XML 37 R99.htm IDEA: XBRL DOCUMENT v3.20.1
Pension and Retirement Plans - Schedule of Weighted-average Assumptions Used to Determine Projected Benefit Obligations and Net Periodic Benefit Cost (Details)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Pension Plan    
Defined Benefit Plan Disclosure [Line Items]    
Discount rate 3.22% 4.23%
Discount rate 4.23% 3.58%
Expected long-term return on plan assets 6.50% 6.50%
Supplemental Retirement Plan    
Defined Benefit Plan Disclosure [Line Items]    
Discount rate 3.04% 4.10%
Rate of compensation increase 4.00% 4.00%
Discount rate 4.10% 3.39%
Rate of compensation increase 4.00% 4.00%
Postretirement Healthcare Plan    
Defined Benefit Plan Disclosure [Line Items]    
Discount rate 3.26% 4.22%
Discount rate 4.22% 3.58%