Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income
Interest and fees on loans	$ 741,001	$ 651,831	$ 613,024
Interest bearing deposits with banks	4,236	1,486	1,472
Federal funds sold and securities purchased under resale agreements	4	4	25
Investment securities	62,038	61,006	52,951
Trading account securities	75	108	79
Federal Home Loan Bank and Federal Reserve Bank stock	4,287	3,232	2,920
Brokerage customer receivables	816	797	796
Total interest income	812,457	718,464	671,267
Interest expense
Interest on deposits	58,409	48,863	48,411
Interest on Federal Home Loan Bank advances	10,886	9,110	10,523
Interest on other borrowings	4,355	3,627	1,773
Interest on subordinated notes	7,111	7,105	3,906
Interest on junior subordinated debentures	9,503	8,230	8,079
Total interest expense	90,264	76,935	72,692
Net interest income	722,193	641,529	598,575
Provision for credit losses	34,084	32,942	20,537
Net interest income after provision for credit losses	688,109	608,587	578,038
Non-interest income
Wealth management	76,018	73,452	71,343
Mortgage banking	128,743	115,011	91,617
Service charges on deposit accounts	31,210	27,384	23,307
Gains (losses) on investment securities, net	7,645	323	(504)
Fees from covered call options	11,470	15,364	7,859
Trading gains (losses), net	91	(247)	(1,609)
Operating lease income, net	16,441	2,728	163
Other	53,812	37,582	23,064
Total non-interest income	325,430	271,597	215,240
Non-interest expense
Salaries and employee benefits	405,158	382,080	335,506
Equipment	37,055	32,889	29,609
Operating lease equipment depreciation	13,259	1,749	142
Occupancy, net	50,912	48,880	42,889
Data processing	28,776	26,940	19,336
Advertising and marketing	24,776	21,924	13,571
Professional fees	20,411	18,225	15,574
Amortization of other intangible assets	4,789	4,621	4,692
FDIC insurance	16,065	12,386	12,168
OREO expenses, net	5,187	4,483	9,367
Other	75,297	74,242	63,993
Total non-interest expense	681,685	628,419	546,847
Income before taxes	331,854	251,765	246,431
Income tax expense	124,979	95,016	95,033
Net income	206,875	156,749	151,398
Preferred stock dividends	14,513	10,869	6,323
Net income applicable to common shares—Basic	$ 192,362	$ 145,880	$ 145,075
Net income per common share - Basic (usd per share)	$ 3.83	$ 3.05	$ 3.12
Net income per common share - Diluted (usd per share)	3.66	2.93	2.98
Cash dividends declared per common share (usd dollars per share)	$ 0.48	$ 0.44	$ 0.40
Weighted average common shares outstanding (in shares)	50,278	47,838	46,524
Dilutive potential common shares (in shares)	3,994	4,099	4,321
Average common shares and dilutive common shares (in shares)	54,272	51,937	50,845