Pension and Other Post Retirement Benefit Plans - Schedule of Plan Assets by Category (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	100.00%	100.00%
Target (as a percent)	100.00%	100.00%
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	4.50%	2.20%
Target (as a percent)	3.00%	2.00%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	55.80%	58.10%
Target (as a percent)	55.00%	60.00%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	37.70%	37.40%
Target (as a percent)	40.00%	36.00%
Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Actual (as a percent)	2.00%	2.30%
Target (as a percent)	2.00%	2.00%