Pension plan and 401(k) Program - Asset Allocation by Percentage of Plan Asset Category (Details)	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, allocation percentage	100.00%	100.00%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, allocation percentage	25.70%	37.90%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, allocation percentage	33.50%	33.20%
Real estate
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, allocation percentage	18.80%	15.40%
Other
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, allocation percentage	20.40%	12.90%
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, allocation percentage	1.60%	0.60%