General - Cash, Cash Equivalents and Restricted Cash Equivalents (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 4,569	$ 2,008	$ 1,011
Restricted cash and restricted cash equivalents	180	170	124
Restricted cash and restricted cash equivalents included in long-term receivables and other assets, net	17		78
Cash, cash equivalents, restricted cash and restricted cash equivalents	$ 4,766	$ 2,194	$ 1,213	$ 3,574