Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Interest income:
Loans and loans held for sale	$ 162,278	$ 161,539
Investment securities:
Taxable	33,149	31,950
Tax-exempt	5,261	6,026
Total investment securities interest	38,410	37,976
Total interest income	200,688	199,515
Deposits:
Interest bearing	929	767
Savings and money market accounts	5,652	5,547
Certificates and other time deposits	3,289	2,177
Federal funds purchased and securities sold under agreements to repurchase	265	243
Wholesale borrowings	1,234	1,160
Long-term debt	4,163	3,998
Total interest expense	15,532	13,892
Net interest income	185,156	185,623
Provision for loan losses	7,809	8,248
Net interest income after provision for loan losses	177,347	177,375
Noninterest income:
Trust department income	10,284	10,149
Service charges on deposits	15,586	15,668
Credit card fees	13,578	12,649
ATM and other service fees	6,234	6,099
Bank owned life insurance income	3,696	3,592
Investment services and insurance	3,905	3,704
Investment securities gains/(losses), net	295	354
Loan sales and servicing income	1,852	1,600
Other operating income	11,964	12,032
Total noninterest income	67,394	65,847
Noninterest expense:
Salaries, wages, pension and employee benefits	85,880	90,526
Net occupancy expense	14,774	15,954
Equipment expense	12,408	11,025
Stationery, supplies and postage	3,619	3,528
Bankcard, loan processing and other costs	11,008	11,139
Professional services	8,351	4,010
Amortization of intangibles	2,304	2,598
FDIC insurance expense	5,445	5,167
Other operating expense	23,174	16,705
Total noninterest expense	166,963	160,652
Income before income tax expense	77,778	82,570
Income tax expense	23,642	25,431
Net income	54,136	57,139
Less: Net income allocated to participating shareholders	387	407
Preferred Stock dividends	1,469	1,469
Net income attributable to common shareholders	52,280	55,263
Net income used in diluted EPS calculation	$ 52,280	$ 55,263
Weighted average number of common shares outstanding - basic	165,745	165,411
Weighted average number of common shares outstanding - diluted	166,239	166,003
Basic earnings per common share (in dollars per share)	$ 0.32	$ 0.33
Diluted earnings per common share (in dollars per share)	0.31	0.33
Cash dividend per common share (in dollars per share)	$ 0.17	$ 0.16