Pension and Other Postretirement Benefits - Weighted average assumptions used to determine net periodic benefit cost (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Rate of compensation increase, year one	3.00%	3.00%
Rate of compensation increase, year one and thereafter	3.50%	3.50%
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Measurement date	12/31/2021	12/31/2020	12/31/2019
Fiscal year end	12/31/2022	12/31/2021	12/31/2020
Discount rate	2.94%	2.77%	3.22%
Rate of compensation increase, group 1	3.00%	3.00%	3.00%
Rate of compensation increase, group 2	3.50%	3.50%	3.50%
Expected return on plan assets	7.25%	7.25%	7.25%
OPEB
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Measurement date	12/31/2021	12/31/2020	12/31/2019
Fiscal year end	12/31/2022	12/31/2021	12/31/2020
Discount rate	2.64%	1.89%	2.79%
Rate of compensation increase, group 1	3.00%	3.00%	3.00%
Rate of compensation increase, group 2	3.50%	3.50%	3.50%
Expected return on plan assets	0.00%	0.00%	0.00%