Allowance for Doubtful Accounts - Age Analysis of Past-Due Note Receivable (Details) $ in Thousands	Sep. 30, 2021 USD ($)
0-90 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	$ 5,709
91 - 180 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	877
Greater than 181 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	8,303
Total
Financing Receivable, Past Due [Line Items]
Notes Receivable	14,889
Standard notes receivable
Financing Receivable, Past Due [Line Items]
Notes Receivable	63,484
Standard notes receivable | 0-90 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	5,709
Standard notes receivable | 91 - 180 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	877
Standard notes receivable | Greater than 181 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	5,589
Standard notes receivable | Total
Financing Receivable, Past Due [Line Items]
Notes Receivable	12,175
Elevated risk notes receivable
Financing Receivable, Past Due [Line Items]
Notes Receivable	2,714
Elevated risk notes receivable | 0-90 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	0
Elevated risk notes receivable | 91 - 180 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	0
Elevated risk notes receivable | Greater than 181 Days
Financing Receivable, Past Due [Line Items]
Notes Receivable	2,714
Elevated risk notes receivable | Total
Financing Receivable, Past Due [Line Items]
Notes Receivable	$ 2,714