Summary of Significant Accounting Policies (Details 3) (USD $) In Thousands, unless otherwise specified
|
12 Months Ended |
Mar. 31, 2015
|
Mar. 31, 2014
|
Mar. 31, 2013
|
Revenue by product |
|
|
|
Total |
$ 115,461us-gaap_Revenues
|
$ 133,105us-gaap_Revenues
|
$ 127,557us-gaap_Revenues
|
C30 |
|
|
|
Revenue by product |
|
|
|
Total |
4,804us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C30Member
|
5,623us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C30Member
|
6,756us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C30Member
|
C65 |
|
|
|
Revenue by product |
|
|
|
Total |
30,118us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C65Member
|
29,107us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C65Member
|
22,899us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C65Member
|
TA100 |
|
|
|
Revenue by product |
|
|
|
Total |
318us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_TA100Member
|
460us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_TA100Member
|
1,485us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_TA100Member
|
C200 |
|
|
|
Revenue by product |
|
|
|
Total |
7,120us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C200Member
|
14,754us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C200Member
|
18,099us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C200Member
|
C600 |
|
|
|
Revenue by product |
|
|
|
Total |
5,848us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C600Member
|
10,374us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C600Member
|
12,384us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C600Member
|
C800 |
|
|
|
Revenue by product |
|
|
|
Total |
8,319us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C800Member
|
10,127us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C800Member
|
5,324us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C800Member
|
C1000 |
|
|
|
Revenue by product |
|
|
|
Total |
32,685us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C1000Member
|
38,141us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C1000Member
|
35,571us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_C1000Member
|
Waste heat recovery generator |
|
|
|
Revenue by product |
|
|
|
Total |
155us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_WasteHeatRecoveryGeneratorMember
|
180us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_WasteHeatRecoveryGeneratorMember
|
|
Unit upgrades |
|
|
|
Revenue by product |
|
|
|
Total |
|
|
129us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_UnitUpgradesMember
|
Total from Micro turbine Products |
|
|
|
Revenue by product |
|
|
|
Total |
89,367us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_MicroTurbineProductsMember
|
108,766us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_MicroTurbineProductsMember
|
102,647us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_MicroTurbineProductsMember
|
Accessories, Parts and Service |
|
|
|
Revenue by product |
|
|
|
Total |
$ 26,094us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_AccessoriesPartsAndServiceMember
|
$ 24,339us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_AccessoriesPartsAndServiceMember
|
$ 24,910us-gaap_Revenues / us-gaap_ProductOrServiceAxis = cpst_AccessoriesPartsAndServiceMember
|