Revenue from Contracts with Customers - Provision for Doubtful Accounts (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue from Contracts with Customers
Threshold period past due for trade accounts receivable for disconnecting service to customers			100 days
Change in the allowance for doubtful accounts
Balance at beginning of period	$ 2.4	$ 5.0	$ 4.3	$ 6.7
Provision charged to expense	2.0	2.1	2.7	5.7
Accounts written off, net of recoveries	(1.0)	(1.6)	(3.6)	(6.9)
Balance at end of period	3.4	$ 5.5	3.4	$ 5.5
Amount released from reserve related to COVID-19	$ 0.0		$ 1.6