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



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 11

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_DefinedContributionPlanCostRecognized
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

Maximum amount per employee, by the terms of the plan, that the employer may contribute to a defined contribution plan.

No definition available.

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