Classes of Members' Capital (Details) - shares	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2018
EOS ENERGY STORAGE, LLC [Member]
Common units outstanding	68,190,000	68,190,000	68,190,000

Number of common units of ownership outstanding of a limited liability company (LLC).

No definition available.

Name:	us-gaap_CommonUnitOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant