Held-to-Maturity Investments - Summary of Debt Securities, Held-to-Maturity (Details) - U.S. treasuries and government agency securities - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	$ 2,956	$ 4,932
Gross Unrealized Gains	1	1
Gross Unrealized losses	0	(3)
Estimated Fair Value (Level 1)	$ 2,957	$ 4,930