Employee Benefit Plans - Schedule of Weighted-Average Assumptions Used (Details)	3 Months Ended			9 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit Cost for Current Plan Year					6.75%	6.75%
Benefit Cost for Subsequent Plan Year	6.75%			6.75%	6.75%	6.75%
Discount Rates:
Service Cost for Plan Year			4.35%	4.26%	3.74%	4.26%
Interest Cost for Plan Year			3.37%	3.26%	3.15%	3.26%
Benefit Obligation at End of Plan Year	4.24%			3.56%	4.24%	3.56%
Salary Scale Inflation					4.60%	4.60%
Post-retirement Benefits
Discount Rates:
Service Cost for Plan Year	4.14%	3.68%	4.20%	4.11%	4.14%	4.11%
Interest Cost for Plan Year	3.45%	2.79%	2.88%	2.78%	3.45%	2.78%
Benefit Obligation at End of Plan Year	3.98%			3.34%	3.98%	3.34%