Debt - Components (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Apr. 22, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Accumulated amortization on debt issuance costs	$ 1,376,000		$ 990,000
Total debt before debt issuance costs	550,000,000		66,977,000
Less: Current portion of long-term debt	0		50,088,000
Less: Debt issuance costs (net of accumulated amortization of $1,376 and $990, respectively)	13,243,000		1,731,000
Total long-term debt	$ 536,757,000		15,158,000
5.875% Senior Secured Green Notes, due 2028
Line of Credit Facility [Line Items]
Stated interest rate (as a percent)	5.875%
Total debt before debt issuance costs	$ 550,000,000		0
4.00% Convertible Senior Notes due in June 2036
Line of Credit Facility [Line Items]
Stated interest rate (as a percent)	4.00%
Face amount	$ 59,619,000
Total debt before debt issuance costs	0		47,057,000
REG Ralston term loan, variable interest rate of LIBOR plus 2.25%, due in October 2025
Line of Credit Facility [Line Items]
Face amount		$ 12,556,000
Total debt before debt issuance costs	$ 0		13,241,000
REG Ralston term loan, variable interest rate of LIBOR plus 2.25%, due in October 2025 | LIBOR
Line of Credit Facility [Line Items]
Variable interest rate	2.25%
REG Capital term loan, fixed interest rate of 3.99%, due in January 2028
Line of Credit Facility [Line Items]
Stated interest rate (as a percent)	3.99%
Face amount		$ 6,596,000
Total debt before debt issuance costs	$ 0		6,665,000
Other
Line of Credit Facility [Line Items]
Total debt before debt issuance costs	$ 0		$ 14,000