Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest income:
Interest and fees on loans	$ 91.7	$ 63.7
Interest and dividends on investment securities:
Taxable	13.2	8.7
Exempt from federal taxes	0.6	0.8
Interest on deposits in banks	2.1	1.2
Total interest income	107.6	74.4
Interest expense:
Interest on deposits	6.2	4.1
Interest on securities sold under repurchase agreements	0.4	0.2
Interest on other borrowed funds	0.1	0.0
Interest on other debt	0.2	0.5
Interest on subordinated debentures held by subsidiary trusts	0.9	0.7
Total interest expense	7.8	5.5
Net interest income	99.8	68.9
Provision for loan losses	2.1	1.7
Net interest income after provision for loan losses	97.7	67.2
Non-interest income:
Payment services revenues	10.5	8.4
Mortgage banking revenues	5.4	6.5
Wealth management revenues	5.9	5.0
Service charges on deposit accounts	5.6	4.4
Other service charges, commissions and fees	3.9	2.7
Investment securities gains (losses), net	0.0	0.0
Other income	3.9	2.1
Total non-interest income	35.2	29.1
Non-interest expense:
Salaries and wages	34.6	25.7
Employee benefits	11.3	9.6
Outsourced technology services	7.0	5.3
Occupancy, net	6.3	4.8
Furniture and equipment	3.1	2.3
OREO expense, net of income	0.2	0.0
Professional fees	1.2	1.0
FDIC insurance premiums	1.5	0.9
Mortgage servicing rights amortization	0.8	0.6
Mortgage servicing rights recovery	0.0	(0.1)
Core deposit intangibles amortization	1.8	0.6
Other expenses	15.8	12.3
Acquisition related expenses	2.3	0.7
Total non-interest expense	85.9	63.7
Income before income tax expense	47.0	32.6
Income tax expense	10.3	9.4
Net income	$ 36.7	$ 23.2
Basic earnings per common share (in dollars per share)	$ 0.65	$ 0.52
Diluted earnings per common share (in dollars per share)	$ 0.65	$ 0.51
Weighted average common shares outstanding for basic earnings per share computation	56,241,201	44,680,258
Weighted Average Number of Shares Outstanding, Diluted	56,652,178	45,238,908