Current Expected Credit Losses - Delinquency Status of Receivables (Details) $ in Millions	Sep. 30, 2020 USD ($)
Financing Receivable, Past Due [Line Items]
Current	$ 103.5
Total	105.8
30-59 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.2
60-89 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.2
90-119 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.2
120+ days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	1.7
Notes receivable, short-term
Financing Receivable, Past Due [Line Items]
Current	4.2
Total	6.5
Notes receivable, short-term | 30-59 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.2
Notes receivable, short-term | 60-89 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.2
Notes receivable, short-term | 90-119 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.2
Notes receivable, short-term | 120+ days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	1.7
Notes receivable, long-term
Financing Receivable, Past Due [Line Items]
Current	22.4
Total	22.4
Notes receivable, long-term | 30-59 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Notes receivable, long-term | 60-89 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Notes receivable, long-term | 90-119 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Notes receivable, long-term | 120+ days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Lease Receivables
Financing Receivable, Past Due [Line Items]
Current	25.5
Total	25.5
Lease Receivables | 30-59 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Lease Receivables | 60-89 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Lease Receivables | 90-119 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Lease Receivables | 120+ days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Equipment Notes
Financing Receivable, Past Due [Line Items]
Current	49.8
Total	49.8
Equipment Notes | 30-59 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Equipment Notes | 60-89 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Equipment Notes | 90-119 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Equipment Notes | 120+ days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Other
Financing Receivable, Past Due [Line Items]
Current	1.6
Total	1.6
Other | 30-59 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Other | 60-89 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Other | 90-119 days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	0.0
Other | 120+ days
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	$ 0.0