Schedule II (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance		$ 1.7	$ 1.5	$ 1.5
Valuation Allowances and Reserves, Charged to Cost and Expense		2.2	3.4	2.6
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	[1]	2.4	3.2	2.6
Valuation Allowances and Reserves, Ending Balance		$ 1.5	$ 1.7	$ 1.5

[1] Uncollectible accounts receivable written off, net of recoveries.