Assets and Liabilities Measured at Fair Value - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2026	Mar. 31, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Change in fair value of exchangeable senior debentures realized gain (loss)	$ 8		$ 176	$ 25	$ 229
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax	$ 701
Cumulative amount of gain in change in fair value						$ 772
4% Exchangeable Senior Debentures due 2029
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate (as a percent)	4.00%			4.00%		4.00%
Repayment Of Long-Term Debt, Principal		$ 59
Repayment Of Long-Term Debt, Carrying Value		3
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax		62
3.75% Exchangeable Senior Debentures due 2030
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate (as a percent)	3.75%			3.75%		3.75%
Repayment Of Long-Term Debt, Principal		14
Repayment Of Long-Term Debt, Carrying Value		1
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, before Tax		$ 13

Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for unrealized gain (loss) from increase (decrease) in instrument-specific credit risk, realized upon derecognition of financial liability measured under fair value option.