Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest income
Interest and fees on loans	$ 651,831	$ 613,024	$ 588,435
Interest bearing deposits with banks	1,486	1,472	1,644
Federal funds sold and securities purchased under resale agreements	4	25	27
Investment securities	61,006	52,951	37,025
Trading account securities	108	79	25
Federal Home Loan Bank and Federal Reserve Bank stock	3,232	2,920	2,773
Brokerage customer receivables	797	796	780
Total interest income	718,464	671,267	630,709
Interest expense
Interest on deposits	48,863	48,411	53,191
Interest on Federal Home Loan Bank advances	9,110	10,523	11,014
Interest on other borrowings	3,627	1,773	4,341
Interest on subordinated notes	7,105	3,906	167
Interest on junior subordinated debentures	8,230	8,079	11,369
Total interest expense	76,935	72,692	80,082
Net interest income	641,529	598,575	550,627
Provision for credit losses	32,942	20,537	46,033
Net interest income after provision for credit losses	608,587	578,038	504,594
Non-interest income
Wealth management	73,452	71,343	63,042
Mortgage banking	115,011	91,617	106,857
Service charges on deposit accounts	27,384	23,307	20,366
Gains (losses) on available-for-sale securities, net	323	(504)	(3,000)
Fees from covered call options	15,364	7,859	4,773
Trading (losses) gains, net	(247)	(1,609)	892
Operating lease income, net	2,728	163	0
Other	37,582	23,064	29,467
Total non-interest income	271,597	215,240	222,397
Non-interest expense
Salaries and employee benefits	382,080	335,506	308,794
Equipment	32,812	29,609	26,450
Equipment on operating lease	1,826	142	0
Occupancy, net	48,880	42,889	36,633
Data processing	26,940	19,336	18,672
Advertising and marketing	21,924	13,571	11,051
Professional fees	18,225	15,574	14,922
Amortization of other intangible assets	4,621	4,692	4,627
FDIC insurance	12,386	12,168	12,728
OREO expenses, net	4,483	9,367	5,834
Other	74,242	63,993	62,840
Total non-interest expense	628,419	546,847	502,551
Income before taxes	251,765	246,431	224,440
Income tax expense	95,016	95,033	87,230
Net income	156,749	151,398	137,210
Preferred stock dividends and discount accretion	10,869	6,323	8,395
Net income applicable to common shares	$ 145,880	$ 145,075	$ 128,815
Net income per common share - Basic	$ 3.05	$ 3.12	$ 3.33
Net income per common share - Diluted	2.93	2.98	2.75
Cash dividends declared per common share	$ 0.44	$ 0.40	$ 0.18
Weighted average common shares outstanding	47,838	46,524	38,699
Dilutive potential common shares	4,099	4,321	11,249
Average common shares and dilutive common shares	51,937	50,845	49,948