Pension and Other Postretirement Employee Benefit Plans - Investment Strategy and Weighted Average Asset Allocation (Details) - USD ($) $ in Billions	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Investments sponsored or managed by affiliates	$ 1.7	$ 2.5
Defined benefit pension plans | Debt securities | Minimum | U.S.
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	42.00%
Defined benefit pension plans | Debt securities | Maximum | U.S.
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	100.00%
Defined benefit pension plans | Equity securities | Minimum | U.S.
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	0.00%
Defined benefit pension plans | Equity securities | Maximum | U.S.
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	40.00%
Defined benefit pension plans | Real estate | Minimum | U.S.
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	0.00%
Defined benefit pension plans | Real estate | Maximum | U.S.
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	3.00%
Defined benefit pension plans | Alternatives | Minimum | U.S.
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	0.00%
Defined benefit pension plans | Alternatives | Maximum | U.S.
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	12.00%