Commitments and Contingent Liabilities - Narrative (Details) $ in Millions		9 Months Ended
	Aug. 23, 2017 plaintiff	Sep. 30, 2023 USD ($) plaintiff
Fitzwater Litigation
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff		3
Casey Litigation | Pending Litigation
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff	2
United Mine Workers of America 1992 Benefit Plan Litigation | Pending Litigation | Minimum
Loss Contingencies [Line Items]
Annual servicing costs | $		$ 10
United Mine Workers of America 1992 Benefit Plan Litigation | Pending Litigation | Maximum
Loss Contingencies [Line Items]
Annual servicing costs | $		$ 20