Pensions and Postretirement Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Vested retirement benefit credited service maximum period, prior to January 1, 2008	13 years
Vested retirement benefit credited service maximum period, on or after January 1, 2008	7 years
Vested retirement benefit credited service period	20 years
Percentage of Supplemental Pension received	100.00%
SERP Expense	$ (0.2)	$ 0.2	$ 0.6
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Estimated net loss	0.3
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Estimated net loss	0.1
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Annual supplemental retirement benefit	$ 0.4