Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest income
Interest and fees on loans	$ 1,044,502	$ 856,549	$ 726,048
Mortgage loans held-for-sale	15,738	12,332	14,953
Interest bearing deposits with banks	17,090	9,252	4,236
Federal funds sold and securities purchased under resale agreements	1	2	4
Investment securities	87,382	63,315	62,038
Trading account securities	43	25	75
Federal Home Loan Bank and Federal Reserve Bank stock	5,331	4,370	4,287
Brokerage customer receivables	723	623	816
Total interest income	1,170,810	946,468	812,457
Interest expense
Interest on deposits	166,553	83,326	58,409
Interest on Federal Home Loan Bank advances	12,412	8,798	10,886
Interest on other borrowings	8,599	5,370	4,355
Interest on subordinated notes	7,121	7,116	7,111
Interest on junior subordinated debentures	11,222	9,782	9,503
Total interest expense	205,907	114,392	90,264
Net interest income	964,903	832,076	722,193
Provision for credit losses	34,832	29,768	34,084
Net interest income after provision for credit losses	930,071	802,308	688,109
Non-interest income
Mortgage banking	136,990	113,472	128,743
(Losses) gains on investment securities, net	(2,898)	45	7,645
Fees from covered call options	3,519	4,402	11,470
Trading gains (losses), net	11	(845)	91
Operating lease income, net	38,451	29,646	16,441
Other	52,710	56,507	53,812
Total non-interest income	356,150	319,506	325,430
Non-interest expense
Salaries and employee benefits	480,077	430,078	405,158
Equipment	42,949	38,358	37,055
Operating lease equipment depreciation	29,305	24,107	13,259
Occupancy, net	57,814	52,920	50,912
Data processing	35,027	31,495	28,776
Advertising and marketing	41,140	30,830	24,776
Professional fees	32,306	27,835	20,411
Amortization of other intangible assets	4,571	4,401	4,789
FDIC insurance	17,209	16,231	16,065
OREO expenses, net	6,120	3,593	5,187
Other	79,570	71,969	75,297
Total non-interest expense	826,088	731,817	681,685
Income before taxes	460,133	389,997	331,854
Income tax expense	116,967	132,315	124,979
Net income	343,166	257,682	206,875
Preferred stock dividends	8,200	9,778	14,513
Net income applicable to common shares	$ 334,966	$ 247,904	$ 192,362
Net income per common share - Basic (usd per share)	$ 5.95	$ 4.53	$ 3.83
Net income per common share - Diluted (usd per share)	5.86	4.40	3.66
Cash dividends declared per common share (in usd per share)	$ 0.76	$ 0.56	$ 0.48
Weighted average common shares outstanding (in shares)	56,300	54,703	50,278
Dilutive potential common shares (in shares)	908	1,983	3,994
Average common shares and dilutive common shares (in shares)	57,208	56,686	54,272
Wealth management
Non-interest income
Revenue from contracts with customers	$ 90,963	$ 81,766	$ 76,018
Service charges on deposit accounts
Non-interest income
Revenue from contracts with customers	$ 36,404	$ 34,513	$ 31,210