Line of credit facility amortize period.

No definition available.

Name:	pi_LineOfCreditFacilityAmortizePeriod
Namespace Prefix:	pi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility initial interest-only period.

+ References

No definition available.

+ Details

Name:	pi_LineOfCreditFacilityInitialInterestOnlyPeriod
Namespace Prefix:	pi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate during the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=pi_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=pi_DebtInstrumentRedemptionPeriodSevenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=pi_DebtInstrumentRedemptionPeriodEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Event - Additional Information (Details) - USD ($)	Apr. 26, 2019	Mar. 05, 2018
Term Loan
Subsequent Event [Line Items]
Term loan		$ 20,000,000
Line of credit facility, amortization period		36 months
Line of credit facility, mature date		Mar. 01, 2022
Subsequent Event \| Term Loan
Subsequent Event [Line Items]
Term loan	$ 23,500,000
Line of credit facility, amortization period	36 months
Line of credit facility, initial interest-only period	12 months
Line of credit facility, mature date	Apr. 01, 2023
Subsequent Event \| Term Loan \| Term Loan Prepaid On or Before April 26, 2020
Subsequent Event [Line Items]
Percentage of prepayment fee	2.00%
Subsequent Event \| Term Loan \| Term Loan Prepaid After April 26, 2020, But On or Before April 26, 2021
Subsequent Event [Line Items]
Percentage of prepayment fee	1.00%
Revolving Credit Facility
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity		$ 25,000,000
Revolving Credit Facility \| Subsequent Event
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity	$ 25,000,000
Letter of Credit
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity		$ 5,000,000
Letter of Credit \| Subsequent Event
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity	$ 5,000,000