XML 11 R1.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Document and Entity Information Document | 6 Months Ended
--- | ---
Sep. 30, 2022
Document and Entity Information [Abstract] |
Entity Central Index Key | 0001016178
Current Fiscal Year End Date | --03-31
Document Period End Date | Sep. 30, 2022
Document Fiscal Year Focus | 2023
Document Fiscal Period Focus | Q2
Amendment Flag | false

X
- Definition Document and Entity Information [Abstract] + References No definition available. + Details
Name: | carv_DocumentAndEntityInformationAbstract
Namespace Prefix: | carv_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Boolean flag that is true when the XBRL content amends previously-filed or accepted submission. + References No definition available. + Details
Name: | dei_AmendmentFlag
Namespace Prefix: | dei_
Data Type: | xbrli:booleanItemType
Balance Type: | na
Period Type: | duration

X
- Definition End date of current fiscal year in the format --MM-DD. + References No definition available. + Details
Name: | dei_CurrentFiscalYearEndDate
Namespace Prefix: | dei_
Data Type: | xbrli:gMonthDayItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fiscal period values are FY, Q1, Q2, and Q3. 1st, 2nd and 3rd quarter 10-Q or 10-QT statements have value Q1, Q2, and Q3 respectively, with 10-K, 10-KT or other fiscal year statements having FY. + References No definition available. + Details
Name: | dei_DocumentFiscalPeriodFocus
Namespace Prefix: | dei_
Data Type: | dei:fiscalPeriodItemType
Balance Type: | na
Period Type: | duration

X
- Definition This is focus fiscal year of the document report in YYYY format. For a 2006 annual report, which may also provide financial information from prior periods, fiscal 2006 should be given as the fiscal year focus. Example: 2006. + References No definition available. + Details
Name: | dei_DocumentFiscalYearFocus
Namespace Prefix: | dei_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD. + References No definition available. + Details
Name: | dei_DocumentPeriodEndDate
Namespace Prefix: | dei_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Exchange Act -Number 240 -Section 12 -Subsection b-2 + Details
Name: | dei_EntityCentralIndexKey
Namespace Prefix: | dei_
Data Type: | dei:centralIndexKeyItemType
Balance Type: | na
Period Type: | duration