Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Fair Value Measurements by Level for Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details)

v3.22.2.2
Fair Value Measurements - Fair Value Measurements by Level for Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Millions
Sep. 30, 2022
Dec. 31, 2021
Assets    
Cash and cash equivalents $ 14,987 $ 13,118
Investments:    
Equity securities 6 326
Total assets at fair value 31,720 29,010
U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 648 640
Corporate securities    
Investments:    
Fair Value 8,752 8,200
Municipal securities    
Investments:    
Fair Value 3,660 3,468
Short-term time deposits    
Investments:    
Fair Value 275 109
Asset-backed securities    
Investments:    
Fair Value 1,267 1,308
Residential mortgage-backed securities    
Investments:    
Fair Value 1,019 853
Commercial mortgage-backed securities    
Investments:    
Fair Value 874 873
Investments available-for-sale    
Investments:    
Fair Value 15,528 14,809
Investments available-for-sale | U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 313 171
Investments available-for-sale | Corporate securities    
Investments:    
Fair Value 8,721 8,170
Investments available-for-sale | Municipal securities    
Investments:    
Fair Value 3,053 2,999
Investments available-for-sale | Short-term time deposits    
Investments:    
Fair Value 275 109
Investments available-for-sale | Asset-backed securities    
Investments:    
Fair Value 1,267 1,308
Investments available-for-sale | Residential mortgage-backed securities    
Investments:    
Fair Value 1,019 853
Investments available-for-sale | Commercial mortgage-backed securities    
Investments:    
Fair Value 874 873
Restricted deposits    
Investments:    
Fair Value 1,205 1,068
Restricted deposits | U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 335 469
Restricted deposits | Corporate securities    
Investments:    
Fair Value 31 30
Restricted deposits | Municipal securities    
Investments:    
Fair Value 607 469
Restricted deposits | Cash and cash equivalents    
Investments:    
Fair Value 228 96
Restricted deposits | Certificates of deposit    
Investments:    
Fair Value 4 4
Other long-term assets: | Interest rate swap agreements    
Investments:    
Derivative asset   15
Level I    
Assets    
Cash and cash equivalents 14,987 13,118
Investments:    
Equity securities 4 324
Total assets at fair value 15,867 14,178
Level I | Investments available-for-sale    
Investments:    
Fair Value 317 495
Level I | Investments available-for-sale | U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 313 171
Level I | Investments available-for-sale | Corporate securities    
Investments:    
Fair Value 0 0
Level I | Investments available-for-sale | Municipal securities    
Investments:    
Fair Value 0 0
Level I | Investments available-for-sale | Short-term time deposits    
Investments:    
Fair Value 0 0
Level I | Investments available-for-sale | Asset-backed securities    
Investments:    
Fair Value 0 0
Level I | Investments available-for-sale | Residential mortgage-backed securities    
Investments:    
Fair Value 0 0
Level I | Investments available-for-sale | Commercial mortgage-backed securities    
Investments:    
Fair Value 0 0
Level I | Restricted deposits    
Investments:    
Fair Value 563 565
Level I | Restricted deposits | U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 335 469
Level I | Restricted deposits | Corporate securities    
Investments:    
Fair Value 0 0
Level I | Restricted deposits | Municipal securities    
Investments:    
Fair Value 0 0
Level I | Restricted deposits | Cash and cash equivalents    
Investments:    
Fair Value 228 96
Level I | Restricted deposits | Certificates of deposit    
Investments:    
Fair Value 0 0
Level I | Other long-term assets: | Interest rate swap agreements    
Investments:    
Derivative asset   0
Level II    
Assets    
Cash and cash equivalents 0 0
Investments:    
Equity securities 2 2
Total assets at fair value 15,853 14,832
Level II | Investments available-for-sale    
Investments:    
Fair Value 15,211 14,314
Level II | Investments available-for-sale | U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 0 0
Level II | Investments available-for-sale | Corporate securities    
Investments:    
Fair Value 8,721 8,170
Level II | Investments available-for-sale | Municipal securities    
Investments:    
Fair Value 3,053 2,999
Level II | Investments available-for-sale | Short-term time deposits    
Investments:    
Fair Value 275 109
Level II | Investments available-for-sale | Asset-backed securities    
Investments:    
Fair Value 1,267 1,308
Level II | Investments available-for-sale | Residential mortgage-backed securities    
Investments:    
Fair Value 1,019 853
Level II | Investments available-for-sale | Commercial mortgage-backed securities    
Investments:    
Fair Value 874 873
Level II | Restricted deposits    
Investments:    
Fair Value 642 503
Level II | Restricted deposits | U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 0 0
Level II | Restricted deposits | Corporate securities    
Investments:    
Fair Value 31 30
Level II | Restricted deposits | Municipal securities    
Investments:    
Fair Value 607 469
Level II | Restricted deposits | Cash and cash equivalents    
Investments:    
Fair Value 0 0
Level II | Restricted deposits | Certificates of deposit    
Investments:    
Fair Value 4 4
Level II | Other long-term assets: | Interest rate swap agreements    
Investments:    
Derivative asset   15
Level III    
Assets    
Cash and cash equivalents 0 0
Investments:    
Equity securities 0 0
Total assets at fair value 0 0
Level III | Investments available-for-sale    
Investments:    
Fair Value 0 0
Level III | Investments available-for-sale | U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 0 0
Level III | Investments available-for-sale | Corporate securities    
Investments:    
Fair Value 0 0
Level III | Investments available-for-sale | Municipal securities    
Investments:    
Fair Value 0 0
Level III | Investments available-for-sale | Short-term time deposits    
Investments:    
Fair Value 0 0
Level III | Investments available-for-sale | Asset-backed securities    
Investments:    
Fair Value 0 0
Level III | Investments available-for-sale | Residential mortgage-backed securities    
Investments:    
Fair Value 0 0
Level III | Investments available-for-sale | Commercial mortgage-backed securities    
Investments:    
Fair Value 0 0
Level III | Restricted deposits    
Investments:    
Fair Value 0 0
Level III | Restricted deposits | U.S. Treasury securities and obligations of U.S. government corporations and agencies    
Investments:    
Fair Value 0 0
Level III | Restricted deposits | Corporate securities    
Investments:    
Fair Value 0 0
Level III | Restricted deposits | Municipal securities    
Investments:    
Fair Value 0 0
Level III | Restricted deposits | Cash and cash equivalents    
Investments:    
Fair Value 0 0
Level III | Restricted deposits | Certificates of deposit    
Investments:    
Fair Value $ 0 0
Level III | Other long-term assets: | Interest rate swap agreements    
Investments:    
Derivative asset   $ 0