Operations and Significant Accounting Policies - Revenue - Assets Recognized From the Costs to Obtain a Contract with a Customer (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Capitalized Contract Cost [Line Items]
Contract Asset - Noncurrent	[1]	$ 25.5	$ 28.0
Capitalized Contract Cost, Amortization		$ 2.6	$ 2.6

[1] Contract Assets include payments made to customers as an incentive to execute or extend service agreements. The contract payments are being amortized over the term of the respective agreements as a reduction to revenue.