| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 8-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Interest income | | | | | | | | |
| Interest and fees on loans | 1,507.7 | 1,133.5 | 1,157.2 | 1,228.5 | 1,044.5 | 856.5 | 726.0 | 651.8 |
| Interest-bearing deposits with banks | | 6.6 | 8.6 | 29.8 | 17.1 | 9.3 | 4.2 | 1.5 |
| Federal funds sold and securities purchased under resale agreements | | 0.2 | 0.1 | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 |
| Investment securities | 160.6 | 95.3 | 99.6 | 108.0 | 87.4 | | | |
| Federal Home Loan Bank and Federal Reserve Bank stock | 8.6 | 7.1 | 6.9 | 5.4 | 5.3 | | | 3.2 |
| Brokerage customer receivables | 0.9 | 0.6 | 0.5 | 0.7 | 0.7 | | | 0.8 |
| Total interest income | 1,747.4 | 1,275.5 | 1,293.0 | 1,385.1 | 1,170.8 | 946.5 | 812.5 | 718.5 |
| |
| Interest expense | | | | | | | | |
| Interest on deposits | 175.2 | 88.1 | 189.2 | 278.9 | 166.6 | 83.3 | 58.4 | 48.9 |
| Interest on Federal Home Loan Bank advances | | 19.6 | 18.2 | 9.9 | 12.4 | 8.8 | 10.9 | 9.1 |
| Interest on subordinated notes | | 22.0 | 22.0 | 15.6 | 7.1 | 7.1 | 7.1 | 7.1 |
| Interest on junior subordinated debentures | | 22.0 | 22.0 | 15.6 | 7.1 | 7.1 | 7.1 | 7.1 |
| Total interest expense | 252.1 | 150.5 | 253.1 | 330.2 | 205.9 | 114.4 | 90.3 | 76.9 |
| Net interest income | 1,495.4 | 1,125.0 | 1,039.9 | 1,054.9 | 964.9 | 832.1 | 722.2 | 641.5 |
| Provision for credit losses | | -59.3 | 214.2 | 53.9 | 34.8 | 29.8 | 34.1 | 32.9 |
| Net interest income after provision for credit losses | 1,416.8 | 1,184.2 | 825.7 | 1,001.1 | 930.1 | 802.3 | 688.1 | 608.6 |
| |
| Non-interest income | | | | | | | | |
| Revenue from contracts with customers | | | | | | | | |
| Mortgage banking | | 273.0 | 346.0 | 154.3 | 137.0 | 113.5 | 128.7 | 115.0 |
| Fees from covered call options | 14.1 | 3.7 | 2.3 | 3.7 | 3.5 | 4.4 | 11.5 | 15.4 |
| Trading gains, net | | 0.2 | -1.0 | -0.2 | 0.0 | | | -0.2 |
| Operating lease income, net | 55.5 | 53.7 | 47.6 | 47.0 | 38.5 | | | |
| Other | | 78.4 | 65.9 | 62.6 | 52.7 | 56.5 | 53.8 | 37.6 |
| Total non-interest income | 461.1 | 586.1 | 604.2 | 407.2 | 356.2 | 319.5 | 325.4 | 271.6 |
| |
| Non-interest expense | | | | | | | | |
| Salaries and employee benefits | | 691.7 | 626.1 | 546.4 | 480.1 | 430.1 | 405.2 | 382.1 |
| Software and equipment | | 87.5 | 68.5 | 52.3 | 42.9 | 38.4 | 37.1 | 32.9 |
| Occupancy, net | | 74.2 | 70.0 | 64.3 | 57.8 | 52.9 | 50.9 | 48.9 |
| Data processing | | 27.3 | 30.2 | 27.8 | 35.0 | 31.5 | 28.8 | 26.9 |
| Advertising and marketing | 59.4 | 47.3 | 36.3 | 48.6 | 41.1 | 30.8 | 24.8 | 21.9 |
| Professional fees | | 29.5 | 27.4 | 27.5 | 32.3 | 27.8 | 20.4 | 18.2 |
| Amortization of other acquisition-related intangible assets | 6.1 | 7.7 | 11.0 | 11.8 | 4.6 | 4.4 | 4.8 | 4.6 |
| FDIC insurance | | 27.0 | 25.0 | 9.2 | 17.2 | 16.2 | 16.1 | 12.4 |
| Other | | 101.1 | 108.6 | 100.8 | 79.6 | 72.0 | 75.3 | 74.2 |
| Total non-interest expense | 1,177.3 | 1,132.5 | 1,040.1 | 928.1 | 826.1 | 731.8 | 681.7 | 628.4 |
| Income tax expense | 190.9 | 171.6 | 96.8 | 124.4 | 117.0 | 132.3 | 125.0 | 95.0 |
| Net income | 509.7 | 466.2 | 293.0 | 355.7 | 343.2 | 257.7 | 206.9 | 156.7 |
| Preferred stock dividends | | 55.9 | 21.4 | 8.2 | 8.2 | 9.8 | 14.5 | 10.9 |
| Net income applicable to common shares | 481.7 | 438.2 | 271.6 | 347.5 | 335.0 | 247.9 | 192.4 | 145.9 |
| |
| Net income per common share-Basic (usd per share) | $8.14 | $7.69 | $4.72 | $6.11 | $5.95 | $4.53 | $3.83 | $3.05 |
| Net income per common share-Diluted (usd per share) | $8.02 | $7.58 | $4.68 | $6.03 | $5.86 | $4.40 | $3.66 | $2.93 |
| |
| Cash dividends declared per common share (usd per share) | $1,360.00 | $1.24 | $1.12 | $1.00 | $0.76 | $0.56 | $0.48 | $0.44 |
| |
| Weighted average common shares outstanding (in shares) | 59.2 | 57.0 | 57.5 | 56.9 | 56.3 | 54.7 | 50.3 | 47.8 |
| Dilutive potential common shares (in shares) | | 0.8 | 0.5 | 0.8 | 0.9 | 2.0 | 4.0 | 4.1 |
| Average common shares and dilutive common shares (in shares) | 59.2 | 57.8 | 58.0 | 57.6 | 57.2 | 56.7 | 54.3 | 51.9 |