Short-term and Long-term Investments, Restricted Deposits - Fair Value of Available-For-Sale Investments with Gross Unrealized Losses by Investment Type and Length of Time (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Unrealized Losses
Less Than 12 Months	$ (134)	$ (620)
12 Months or More	(1,119)	(744)
Fair Value
Fair Value, Less Than 12 Months	5,711	10,075
Fair Value, 12 Months or More	10,559	5,747
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Unrealized Losses
Less Than 12 Months	(3)	(5)
12 Months or More	(12)	(11)
Fair Value
Fair Value, Less Than 12 Months	207	342
Fair Value, 12 Months or More	191	184
Corporate securities
Unrealized Losses
Less Than 12 Months	(73)	(340)
12 Months or More	(651)	(438)
Fair Value
Fair Value, Less Than 12 Months	2,942	5,368
Fair Value, 12 Months or More	6,049	3,400
Municipal securities
Unrealized Losses
Less Than 12 Months	(26)	(142)
12 Months or More	(208)	(138)
Fair Value
Fair Value, Less Than 12 Months	1,413	2,437
Fair Value, 12 Months or More	1,990	995
Asset-backed securities
Unrealized Losses
Less Than 12 Months	(8)	(29)
12 Months or More	(52)	(41)
Fair Value
Fair Value, Less Than 12 Months	431	786
Fair Value, 12 Months or More	949	486
Residential mortgage-backed securities
Unrealized Losses
Less Than 12 Months	(16)	(55)
12 Months or More	(104)	(66)
Fair Value
Fair Value, Less Than 12 Months	494	629
Fair Value, 12 Months or More	644	352
Commercial mortgage-backed securities
Unrealized Losses
Less Than 12 Months	(8)	(49)
12 Months or More	(92)	(50)
Fair Value
Fair Value, Less Than 12 Months	224	513
Fair Value, 12 Months or More	$ 736	$ 330