Debt (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Company's borrowings

The Company’s term debt at December 31 is as follows:

	2017		2016
4.00% Convertible Senior Notes, $152,000 face amount, due in June 2036	$	116,255	$	113,446
2.75% Convertible Senior Notes, $73,838 face amount, due in June 2019	69,859		67,254
REG Danville term loan, secured, variable interest rate of LIBOR plus 4%, due in July 2022	11,460		8,163
REG Newton term loan, secured, variable interest rate of LIBOR plus 4%, due in December 2018	8,189		13,063
REG Mason City term loan, fixed interest rate of 5%, due in July 2019	1,153		2,659
REG Ralston term loan, fixed interest rate of 5%, due in October 2025	6,183		—
REG Ames term loans, secured, fixed interest rates of 3.5% and 4.25%, due in January 2018 and December 2019, respectively	—		3,565
REG Grays Harbor term loan, variable interest of minimum 3.5% or Prime Rate plus 0.25%, due in May 2022	7,882		9,273
REG Capital term loan, fixed interest rate of 3.99%, due in January 2028	7,400		—
Other	179		468
Total debt before debt issuance costs	228,560		217,891
Less: Current portion of long-term debt	13,397		15,402
Less: Debt issuance costs (net of accumulated amortization of $3,510 and $2,396, respectively)	6,627		6,286
Total long-term debt	$	208,536	$	196,203

Summary of company's revolving borrowings

The Company’s revolving debt at December 31 are as follows:

	2017		2016
Total revolving loans (current)	$	65,525	$	52,844
Maximum remaining available to be borrowed under revolving lines of credit	$	60,839	$	100,237

Summary of maturities of the term borrowings

Maturities of the term debt, including the convertible debt, are as follows for the years ending December 31:

2018	$	13,397
2019	76,856
2020	6,824
2021	5,613
2022	3,548
Thereafter	122,322
Total term debt	228,560
Less: current portion	13,397
Total long-term debt	$	215,163