v3.22.0.1

Pension and Other Postretirement Benefits - Fair Value of Plan Assets (Details) - Pension benefits​ - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 2,124	$ 2,754	$ 79
Plan Assets
Defined Benefit Plan Disclosure [Line Items]
Plan assets	2,128	2,654
Plan Assets | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	130	158
Plan Assets | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	412	602
Plan Assets | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Plan Assets | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	1,586	1,894
Equities
Defined Benefit Plan Disclosure [Line Items]
Plan assets	652	527
Equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	12	1
Equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Equities | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	640	526
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Plan assets	404	277
Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	12	1
Equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Equity securities | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	392	276
Long/short equity hedge funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets	24	107
Long/short equity hedge funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Long/short equity hedge funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Long/short equity hedge funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Long/short equity hedge funds | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	24	107
Private equity
Defined Benefit Plan Disclosure [Line Items]
Plan assets	224	143
Private equity | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Private equity | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Private equity | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Private equity | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	224	143
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Plan assets	1,192	1,370
Fixed income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	118	118
Fixed income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	412	602
Fixed income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Fixed income | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	662	650
Intermediate and long duration government/credit
Defined Benefit Plan Disclosure [Line Items]
Plan assets	1,119	1,325
Intermediate and long duration government/credit | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	95	117
Intermediate and long duration government/credit | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	412	602
Intermediate and long duration government/credit | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Intermediate and long duration government/credit | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	612	606
Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets	73	45
Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	23	1
Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Other | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	50	44
Other investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets	284	757
Other investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	39
Other investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Other investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Other investments | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	284	718
Real estate
Defined Benefit Plan Disclosure [Line Items]
Plan assets	108	132
Real estate | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	39
Real estate | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Real estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Real estate | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	108	93
Discretionary and systematic macro hedge funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets		531
Discretionary and systematic macro hedge funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Discretionary and systematic macro hedge funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Discretionary and systematic macro hedge funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Discretionary and systematic macro hedge funds | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets		531
Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets	77	94
Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Other | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Plan assets	77	94
Net receivable
Defined Benefit Plan Disclosure [Line Items]
Plan assets		$ 100
Defined Benefit Plan, Net Payable
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ (4)

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