Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	10 years
Contract with Customer, Liability		$ 4.3
Contracts with Customers, Performance Obligation Satisfied within One Year	35.40%
Deferred Revenue, Revenue Recognized	$ 12.7