CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) $ in Thousands	12 Months Ended
Apr. 30, 2017 USD ($)
Statement of Stockholders' Equity [Abstract]
Issuance cost of common stock	$ 742

The cost incurred during the period for sale of common stock.

No definition available.

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