Fair Value Measurements - Assets at Fair Value Recurring Basis (Details) - USD ($) $ in Millions | Sep. 30, 2023 | Dec. 31, 2022 | Sep. 30, 2022 | [1] |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | $ 1,567 | | $ 1,729 | |
Other securities | 68 | | 71 | |
Restricted cash and restricted cash equivalents | 580 | [1] | 461 | $ 483 |
U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 14 | | 16 | |
Obligations of states, municipalities, and political subdivisions | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 64 | | 66 | |
Corporate debt | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 1,025 | | 1,137 | |
RMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 172 | | 192 | |
CMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 33 | | 35 | |
CDO/ABS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 83 | | 86 | |
Level 1 | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Total investment securities | 50 | | 51 | |
Restricted cash and restricted cash equivalents | 580 | | 450 | |
Level 2 | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Total investment securities | 1,581 | | 1,744 | |
Restricted cash and restricted cash equivalents | 0 | | 11 | |
Level 3 | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Total investment securities | 4 | | 5 | |
Restricted cash and restricted cash equivalents | 0 | | 0 | |
Fair Value, Measurements, Recurring | | | | |
Assets | | | | |
Cash equivalents in mutual funds | 113 | | 77 | |
Cash equivalents in securities | 10 | | 17 | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 1,567 | | 1,729 | |
Other securities | 68 | | 71 | |
Total investment securities | 1,635 | | 1,800 | |
Restricted cash equivalents in mutual funds | 566 | | 445 | |
Restricted cash and restricted cash equivalents | | | 11 | |
Total | 2,324 | | 2,350 | |
Fair Value, Measurements, Recurring | Total bonds | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 22 | | 23 | |
Fair Value, Measurements, Recurring | U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 14 | | 16 | |
Fair Value, Measurements, Recurring | Obligations of states, municipalities, and political subdivisions | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 64 | | 66 | |
Fair Value, Measurements, Recurring | Commercial paper | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 23 | | 55 | |
Fair Value, Measurements, Recurring | Non-U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 153 | | 142 | |
Fair Value, Measurements, Recurring | Corporate debt | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 1,025 | | 1,137 | |
Other securities | 5 | | 6 | |
Fair Value, Measurements, Recurring | RMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 172 | | 192 | |
Other securities | | | 1 | |
Fair Value, Measurements, Recurring | CMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 33 | | 35 | |
Fair Value, Measurements, Recurring | CDO/ABS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 83 | | 86 | |
Other securities | 17 | | 16 | |
Fair Value, Measurements, Recurring | Preferred stock | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 15 | | 15 | |
Fair Value, Measurements, Recurring | Common stock | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 31 | | 33 | |
Fair Value, Measurements, Recurring | Level 1 | | | | |
Assets | | | | |
Cash equivalents in mutual funds | 113 | | 77 | |
Cash equivalents in securities | 0 | | 0 | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 6 | | 5 | |
Other securities | 44 | | 46 | |
Total investment securities | 50 | | 51 | |
Restricted cash equivalents in mutual funds | 566 | | 445 | |
Restricted cash and restricted cash equivalents | | | 0 | |
Total | 729 | | 573 | |
Fair Value, Measurements, Recurring | Level 1 | Total bonds | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | Obligations of states, municipalities, and political subdivisions | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | Commercial paper | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | Non-U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | Corporate debt | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 6 | | 5 | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | RMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Other securities | | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | CMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | CDO/ABS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 1 | Preferred stock | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 15 | | 15 | |
Fair Value, Measurements, Recurring | Level 1 | Common stock | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 29 | | 31 | |
Fair Value, Measurements, Recurring | Level 2 | | | | |
Assets | | | | |
Cash equivalents in mutual funds | 0 | | 0 | |
Cash equivalents in securities | 10 | | 17 | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 1,559 | | 1,721 | |
Other securities | 22 | | 23 | |
Total investment securities | 1,581 | | 1,744 | |
Restricted cash equivalents in mutual funds | 0 | | 0 | |
Restricted cash and restricted cash equivalents | | | 11 | |
Total | 1,591 | | 1,772 | |
Fair Value, Measurements, Recurring | Level 2 | Total bonds | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 22 | | 23 | |
Fair Value, Measurements, Recurring | Level 2 | U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 14 | | 16 | |
Fair Value, Measurements, Recurring | Level 2 | Obligations of states, municipalities, and political subdivisions | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 64 | | 66 | |
Fair Value, Measurements, Recurring | Level 2 | Commercial paper | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 23 | | 55 | |
Fair Value, Measurements, Recurring | Level 2 | Non-U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 153 | | 142 | |
Fair Value, Measurements, Recurring | Level 2 | Corporate debt | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 1,017 | | 1,129 | |
Other securities | 5 | | 6 | |
Fair Value, Measurements, Recurring | Level 2 | RMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 172 | | 192 | |
Other securities | | | 1 | |
Fair Value, Measurements, Recurring | Level 2 | CMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 33 | | 35 | |
Fair Value, Measurements, Recurring | Level 2 | CDO/ABS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 83 | | 86 | |
Other securities | 17 | | 16 | |
Fair Value, Measurements, Recurring | Level 2 | Preferred stock | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 2 | Common stock | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | | | | |
Assets | | | | |
Cash equivalents in mutual funds | 0 | | 0 | |
Cash equivalents in securities | 0 | | 0 | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 2 | | 3 | |
Other securities | 2 | | 2 | |
Total investment securities | 4 | | 5 | |
Restricted cash equivalents in mutual funds | 0 | | 0 | |
Restricted cash and restricted cash equivalents | | | 0 | |
Total | 4 | | 5 | |
Fair Value, Measurements, Recurring | Level 3 | Total bonds | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | Obligations of states, municipalities, and political subdivisions | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | Commercial paper | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | Non-U.S. government and government sponsored entities | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | Corporate debt | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 2 | | 3 | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | RMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Other securities | | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | CMBS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | CDO/ABS | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Available-for-sale securities | 0 | | 0 | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | Preferred stock | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | 0 | | 0 | |
Fair Value, Measurements, Recurring | Level 3 | Common stock | | | | |
Investments, Debt and Equity Securities [Abstract] | | | | |
Other securities | $ 2 | | $ 2 | |
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[1]Restricted cash and restricted cash equivalents primarily represent funds required to be used for future debt payments relating to our secured transactions. |