Commitments and Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Long-term Purchase Commitment [Line Items]
Rent expense including operating costs	$ 9.1us-gaap_OperatingLeasesRentExpenseNet	$ 9.1us-gaap_OperatingLeasesRentExpenseNet	$ 10.5us-gaap_OperatingLeasesRentExpenseNet
Additional rent and operating costs not included in rent expense, related to excess facilities, which were previously accrued	0.3	0.1	0.2
Long-term Post-retirement Health Care, Severance and Pension Benefits, and Deferred Rent Liabilities	8.9us-gaap_OtherLongTermDebtNoncurrent
Raid Software License [Member]
Long-term Purchase Commitment [Line Items]
Long-term purchase obligation	$ 24

Additional Rent And Operating Costs Not Included In Rent Expense Related To Excess Facilities Which Were Previously Accrued

No definition available.

+ Details

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Namespace Prefix:	pmcs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

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- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41499-112717

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- Definition

Carrying value as of the balance sheet date of debt not otherwise defined (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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

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Period Type:	instant

- Details

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