Expiration year of each operating loss carryforward included in operating loss carryforward.

No definition available.

Name:	csbr_OperatingLossCarryforwardsExpirationYear
Namespace Prefix:	csbr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

+ Details

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

+ Details

Name:	us-gaap_OperatingLossCarryforwards
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Carryforwards

-URI http://asc.fasb.org/extlink&oid=6506874

+ Details

Name:	us-gaap_TaxCreditCarryforwardAmount
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Provision for Income Taxes (Details Textual) (USD $)				12 Months Ended
Provision for Income Taxes (Details Textual) (USD $)	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2013 Research Tax Credit Carryforward [Member]	Apr. 30, 2013 State and Local Jurisdiction [Member]	Apr. 30, 2013 Foreign Tax Authority [Member]	Apr. 30, 2012 Foreign Tax Authority [Member]	Apr. 30, 2013 Domestic Tax Authority [Member]	Apr. 30, 2012 Domestic Tax Authority [Member]
Operating Loss Carryforwards					$ 1,744,000	$ 1,138,000	$ 11,216,000	$ 6,825,000
Tax Credit Carryforward, Amount	607,000		542,000
Operating Loss Carryforwards Expiration Year				begin expiring in 2029
Deferred Tax Assets, Valuation Allowance	$ 8,926,000	$ 6,373,000