,250	8,000	16,500	16,000
Other intangible amortization	2,168	496	3,693	1,009
Acquisition related costs(1)	7,107	0	27,712	0
Other	11,732	10,196	21,873	19,342
Total noninterest expense	211,258	176,316	424,223	350,007
Income before income taxes	103,947	77,913	191,232	155,327
Income tax expense	14,754	19,930	32,583	41,074
Net income	89,192	57,983	158,648	114,253
Preferred stock dividends	2,329	2,339	4,668	4,669
Net income available to common equity	$ 86,863	$ 55,644	$ 153,980	$ 109,584
Earnings per common share:
Basic	$ 0.51	$ 0.36	$ 0.92	$ 0.72
Diluted	$ 0.50	$ 0.36	$ 0.90	$ 0.71
Average common shares outstanding:
Basic	170,633	151,573	167,096	151,196
Diluted	173,409	154,302	169,920	154,147
Insurance Commissions and Fees [Member]
Noninterest Income
Service charges on deposit account fees	$ 23,996	$ 20,853	$ 46,644	$ 42,473
Deposit Account [Member]
Noninterest Income
Service charges on deposit account fees	16,390	16,030	32,810	32,386
Card-Based and Loan Fees [Member]
Noninterest Income
Service charges on deposit account fees	14,387	13,764	27,809	26,229
Fiduciary and Trust [Member]
Noninterest Income
Service charges on deposit account fees	13,437	12,346	26,806	24,281
Brokerage Commission and Fees [Member]
Noninterest Income
Service charges on deposit account fees	$ 6,896	$ 4,346	$ 14,169	$ 8,679