Debt instrument, amount of indebtedness or judgments against company to be considered as threshold limit for default

No definition available.

Name:	pbyi_DebtInstrumentAmountOfIndebtednessOrJudgmentsAgainstCompanyToBeConsideredAsThresholdLimitForDefault
Namespace Prefix:	pbyi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt instrument, event of default, percentage of additional interest rate payable.

+ References

No definition available.

+ Details

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Namespace Prefix:	pbyi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument, percentage of original principal amount payable in final payment.

+ References

No definition available.

+ Details

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Namespace Prefix:	pbyi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument, prepayment fee, percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	pbyi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility capacity available upon achievement of specified minimum revenue milestone.

+ References

No definition available.

+ Details

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Namespace Prefix:	pbyi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of credit facility initiation month and year.

+ References

No definition available.

+ Details

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Namespace Prefix:	pbyi_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of issued and outstanding capital stock of its subsidiary pledged.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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
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-SubTopic 30
-Section 55
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+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Start date of debt instrument redemption period, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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(22))
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-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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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

+ Details

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

- Definition

Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

The cash inflow from bank borrowing during the year.

+ References

+ Details

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

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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

- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 230
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-Paragraph 15
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+ Details

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

- Details

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- Details

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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Debt - Additional Information (Detail) - USD ($)			1 Months Ended		6 Months Ended
Debt - Additional Information (Detail) - USD ($)	Apr. 20, 2020	Jun. 28, 2019	May 31, 2018	Oct. 31, 2017	Jun. 30, 2020
Silicon Valley Bank and Oxford Finance LLC \| Paycheck Protection Program Loan
Debt Instrument [Line Items]
Proceeds from loan	$ 8,400,000
Silicon Valley Bank and Oxford Finance LLC \| Term Loan
Debt Instrument [Line Items]
Line of credit facility, effective date					2017-10
Amount borrowed under credit facility			$ 125,000,000.0	$ 50,000,000.0
Term loan, maximum borrowing capacity			155,000,000.0
Payment of existing credit facility			50,000,000.0
Line of credit facility available upon achievement of specified minimum revenue milestone			$ 30,000,000.0
Interest rate, description					Prior to the amendment and restatement of the loan and security agreement in June 2019, which provided for a new credit facility, or the New Credit Facility, the term loans under the Amended Credit Facility bore interest at an annual rate equal to the greater of (i) 8.25% and (ii) the sum of (a) the “prime rate,” as reported in The Wall Street Journal on the last business day of the month that immediately preceded the month in which the interest accrued, plus (b) 3.5%. The Company was required to make monthly interest-only payments on each term loan commencing on the first calendar day of the calendar month following the funding date of such term loan, and continuing on the first calendar day of each calendar month thereafter through July 1, 2020
Annual interest rate			8.25%
Redemption period start date			Jul. 01, 2020
Line of credit facility closing date			May 01, 2023
Percentage of original principal amount payable in final payment			7.50%
Silicon Valley Bank and Oxford Finance LLC \| Term Loan \| First Anniversary of Funding
Debt Instrument [Line Items]
Prepayment fee, percentage			3.00%
Silicon Valley Bank and Oxford Finance LLC \| Term Loan \| Between First Anniversary and Second Anniversary
Debt Instrument [Line Items]
Prepayment fee, percentage			2.00%
Silicon Valley Bank and Oxford Finance LLC \| Term Loan \| After Second Anniversary and Prior to May 1, 2023
Debt Instrument [Line Items]
Prepayment fee, percentage			1.00%
Silicon Valley Bank and Oxford Finance LLC \| Term Loan \| Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate			3.50%
Oxford \| Secured Promissory Notes
Debt Instrument [Line Items]
Term loan, maximum borrowing capacity		$ 100,000,000.0
Payment of existing credit facility		$ 155,000,000.0
Interest rate, description					The term loans under the New Credit Facility bear interest at an annual rate equal to the greater of (i) 9.0% and (ii) the sum of (a) the “prime rate,” as reported in The Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue, plus (b) 3.5%. The Company is required to make monthly interest-only payments on each term loan under the New Credit Facility commencing on the first calendar day of the calendar month following the funding date of such term loan, and continuing on the first calendar day of each calendar month thereafter through August 1, 2021, or the Amortization Date.
Annual interest rate		9.00%
Redemption period start date		Jun. 01, 2024
Line of credit facility closing date		Jun. 01, 2024
Percentage of original principal amount payable in final payment		7.50%
Aggregate principal amount		$ 100,000,000.0
Additional money remains available under new credit facility		$ 0
Percentage of issued and outstanding capital stock of its subsidiary pledged		65.00%
Percentage of additional interest rate to be charged on the event of default		5.00%
Amount of indebtedness or judgments against company to be considered as threshold limit for default		$ 500,000
Principal amounts outstanding					$ 100,000,000.0
Oxford \| Secured Promissory Notes \| First Anniversary of Funding
Debt Instrument [Line Items]
Prepayment fee, percentage		3.00%
Oxford \| Secured Promissory Notes \| Between First Anniversary and Second Anniversary
Debt Instrument [Line Items]
Prepayment fee, percentage		2.00%
Oxford \| Secured Promissory Notes \| After Second Anniversary and Prior to Maturity Date
Debt Instrument [Line Items]
Prepayment fee, percentage		1.00%
Oxford \| Secured Promissory Notes \| Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate		3.50%