SEGMENT INFORMATION (Details 2) - USD ($) $ in Thousands	12 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Operations and identifiable assets by industry segment
Total revenues	$ 958,202	$ 906,742	$ 802,047
Income (loss) from operations	92,108	81,295	74,438
Segments assets	979,674	1,011,077	952,739
Capital expenditures	15,286	54,598	157,367
Depreciation and amortization	58,976	54,239	27,507
Security Division
Operations and identifiable assets by industry segment
Total revenues	481,087	440,439	372,164
Capital expenditures	7,601	38,066	131,314
Depreciation and amortization	45,231	40,573	15,412
Healthcare Division
Operations and identifiable assets by industry segment
Total revenues	255,691	222,313	231,331
Capital expenditures	2,628	6,718	8,198
Depreciation and amortization	7,223	7,289	6,674
Optoelectronics and Manufacturing Division
Operations and identifiable assets by industry segment
Total revenues	221,424	243,990	198,552
Income (loss) from operations	17,533
Segments assets	164,922
Capital expenditures	3,411	2,801	3,185
Depreciation and amortization	5,028	4,971	4,169
Corporate
Operations and identifiable assets by industry segment
Income (loss) from operations	(17,455)	(11,497)	(14,002)
Segments assets	125,174	120,727	79,372
Capital expenditures	1,646	7,013	14,670
Depreciation and amortization	1,494	1,406	1,252
Operating Segments \| Security Division
Operations and identifiable assets by industry segment
Total revenues	481,087		372,164
Income (loss) from operations	67,804	59,501	43,748
Segments assets	470,808	535,306	519,081
Operating Segments \| Healthcare Division
Operations and identifiable assets by industry segment
Total revenues	255,691		231,331
Income (loss) from operations	24,666	18,495	25,224
Segments assets	223,412	190,612	192,994
Operating Segments \| Optoelectronics and Manufacturing Division
Operations and identifiable assets by industry segment
Total revenues	267,872	284,496	239,100
Income (loss) from operations		14,663	18,213
Segments assets		169,084	156,784
Eliminations
Operations and identifiable assets by industry segment
Total revenues	(46,448)	(40,506)	(40,548)
Income (loss) from operations	(440)	133	1,255
Segments assets	(4,642)	(4,652)	4,508
Eliminations \| Optoelectronics and Manufacturing Division
Operations and identifiable assets by industry segment
Total revenues	$ 46,448	$ 40,506	$ 40,548

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.18)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 12

-Article 7

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 18

-Article 5

+ Details

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

- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ 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=31042434&loc=d3e3602-108585

+ Details

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

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

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

- Definition

The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

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

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=osis_SecurityDivisionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=osis_HealthcareDivisionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=osis_OptoelectronicsAndManufacturingDivisionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: