Quarterly report pursuant to Section 13 or 15(d)

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- Document and Entity Information
Financial Statements
Notes to Financial Statements
Notes Tables
Notes Details

Commitments and Contingencies (Details 3)

v2.4.1.9

Commitments and Contingencies (Details 3) (USD $) In Millions, unless otherwise specified	1 Months Ended		9 Months Ended
	May 31, 2014	Sep. 30, 2010 kW	Dec. 31, 2014
DOE
Commitments and Contingencies
Projected cost of research, development and testing project	$ 0.2
Percentage Contribution by ORNL	100.00%
Period of contract	19 months
Cumulative amount of bill under contract	0.1
Research, development and testing of a more efficient microturbine Combined Heat and Power (CHP) system
Commitments and Contingencies
Projected electrical efficiency of microturbine (as a percent)		42.00%
Power output of microturbine (in kW)		370
Projected cost of research, development and testing project		15.0
Contribution by other party		5.0
Expense to be incurred by the company in research and development		10.0
Period of contract			5 years
Cumulative amount of bill under contract			$ 3.9

- Definition

Represents the contribution of other party towards research, development and testing project.

+ References

No definition available.

+ Details

Name:	cpst_ContributionToBeMadeByOtherPartyTowardsResearchDevelopmentAndTestingProject
Namespace Prefix:	cpst_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the cumulative amount billed to other party under research, development and testing of project.

+ References

No definition available.

+ Details

Name:	cpst_CumulativeAmountOfBillToOtherPartyTowardsResearchDevelopmentAndTestingProject
Namespace Prefix:	cpst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the percentage of contribution by other party towards research, development and testing project.

+ References

No definition available.

+ Details

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

- Definition

Represents the percentage of projected electrical efficiency of microturbine.

+ References

No definition available.

+ Details

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

- Definition

Represents the period of contract with other party under research, development and testing of project.

+ References

No definition available.

+ Details

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

- Definition

Represents the power output of microturbine system.

+ References

No definition available.

+ Details

Name:	cpst_PowerOutputOfMicroturbine
Namespace Prefix:	cpst_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the cost of research, development and testing project.

+ References

No definition available.

+ Details

Name:	cpst_ProjectedCostOfResearchDevelopmentAndTestingProject
Namespace Prefix:	cpst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the research and development expense to be incurred by the entity.

+ References

No definition available.

+ Details

Name:	cpst_ResearchAndDevelopmentExpenseToBeIncurredByEntity
Namespace Prefix:	cpst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Details

Name:	dei_LegalEntityAxis=cpst_DepartmentOfEnergyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=cpst_ResearchDevelopmentAndTestingOfMoreEfficientMicroturbineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: