XML 110 R101.htm IDEA: XBRL DOCUMENT v2.4.0.8

Fair Value Measurements Text Tag (Details)	12 Months Ended
	Mar. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percent of Total Assets Level 3	0.10%

X

- Definition

Percent of Total Assets Level 3

+ References

No definition available.

+ Details

Name:	carv_PercentOfTotalAssetsLevel3
Namespace Prefix:	carv_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

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