Employee Benefit Plans (Asset Allocation Targets Reflecting a Percentage of Total Assets by Asset Class) (Details)	Dec. 31, 2021
Minimum | Pension Benefits | U.S. Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	2.00%
Minimum | Pension Benefits | International Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	3.00%
Minimum | Pension Benefits | Fixed Maturities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	50.00%
Minimum | Pension Benefits | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	0.00%
Minimum | Pension Benefits | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	2.00%
Minimum | Pension Benefits | Other
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	5.00%
Minimum | Postretirement | U.S. Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	34.00%
Minimum | Postretirement | International Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	2.00%
Minimum | Postretirement | Fixed Maturities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	10.00%
Minimum | Postretirement | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	0.00%
Minimum | Postretirement | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	0.00%
Minimum | Postretirement | Other
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	0.00%
Maximum | Pension Benefits | U.S. Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	6.00%
Maximum | Pension Benefits | International Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	8.00%
Maximum | Pension Benefits | Fixed Maturities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	65.00%
Maximum | Pension Benefits | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	13.00%
Maximum | Pension Benefits | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	16.00%
Maximum | Pension Benefits | Other
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	32.00%
Maximum | Postretirement | U.S. Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	74.00%
Maximum | Postretirement | International Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	25.00%
Maximum | Postretirement | Fixed Maturities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	43.00%
Maximum | Postretirement | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	26.00%
Maximum | Postretirement | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	0.00%
Maximum | Postretirement | Other
Defined Benefit Plan Disclosure [Line Items]
Asset allocation targets	0.00%