Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Billions	Dec. 31, 2023	Dec. 31, 2022
Cash equivalents	$ 4.8	$ 2.6
Investment, Type [Extensible Enumeration]	us-gaap:USTreasuryBillSecuritiesMember	us-gaap:USTreasuryBillSecuritiesMember