Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity (Details 6)

v2.4.1.9
Stockholders' Equity (Details 6)
0 Months Ended 12 Months Ended
Oct. 31, 2013
Mar. 31, 2015
Mar. 31, 2013
Mar. 31, 2012
Shares        
Balance at the end of period (in shares)     22,600,000us-gaap_ClassOfWarrantOrRightOutstanding  
March 2012        
Shares        
Balance at the beginning of period (in shares)       22,550,000us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_WarrantMarch2012Member
Warrants exercised (in shares) (4,700,000)cpst_ClassOfWarrantOrRightNumberOfWarrantsExercised
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_WarrantMarch2012Member
(4,725,000)cpst_ClassOfWarrantOrRightNumberOfWarrantsExercised
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_WarrantMarch2012Member
   
Warrants expired (in shares)   (17,825,000)cpst_ClassOfWarrantOrRightNumberOfWarrantsExpired
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_WarrantMarch2012Member
   
Balance at the end of period (in shares)     22,550,000us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_WarrantMarch2012Member
22,550,000us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_WarrantMarch2012Member
September 2008        
Shares        
Balance at the beginning of period (in shares)     3,910,034us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_Warrant2008Member
 
Anti-dilution provision (in shares)     51,437cpst_ClassOfWarrantOrRightNumberOfWarrantsNumberOfWarrantsAdjustedAgainstAntiDilutionProvision
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_Warrant2008Member
 
Warrants expired (in shares)   (3,961,471)cpst_ClassOfWarrantOrRightNumberOfWarrantsExpired
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_Warrant2008Member
   
Balance at the end of period (in shares)     3,961,471us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= cpst_Warrant2008Member