Business Acquisition, Additional Percentage Of Voting Interests Acquired

No definition available.

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Data Type:	num:percentItemType
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Period Type:	instant

- Details

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- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the purchase of noncontrolling interest during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

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

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=issi_ChingisTechnologyCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Basis of Presentation Basis of Presentation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		1 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	May 31, 2013	Sep. 30, 2014	Sep. 14, 2012
Business Acquisition [Line Items]
Additional interest acquired	$ 0	$ 199
Chingis Technology Corporation
Business Acquisition [Line Items]
Percentage of interests acquired					94.10%
Percentage of additional voting interests acquired			4.80%	1.10%
Additional interest acquired			$ 1,600	$ 400
Percentage ownership of Chingis	100.00%