Noncash Stock Modification Expense

No definition available.

Name:	csii_NoncashStockModificationExpense
Namespace Prefix:	csii_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of shares available to vest if year end performance criteria is met.

+ References

No definition available.

+ Details

Name:	csii_NumberofPerformanceSharesAvailabletoVest
Namespace Prefix:	csii_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares of restricted stock that accelerate vesting upon termination of employment.

+ References

No definition available.

+ Details

Name:	csii_NumberofSharesAccelerated
Namespace Prefix:	csii_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Restructuring and Related Cost, Severance Costs, Period

+ References

No definition available.

+ Details

Name:	csii_RestructuringandRelatedCostSeveranceCostsPeriod
Namespace Prefix:	csii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of severance accrual expected to be paid within the next twelve months.

+ References

No definition available.

+ Details

Name:	csii_SeveranceAccrualCurrent
Namespace Prefix:	csii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Portion of the severance accrual that is non-current

+ References

No definition available.

+ Details

Name:	csii_SeveranceAccrualNonCurrent
Namespace Prefix:	csii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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

- Definition

Amount, after cash payment, of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

+ Details

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

- Definition

Carrying amount as of the balance sheet date of known and estimated obligations associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid in the next twelve months or in the normal operating cycle if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b)(2))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

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

- Definition

Carrying amount as of the balance sheet date of known and estimated costs associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid after one year or beyond the next operating cycle, if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, and relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

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

- Definition

Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)(10)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140864-122747

+ Details

Name:	us-gaap_SeveranceCosts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=csii_ExecutiveSeverancePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_SellingGeneralAndAdministrativeExpensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=csii_SeverancePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Selected Consolidated Financial Statement Information (Details Textual) - USD ($) $ in Thousands			12 Months Ended
	May 26, 2016	Feb. 26, 2016	Jun. 30, 2016	Jun. 30, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring expense			$ 2,364
Restructuring accrual to be paid within the next twelve months			1,337	$ 0
Employee Severance \| Executive Severance Plan \| CHPO
Restructuring Cost and Reserve [Line Items]
Salary continuation benefits, period	18 months
Gross amount of salary continuation benefits	$ 516
Employee Severance \| Executive Severance Plan \| CHPO \| Restricted Stock
Restructuring Cost and Reserve [Line Items]
Number of shares accelerated	7,996
Employee Severance \| Executive Severance Plan \| CHPO \| Performance Shares
Restructuring Cost and Reserve [Line Items]
Number of performance shares available to vest	30,624
Employee Severance \| Executive Severance Plan \| CEO
Restructuring Cost and Reserve [Line Items]
Non-cash stock modification expense			190
Employee Severance \| Executive Severance Plan \| CEO \| Selling, General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Gross amount of salary continuation benefits			1,507
Employee Severance \| Executive Severance Plan \| CEO \| Accrued Expenses
Restructuring Cost and Reserve [Line Items]
Severance accrual, current			708
Employee Severance \| Executive Severance Plan \| CEO \| Other Liabilities
Restructuring Cost and Reserve [Line Items]
Severance accrual, noncurrent			427
Employee Severance \| Executive Severance Plan \| CEO \| Restricted Stock
Restructuring Cost and Reserve [Line Items]
Number of shares accelerated		27,140
Employee Severance \| Executive Severance Plan \| CEO \| Performance Shares
Restructuring Cost and Reserve [Line Items]
Number of performance shares available to vest		112,072
Employee Severance \| Severance Plan \| Accrued Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring accrual to be paid within the next twelve months			1,337
Employee Severance \| Severance Plan \| CHPO \| Other Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring accrual, long-term portion			$ 184