Convertible Notes Payable (Tables) - EOS ENERGY STORAGE, LLC [Member]

6 Months Ended

12 Months Ended

Jun. 30, 2020

Dec. 31, 2019

Schedule of convrtible notes recognized upon issuance

	December 31, 2019						June 30, 2020 Phase II			Total
	Phase I			Phase II
Convertible notes payable	$	40,587		$	35,973		$	9,077		$	85,637
Discount, original issuance		(20,946	)		(23,982	)		(6,051	)		(50,979	)
Premium (discount), embedded derivative		181			(1,145	)		(199	)		(1,163	)
Discount, fair value of preferred units		—			(2,031	)		(469	)		(2,500	)
Discount, beneficial conversion features		(1,799	)		—			—			(1,799	)
Convertible notes payable, net	$	18,023		$	8,815		$	2,358		$	29,196

	Phase 1			Phase 2			Total
Convertible notes payable	$	40,587		$	35,973		$	76,560
Discount, original issuance		(20,946	)		(23,982	)		(44,928	)
Premium (Discount), embedded derivative		181			(1,145	)		(964	)
Discount, fair value of preferred units		—			(2,031	)		(2,031	)
Discount, beneficial conversion features		(1,799	)		—			(1,799	)
Convertible notes payable, net	$	18,023		$	8,815		$	26,838

Schedule of balances attributable to convertible notes payable

	Phase I			Phase II			June 30, 2020
Convertible notes payable	$	40,587		$	45,049		$	85,636
Discount, original issuance		(20,946	)		(30,033	)		(50,979	)
Premium (discount), embedded derivative		181			(1,344	)		(1,163	)
Discount, fair value of preferred units					(2,500	)		(2,500	)
Discount, beneficial conversion features		(1,799	)		—			(1,799	)
Discount, accumulated amortization		22,564			33,877			56,441
Convertible notes payable, net	$	40,587		$	45,049		$	85,636

	Phase I			Phase II			December 31, 2019
Convertible notes payable	$	40,587		$	35,973		$	76,560
Discount, original issuance		(20,946	)		(23,982	)		(51,040	)
Premium (discount), embedded derivative		181			(1,145	)		(964	)
Discount, fair value of preferred units		—			(2,031	)		(2,031	)
Discount, beneficial conversion features		(1,799	)		—			(1,799	)
Discount, accumulated amortization		26,564			27,158			49,722
Convertible notes payable, net	$	40,587		$	35,973		$	76,560

	Phase 1			Phase 2			Total
Convertible notes payable	$	40,587		$	35,973		$	76,560
Discount, original issuance		(20,946	)		(23,982	)		(44,928	)
Discount, embedded derivative		181			(1,145	)		(964	)
Discount, fair value of preferred units		—			(2,031	)		(2,031	)
Discount, beneficial conversion features		(1,799	)		—			(1,799	)
Discount, accumulated amortization		22,564			27,158			49,722
Convertible notes payable, net	$	40,587		$	35,973		$	76,560