Current Expected Credit Losses ("CECL") - Changes in the Allowance for Credit Losses (Details) $ in Millions	6 Months Ended
Jun. 30, 2021 USD ($)
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2020	$ 23.1
Bad debt (credit) expense for the six months ended June 30, 2021	(2.3)
Advertising provision adjustment	(2.9)
Write-offs	(2.4)
Other	0.1
Balance, June 30, 2021	15.6
Accounts Receivable
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2020	11.2
Bad debt (credit) expense for the six months ended June 30, 2021	(2.2)
Advertising provision adjustment	(2.9)
Write-offs	(0.2)
Other	0.0
Balance, June 30, 2021	5.9
Notes receivable, short-term
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2020	3.6
Bad debt (credit) expense for the six months ended June 30, 2021	0.4
Advertising provision adjustment	0.0
Write-offs	0.0
Other	0.0
Balance, June 30, 2021	4.0
Notes receivable, long-term
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2020	5.3
Bad debt (credit) expense for the six months ended June 30, 2021	(0.1)
Advertising provision adjustment	0.0
Write-offs	0.0
Other	0.0
Balance, June 30, 2021	5.2
Lease Receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2020	0.4
Bad debt (credit) expense for the six months ended June 30, 2021	0.1
Advertising provision adjustment	0.0
Write-offs	(0.5)
Other	0.1
Balance, June 30, 2021	0.1
Equipment Notes
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2020	2.3
Bad debt (credit) expense for the six months ended June 30, 2021	(0.4)
Advertising provision adjustment	0.0
Write-offs	(1.7)
Other	0.0
Balance, June 30, 2021	0.2
Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2020	0.3
Bad debt (credit) expense for the six months ended June 30, 2021	(0.1)
Advertising provision adjustment	0.0
Write-offs	0.0
Other	0.0
Balance, June 30, 2021	$ 0.2

Financing Receivable, Allowance for Credit Loss, Other

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- Definition

Financing Receivable, Allowance for Credit Loss, Advertising Provision Adjustment

+ References

No definition available.

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
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-Name Accounting Standards Codification
-Topic 326
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-Section 55
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- Definition

Amount of credit loss expense (reversal of expense) for financing receivable.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
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-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SX 210.9-04(11))
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