Represents the vesting period of employer's matching contributions to a defined contribution plan starting from the hiring date of employee's.

No definition available.

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

Represents the maximum employee's contributions as a percentage of their eligible compensation.

No definition available.

Name:	cpst_DefinedContributionPlanMaximumEmployeeContributionAsPercentageOfTheirEligibleCompensation
Namespace Prefix:	cpst_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the maximum percentage of employee's contribution for employer's matching contribution of 50 cents for every dollar contributed by employees.

No definition available.

Name:	cpst_DefinedContributionPlanMaximumPercentageOfEmployeesContributionForEmployersMatchingContributionOf50CentsForEveryDollarContributionByEmployees
Namespace Prefix:	cpst_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of the cost recognized during the period for defined contribution plans.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of employer's matching contributions to a defined contribution plan that vests in a given year.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration