Benefit Plans Actuarial Calculation Assumptions (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate		3.52%	4.04%
Net periodic benefit cost, expected return on plan assets		7.00%	7.00%
Net periodic benefit cost, rate of compensation increase	4.00%	4.00%	4.00%
Benefit obligations, discount rate		4.16%
Benefit obligations, rate of compensation increase	4.00%	4.00%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate		3.45%	3.93%
Net periodic benefit cost, expected return on plan assets		7.00%	7.00%
Benefit obligations, discount rate		4.09%
Maximum [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate	4.16%
Net periodic benefit cost, expected return on plan assets	7.25%
Benefit obligations, discount rate	3.23%
Maximum [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate	4.09%
Net periodic benefit cost, expected return on plan assets	7.00%
Benefit obligations, discount rate	3.18%
Minimum [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate	3.04%
Net periodic benefit cost, expected return on plan assets	7.00%
Benefit obligations, discount rate	3.05%
Minimum [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate	2.52%
Net periodic benefit cost, expected return on plan assets	4.00%
Benefit obligations, discount rate	2.59%