Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest income:
Interest and fees on loans	$ 112.1	$ 120.9	$ 224.1	$ 232.3
Interest and dividends on investment securities:
Taxable	15.7	15.7	32.9	30.8
Exempt from federal taxes	0.5	0.5	1.0	1.0
Interest on deposits in banks	0.5	5.0	3.0	8.6
Total interest income	128.8	142.1	261.0	272.7
Interest expense:
Interest on deposits	4.5	14.1	11.8	26.2
Interest on securities sold under repurchase agreements	0.1	1.1	0.6	2.1
Interest on other debt	1.0	0.4	1.3	0.7
Interest on subordinated debentures held by subsidiary trusts	0.7	1.2	1.7	2.4
Total interest expense	6.3	16.8	15.4	31.4
Net interest income	122.5	125.3	245.6	241.3
Provision for credit losses	19.5	3.8	48.5	7.5
Net interest income after provision for credit losses	103.0	121.5	197.1	233.8
Non-interest income:
Mortgage banking revenues	14.2	9.0	25.1	14.2
Investment securities gains (losses), net	0.0	0.0	0.0	0.0
Other income	4.3	5.1	7.9	9.4
Total non-interest income	39.7	37.6	78.1	69.3
Non-interest expense:
Salaries and wages	44.2	40.1	84.1	75.2
Employee benefits	10.4	14.0	24.6	28.4
Outsourced technology services	8.3	8.1	16.1	16.0
Occupancy, net	6.8	7.1	14.1	14.1
Furniture and equipment	4.2	3.4	7.0	6.9
OREO expense, net of income	0.1	0.2	(0.4)	0.3
Professional fees	3.0	2.6	5.7	5.8
FDIC insurance premiums	1.6	1.6	3.2	3.1
Mortgage servicing rights impairment			8.4	0.0
Core deposit intangibles amortization	2.7	3.0	5.6	5.3
Other expenses	14.3	16.7	30.6	30.4
Acquisition related expenses	0.0	13.5	0.0	15.8
Noninterest Expense	95.6	110.3	190.6	201.3
Income before income tax expense	47.1	48.8	84.6	101.8
Income tax expense	10.4	10.9	18.6	22.3
Net income	$ 36.7	$ 37.9	$ 66.0	$ 79.5
Earnings per common share, basic (in dollars per share)	$ 0.57	$ 0.59	$ 1.02	$ 1.27
Earnings per common share, diluted (in dollars per share)	$ 0.57	$ 0.59	$ 1.02	$ 1.27
Weighted average common shares outstanding, basic (in shares)	64,004,455	64,504,546	64,397,320	62,419,442
Weighted average common shares outstanding, diluted (in shares)	64,082,489	64,707,459	64,513,886	62,668,391
Payment services revenues
Non-interest income:
Non-interest income	$ 9.3	$ 10.5	$ 19.5	$ 19.9
Wealth management revenues
Non-interest income:
Wealth management revenues	5.4	5.8	11.6	11.9
Service charges on deposit accounts
Non-interest income:
Non-interest income	3.6	5.4	9.0	10.4
Other service charges, commissions and fees
Non-interest income:
Non-interest income	$ 2.9	$ 1.8	$ 5.0	$ 3.5