Pension and Other Post-Retirement Benefits (Details 4)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Post Age 65	5.80%	6.00%
Medical Claims [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Pre Age 65	6.60%	7.00%
Review of historical returns
Rate to which the cost trend is expected to decline (the ultimate trend rate)	4.50%	4.50%
Year that rate reaches the ultimate trend rate	2022	2022
Prescription Drugs Claims [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Pre Age 65	9.30%	10.00%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year, Post Age 65	9.80%	10.50%
Review of historical returns
Rate to which the cost trend is expected to decline (the ultimate trend rate)	4.50%	4.50%
Year that rate reaches the ultimate trend rate	2024	2024