Name:	pre_AccruedInvestmentIncomeFundsHeldDirectlyManaged
Namespace Prefix:	pre_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the amount of cash and cash equivalents held in the portfolio underlying the funds held - directly managed account.

No definition available.

Name:	pre_CashAndCashEquivalentsFundsHeldDirectlyManaged
Namespace Prefix:	pre_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

No definition available.

Name:	pre_FairValueAssetsLevel2ToLevel1TransfersAmount
Namespace Prefix:	pre_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	pre_FairValueOtherDetailsLineItems
Namespace Prefix:	pre_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Investments that the Company did not measure at fair value on the balance sheet date, which primarily relate to the company's investments that are accounted for using the cost method of accounting, equity method of accounting or investment company accounting.

No definition available.

Name:	pre_InvestmentsNotCarriedAtFairValue
Namespace Prefix:	pre_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Other invested assets and liabilities carried at cost, which are related to the underlying business related to the funds held - directly managed account.

No definition available.

Name:	pre_OtherNetAssets
Namespace Prefix:	pre_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Transfers into assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258