Percentage of cash penalty equal to the aggregate purchase price paid by investor.

No definition available.

Name:	csbr_PercentageOfCashPenalties
Namespace Prefix:	csbr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of potential penalties under this registration payment arrangement.

+ References

No definition available.

+ Details

Name:	csbr_PotentialPenaltiesAmount
Namespace Prefix:	csbr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage describes the limit of the aggregate Purchase Price paid by the investors.

+ References

No definition available.

+ Details

Name:	csbr_PurchasePriceLimitPercentage
Namespace Prefix:	csbr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of share warrants outstanding in connection with the financing arrangement.

+ References

No definition available.

+ Details

Name:	csbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardWarrantsOutstanding
Namespace Prefix:	csbr_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The number warrants issued during the period for purchase of common stock.

+ References

No definition available.

+ Details

Name:	csbr_WarrantsIssuedDuringPeriodForCommonStock
Namespace Prefix:	csbr_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Net number of share options (or share units) granted during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iv)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(i))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph i

-Article 4

+ Details

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

- Definition

Fair value portion of warrants not settleable in cash classified as equity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

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

- Details

Name:	us-gaap_EligibleItemOrGroupForFairValueOptionAxis=us-gaap_AccruedLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=csbr_April2011PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=csbr_January2013PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_EquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=csbr_ChiefExecutiveOfficerAndPresidentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Share-Based Payments (Details Textual) (USD $)	3 Months Ended		9 Months Ended
Share-Based Payments (Details Textual) (USD $)	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014	Apr. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			1,093,175
Share Based Compensation Arrangement By Share Based Payment Award Warrants Outstanding	3,276,667		3,276,667		3,276,667
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 0	$ 0.97	$ 0.67	$ 0.96
Warrants Not Settleable in Cash, Fair Value Disclosure	$ 600,000		$ 600,000		$ 2,010,000
Percentage Of Cash Penalties			1.00%csbr_PercentageOfCashPenalties
Purchase Price Limit Percentage			10.00%csbr_PurchasePriceLimitPercentage
Allocated Share-based Compensation Expense, Total	657,000	941,000	2,284,000	1,968,000
Accrued Liabilities [Member]
Allocated Share-based Compensation Expense, Total			158,000
Minimum [Member]
Potential Penalties Amount			50,000
Maximum [Member]
Potential Penalties Amount			130,000
Chief Executive Officer and President [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures, Total			3,000,000
April 2011 Private Placement [Member]
Warrants Issued During Period for Common Stock			1,266,667
April 2011 Private Placement [Member] \| Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.50		$ 0.50
April 2011 Private Placement [Member] \| Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 0.90		$ 0.90
January 2013 Private Placement [Member]
Warrants Issued During Period for Common Stock			1,860,000
Warrants and Rights Outstanding	$ 800,000		$ 800,000
Equity [Member]
Warrants Issued During Period for Common Stock			150,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 1.00		$ 1.00