Current Expected Credit Losses ("CECL") - Changes in the Allowance for Credit Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Allowance for Doubtful Accounts
Balance at beginning of period	$ 23.1	$ 11.3
Increase due to CECL adoption	11.9	23.1
Bad debt (credit) expense for the year ended December 31, 2021	(4.9)	12.8
Advertising provision adjustment	(1.9)	3.5
Write-offs	(4.6)	(5.2)
Recoveries	0.2	0.0
Balance at end of period	11.9	23.1
Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Doubtful Accounts
Balance at beginning of period		0.7
Increase due to CECL adoption
Accounts Receivable
Allowance for Doubtful Accounts
Balance at beginning of period	11.2	0.7
Increase due to CECL adoption	1.0	11.2
Bad debt (credit) expense for the year ended December 31, 2021	(8.2)	5.0
Advertising provision adjustment	(1.8)	5.4
Write-offs	(0.2)	(0.2)
Recoveries	0.0	0.0
Balance at end of period	1.0	11.2
Accounts Receivable | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Doubtful Accounts
Balance at beginning of period		0.3
Increase due to CECL adoption
Notes receivable, short-term
Allowance for Doubtful Accounts
Balance at beginning of period	3.6	2.4
Increase due to CECL adoption	3.8	3.6
Bad debt (credit) expense for the year ended December 31, 2021	1.4	2.5
Advertising provision adjustment	(0.3)	(0.7)
Write-offs	(0.9)	(0.6)
Recoveries	0.0	0.0
Balance at end of period	3.8	3.6
Notes receivable, short-term | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Doubtful Accounts
Balance at beginning of period		0.0
Increase due to CECL adoption
Notes receivable, long-term
Allowance for Doubtful Accounts
Balance at beginning of period	5.3	8.2
Increase due to CECL adoption	6.6	5.3
Bad debt (credit) expense for the year ended December 31, 2021	1.1	0.5
Advertising provision adjustment	0.2	(1.2)
Write-offs	0.0	(2.3)
Recoveries	0.0	0.0
Balance at end of period	6.6	5.3
Notes receivable, long-term | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Doubtful Accounts
Balance at beginning of period		0.1
Increase due to CECL adoption
Lease Receivables
Allowance for Doubtful Accounts
Balance at beginning of period	0.4	0.0
Increase due to CECL adoption	0.2	0.4
Bad debt (credit) expense for the year ended December 31, 2021	0.1	1.2
Advertising provision adjustment	0.0	0.0
Write-offs	(0.5)	(0.9)
Recoveries	0.2	0.0
Balance at end of period	0.2	0.4
Lease Receivables | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Doubtful Accounts
Balance at beginning of period		0.1
Increase due to CECL adoption
Equipment Receivables
Allowance for Doubtful Accounts
Balance at beginning of period	2.3	0.0
Increase due to CECL adoption	0.1	2.3
Bad debt (credit) expense for the year ended December 31, 2021	0.8	3.4
Advertising provision adjustment	0.0	0.0
Write-offs	(3.0)	(1.2)
Recoveries	0.0	0.0
Balance at end of period	0.1	2.3
Equipment Receivables | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Doubtful Accounts
Balance at beginning of period		0.1
Increase due to CECL adoption
Other
Allowance for Doubtful Accounts
Balance at beginning of period	0.3	0.0
Increase due to CECL adoption	0.2	0.3
Bad debt (credit) expense for the year ended December 31, 2021	(0.1)	0.2
Advertising provision adjustment	0.0	0.0
Write-offs	0.0	0.0
Recoveries	0.0	0.0
Balance at end of period	$ 0.2	0.3
Other | Cumulative Effect, Period Of Adoption, Adjustment
Allowance for Doubtful Accounts
Balance at beginning of period		$ 0.1
Increase due to CECL adoption