XML 45 R35.htm IDEA: XBRL DOCUMENT
v3.22.2

Investments (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2022
Investments [Abstract] |
Amortized Cost and Fair Value of the Trust Investments | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | Amortized Cost | ​ | Fair Value | ​
​ | ​ | Longest | ​ | June 30, | ​ | December 31, | ​ | June 30, | ​ | December 31, | ​
(in millions) |  | Maturity Dates |  | 2022 |  | 2021 |  | 2022 |  | 2021 | ​
Stocks |  | — |  | ​ | * |  | ​ | * | ​ | $ | 1,548 | ​ | $ | 1,972 | ​
Municipal bonds |  | 2058 |  | $ | 843 |  | $ | 875 | ​ |  | 905 | ​ |  | 1,033 | ​
Government and agency securities |  | 2067 |  | ​ | 933 |  | ​ | 1,095 | ​ |  | 986 | ​ |  | 1,212 |
Corporate bonds |  | 2070 |  | ​ | 371 |  | ​ | 386 | ​ |  | 390 | ​ |  | 446 |
Short-term investments and receivables/payables1 |  | One-year |  | ​ | 200 |  | ​ | 199 | ​ |  | 210 | ​ |  | 207 |
Total |  |  | ​ | $ | 2,347 | ​ | $ | 2,555 | ​ | $ | 4,039 | ​ | $ | 4,870 |
* | Not applicable
1 | Short-term investments include $48 million and $37 million of repurchase agreements payable by financial institutions which earn interest, are fully secured by U.S. Treasury securities and mature by July 1, 2022 and January 3, 2022 as of June 30, 2022 and December 31, 2021, respectively.
Summary of gains and losses | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Three months ended June 30, | ​ | Six months ended June 30,
(in millions) |  | 2022 |  | 2021 |  | 2022 |  | 2021
Gross realized gains | ​ | $ | 74 | ​ | $ | 140 | ​ | $ | 89 | ​ | $ | 251
Gross realized losses | ​ |  | 45 | ​ |  | 4 | ​ |  | 61 | ​ |  | 16
Net unrealized (losses) gains for equity securities | ​ |  | (332) | ​ |  | 16 | ​ |  | (432) | ​ |  | 34

X
- Definition Tabular disclosure of realized and unrealized gain (loss) on investment in security. + References No definition available. + Details
Name: | us-gaap_GainLossOnInvestmentsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RegulatedEntityOtherAssetsNoncurrentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration