Benefit Plans and Other Postretirement Benefits, Expected long-term rate of return (Details) - Pension Benefits - United States	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure
Historical compounded return on plan assets (as a percent)	8.60%
Expected long-term return on assets (as a percent)	7.50%	7.75%	7.75%
Equity securities
Defined Benefit Plan Disclosure
Target allocation (as a percent)	60.00%
Plan asset allocations, assumptions (as a percent)	60.00%
Expected long-term return on assets (as a percent)	8.00%
Fixed income securities
Defined Benefit Plan Disclosure
Target allocation (as a percent)	40.00%
Plan asset allocations, assumptions (as a percent)	40.00%
Expected long-term return on assets (as a percent)	6.00%