Summary of Fair Value of Plan Assets by Asset Category (Parenthetical) (Details)	Dec. 31, 2021	Dec. 31, 2020
Bonds | Balanced Fund
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	39.00%	37.00%
Bonds | Fixed Income
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	88.00%	83.00%
Equity Securities | Balanced Fund
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	35.00%	35.00%
Other Asset | Balanced Fund
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	21.00%	19.00%
Other Asset | Fixed Income
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	6.00%	16.00%
Cash | Balanced Fund
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	5.00%	9.00%
Cash | Fixed Income
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	6.00%	1.00%