Current Expected Credit Losses - Changes in the Allowance for Credit Losses (Details)	9 Months Ended
	Sep. 30, 2020 USD ($)
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	$ 11,300,000
Bad debt expense for the nine months ended September 30, 2020	8,400,000
Advertising provision adjustment	2,100,000
Write-offs	(400,000)
Recoveries	0.0
Balance, September 30, 2020	22,100,000
Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	700,000
Accounts Receivable
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	700,000
Bad debt expense for the nine months ended September 30, 2020	3,800,000
Advertising provision adjustment	2,400,000
Write-offs	(200,000)
Recoveries	0.0
Balance, September 30, 2020	7,000,000.0
Accounts Receivable | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	300,000
Notes receivable, short-term
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	2,400,000
Bad debt expense for the nine months ended September 30, 2020	2,700,000
Advertising provision adjustment	(100,000)
Write-offs	(100,000)
Recoveries	0
Balance, September 30, 2020	4,900,000
Notes receivable, short-term | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	0.0
Notes receivable, long-term
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	8,200,000
Bad debt expense for the nine months ended September 30, 2020	1,400,000
Advertising provision adjustment	(200,000)
Write-offs	0
Recoveries	0
Balance, September 30, 2020	9,500,000
Notes receivable, long-term | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	100,000
Lease Receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	0
Bad debt expense for the nine months ended September 30, 2020	100,000
Advertising provision adjustment	0
Write-offs	(0.0)
Recoveries	0.0
Balance, September 30, 2020	200,000
Lease Receivables | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	100,000
Equipment Notes
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	0
Bad debt expense for the nine months ended September 30, 2020	200,000
Advertising provision adjustment	0
Write-offs	(100,000)
Recoveries	0
Balance, September 30, 2020	200,000
Equipment Notes | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	100,000
Other
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	0
Bad debt expense for the nine months ended September 30, 2020	200,000
Advertising provision adjustment	0
Write-offs	0
Recoveries	0
Balance, September 30, 2020	300,000
Other | Cumulative Effect, Period Of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, December 31, 2019	$ 100,000