| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 |
| | 10-K | 10-K | 10-K | 10-K | 10-K |
| Operating activities | | | | | |
| Net income (loss) | 199.8 | 154.7 | 22.7 | 135.1 | 122.7 |
| |
| Adjustments to reconcile net income to net cash provided by operating activities | | | | | |
| Depreciation and amortization | 15.0 | 14.5 | 15.8 | 19.5 | 20.1 |
| Deferred income tax (benefit) expense | 6.0 | -5.3 | -20.4 | 1.4 | -4.9 |
| Amortization of investment security premiums and discounts, net | 18.3 | 16.7 | 5.6 | 3.1 | 3.3 |
| Right-of-use asset amortization | 13.0 | 12.7 | 12.1 | | |
| Share-based compensation | 10.5 | | | | |
| Increase in cash surrender value of bank-owned life insurance | -3.7 | -2.3 | -2.2 | -2.1 | 0.0 |
| Accretion of gains from terminated interest rate swaps | -10.2 | -31.2 | -15.9 | | |
| Other | 0.0 | -0.5 | -0.6 | | |
| |
| Change in: | | | | | |
| Loans held for sale | -3.4 | 0.0 | -1.1 | 0.0 | 2.3 |
| Prepaid pension expense | 4.3 | 1.1 | -24.1 | -11.0 | 11.2 |
| Other assets | 0.8 | 61.5 | -89.6 | -31.0 | 21.5 |
| Other liabilities | -49.9 | -22.9 | 49.0 | 19.7 | 18.2 |
| Net cash provided by operating activities | 229.9 | 174.5 | 69.9 | 196.2 | 205.0 |
| |
| Investing activities | | | | | |
| Proceeds from sales of securities available for sale | 431.2 | 23.8 | 9.1 | 48.0 | 11.7 |
| Proceeds from maturities and principal paydowns of securities available for sale | 1,049.5 | 939.6 | 452.4 | 204.1 | 162.4 |
| Purchases of securities available for sale | -740.8 | -3,323.9 | -2,111.8 | -252.6 | -167.6 |
| Proceeds from maturities and principal paydowns of securities held to maturity | 17.4 | | | | |
| Purchases of securities held to maturity | -493.7 | | | | |
| Proceeds from sale of Federal Home Loan Bank stock | 63.7 | 6.7 | 0.7 | | |
| Purchases of Federal Home Loan Bank stock | -94.2 | -2.1 | -0.5 | | |
| Contributions to low income housing tax credit investments | -19.5 | -11.4 | -12.4 | -6.3 | -3.3 |
| Contributions to other equity investments | -0.8 | -2.5 | -4.4 | -4.5 | -0.1 |
| Distributions from other equity investments | 1.2 | 0.3 | 0.2 | 0.1 | 0.2 |
| Purchases of loans | -380.2 | | | | |
| Proceeds from life insurance policies | 20.4 | | 1.3 | | 0.7 |
| Acquisitions, net of cash and cash equivalents acquired | -13.4 | -13.4 | -1.4 | | -11.5 |
| Purchased banking premises and equipment | -8.6 | -5.7 | -5.1 | -7.2 | -9.0 |
| Proceeds from sale of premises held for sale | 17.3 | 22.0 | | | |
| Net cash provided by (used in) investing activities | -1,076.7 | -1,985.7 | -2,390.2 | -145.3 | -647.1 |
| |
| Financing activities | | | | | |
| Net increase (decrease) in time deposits | 1,098.0 | -58.1 | -70.3 | | |
| Contingent consideration paid | -0.7 | -0.3 | -0.2 | -0.7 | -1.2 |
| Payments for repurchases of common stock | -201.6 | -23.2 | | | |
| Dividends declared and paid to common shareholders | -65.9 | -51.6 | | | |
| Net cash used in financing activities | -215.6 | 989.0 | 4,011.8 | 51.9 | 390.7 |
| |
| Supplemental disclosure of cash flow information | | | | | |
| Cash paid during the period for: | | | | | |
| Interest paid on deposits and borrowings | 35.2 | 5.4 | 13.7 | 34.2 | 23.7 |
| Income taxes | 41.8 | 43.3 | 35.1 | 31.3 | 29.7 |
| Non-cash activities | | | | | |
| Net increase in capital commitments relating to low income housing tax credit projects | 55.2 | 28.3 | 25.8 | 10.0 | 13.0 |