Notes Receivable and Allowance for Credit Losses - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Notes Receivable and Allowance for Losses [Line Items]
Loan reserves	$ 19,618	$ 19,484	$ 4,556
Loans and financing receivable	82,651	95,785
Variable Interest Entity, Not Primary Beneficiary
Notes Receivable and Allowance for Losses [Line Items]
Loans and financing receivable	120,100	119,300
Impaired Loans
Notes Receivable and Allowance for Losses [Line Items]
Average notes receivable, nonaccrual status	50,700	28,900
Collateral-Dependent Loans
Notes Receivable and Allowance for Losses [Line Items]
Loan reserves	3,500	7,800
Interest Rate Below Market Reduction | Variable Interest Entity, Not Primary Beneficiary
Notes Receivable and Allowance for Losses [Line Items]
Loans and financing receivable	13,100	13,100
Receivable with Imputed Interest, discount	$ 600	$ 800