Financing Receivables - Schedule of Amortized Cost by Origination Year (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
PSAs
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 165.7
2019	84.5
2018	44.0
2017	18.2
2016	4.9
Prior	0.9
Total	318.2	$ 327.5
PSAs | Less than 400
Financing Receivable, Credit Quality Indicator [Line Items]
2020	17.5
2019	10.1
2018	4.7
2017	2.1
2016	0.5
Prior	0.1
Total	35.0
PSAs | 400-599
Financing Receivable, Credit Quality Indicator [Line Items]
2020	25.1
2019	13.6
2018	7.5
2017	3.1
2016	0.9
Prior	0.3
Total	50.5
PSAs | 600-799
Financing Receivable, Credit Quality Indicator [Line Items]
2020	51.3
2019	26.1
2018	13.9
2017	6.2
2016	2.0
Prior	0.3
Total	99.8
PSAs | 800+
Financing Receivable, Credit Quality Indicator [Line Items]
2020	71.8
2019	34.7
2018	17.9
2017	6.8
2016	1.5
Prior	0.2
Total	132.9
Franchisee Notes
Financing Receivable, Credit Quality Indicator [Line Items]
2020	20.6
2019	22.7
2018	11.0
2017	7.7
2016	4.8
Prior	7.3
Total	74.1
Franchisee Notes | Active distributors
Financing Receivable, Credit Quality Indicator [Line Items]
2020	20.5
2019	21.3
2018	9.2
2017	5.6
2016	3.1
Prior	3.6
Total	63.3
Franchisee Notes | Separated distributors
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0.1
2019	1.4
2018	1.8
2017	2.1
2016	1.7
Prior	3.7
Total	$ 10.8