Postretirement Benefit Obligations - Schedule of Target Asset Allocation of Pension Plan Assets (Details)	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	100.00%	100.00%
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	2.00%	2.00%
US and non-US equity securities
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	65.00%	65.00%
Fixed income / real estate / other securities
Defined Benefit Plan Disclosure [Line Items]
Actual plan asset allocation percentage	33.00%	33.00%