Quarterly report pursuant to Section 13 or 15(d)

Debt (Details)

v3.19.2
Debt (Details) - USD ($)
6 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Line of Credit Facility [Line Items]    
Accumulated amortization on debt issuance costs $ 4,201,000 $ 3,813,000
Company's borrowings    
Total term debt before debt issuance costs 116,841,000 185,817,000
Less: Current portion of long-term debt 83,324,000 149,006,000
Less: Debt issuance costs (net of accumulated amortization of $4,201 and $3,813, respectively) 3,063,000 3,390,000
Total long-term debt $ 30,454,000 33,421,000
4.00% Convertible Senior Notes    
Line of Credit Facility [Line Items]    
Interest rate 4.00%  
Face amount $ 96,300,000  
Company's borrowings    
Total term debt before debt issuance costs $ 76,406,000 75,477,000
2.75% Convertible Senior Notes    
Line of Credit Facility [Line Items]    
Interest rate 2.75%  
Face amount $ 67,380,000  
Company's borrowings    
Total term debt before debt issuance costs $ 0 66,361,000
REG Danville term loan    
Line of Credit Facility [Line Items]    
Description of variable rate basis LIBOR plus 4% per annum  
Company's borrowings    
Total term debt before debt issuance costs $ 7,924,000 8,964,000
REG Danville term loan | LIBOR    
Line of Credit Facility [Line Items]    
Basis spread on variable rate 4.00%  
REG Newton term loan    
Line of Credit Facility [Line Items]    
Description of variable rate basis LIBOR plus 4% per annum  
REG Newton term loan | LIBOR    
Line of Credit Facility [Line Items]    
Basis spread on variable rate 4.00%  
REG Ralston term loan    
Line of Credit Facility [Line Items]    
Description of variable rate basis Prime Rate plus 2.25%  
Company's borrowings    
Total term debt before debt issuance costs $ 17,350,000 18,948,000
REG Ralston term loan | Prime Rate    
Line of Credit Facility [Line Items]    
Basis spread on variable rate 2.25%  
REG Mason City term loan    
Line of Credit Facility [Line Items]    
Interest rate 5.00%  
REG Grays Harbor term loan    
Line of Credit Facility [Line Items]    
Description of variable rate basis Prime Rate plus 0.25%  
Basis spread on variable rate 3.50%  
Company's borrowings    
Total term debt before debt issuance costs $ 8,061,000 8,828,000
REG Grays Harbor term loan | Prime Rate    
Line of Credit Facility [Line Items]    
Basis spread on variable rate 0.25%  
REG Capital term loan    
Line of Credit Facility [Line Items]    
Interest rate 3.99%  
Company's borrowings    
Total term debt before debt issuance costs $ 7,058,000 7,185,000
Other    
Company's borrowings    
Total term debt before debt issuance costs $ 42,000 $ 54,000