Consolidated Statements Of Income (Unaudited) - 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	$ 255,063	$ 209,289	$ 490,057	$ 406,205
Mortgage loans held-for-sale	4,226	3,420	7,044	5,818
Interest bearing deposits with banks	3,243	1,634	6,039	3,257
Federal funds sold and securities purchased under resale agreements	1	1	1	2
Investment securities	19,888	15,524	39,016	29,097
Trading account securities	4	4	18	15
Federal Home Loan Bank and Federal Reserve Bank stock	1,455	1,153	2,753	2,223
Brokerage customer receivables	167	156	324	323
Total interest income	284,047	231,181	545,252	446,940
Interest expense
Interest on deposits	35,293	18,471	61,842	34,741
Interest on Federal Home Loan Bank advances	4,263	2,933	7,902	4,523
Interest on other borrowings	1,698	1,149	3,397	2,288
Interest on subordinated notes	1,787	1,786	3,560	3,558
Interest on junior subordinated debentures	2,836	2,433	5,299	4,841
Total interest expense	45,877	26,772	82,000	49,951
Net interest income	238,170	204,409	463,252	396,989
Provision for credit losses	5,043	8,891	13,389	14,100
Net interest income after provision for credit losses	233,127	195,518	449,863	382,889
Non-interest income
Wealth management	22,617	19,905	45,603	40,053
Mortgage banking	39,834	35,939	70,794	57,877
Service charges on deposit accounts	9,151	8,696	18,008	16,961
Gains (losses) on investment securities, net	12	47	(339)	(8)
Fees from covered call options	669	890	2,266	1,649
Trading gains (losses), net	124	(420)	227	(740)
Operating lease income, net	8,746	6,805	18,437	12,587
Other	14,080	18,110	25,916	30,358
Total non-interest income	95,233	89,972	180,912	158,737
Non-interest expense
Salaries and employee benefits	121,675	106,502	234,111	205,818
Equipment	10,527	9,909	20,599	18,911
Operating lease equipment depreciation	6,940	5,662	13,473	10,298
Occupancy, net	13,663	12,586	27,430	25,687
Data processing	8,752	7,804	17,245	15,729
Advertising and marketing	11,782	8,726	20,606	13,876
Professional fees	6,484	7,510	13,133	12,170
Amortization of other intangible assets	997	1,141	2,001	2,305
FDIC insurance	4,598	3,874	8,960	8,030
OREO expense, net	980	739	3,906	2,404
Other	20,371	19,091	39,654	36,434
Total non-interest expense	206,769	183,544	401,118	351,662
Income before taxes	121,591	101,946	229,657	189,964
Income tax expense	32,011	37,049	58,096	66,689
Net income	89,580	64,897	171,561	123,275
Preferred stock dividends	2,050	2,050	4,100	5,678
Net income applicable to common shares	$ 87,530	$ 62,847	$ 167,461	$ 117,597
Net income per common share-Basic (usd per share)	$ 1.55	$ 1.15	$ 2.98	$ 2.20
Net income per common share-Diluted (usd per share)	1.53	1.11	2.93	2.11
Cash dividends declared per common share (usd per share)	$ 0.19	$ 0.14	$ 0.38	$ 0.28
Weighted average common shares outstanding (in shares)	56,299	54,775	56,218	53,528
Dilutive potential common shares (in shares)	928	1,812	909	2,981
Average common shares and dilutive common shares (in shares)	57,227	56,587	57,127	56,509