Related Party Transactions - Narrative (Details) - USD ($)	12 Months Ended
Apr. 30, 2016	Apr. 30, 2015
Private Placement [Member]
Related Party Transaction [Line Items]
Stock issued during period for services (in shares)		451,754
Common stock, purchase price (in usd per share)		$ 4.80
Warrants issued during period for common stock (in shares)		248,460
Warrants exercise price per share (in dollars per share)		$ 5.76
Board of Directors Chairman [Member]
Related Party Transaction [Line Items]
Related related party transaction, amounts of transaction	$ 72,000	$ 62,500
Substantial Stockholders [Member]
Related Party Transaction [Line Items]
Bank servicing fees	$ 8,800	$ 3,700

The price per share at which the common stock purchased during the period.

No definition available.

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Namespace Prefix:	csbr_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The warrants exercise price per share.

+ References

No definition available.

+ Details

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Namespace Prefix:	csbr_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Amount of revenue from servicing real estate mortgages, credit cards, and other financial assets held by others. Includes premiums received in lieu of regular servicing fees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13 (d))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

Name:	us-gaap_ServicingFeesNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

+ References

No definition available.

+ Details

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

- Details

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

- Details

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

- Details

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