Retirement Plans, Asset Allocation for Pension Plan Table (Details) - Pension Plan [Member]	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total	100.00%	100.00%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Total	51.00%	49.00%
Fixed-income securities
Defined Benefit Plan Disclosure [Line Items]
Total	33.00%	34.00%
Group annuity contracts
Defined Benefit Plan Disclosure [Line Items]
Total	11.00%	12.00%
Alternative securities
Defined Benefit Plan Disclosure [Line Items]
Total	3.00%	3.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Total	2.00%	2.00%