Fair Value Measurements - Schedule of Pension Plan Assets at Fair Value by Level (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	$ 3,016	$ 3,000
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	3,016	3,000	$ 2,825
Pension Plans | Total
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	1,893	2,020
Pension Plans | Total | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	487	337
Pension Plans | Total | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	14	21
Pension Plans | Total | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	108	387
Pension Plans | Total | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	1,013	1,026
Pension Plans | Total | Government securities
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	173	164
Pension Plans | Total | Asset-backed securities, derivatives and other
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	98	85
Pension Plans | Level 1
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	609	745
Pension Plans | Level 1 | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	487	337
Pension Plans | Level 1 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	14	21
Pension Plans | Level 1 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	108	387
Pension Plans | Level 1 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	0	0
Pension Plans | Level 1 | Government securities
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	0	0
Pension Plans | Level 1 | Asset-backed securities, derivatives and other
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	0	0
Pension Plans | Level 2
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	1,284	1,275
Pension Plans | Level 2 | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	0	0
Pension Plans | Level 2 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	0	0
Pension Plans | Level 2 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	0	0
Pension Plans | Level 2 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	1,013	1,026
Pension Plans | Level 2 | Government securities
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	173	164
Pension Plans | Level 2 | Asset-backed securities, derivatives and other
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	98	85
Pension Plans | Investments measured at net asset value
Defined Benefit Plan Disclosure [Line Items]
Investments at fair value	$ 1,123	$ 980