Senior notes payable and letter of credit facilities (Letters of credit) (Details)	Jun. 30, 2019 USD ($)
Line of Credit Facility
Utilized	$ 395,791,000
Collateral	237,764,000
Unsecured facility
Line of Credit Facility
Facility	200,000,000
Utilized	158,027,000
Committed, secured facility [Member]
Line of Credit Facility
Facility	125,000,000
Utilized	60,231,000
Collateral	60,231,000
Uncommitted, unsecured facility [Member]
Line of Credit Facility
Utilized	177,533,000
Collateral	$ 177,533,000

Restricted cash securing credit facilities and reinsurance contracts

No definition available.

Name:	tpre_Restrictedcashsecuringcreditfacilitiesandreinsurancecontracts
Namespace Prefix:	tpre_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

+ Details

Name:	us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

Name:	us-gaap_LineOfCreditFacilityLineItems
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

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

- Details

Name:	tpre_LetterofcreditfacilitytypeAxis=tpre_UnsecuredfacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	tpre_LetterofcreditfacilitytypeAxis=tpre_CommittedsecuredfacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	tpre_LetterofcreditfacilitytypeAxis=tpre_UncommittedunsecuredfacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: