Commitments, Contingencies and Uncertainties (Union Matters) (Details)	12 Months Ended
	Dec. 31, 2017	Sep. 03, 2018	Sep. 03, 2017	Sep. 03, 2016
Commitments and Contingencies Disclosure [Abstract]
Entity Number of Employees	1,100
Number of Employees Cover by Collective Bargaining Agreements, Percentage	38.00%
Collective Bargaining Agreement Effective Date	Sep. 03, 2016
Term of Collective Bargaining Agreement, Year	P3Y
Collective Bargaining Agreement Expiration Date	Sep. 03, 2019
Subsequent Event [Line Items]
Pay increase, percentage			3.00%	3.00%
Scenario, Forecast
Subsequent Event [Line Items]
Pay increase, percentage		3.00%