Debt securities available-for-sale	12 Months Ended
Debt securities available-for-sale	Dec. 31, 2022
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 December 31, 2022 and December 31, 2021. 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. At December 31, 2021 Gross Gross Weighted Amortized unrealized unrealized Fair average (In thousands) cost gains losses value yield U.S. Treasury securities Within 1 year $ 1,225,558 $ 13,556 $ 69 $ 1,239,045 2.33 % After 1 to 5 years 10,059,163 98,808 65,186 10,092,785 1.18 After 5 to 10 years 4,563,265 739 36,804 4,527,200 1.22 Total U.S. Treasury securities 15,847,986 113,103 102,059 15,859,030 1.27 Obligations of U.S. Government sponsored entities Within 1 year 70 - - 70 5.63 Total obligations of U.S. Government sponsored entities 70 - - 70 5.63 Collateralized mortgage obligations - federal agencies After 1 to 5 years 2,433 42 - 2,475 2.16 After 5 to 10 years 43,241 295 6 43,530 1.54 After 10 years 172,176 3,441 357 175,260 2.13 Total collateralized mortgage obligations - federal agencies 217,850 3,778 363 221,265 2.01 Mortgage-backed securities Within 1 year 11 1 - 12 4.79 After 1 to 5 years 65,749 2,380 11 68,118 2.23 After 5 to 10 years 665,600 17,998 5 683,593 1.97 After 10 years 8,263,835 68,128 195,910 8,136,053 1.67 Total mortgage-backed securities 8,995,195 88,507 195,926 8,887,776 1.69 Other After 1 to 5 years 123 5 - 128 3.62 Total other 123 5 - 128 3.62 Total debt securities available-for-sale [1] $ 25,061,224 $ 205,393 $ 298,348 $ 24,968,269 1.42 % [1] Includes $ 22 .0 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 $ 20.9 billion serve as collateral for public funds. 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. 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. The following table presents the aggregate amortized cost and fair value of debt securities available-for-sale at December 31, 2022 by contractual maturity. (In thousands) Amortized cost Fair value Within 1 year $ 4,576,127 $ 4,529,477 After 1 to 5 years 6,873,043 6,458,553 After 5 to 10 years 1,223,590 1,120,944 After 10 years 6,889,789 5,695,400 Total debt securities available-for-sale $ 19,562,549 $ 17,804,374 There were no debt securities available-for-sale sold during the year ended December 31, 2022. During the year ended December 31, 2021, the Corporation sold U.S Treasury Notes. The proceeds from these sales were $ 236 million. Gross realized gains and losses on the sale of debt securities available-for-sale for the years ended December 31, 2022, 2021 and 2020 were as follows: (In thousands) 2022 2021 2020 Gross realized gains $ - $ 695 $ 41 Gross realized losses - (672) - Net realized gains (losses) on sale of debt securities available -for-sale $ - $ 23 $ 41 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 December 31, 2022 and 2021. 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 At December 31, 2021 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 $ 9,590,448 $ 102,059 $ - $ - $ 9,590,448 $ 102,059 Collateralized mortgage obligations - federal agencies 35,533 334 1,084 29 36,617 363 Mortgage-backed securities 5,767,556 170,614 595,051 25,312 6,362,607 195,926 Total debt securities available-for-sale in an unrealized loss position $ 15,393,537 $ 273,007 $ 596,135 $ 25,341 $ 15,989,672 $ 298,348 As of December 31, 2022, the portfolio of available-for-sale debt securities reflects gross unrealized losses of approximately $ 1.8 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, 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.