Benefit Plans Schedule of Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Weighted average assumptions used to determine benefit obligations: [Abstract]
Discount rate	1.20%	1.30%	2.30%
Rate of compensation increase	3.10%	3.10%	3.00%
Cash balance credit interest rate	1.50%	1.50%	1.70%
Weighted average assumptions used to determine net benefit cost for the year ended December 31:
Discount rate	1.30%	2.30%	2.20%
Expected return on plan assets	3.80%	4.10%	4.40%
Rate of compensation increase	3.10%	3.00%	3.00%
Cash balance credit interest rate	1.50%	1.70%	1.70%