Revenue Recognition - Contract Balances and Cost (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Contract with Customer, Asset and Liability [Abstract]
Total contract liabilities	$ 8.7	$ 9.0
Contract liabilities, revenue recognition period	36 months
Capitalized Contract Cost [Abstract]
Deferred sales commissions	$ 6.5	$ 7.5
Minimum
Capitalized Contract Cost [Abstract]
Contract acquisition costs, amortization period	4 years
Maximum
Capitalized Contract Cost [Abstract]
Contract acquisition costs, amortization period	5 years