Debt Agreement, Extension Term

No definition available.

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Namespace Prefix:	spnt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Issue Price, Percentage

+ References

No definition available.

+ Details

Name:	spnt_DebtInstrumentIssuePricePercentage
Namespace Prefix:	spnt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
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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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Namespace Prefix:	us-gaap_
Data Type:	dtr-types: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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Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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

- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

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+ Details

Name:	us-gaap_InterestExpenseDebt
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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.

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+ Details

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Balance Type:	credit
Period Type:	instant

- 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_
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Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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Balance Type:	debit
Period Type:	duration

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- Details

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- Details

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Debt and letter of credit facilities - Narrative (Details)				3 Months Ended				6 Months Ended	9 Months Ended	12 Months Ended
	Feb. 26, 2021 USD ($)	Sep. 22, 2017 USD ($)	Nov. 01, 2016 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 22, 2017 SEK (kr)
Debt Instrument [Line Items]
Interest expense										$ 34,000,000	$ 8,200,000
Foreign exchange gains (losses)				$ 27,500,000	$ 16,100,000	$ (12,000,000.0)	$ 12,400,000	$ 400,000	$ 16,500,000	44,000,000.0	(5,200,000)	$ (3,600,000)
Revolving Credit Facility
Debt Instrument [Line Items]
Contractual term	3 years
Maximum borrowing capacity	$ 300,000,000
Extension term	12 months
Outstanding borrowings				0						0
Subordinated Notes
Debt Instrument [Line Items]
Face value of debt issued		$ 346,100,000											kr 2,750,000,000
Debt issue price, percentage		100.00%
Interest expense										11,100,000
Foreign exchange gains (losses)										25,200,000
Senior Notes \| 2016 SIG Senior Notes
Debt Instrument [Line Items]
Face value of debt issued			$ 400,000,000
Debt issue price, percentage			99.20%
Interest expense										14,700,000
Proceeds from issuance of debt, net of costs			$ 392,400,000
Interest rate			4.60%
Senior Notes \| 2015 TPRUSA Senior Notes
Debt Instrument [Line Items]
Face value of debt issued				$ 115,000,000						115,000,000
Interest expense										$ 8,200,000	$ 8,200,000
Interest rate				7.00%						7.00%