Employee Benefits - Fair Value of Plan Assets and Liabilities (Details) - Combined Pension Plan - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 4,715	$ 8,531	$ 10,546	$ 10,493
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	11	8
NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,259	2,690
Investment Grade Bonds | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	99	127
High Yield Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	6	6
High Yield Bonds | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	81	70
U.S. Stocks | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	5	$ 2
U.S. Stocks | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	79	71
Non-U.S. Stocks | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	270	398
Emerging Market Stocks | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15	11
Private Equity | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	326	348
Private Debt | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	438	495
Market Neutral Hedge Funds | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	135	141
Directional Hedge Funds | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	166	241
Real Estate | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	333	420
Multi-Asset Strategies | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	24	38
Cash equivalents and short-term investments | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	293	330
Fair Value, Measurements, Recurring
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,715	8,531
Fair Value, Measurements, Recurring | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,259	2,690
Fair Value, Measurements, Recurring | Total Excluding Investments Valued at NAV | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,736	6,034
Fair Value, Measurements, Recurring | Total Excluding Investments Valued at NAV | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	883	1,555
Fair Value, Measurements, Recurring | Total Excluding Investments Valued at NAV | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,848	4,468
Fair Value, Measurements, Recurring | Total Excluding Investments Valued at NAV | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	11
Fair Value, Measurements, Recurring | Investment Grade Bonds | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,166	4,606
Fair Value, Measurements, Recurring | Investment Grade Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	446	862
Fair Value, Measurements, Recurring | Investment Grade Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,720	3,744
Fair Value, Measurements, Recurring | Investment Grade Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | High Yield Bonds | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	52	178
Fair Value, Measurements, Recurring | High Yield Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | High Yield Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	48	172
Fair Value, Measurements, Recurring | High Yield Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	6
Fair Value, Measurements, Recurring | Emerging Market Bonds | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	127	233
Fair Value, Measurements, Recurring | Emerging Market Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49	64
Fair Value, Measurements, Recurring | Emerging Market Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	78	169
Fair Value, Measurements, Recurring | Emerging Market Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | U.S. Stocks | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	215	338
Fair Value, Measurements, Recurring | U.S. Stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	214	330
Fair Value, Measurements, Recurring | U.S. Stocks | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	3
Fair Value, Measurements, Recurring | U.S. Stocks | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	5
Fair Value, Measurements, Recurring | Non-U.S. Stocks | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	150	256
Fair Value, Measurements, Recurring | Non-U.S. Stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	149	256
Fair Value, Measurements, Recurring | Non-U.S. Stocks | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	0
Fair Value, Measurements, Recurring | Non-U.S. Stocks | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | Multi-Asset Strategies | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25	41
Fair Value, Measurements, Recurring | Multi-Asset Strategies | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25	41
Fair Value, Measurements, Recurring | Multi-Asset Strategies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | Multi-Asset Strategies | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | Derivatives | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(11)	1
Fair Value, Measurements, Recurring | Derivatives | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(1)	0
Fair Value, Measurements, Recurring | Derivatives | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(10)	1
Fair Value, Measurements, Recurring | Derivatives | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | Cash equivalents and short-term investments | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	381
Fair Value, Measurements, Recurring | Cash equivalents and short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	2
Fair Value, Measurements, Recurring | Cash equivalents and short-term investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	379
Fair Value, Measurements, Recurring | Cash equivalents and short-term investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | Repurchase Agreements | Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(269)	(193)
Fair Value, Measurements, Recurring | Repurchase Agreements | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Measurements, Recurring | Repurchase Agreements | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(269)	(193)
Fair Value, Measurements, Recurring | Repurchase Agreements | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0