Business and Organization (Details)	3 Months Ended
Jun. 30, 2020
Minimum
Factory Protection Plan	5 years
Maximum
Factory Protection Plan	20 years

The term of long-term service agreements under Factory Protection Plan.

No definition available.

Name:	cpst_FactoryProtectionPlanServiceAgreementTerm
Namespace Prefix:	cpst_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration