Loan and Security Agreement (Details) - Revolving Credit Facility - Silicon Valley Bank $ in Millions	9 Months Ended
Sep. 30, 2021 USD ($)
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 25.0
Line of credit facility, borrowing capacity, percentage of eligible accounts receivable, net,	80.00%
Debt instrument, interest rate	3.25%
Line of credit facility, unused capacity, commitment fee percentage	0.40%
Line of credit facility, borrowing capacity, unused capacity fee, closing balance threshold	$ 5.0
Debt instrument, covenant, quick ratio, minimum	1.0

Debt Instrument, Covenant, Quick Ratio, Minimum

No definition available.

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- Definition

Line Of Credit Facility, Borrowing Capacity, Percentage Of Eligible Accounts Receivable, Net,

+ References

No definition available.

+ Details

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- Definition

Line of Credit Facility, Borrowing Capacity, Unused Capacity Fee, Closing Balance Threshold

+ References

No definition available.

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt 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(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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- 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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- 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

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=120391452&loc=d3e13212-122682

+ Details

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Balance Type:	credit
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- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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Period Type:	duration

- Details

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- Details

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