Investments and Restricted Cash and Cash Equivalents and Investments - EGTS - Reconciliation of Cash (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	$ 2,229	$ 1,591
Restricted cash and cash equivalents, current	158	173
Restricted cash, cash equivalents and investments, noncurrent	53	53
Total cash and cash equivalents and restricted cash and cash equivalents	2,440	1,817	$ 2,301	$ 1,244
EGTS
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents	22	16
Restricted cash and cash equivalents, current	28	29
Total cash and cash equivalents and restricted cash and cash equivalents	$ 50	$ 45	$ 53	$ 26