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v3.23.3

Investments (Tables) | 9 Months Ended
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Sep. 30, 2023
Investments |
Summary of amortized cost and fair value of the trust investments | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | Amortized Costs | ​ | Fair Values
​ | ​ | Longest | ​ | September 30, | ​ | December 31, | ​ | September 30, | ​ | December 31,
(in millions) |  | Maturity Dates |  | 2023 |  | 2022 |  | 2023 |  | 2022
Municipal bonds |  | 2061 |  | $ | 632 |  | $ | 672 | ​ | $ | 682 | ​ | $ | 754
Government and agency securities |  | 2073 |  | ​ | 1,146 |  | ​ | 1,025 | ​ |  | 1,210 | ​ |  | 1,091
Corporate bonds |  | 2070 |  | ​ | 350 |  | ​ | 351 | ​ |  | 376 | ​ |  | 377
Short-term investments and receivables/payables1 |  | One-year |  | ​ | 115 |  | ​ | 110 | ​ |  | 125 | ​ |  | 116
Total debt securities and other | ​ | ​ | ​ | $ | 2,243 | ​ | $ | 2,158 | ​ | ​ | 2,393 | ​ | ​ | 2,338
Equity securities |  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | 1,550 | ​ | ​ | 1,610
Total |  |  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | $ | 3,943 | ​ | $ | 3,948
1 | As of December 31, 2022, short-term investments included $41 million of repurchase agreement payable by financial institutions which earned interest, was 97% secured by U.S. Treasury securities and matured on January 3, 2023.
Summary of gains and losses | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Three months ended September 30, | ​ | Nine months ended September 30,
(in millions) |  | 2023 |  | 2022 |  | 2023 |  | 2022
Gross realized gains | ​ | $ | 48 | ​ | $ | 22 | ​ | $ | 243 | ​ | $ | 111
Gross realized losses | ​ |  | (38) | ​ |  | (35) | ​ |  | (69) | ​ |  | (96)
Net unrealized (losses)/gains for equity securities | ​ |  | (81) | ​ |  | (83) | ​ |  | (17) | ​ |  | (515)

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- Definition Tabular disclosure of realized and unrealized gain (loss) on investment in security. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(7)(c)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(9)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 + Details
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