Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest income:
Interest and fees on loans	$ 111.9	$ 112.3	$ 325.1	$ 336.4
Interest and dividends on investment securities:
Taxable	17.1	15.5	48.7	48.4
Exempt from federal taxes	1.4	0.6	4.2	1.6
Interest on deposits in banks	0.7	0.5	1.7	3.5
Total interest income	131.1	128.9	379.7	389.9
Interest expense:
Interest on deposits	1.9	3.4	6.4	15.2
Interest on securities sold under repurchase agreements	0.1	0.1	0.3	0.7
Interest on other debt	1.5	1.7	4.5	3.0
Interest on subordinated debentures held by subsidiary trusts	0.7	0.7	2.1	2.4
Total interest expense	4.2	5.9	13.3	21.3
Net interest income	126.9	123.0	366.4	368.6
(Reversal of) provision for credit losses	0.0	5.2	(5.1)	53.7
Net interest income after provision for (reversal of) credit losses	126.9	117.8	371.5	314.9
Non-interest income:
Debt Securities, Available-for-sale, Gain (Loss)	0.3	0.1	0.2	0.1
Mortgage banking revenues	11.6	14.3	32.8	39.4
Other income	3.3	4.6	10.0	12.5
Total non-interest income	39.7	44.7	113.1	122.8
Non-interest expense:
Salaries and wages	42.0	46.0	122.6	130.1
Employee benefits	12.9	11.8	43.7	36.4
Outsourced technology services	8.2	8.4	24.7	24.5
Occupancy, net	7.3	7.2	21.7	21.3
Furniture and equipment	4.5	4.1	13.0	11.1
OREO expense, net of income	0.0	0.0	(0.1)	(0.4)
Professional fees	2.7	2.9	9.3	8.6
FDIC insurance premiums	1.7	1.3	4.8	4.5
Core deposit intangibles amortization	2.4	2.7	7.4	8.3
Other expenses	17.6	15.1	49.6	45.7
Acquisition related expenses	6.6	0.0	6.6	0.0
Noninterest Expense	105.9	99.5	303.3	290.1
Income before income tax expense	60.7	63.0	181.3	147.6
Income tax expense	13.6	14.7	40.3	33.3
Net income	$ 47.1	$ 48.3	$ 141.0	$ 114.3
Earnings per common share, basic (in dollars per share)	$ 0.76	$ 0.76	$ 2.29	$ 1.78
Earnings per common share, diluted (in dollars per share)	$ 0.76	$ 0.76	$ 2.28	$ 1.78
Weighted average common shares outstanding, basic (in shares)	61,673,656	63,764,474	61,641,342	64,184,832
Weighted average common shares outstanding, diluted (in shares)	61,747,972	63,861,457	61,732,822	64,295,525
Payment services revenues
Non-interest income:
Non-interest income	$ 12.2	$ 10.5	$ 33.8	$ 30.0
Wealth management revenues
Non-interest income:
Wealth management revenues	6.5	5.9	19.1	17.5
Service charges on deposit accounts
Non-interest income:
Non-interest income	4.4	4.3	12.1	13.3
Other service charges, commissions, and fees
Non-interest income:
Non-interest income	$ 1.4	$ 5.0	$ 5.1	$ 10.0