Name:	prbm_NumberOfSharesSubjectToForfeiture
Namespace Prefix:	prbm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The amount of issuance costs associated with temporary equity.

No definition available.

Name:	prbm_TemporaryEquityIssuanceCosts
Namespace Prefix:	prbm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Period of option available to the underwriters to purchase additional shares.

No definition available.

Name:	prbm_UnderwritersOptionPeriod
Namespace Prefix:	prbm_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Number of options vested.

No definition available.

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementClassOfStockAxis=prbm_CommonClassaSubjectToRedemptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: