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v3.23.1

Investment Securities - Amortized Cost and Approximate Fair Values of Investment Securities (Details) - USD ($) $ in Millions | 3 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2023 | Mar. 31, 2022 | Dec. 31, 2022 | Dec. 31, 2021
Available-for-Sale: |  |  |  |
Gross Unrealized Gains | $ 0.2 |  | $ 2.3 |
Gross Unrealized Losses | (533.1) |  | (629.7) |
Held-to-Maturity: |  |  |  |
Investment securities classified as held to maturity | 3,376.9 |  | 3,453.7 |
Allowance for Credit Losses | (0.7) | $ (1.6) | (1.9) | $ 0.0
Net Amortized Cost | 3,376.2 |  | 3,451.8 |
Gross Unrealized Gains | 1.4 |  | 0.4 |
Gross Unrealized Losses | (351.8) |  | (400.0) |
Investment debt securities held-to-maturity | 3,025.8 |  | 3,052.2 |
Estimated Fair Value | 6,049.3 |  | 6,946.1 |
Debt Securities, Available-for-Sale, Amortized Cost, after Allowance for Credit Loss | 6,582.2 |  | 7,573.5 |
U.S. Treasury notes |  |  |  |
Available-for-Sale: |  |  |  |
Gross Unrealized Gains | 0.0 |  | 2.1 |
Gross Unrealized Losses | (26.9) |  | (34.5) |
Held-to-Maturity: |  |  |  |
Investment securities classified as held to maturity | 397.2 |  | 396.6 |
Allowance for Credit Losses | 0.0 |  | 0.0 |
Net Amortized Cost | 397.2 |  | 396.6 |
Gross Unrealized Gains | 0.0 |  | 0.0 |
Gross Unrealized Losses | (7.6) |  | (10.2) |
Investment debt securities held-to-maturity | 389.6 |  | 386.4 |
Estimated Fair Value | 223.2 |  | 642.7 |
Debt Securities, Available-for-Sale, Amortized Cost, after Allowance for Credit Loss | 250.1 |  | 675.1 |
State, county, and municipal securities |  |  |  |
Available-for-Sale: |  |  |  |
Gross Unrealized Gains | 0.0 |  | 0.0 |
Gross Unrealized Losses | (40.9) |  | (50.6) |
Held-to-Maturity: |  |  |  |
Investment securities classified as held to maturity | 180.9 |  | 181.2 |
Allowance for Credit Losses | 0.0 |  | (0.1) |
Net Amortized Cost | 180.9 |  | 181.1 |
Gross Unrealized Gains | 0.4 |  | 0.2 |
Gross Unrealized Losses | (25.2) |  | (31.6) |
Investment debt securities held-to-maturity | 156.1 |  | 149.7 |
Estimated Fair Value | 221.1 |  | 263.7 |
Debt Securities, Available-for-Sale, Amortized Cost, after Allowance for Credit Loss | 262.0 |  | 314.3 |
Obligations of U.S. government agencies |  |  |  |
Available-for-Sale: |  |  |  |
Gross Unrealized Gains | 0.0 |  | 0.0 |
Gross Unrealized Losses | (12.3) |  | (17.3) |
Held-to-Maturity: |  |  |  |
Investment securities classified as held to maturity | 352.3 |  | 351.7 |
Allowance for Credit Losses | 0.0 |  | 0.0 |
Net Amortized Cost | 352.3 |  | 351.7 |
Gross Unrealized Gains | 0.0 |  | 0.0 |
Gross Unrealized Losses | (44.7) |  | (49.6) |
Investment debt securities held-to-maturity | 307.6 |  | 302.1 |
Estimated Fair Value | 174.1 |  | 198.9 |
Debt Securities, Available-for-Sale, Amortized Cost, after Allowance for Credit Loss | 186.4 |  | 216.2 |
U.S. agency residential & commercial mortgage-backed securities & collateralized mortgage obligations |  |  |  |
Available-for-Sale: |  |  |  |
Gross Unrealized Gains | 0.2 |  | 0.2 |
Gross Unrealized Losses | (362.8) |  | (426.0) |
Held-to-Maturity: |  |  |  |
Investment securities classified as held to maturity | 2,389.4 |  | 2,444.1 |
Allowance for Credit Losses | 0.0 |  | 0.0 |
Net Amortized Cost | 2,389.4 |  | 2,444.1 |
Gross Unrealized Gains | 1.0 |  | 0.2 |
Gross Unrealized Losses | (269.7) |  | (301.6) |
Investment debt securities held-to-maturity | 2,120.7 |  | 2,142.7 |
Debt Securities, Held-To-Maturity, Transfer, Unamortized Gain | 13.2 | $ 20.1 |  |
Debt Securities, Held-To-Maturity, Transfer, Unamortized Loss | (19.7) |  |  |
Estimated Fair Value | 3,858.4 |  | 4,259.7 |
Debt Securities, Available-for-Sale, Amortized Cost, after Allowance for Credit Loss | 4,221.0 |  | 4,685.5 |
Private mortgage-backed securities |  |  |  |
Available-for-Sale: |  |  |  |
Gross Unrealized Gains | 0.0 |  | 0.0 |
Gross Unrealized Losses | (35.2) |  | (36.9) |
Held-to-Maturity: |  |  |  |
Estimated Fair Value | 225.1 |  | 228.0 |
Debt Securities, Available-for-Sale, Amortized Cost, after Allowance for Credit Loss | 260.3 |  | 264.9 |
Collateralized Loan Obligations |  |  |  |
Available-for-Sale: |  |  |  |
Gross Unrealized Gains | 0.0 |  | 0.0 |
Gross Unrealized Losses | (29.4) |  | (33.6) |
Held-to-Maturity: |  |  |  |
Estimated Fair Value | 1,113.9 |  | 1,111.6 |
Debt Securities, Available-for-Sale, Amortized Cost, after Allowance for Credit Loss | 1,143.3 |  | 1,145.2 |
Corporate Debt Securities |  |  |  |
Available-for-Sale: |  |  |  |
Gross Unrealized Gains | 0.0 |  | 0.0 |
Gross Unrealized Losses | (25.6) |  | (30.8) |
Held-to-Maturity: |  |  |  |
Investment securities classified as held to maturity | 57.1 |  | 80.1 |
Allowance for Credit Losses | (0.7) |  | (1.8) |
Net Amortized Cost | 56.4 |  | 78.3 |
Gross Unrealized Gains | 0.0 |  | 0.0 |
Gross Unrealized Losses | (4.6) |  | (7.0) |
Investment debt securities held-to-maturity | 51.8 |  | 71.3 |
Estimated Fair Value | 233.5 |  | 241.5 |
Debt Securities, Available-for-Sale, Amortized Cost, after Allowance for Credit Loss | $ 259.1 |  | $ 272.3 |

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