Employee Benefit Plans - Weighted Average Assumptions Used in Calculating the Net Periodic Benefit Cost (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.35%	3.73%	4.22%
Expected long-term rate of return on plan assets	6.45%	6.60%	6.60%
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.23%	3.55%	3.97%
Expected long-term rate of return on plan assets	6.00%	6.60%	6.60%