XML 62 R49.htm IDEA: XBRL DOCUMENT
v3.22.2

Organization Text Tag (Details) $ / shares in Units, $ in Thousands | 12 Months Ended |
--- | --- | ---
Mar. 31, 2022 USD ($) | Mar. 31, 2021 USD ($) | Mar. 31, 2003 USD ($) | Sep. 17, 2003 $ / shares shares
Organization, Consolidation and Presentation of Financial Statements [Abstract] |  |  |  |
subordinated debt issued shares (in shares) | shares |  |  |  | 13,000
Liquidation amount subordinated debt (in dollars per share) | $ / shares |  |  |  | $ 1,000
Proceeds from Issuance of Long-term Debt |  |  | $ 13,000 |
Proceeds from (Payments for) Other Financing Activities |  |  | 400 |
Payments for Repurchase of Trust Preferred Securities |  |  | $ 13,400 |
Debt Instrument, Basis Spread on Variable Rate | 3.05% |  |  |
Subordinated Borrowing, Interest Rate | 3.97% | 3.23% |  |
Accrued interest expense subordinated debt | $ 22 | $ 3,100 |  |
Tier One Leverage Capital IMCR to Average Assets | 0.0900 | 0.0900 |  |
Total Risk Based Capital IMCR to Risk Weighted Assets | 0.1200 | 0.1200 |  |

X
- Definition Accrued interest expense subordinated debt + References No definition available. + Details
Name: | carv_AccruedInterestExpenseSubordinatedDebt
Namespace Prefix: | carv_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Liquidation amount subordinated debt + References No definition available. + Details
Name: | carv_LiquidationAmountSubordinatedDebt
Namespace Prefix: | carv_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition subordinated debt issued shares + References No definition available. + Details
Name: | carv_SubordinatedDebtIssuedShares
Namespace Prefix: | carv_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ratio of minimum total risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash outflow to reacquire preferred stocks issued by a business trust or other special purpose entity, mainly established by a bank holding entity, to third party investors. The trust's assets are deeply subordinated debentures of the bank holding entity. Most trust preferred securities are subject to a mandatory redemption upon the repayment of the debentures. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585 + Details
Name: | us-gaap_PaymentsForRepurchaseOfTrustPreferredSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from financing activities classified as other. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585 + Details
Name: | us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Stated interest rate of the subordinated debt. + References No definition available. + Details
Name: | us-gaap_SubordinatedBorrowingInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ratio of minimum Tier 1 leverage capital to average assets categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant