Debt securities available-for-sale	3 Months Ended
Debt securities available-for-sale	Mar. 31, 2023
Debt securities available-for-sale
Schedule of Available-for-sale Securities [Line Items]
Investments in debt and marketable equity securities	Note 6 – Debt securities available-for-sale The following tables present the amortized cost, gross unrealized gains and losses, approximate fair value, weighted average yield and contractual maturities of debt securities available-for-sale at March 31, 2023 and December 31, 2022. At March 31, 2023 Gross Gross Weighted Amortized unrealized unrealized Fair average (In thousands) cost gains losses value yield U.S. Treasury securities Within 1 year $ 4,724,780 $ 622 $ 50,140 $ 4,675,262 2.69 % After 1 to 5 years 5,991,694 43 308,049 5,683,688 1.33 After 5 to 10 years 308,525 - 32,728 275,797 1.63 Total U.S. Treasury securities 11,024,999 665 390,917 10,634,747 1.92 Collateralized mortgage obligations - federal agencies After 1 to 5 years 13,109 - 733 12,376 1.58 After 5 to 10 years 34,671 - 2,230 32,441 1.80 After 10 years 123,200 34 9,279 113,955 2.56 Total collateralized mortgage obligations - federal agencies 170,980 34 12,242 158,772 2.33 Mortgage-backed securities Within 1 year 460 - 3 457 3.37 After 1 to 5 years 71,211 14 2,721 68,504 2.36 After 5 to 10 years 837,061 47 52,682 784,426 2.19 After 10 years 6,610,019 1,220 1,086,066 5,525,173 1.63 Total mortgage-backed securities 7,518,751 1,281 1,141,472 6,378,560 1.70 Other After 1 to 5 years 1,049 - - 1,049 3.98 Total other 1,049 - - 1,049 3.98 Total debt securities available-for-sale [1] $ 18,715,779 $ 1,980 $ 1,544,631 $ 17,173,128 1.84 % [1] Includes $ 10.3 billion pledged to secure government and trust deposits, assets sold under agreements to repurchase, credit facilities and loan servicing agreements that the secured parties are not permitted to sell or repledge the collateral, of which $ 9.4 billion serve as collateral for public funds. The Corporation had unpledged Available for Sale securities with a fair value of $ 6.7 billion that could be used to increase its borrowing facilities. At December 31, 2022 Gross Gross Weighted Amortized unrealized unrealized Fair average (In thousands) cost gains losses value yield U.S. Treasury securities Within 1 year $ 4,576,127 $ 506 $ 47,156 $ 4,529,477 2.42 % After 1 to 5 years 6,793,739 - 410,858 6,382,881 1.35 After 5 to 10 years 308,854 - 40,264 268,590 1.63 Total U.S. Treasury securities 11,678,720 506 498,278 11,180,948 1.78 Collateralized mortgage obligations - federal agencies After 1 to 5 years 3,914 - 213 3,701 1.77 After 5 to 10 years 47,979 - 3,428 44,551 1.73 After 10 years 127,639 24 10,719 116,944 2.53 Total collateralized mortgage obligations - federal agencies 179,532 24 14,360 165,196 2.30 Mortgage-backed securities After 1 to 5 years 74,328 11 3,428 70,911 2.33 After 5 to 10 years 866,757 43 58,997 807,803 2.16 After 10 years 6,762,150 932 1,184,626 5,578,456 1.61 Total mortgage-backed securities 7,703,235 986 1,247,051 6,457,170 1.68 Other After 1 to 5 years 1,062 - 2 1,060 3.98 Total other 1,062 - 2 1,060 3.98 Total debt securities available-for-sale [1] $ 19,562,549 $ 1,516 $ 1,759,691 $ 17,804,374 1.75 % [1] Includes $ 11.3 billion pledged to secure government and trust deposits, assets sold under agreements to repurchase, credit facilities and loan servicing agreements that the secured parties are not permitted to sell or repledge the collateral, of which $ 10.3 billion serve as collateral for public funds. The Corporation had unpledged Available for Sale securities with a fair value of $ 6.4 billion that could be used to increase its borrowing facilities. The weighted average yield on debt securities available-for-sale is based on amortized cost; therefore, it does not give effect to changes in fair value. Debt securities not due on a single contractual maturity date, such as mortgage-backed securities and collateralized mortgage obligations, are classified in the period of final contractual maturity. The expected maturities of collateralized mortgage obligations, mortgage-backed securities and certain other securities may differ from their contractual maturities because they may be subject to prepayments or may be called by the issuer. There were no debt securities sold during the quarters ended March 31, 2023 and 2022. The following tables present the Corporation’s fair value and gross unrealized losses of debt securities available-for-sale, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2023 and December 31, 2022. At March 31, 2023 Less than 12 months 12 months or more Total Gross Gross Gross Fair unrealized Fair unrealized Fair unrealized (In thousands) value losses value losses value losses U.S. Treasury securities $ 2,162,329 $ 42,295 $ 6,598,099 $ 348,622 $ 8,760,428 $ 390,917 Collateralized mortgage obligations - federal agencies 42,946 1,526 113,220 10,716 156,166 12,242 Mortgage-backed securities 440,122 22,396 5,881,221 1,119,076 6,321,343 1,141,472 Total debt securities available-for-sale in an unrealized loss position $ 2,645,397 $ 66,217 $ 12,592,540 $ 1,478,414 $ 15,237,937 $ 1,544,631 At December 31, 2022 Less than 12 months 12 months or more Total Gross Gross Gross Fair unrealized Fair unrealized Fair unrealized (In thousands) value losses value losses value losses U.S. Treasury securities $ 6,027,786 $ 288,582 $ 3,244,572 $ 209,696 $ 9,272,358 $ 498,278 Collateralized mortgage obligations - federal agencies 139,845 10,655 22,661 3,705 162,506 14,360 Mortgage-backed securities 1,740,214 138,071 4,662,195 1,108,980 6,402,409 1,247,051 Other 60 2 - - 60 2 Total debt securities available-for-sale in an unrealized loss position $ 7,907,905 $ 437,310 $ 7,929,428 $ 1,322,381 $ 15,837,333 $ 1,759,691 As of March 31, 2023, the portfolio of available-for-sale debt securities reflects gross unrealized losses of approximately $ 1.5 billion, driven mainly by fixed-rate U.S. Treasury Securities and mortgage-backed securities, which have been impacted by a decline in fair value as a result of the rising interest rate environment. The portfolio of available-for-sale debt securities is comprised mainly of U.S Treasuries and obligations from the U.S. Government, its agencies or government sponsored entities, including FNMA, FHMLC and GNMA. As discussed in Note 2 to the Consolidated Financial Statements in the 2022 Form 10-K, these securities carry an explicit or implicit guarantee from the U.S. Government, are highly rated by major rating agencies, and have a long history of no credit losses. Accordingly, the Corporation applies a zero-credit loss assumption and no ACL for these securities has been established. In October 2022, the Corporation transferred U.S. Treasury securities with a fair value of $ 6.5 billion (par value of $ 7.4 billion) from its available-for-sale portfolio to its held-to-maturity portfolio. Management changed its intent, given its ability to hold these securities to maturity due to the Corporation’s liquidity position and its intention to reduce the impact on accumulated other comprehensive income (loss) (“AOCI”) and tangible capital of further increases in interest rates. The securities were reclassified at fair value at the time of the transfer. At the date of the transfer, these securities had pre-tax unrealized losses of $ 873.0 million recorded in AOCI. This fair value discount is being accreted to interest income and the unrealized loss remaining in AOCI is being amortized, offsetting each other through the remaining life of the securities. There were no realized gains or losses recorded as a result of this transfer.