Sirius International Insurance 8-K 1 Sep 20 Other Events Financial data

Document and Entity Information

Document and Entity Information	Sep. 01, 2020
Cover [Abstract]
Entity Registrant Name	Sirius International Insurance Group, Ltd.
Entity Central Index Key	0001744894
Document Type	8-K
Document Period End Date	Sep. 1, 2020
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets
Fixed maturity investments, trading, at fair value (Amortized cost 2019: $1,656.6; 2018: $1,952.9)	$ 1,681	$ 1,949.2
Short-term investments, at fair value (Amortized cost 2019: $1,090.8; 2018: $716.1)	1,085.2	715.5
Equity securities, trading, at fair value (Cost 2019: $379.2; 2018: $409.4)	405.2	380
Other long-term investments, at fair value (Cost 2019: $315.4; 2018: $337.6)	346.8	365
Cash	136.3	119.4
Restricted cash	14.3	12.8
Total investments and cash	3,668.8	3,541.9
Accrued investment income	11.2	14.1
Insurance and reinsurance premiums receivable	730.1	630.6
Reinsurance recoverable on unpaid losses	410.3	350.2
Reinsurance recoverable on paid losses	73.9	55
Funds held by ceding companies	293.9	186.8
Ceded unearned insurance and reinsurance premiums	162	159.8
Deferred acquisition costs	148.2	141.6
Deferred tax asset	166.7	202.5
Accounts receivable on unsettled investment sales	6.7	5
Goodwill	400.8	400.6
Intangible assets	179.8	195.6
Other assets	161.4	124
Total assets	6,413.8	6,007.7
Liabilities
Loss and loss adjustment expense reserves	2,331.5	2,016.7
Unearned insurance and reinsurance premiums	708	647.2
Ceded reinsurance payable	244.7	206.9
Funds held under reinsurance treaties	169.1	110.6
Deferred tax liability	205.9	237.4
Debt	685.2	696.8
Accounts payable on unsettled investment purchases	2.3	3.2
Other liabilities	201.3	150.5
Total liabilities	4,548	4,069.3
Commitments and contingencies (see Note 22)
Mezzanine equity
Series B preference shares	223	232.2
Total mezzanine equity	223	232.2
Common shareholders' equity
Common shares (shares issued and outstanding, 2019: 115,299,341, 2018: 115,151,251)	1.2	1.2
Additional paid-in surplus	1,098.2	1,089.1
Retained earnings	778.5	816.6
Accumulated other comprehensive (loss)	(237.5)	(202.4)
Total common shareholders' equity	1,640.4	1,704.5
Non-controlling interests	2.4	1.7
Total equity	1,642.8	1,706.2
Total liabilities, mezzanine equity, and equity	$ 6,413.8	$ 6,007.7

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed maturity investments, trading, amortized cost	$ 1,656.6	$ 1,952.9
Short-term investments, amortized cost	1,090.8	716.1
Equity securities, trading, cost	379.2	409.4
Other long-term investments, cost	$ 315.4	$ 337.6
Common shares issued (in shares)	115,299,341	115,151,251
Common shares outstanding (in shares)	115,299,341	115,151,251

Consolidated Statements of (Los

Consolidated Statements of (Loss) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Net earned insurance and reinsurance premiums									$ 1,441.6	$ 1,262.3	$ 1,035.3
Net investment income									84.7	71.4	56.8
Net realized investment gains (losses)									56.7	2.3	(27.2)
Net unrealized investment gains (losses)									80.6	(23.2)	(10.5)
Net foreign exchange gains									7.7	22.7	9.2
Revaluation of contingent consideration									(6.3)	9.6	48.8
Other revenue									55.1	112.7	21.7
Total revenues	$ 352	$ 487.4	$ 441	$ 439.7	$ 336.8	$ 351.7	$ 441.8	$ 327.5	1,720.1	1,457.8	1,134.1
Expenses
Loss and loss adjustment expenses									1,170.3	900	811.2
Insurance and reinsurance acquisition expenses									288.7	255.4	197.2
Other underwriting expenses									138.2	146.2	106.1
General and administrative expenses									109.8	77.9	91.9
Intangible asset amortization expenses									15.8	15.8	10.2
Impairment of intangible assets									0	8	5
Interest expense on debt									31	30.8	22.4
Total expenses	506	498.7	430.7	318.4	482.3	386.3	292.4	273.1	1,753.8	1,434.1	1,244
Pre-tax (loss) income									(33.7)	23.7	(109.9)
Income tax (expense)									(11.9)	(40.4)	(26.4)
Net (loss)									(45.6)	(16.7)	(136.3)
Less: Income attributable to non-controlling interests									(1.7)	(1.4)	(13.7)
Net (loss) attributable to Sirius Group									(47.3)	(18.1)	(150)
Change in carrying value of Series B preference shares									9.2	(36.4)	0
Add: Redemption of Series A redeemable preference shares									0	13.8	0
Less: Accrued dividends on Series A redeemable preference shares									0	(2.6)	(6.1)
Net (loss) attributable to Sirius Group's common shareholders	$ (137.3)	$ (2.7)	$ 6.6	$ 95.3	$ (153.6)	$ (28)	$ 97.8	$ 40.5	$ (38.1)	$ (43.3)	$ (156.1)
Net (loss) per common share and common share equivalent
Basic earnings per common share and common share equivalent (in dollars per share)	$ (1.19)	$ (0.02)	$ 0.05	$ 0.75	$ (1.31)	$ (0.23)	$ 0.78	$ 0.32	$ (0.33)	$ (0.36)	$ (1.30)
Diluted earnings per common share and common share equivalent (in dollars per share)	$ (1.19)	$ (0.06)	$ 0.05	$ 0.74	$ (1.31)	$ (0.23)	$ 0.78	$ 0.32	$ (0.37)	$ (0.36)	$ (1.30)
Weighted average number of common shares and common share equivalents outstanding:
Basic weighted average number of common shares and common share equivalents outstanding (in shares)									115,234,105	119,253,924	120,000,000
Diluted weighted average number of common shares and common share equivalents outstanding (in shares)									127,135,775	119,253,924	120,000,000

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Comprehensive (loss)
Net (loss)	$ (45.6)	$ (16.7)	$ (136.3)
Other comprehensive (loss) income
Change in foreign currency translation, net of tax	(35.1)	(61.9)	71.7
Total other comprehensive (loss) income	(35.1)	(61.9)	71.7
Comprehensive (loss)	(80.7)	(78.6)	(64.6)
Net (income) attributable to non-controlling interests	(1.7)	(1.4)	(13.7)
Comprehensive (loss) attributable to Sirius Group	$ (82.4)	$ (80)	$ (78.3)

Consolidated Statements of Shar

Consolidated Statements of Shareholder's Equity - USD ($) $ in Millions	Total	Total common shareholders' equity	Common shares	Additional paid-in surplus	Retained earnings	Accumulated other comprehensive (loss)	Non-controlling interests	AdjustmentRetained earnings	Adjusted balanceRetained earnings
Balance at beginning of year at Dec. 31, 2016			$ 1.2	$ 1,184.6	$ 1,014.5	$ (212.2)		$ 0	$ 1,014.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share compensation expense				0
Issuance of common shares			0	0
Share repurchase from CM Bermuda			0	0
Return of capital to CM Bermuda				0
Capital contribution from former parent				13.3
Other, net				0
Net (loss)					(136.3)
Change in carrying value of Series B preference shares					0
Income attributable to non-controlling interests					(13.7)
Accrued dividends on Series A redeemable preference shares	$ (6.1)				(6.1)
Redemption of Series A redeemable preference shares					0
Other, net					0
Balance at beginning of year at Dec. 31, 2016						(212.2)
Accumulated net foreign currency translation (losses)
Net change in foreign currency translation						71.7
Balance at end of year at Dec. 31, 2017						(140.5)
Balance at end of year at Dec. 31, 2017	$ 1,917.2	$ 1,917	1.2	1,197.9	858.4	(140.5)	$ 0.2	1.6	860
Accumulated net foreign currency translation (losses)
Dividends declared per common share (in dollars per share)	$ 0
Share compensation expense				2.5
Issuance of common shares			0.1	52.7
Share repurchase from CM Bermuda			(0.1)	(163.9)
Return of capital to CM Bermuda				(1.6)
Capital contribution from former parent				1.4
Other, net				0.1
Net (loss)					(16.7)
Change in carrying value of Series B preference shares					(36.4)
Income attributable to non-controlling interests					(1.4)
Accrued dividends on Series A redeemable preference shares	$ (2.6)				(2.6)
Redemption of Series A redeemable preference shares					13.8
Other, net					(0.1)
Net change in foreign currency translation						(61.9)
Balance at end of year at Dec. 31, 2018	(202.4)					(202.4)
Balance at end of year at Dec. 31, 2018	$ 1,706.2	1,704.5	1.2	1,089.1	816.6	(202.4)	1.7	$ 0	$ 816.6
Accumulated net foreign currency translation (losses)
Dividends declared per common share (in dollars per share)	$ 0
Share compensation expense				9.1
Issuance of common shares			0	0
Share repurchase from CM Bermuda			0	0
Return of capital to CM Bermuda				0
Capital contribution from former parent				0
Other, net				0
Net (loss)					(45.6)
Change in carrying value of Series B preference shares					9.2
Income attributable to non-controlling interests					(1.7)
Accrued dividends on Series A redeemable preference shares	$ 0				0
Redemption of Series A redeemable preference shares					0
Other, net					0
Net change in foreign currency translation						(35.1)
Balance at end of year at Dec. 31, 2019	(237.5)					(237.5)
Balance at end of year at Dec. 31, 2019	$ 1,642.8	$ 1,640.4	$ 1.2	$ 1,098.2	$ 778.5	$ (237.5)	$ 2.4
Accumulated net foreign currency translation (losses)
Dividends declared per common share (in dollars per share)	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operations:
Net (loss)	$ (45.6)	$ (16.7)	$ (136.3)
Adjustments to reconcile net (loss) to net cash provided from (used for) operations:
Net realized and unrealized investment gains (losses)	(137.3)	20.9	37.7
Amortization of premium on fixed maturity investments	(5.9)	5.8	16.6
Amortization of intangible assets	15.8	15.8	10.2
Depreciation and other amortization	8.2	9.5	8.9
Share-based compensation	9.1	2	0
Revaluation of contingent consideration	6.3	(9.6)	(48.8)
Impairment of intangible assets	0	8	5
Other operating items:
Net change in loss and loss adjustment expense reserves	357.8	203.7	188.3
Net change in reinsurance recoverable on paid and unpaid losses	(90.9)	(95.7)	(11.1)
Net change in funds held by ceding companies	(111.1)	(48)	(38.9)
Net change in unearned insurance and reinsurance premiums	89.1	195.5	55.7
Net change in ceded reinsurance payable	48.4	93.4	22.8
Net change in ceded unearned insurance and reinsurance premiums	(13.3)	(76.3)	14.4
Net change in insurance and reinsurance premiums receivable	(127)	(144.1)	(102.3)
Net change in deferred acquisition costs	(10.7)	(28.4)	(27)
Net change in funds held under reinsurance treaties	60.6	42.7	5.8
Net change in current and deferred income taxes, net	(5.5)	18.7	13.3
Net change in other assets and liabilities, net	61.8	(89.2)	(50.3)
Net cash provided from (used for) operations	109.8	108	(36)
Cash flows from investing activities:
Net change in short-term investments	(362.3)	(90.1)	(1)
Sales of fixed maturities and convertible fixed maturity investments	573.3	1,373.1	1,422.4
Maturities, calls, and paydowns of fixed maturity and convertible fixed maturity investments	407.7	102.7	292.2
Sales of common equity securities	369.3	353.1	87.6
Distributions and redemptions of other long-term investments	74.6	72.4	40.6
Sales of consolidated subsidiaries and unconsolidated affiliates, net of cash sold	0	0	0.8
Contributions to other long-term investments	(53.4)	(160.1)	(167.5)
Purchases of common equity securities	(336.9)	(505.7)	(222.3)
Purchases of fixed maturities and convertible fixed maturity investments	(726.7)	(1,321.3)	(1,018.5)
Purchases of loan participations	(20)	0	0
Purchases of consolidated subsidiaries, net of cash acquired	0	(7.9)	(354.5)
Net change in unsettled investment purchases and sales	(2.6)	(1.2)	(7.9)
Other, net	(0.7)	(4.9)	(5.9)
Net cash (used for) provided from investing activities	(77.7)	(189.9)	66
Cash flows from financing activities:
Payment of contingent consideration	(6.9)	(4.4)	(30.6)
Change in collateral held on Interest Rate Cap	(0.1)	0	(1.1)
Cash dividends paid to non-controlling interests	(1)	0	(14.1)
Proceeds from issuance of common shares, net of expenses	0	61.2	0
Proceeds from issuance of Series B preference shares	0	195.8	0
Redemption of common shares from CM Bermuda	0	(164)	0
Return of capital to CM Bermuda	0	(1.6)	0
Redemption of Series A redeemable preference shares	0	(95)	0
Capital contribution from former parent	0	1.4	13.3
Issuance of debt, net of issuance costs	0	0	340.8
Redemption of SIG Preference Shares	0	0	(250)
Repayment of debt	0	0	(3.8)
Other, net	0	0	(0.9)
Net cash (used for) provided from financing activities	(8)	(6.6)	53.6
Effect of exchange rate changes on cash	(5.7)	(9.9)	9.9
Net increase (decrease) in cash during year	18.4	(98.4)	93.5
Cash and restricted cash balance at beginning of year	132.2	230.6	137.1
Cash and restricted cash balance at end of year	150.6	132.2	230.6
Supplemental disclosures of cash flow information:
Income taxes paid	9.3	19.1	16.7
Interest paid	$ 29.9	$ 30	$ 22

General

General	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General Sirius International Insurance Group, Ltd. ("the Company") is a Bermuda exempted company that provides multi-line insurance and reinsurance on a worldwide basis through its wholly owned subsidiaries (collectively with the Company, "Sirius Group").

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of significant accounting policies	Summary of significant accounting policies Basis of presentation The accompanying consolidated financial statements at December 31, 2019 , have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP") and the rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). The accompanying consolidated financial statements present the consolidated results of operations, financial condition, and cash flows of the Company and its subsidiaries and those entities in which the Company has control and a majority economic interest as well as those variable interest entities ("VIEs") that meet the requirements for consolidation. All significant intercompany transactions have been eliminated in consolidation. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Certain amounts in the prior period financial statements have been reclassified to conform to the current presentation. Tabular dollar amounts are in millions, with the exception of share and per share amounts. All amounts are reported in U.S. dollars, except where noted otherwise. Significant accounting policies Investment securities Sirius Group's invested assets consist of securities and other investments held for general investment purposes. Sirius Group's portfolio of fixed maturity investments and equity securities held for general investment purposes are classified as trading and are reported at fair value as of the balance sheet date. Changes in unrealized gains and losses are reported pre-tax in revenues. Realized investment gains and losses are accounted for using the first-in first-out method and are reported pre-tax in revenues. Premiums and discounts on all fixed maturity investments are amortized and/or accreted to income over the anticipated life of the investment and are reported in Net investment income. Sirius Group's invested assets that are measured at fair value include fixed maturity investments, common and preferred equity securities, and other long-term investments, such as interests in hedge funds and private equities. Fair value is defined as the price received to sell an asset in an orderly transaction between market participants at the measurement date reflecting the highest and best use valuation concepts. In determining its estimates of fair value, Sirius Group uses a variety of valuation approaches and inputs. Whenever possible, Sirius Group estimates fair value using valuation methods that maximize the use of quoted prices and other observable inputs. Short-term investments Short-term investments consist of money market funds, certificates of deposit and other securities which, at the time of purchase, mature or become available for use within one year. Short-term investments are carried at fair value. Other long-term investments Other long-term investments consist primarily of hedge funds, private equity funds, other investments in limited partnerships and other private equity securities. The fair value of other long-term investments is generally based upon Sirius Group's proportionate interest in the underlying fund's net asset value, which is deemed to approximate fair value. In addition, due to a lag in reporting, some of the fund managers, fund administrators, or both, are unable to provide final fund valuations as of the Company's reporting date. In these circumstances, Sirius Group estimates the return of the current period and uses all credible information available. This includes utilizing preliminary estimates reported by its fund managers and using information that is available to Sirius Group with respect to the underlying investments, as necessary. The changes in fair value are reported in pre-tax revenues in Net unrealized investment gains (losses). Actual final fund valuations may differ from Sirius Group's estimates and these differences are recorded in the period they become known as a change in estimate. Other long-term investments also includes certain investments that are eligible for the equity method where Sirius Group has elected the fair value option under which the changes in fair value are reported in pre-tax revenues in Net unrealized investment gains (losses). (See Note 19 .) Loan participations Loan participations that qualify for sale accounting under the Accounting Standards Codification ("ASC") Topic 860, "Transfers and Servicing of Financial Assets", are carried at fair value. The fair value of loan participations is estimated using discounted cash flow analysis. Sirius Group includes Loan particpations in Other assets in the Consolidated Balance Sheets. Cash Cash includes amounts on hand and demand deposits with banks and other financial institutions. Amounts presented in the statement of cash flows are shown net of balances acquired and sold in the purchase or sale of the Company's consolidated subsidiaries. Restricted cash Restricted cash represents cash and cash equivalents that Sirius Group is (a) holding for the benefit of a third party and is legally or contractually restricted as to withdrawal or usage for general corporate purposes; and (b) not replaceable by another type of asset other than cash or cash equivalents, under the terms of Sirius Group's contractual arrangements with such third parties. Insurance and reinsurance operations Premiums written are recognized as revenues and are earned ratably over the term of the related policy or reinsurance treaty. Premiums written include amounts reported by brokers, managing general underwriters, and ceding companies, supplemented by the Company's own estimates of premiums where reports have not been received. The determination of premium estimates requires a review of the Company's experience with the ceding companies, managing general underwriters, familiarity with each market, the timing of the reported information, an analysis and understanding of the characteristics of each class of business, and management's judgment of the impact of various factors, including premium or loss trends, on the volume of business written and ceded to the Company. On an ongoing basis, the Company's underwriters review the amounts reported by these third parties for reasonableness based on their experience and knowledge of the subject class of business, taking into account the Company's historical experience with the brokers or ceding companies. Unearned premiums represent the portion of premiums written that are applicable to future insurance or reinsurance coverage provided by policies or treaties in force. Deferred acquisition costs represent commissions, premium taxes, brokerage expenses, and other costs which are directly attributable to the successful acquisition or renewal of contracts and vary with the production of business. These costs are deferred and amortized over the period during which the premiums are earned. Amortization of Deferred acquisition costs are shown net of contractual commissions earned on reinsurance ceded within Insurance and reinsurance acquisition expenses. Deferred acquisition costs are limited to the amount expected to be recovered from future earned premiums and anticipated investment income. This limitation is referred to as a premium deficiency. A premium deficiency is recognized if the sum of expected loss and loss adjustment expenses ("LAE"), expected dividends to policyholders, unamortized acquisition costs, and maintenance costs exceeds related unearned premiums and anticipated investment income. A premium deficiency is recognized by charging any unamortized acquisition costs to expense to the extent required in order to eliminate the deficiency. If the premium deficiency exceeds unamortized acquisition costs, then a liability is accrued for the excess deficiency. Other underwriting expenses consist primarily of personnel related expenses (including salaries, benefits, and variable compensation expense) and other general operating expenses related to the underwriting operations. Losses and LAE are charged against income as incurred. Unpaid insurance loss and LAE reserves are based on estimates (generally determined by claims adjusters, legal counsel, and actuarial staff) of the ultimate costs of settling claims, including the effects of inflation and other societal and economic factors. Unpaid reinsurance loss and LAE reserves are based primarily on reports received from ceding companies and actuarial projections. Unpaid loss and LAE reserves represent management's best estimate of ultimate losses and LAE, net of estimated salvage and subrogation recoveries, if applicable. Such estimates are regularly reviewed and updated and any resulting adjustments are reflected in current operations. The process of estimating loss and LAE reserves involves a considerable degree of judgment by management and the ultimate amount of expense to be incurred could be greater or less than the amounts currently reflected in the financial statements. Sirius Group enters into ceded reinsurance contracts to protect its businesses from losses due to concentration of risk, to manage its operating leverage ratios and to limit losses arising from catastrophic events. Such reinsurance contracts are executed through excess of loss treaties and catastrophe contracts under which the reinsurer indemnifies for a specified part or all of certain types of losses over stipulated amounts arising from any one occurrence or event. Sirius Group has also entered into quota share treaties with reinsurers under which all risks meeting prescribed criteria are covered on a pro-rata basis. The amount of each risk ceded by Sirius Group is subject to maximum limits which vary by line of business and type of coverage. Although these contracts protect Sirius Group, these reinsurance arrangements do not relieve Sirius Group from its primary obligations to insureds. Amounts recoverable from reinsurers are estimated in a manner consistent with the claim liability associated with the reinsured policies. The collectability of reinsurance recoverables is subject to the solvency of the reinsurers. Sirius Group is selective in regard to its reinsurers, principally placing reinsurance with those reinsurers with a strong financial condition, industry ratings, and underwriting ability. Management monitors the financial condition and ratings of its reinsurers on an ongoing basis. Reinsurance premiums, commissions, expense reimbursements, and reserves related to reinsured business are accounted for on a basis consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Reinsurance premiums ceded are expensed over the period the reinsurance coverage is provided. Ceded unearned insurance and reinsurance premiums represent the portion of premiums ceded applicable to the unexpired term of policies in force. Funds held by ceding companies represent amounts due to Sirius Group in connection with certain assumed reinsurance agreements in which the ceding company retains a portion of the premium to provide security against future loss payments. The funds held by ceding companies are generally invested by the ceding company and a contractually agreed interest amount is credited to Sirius Group and recognized as investment income. Funds held under reinsurance treaties represent contractual payments due from Sirius Group that have been retained to secure such obligations. Accruals for contingent commission liabilities are established for reinsurance contracts that provide for the stated commission percentage to increase or decrease based on the loss experience of the contract. Changes in the estimated liability for contingent commission arrangements are recorded as Insurance and reinsurance acquisition expenses. Accruals for contingent commission liabilities are determined through the review of the contracts that have these adjustable features and are estimated based on expected loss and LAE. Derivative financial instruments Sirius Group holds derivative financial instruments for both risk management and investment purposes. Sirius Group recognizes all derivatives as either assets or liabilities, measured at fair value, in the Consolidated Balance Sheets. Changes in the fair value of derivative instruments are recognized in current period pre-tax income. Deferred software costs Sirius Group capitalizes costs related to computer software developed for internal use during the application development stage of software development projects. These costs generally consist of certain external, payroll, and payroll-related costs. Sirius Group begins amortization of these costs once the project is completed and ready for its intended use. Amortization is on a straight-line basis and over a useful life of three to five years . As of December 31, 2019 and 2018 , Sirius Group had unamortized deferred software costs of $6.8 million and $9.3 million , respectively. For the years ended December 31, 2019 , 2018 , and 2017 , Sirius Group had amortization expenses of $3.6 million , $4.8 million , and $4.6 million , respectively, related to software developed for internal use. Share-based compensation Share-based compensation plans are accounted for in accordance with the ASC Topic 718 "Compensation - Stock Compensation" Sirius Group recognizes the compensation expense for stock restricted share and performance share awards based on the fair value of the award on the date of grant over the requisite service period. Awards under the 2016 Long-term Incentive Plan and 2018 Omnibus Incentive Plan vest over two or three years . The Company has elected to recognize forfeitures as they occur rather than estimate service-based forfeitures over the requisite service period. Defined benefit plans Certain Sirius Group employees in Europe participate in defined benefit plans. The liability for the defined benefit plans that is reported on the Consolidated Balance Sheets is the current value of the defined benefit obligation at the end of the period, reduced by the fair value of the plan's managed assets, with adjustments for actuarial gains and losses. The defined benefit pension plan obligation is calculated annually by independent actuaries. The current value of the defined benefit obligation is determined through discounting of expected future cash flows, using interest rates determined by current market interest rates. The service costs and actuarial gains and losses on the defined benefit obligation and the fair value on the plan assets are recognized in the Consolidated Statements of Income. Commission and other revenue recognition Sirius Group recognizes agent commissions and other revenues when it has fulfilled all of its obligations necessary to earn the revenue and when it can both reliably estimate the amount of revenue, net of any amounts expected to be uncollectible, and any amounts associated with expected cancellations. Earnings per share Earnings per share is reported in accordance with ASC Topic 260 Earnings per Share . Basic earnings (loss) per share is computed by dividing net (loss) available to Sirius Group common shareholders by the weighted-average number of common shares outstanding during the period. Diluted earnings per share is computed by dividing net income available to Sirius Group common shareholders by the weighted-average number of common shares outstanding adjusted to give effect to potentially dilutive securities. (See Note 16 .) Federal and foreign income taxes Certain of Sirius Group's subsidiaries file consolidated tax returns in the United States. Sirius Group has subsidiaries in various jurisdictions, including but not limited to Sweden, the United Kingdom, and Luxembourg, which are subject to applicable taxes in those jurisdictions. Deferred tax assets and liabilities are recorded when a difference between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts for tax purposes exists, and for other temporary differences. The deferred tax asset or liability is recorded based on tax rates expected to be in effect when the difference reverses. The deferred tax asset is recognized when it is more likely than not that it will be realized. The Tax Cuts and Jobs Act (the "TCJA") which was enacted into law in the U.S. in December 31, 2017 includes a new base erosion and anti-abuse tax ("BEAT"), which is essentially a minimum tax that is potentially applicable to certain otherwise deductible payments made by U.S. entities to non-U.S. affiliates, including cross-border interest payments and reinsurance premiums. The statutory BEAT rate is 10% in 2019 -2025, and then rises to 12.5% in 2026 and thereafter. The TCJA also includes provisions for Global Intangible Low-Taxed Income ("GILTI") under which taxes on foreign income are imposed on the excess of a deemed return on tangible assets of certain foreign subsidiaries. Consistent with accounting guidance, Sirius Group is treating BEAT as an in period tax charge when incurred in future periods for which no deferred taxes need to be provided and has made an accounting policy election to treat GILTI taxes in a similar manner. Foreign currency exchange The U.S. dollar is the functional currency for Sirius Group's businesses except for Sirius International Insurance Corporation ("Sirius International"), Lloyd's Syndicate 1945 ("Syndicate 1945"), several subsidiaries of International Medical Group Acquisition, Inc. ("IMG"), and the Canadian reinsurance operations of Sirius America Insurance Company ("Sirius America"). Sirius Group also invests in securities denominated in foreign currencies. Assets and liabilities recorded in these foreign currencies are translated into U.S. dollars at exchange rates in effect at the balance sheet date, and revenues and expenses are converted using the average exchange rates for the period. Net foreign exchange gains and losses arising from the translation of functional currencies are reported in shareholder's equity, in Accumulated other comprehensive (loss). As of December 31, 2019 and 2018 , Sirius Group had Net unrealized foreign currency translation losses of $237.5 million and $202.4 million , respectively, recorded in Accumulated other comprehensive (loss) on its Consolidated Balance Sheets. Assets and liabilities relating to foreign operations are remeasured into the functional currency using current exchange rates; revenues and expenses are remeasured into the functional currency using the weighted average exchange rate for the period. The resulting exchange gains and losses are reported as a component of net income in the period in which they arise within Net realized investment gains (losses), Net unrealized investment gains (losses), and Net foreign exchange gains. The following rates of exchange for the U.S. dollar have been used for translation of assets and liabilities for subsidiaries whose functional currency is not the U.S. dollar at December 31, 2019 and 2018 : Currency Closing Closing Swedish kronor 9.3210 8.9397 British pound 0.7568 0.7850 Euro 0.8912 0.8734 Canadian dollar 1.3003 1.3614 Goodwill and intangible assets Goodwill represents the excess of the purchase price of an acquisition over the fair value of the identifiable net assets acquired and is assigned to the applicable reporting unit at acquisition. Goodwill is evaluated for impairment on an annual basis. Sirius Group initially evaluates goodwill using a qualitative approach to determine whether it is more likely than not that the fair value of goodwill is greater than its carrying value. If the results of the qualitative evaluation indicate that it is more likely than not that the carrying value of goodwill exceeds its fair value, Sirius Group performs the quantitative test for impairment. Indefinite-lived intangible assets are evaluated for impairment similar to goodwill. Finite-lived intangible are amortized on a straight-line basis over their estimated useful lives. The amortization periods approximate the period over which Sirius Group expects to generate future net cash inflows from the use of these assets. All of these assets are subject to impairment testing for the impairment or disposal of long-lived assets when events or conditions indicate that the carrying value of an asset may not be fully recoverable from future cash flows. If goodwill or intangible assets are impaired, such assets are written down to their fair values with the related expense recorded in Sirius Group's results of operations. (See Note 10 .) Non-controlling interests Non-controlling interests consist of the ownership interests of non-controlling shareholders in consolidated subsidiaries, and are presented separately on the balance sheet. Mezzanine equity In connection with significant transactions the Company has entered into, the Company has issued preference shares. (See Note 3 .) At the date of issuance, Sirius Group evaluates the conversion and redemption features associated with the preference shares in order to determine the balance sheet classification of the instrument. The preference shares are classified outside of permanent equity (as Mezzanine equity) when the preference shares are redeemable at a fixed or determinable price on a fixed or determinable date, at the option of the shareholder or upon the occurrence of an event that is not solely within the control of Sirius Group. Sirius Group accounts for the Series B preference shares outside of permanent equity as Mezzanine equity in the Consolidated Balance Sheets as the ability to settle in common shares cannot be assured. Variable interest entities Sirius Group consolidates a VIE when it has both the power to direct the activities of the VIE that most significantly impact its economic performance and either the obligation to absorb losses or the right to receive returns from the VIE that could potentially be significant to the VIE. An entity in which Sirius Group holds a variable interest is a VIE if any of the following conditions exist: (a) the total equity investment at risk is not sufficient to permit the entity to finance its activities without additional subordinated financial support, (b) as a group, the holders of equity investment at risk lack either the direct or indirect ability through voting rights or similar rights to make decisions about an entity's activities that most significantly impact the entity's economic performance or the obligation to absorb the expected losses or right to receive the expected residual returns, or (c) the voting rights of some investors are disproportionate to their obligation to absorb the expected losses of the entity, their rights to receive the expected residual returns of the entity, or both, and substantially all of the entity's activities either involve or are conducted on behalf of an investor with disproportionately few voting rights. The primary beneficiary is defined as the variable interest holder that is determined to have the controlling financial interest as a result of having both (a) the power to direct the activities of a VIE that most significantly impact the economic performance of the VIE and (b) the obligation to absorb losses or right to receive benefits from the VIE that could potentially be significant to the VIE. At inception of the VIE, as well as following an event that requires reassessment, Sirius Group determines whether it is the primary beneficiary based on the facts and circumstances surrounding each entity. (See Note 20 .) Recently adopted changes in accounting principles Leases Effective January 1, 2019, Sirius Group adopted Accounting Standards Update ("ASU") 2016-2, Leases (Accounting Standards Codification ("ASC") 842) which requires lessees to recognize lease assets and liabilities on the balance sheet for both operating and financing leases, with the exception of leases with an original term of 12 months or less. Under previous guidance, recognition of lease assets and liabilities was not required for operating leases. The new guidance requires that lease assets and liabilities to be recognized and measured initially based on the present value of the lease payments. Sirius Group adopted the new guidance using the simplified transition option that allows companies to apply the new lease standard at the adoption date and recognize a cumulative effect adjustment to the opening balance of retained earnings in the period of adoption. Sirius Group also made the following elections: • Sirius Group elected the package of practical expedients to not reassess prior conclusions related to contracts containing leases, lease classification and initial direct costs for all leases upon transition. • Sirius Group did not elect the hindsight practical expedient upon transition, for all leases. • Sirius Group elected the short-term lease measurement and recognition exemption, resulting in lease payments being recorded as an expense on a straight-line basis over the lease term. • Sirius Group elected to include both lease and non-lease components as a single component for all leases. • Sirius Group did not elect the land easement practical expedient as it was not applicable. As a result of the adoption of the new guidance, Sirius Group recognized a lease liability of $36.8 million , which represents the present value of our remaining lease payments and a right-of-use asset of $34.4 million as of January 1, 2019. The adoption of this guidance did not materially impact our results of operations or cash flows. Due to the adoption of the standard using the retrospective cumulative-effect adjustment method, there are no changes to our previously reported results prior to January 1, 2019. Lease expense did not change materially as a result of the adoption of the new guidance. (See Note 22 .) Premium amortization on callable debt securities Effective January 1, 2019, Sirius Group adopted ASU 2017-8, Premium Amortization on Purchased Callable Debt Securities (ASC 310-20), which changes the amortization period for certain purchased callable debt securities. Under the new guidance, for investments in callable debt securities held at a premium, the premium will be amortized over the period to the earliest call date. The new guidance does not change the amortization period for callable debt securities held at a discount. The adoption of this guidance did not have a significant effect on our financial statements. Recent accounting pronouncements Credit losses In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (ASC 326), which establishes new guidance for the recognition of credit losses for financial assets measured at amortized cost. The new guidance, which applies to financial assets that have the contractual right to receive cash, including reinsurance receivables, requires reporting entities to estimate the credit losses expected over the life of a credit exposure using historical information, current information and reasonable and supportable forecasts that affect the collectability of the financial asset. The new guidance is effective for smaller reporting companies for annual and interim periods beginning after December 15, 2022. Adoption of this guidance is on a modified retrospective basis. Early adoption of the guidance is permitted. We plan to early adopt the standard on its effective date of January 1, 2020. This guidance is currently not expected to have a material impact on the consolidated financial statements. Fair Value Measurement Disclosures In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement , which modifies the disclosure requirements of fair value measurements. The new guidance is effective for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. The adoption of this guidance will not have a material impact on the consolidated financial statements.

Significant transactions

Significant transactions	12 Months Ended
	Dec. 31, 2019
Significant transactions
Significant transactions	Significant transactions Easterly Acquisition Corp. On November 5, 2018, the Company completed the transactions contemplated by the definitive Agreement and Plan of Merger ("Merger Agreement"). Under the terms of the Merger Agreement, Easterly Acquisition Corp. ("Easterly") merged with Sirius Acquisitions Holding Company III and became a wholly-owned subsidiary of the Company (the "Merger"). Upon the closing of the Merger, Easterly's common stock was exchanged for the Company's common shares at an exchange ratio (the "Exchange Ratio") calculated as (i) the amount of cash per public share of Easterly common stock in Easterly's trust account (the "Trust Account") immediately prior to the closing of the Merger divided by (ii) (x) 1.05 multiplied by (y) Sirius Group's adjusted diluted book value per common share as of September 30, 2018 ("Sirius Group September 30 Adjusted DBVPS"). Based on the Sirius Group September 30 Adjusted DBVPS, estimated as of September 30, 2018, and funds in the Trust Account on November 5, 2018, the Exchange Ratio was equal to 0.609 . Following the Merger, the Company's common shares are traded on the Nasdaq Global Select Market under the symbol "SG." Easterly held a special meeting of Easterly stockholders on November 2, 2018 to approve the completion of the transactions contemplated by the Merger Agreement. Easterly Acquisition Sponsor, LLC (the "Sponsor") and Easterly's other stockholders approved each of the proposals presented at the special meeting. After the special meeting, but prior to the consummation of the Merger, certain Easterly public stockholders exercised their redemption rights as provided for by Easterly's charter. In total, out of the Trust Account balance of $149.0 million , there were $109.7 million of redemptions by Easterly public stockholders, which decreased the amount of cash in the Trust Account available for general corporate purposes following the Merger. After the redemption of shares held by Easterly's public stockholders, there was $39.3 million in the Trust Account. This resulted in the issuance of 2,280,241 common shares to Easterly public stockholders. Pursuant to the letter agreement among Easterly, the Sponsor and the Company, the private placement warrants issued to the Sponsor at the closing of the Merger were cancelled. Pursuant to the Merger Agreement, each issued and outstanding public warrant was converted into a warrant exercisable for Company common shares. The number of Company common shares subject to converted warrants was equal to the number of shares of Easterly common stock subject to each Easterly warrant immediately prior to the closing of the Merger multiplied by the Exchange Ratio, and each converted warrant had an exercise price per Company common share equal to the exercise price per share of Easterly common stock subject to such Easterly warrant immediately prior to the closing of the Merger divided by the Exchange Ratio. This resulted in the issuance of 6,088,535 converted warrants. Sirius Group Private Placement In connection with the closing of the Merger, the Company completed a private placement of Series B preference shares, common shares, and warrants (the "Sirius Group Private Placement") at a price per preference and common share equal to (i) 1.05 multiplied by (ii) the Sirius Group September 30 Adjusted DBVPS, or $17.22447 . Investors in the Sirius Group Private Placement included affiliated funds of Gallatin Point Capital, The Carlyle Group, Centerbridge Partners, L.P. and Bain Capital Credit (the "Preference Share Investors"), together with certain employees, directors and "friends & family". The Sirius Group Private Placement raised proceeds of $226.1 million and incurred issuance costs of $2.0 million , resulting in the issuance of: • 11,901,670 Series B preference shares with a cost basis of $195.8 million , • 1,225,954 common shares with a cost basis of $20.8 million , • 5,418,434 warrants that are exercisable for common shares for a period of five years after the Merger at a strike price equal to 125% of the per share purchase price, or $21.53 with a cost basis of $9.6 million . ESPP In connection with the Merger, Sirius Group implemented the Employee Share Purchase Plan ("ESPP"), which provided all employees of Sirius Group with a one-time opportunity to purchase between 100 and 1,000 Company common shares at a price equal to 85% of market value for the first 100 shares and 100% of market value for the next 900 shares. For this purpose, market value of the Company common shares was equal to 1.05 times the Sirius Group September 30 Adjusted DBVPS. Employees had the option of paying for the shares upfront or, in the case of employees who are not executive officers, through a loan that is repaid over a two years period through payroll deductions. Through the ESPP, 405 employees purchased 149,236 Company common shares prior to the consummation of the Merger, with a cost basis of $2.6 million . (See Note 14 .) Gross proceeds of the cash in the Easterly Trust Account assumed by Sirius Group upon the closing of the Merger, the Sirius Group Private Placement, and the ESPP sum to $268.0 million . Common shares redemption In connection with the Merger, the Company and CM Bermuda Ltd. ("CM Bermuda"), the sole holder of the Company's common shares prior to the Merger, completed the transactions contemplated by its previously announced redemption agreement and the Company redeemed 9,519,280 of the Company's common shares at a price per share equal to $17.22447 for $164.0 million , which were paid on November 16, 2018. Also in connection with the Merger, on November 16, 2018 the Company completed a post-closing adjustment of $1.6 million that was settled in cash to CM Bermuda based on the reported book value per share of $16.44 as of September 30, 2018, pursuant to the Merger Agreement. Sirius Group incurred certain contractual costs associated with the Merger of $9.0 million and $7.1 million of various legal, advisory, and other consulting costs for the Merger and the Sirius Group Private Placement that were charged to Additional paid-in surplus. Series A preference shares redemption In connection with the Merger, the Company, IMG Acquisition Holdings, LLC ("IMGAH") and Sirius Acquisitions Holding Company II completed the transactions contemplated by its previously announced redemption agreement and the Company redeemed all of the outstanding Series A redeemable preference shares, which were held by IMGAH, for $95.0 million in cash. Effective as of the completion of the redemption, the parties terminated the registration rights agreement and the shareholder's agreement between the Company and IMGAH. In addition, the parties agreed that any remaining contingent consideration in respect of the IMG acquisition, will be paid in cash, not in Series A redeemable preference shares as previously contemplated in the agreement in respect of the IMG acquisition. (See " IMG " below.) Cedar Insurance Company (formerly WRM America Indemnity Company, Inc.) On August 16, 2018, Sirius Group acquired 100% ownership of WRM America Indemnity Company, Inc. ("WRM America") from WRM America Indemnity Holding Company, LLC for $16.9 million in cash. During 2019, WRM America changed its name to Cedar Insurance Company ("Cedar"). Cedar is a New York-domiciled insurer with a run-off book of business mainly comprised of general liability, educator's legal liability, automobile liability and physical damage, property and excess catastrophe liability. As part of the purchase of Cedar, Sirius Group acquired $3.1 million of indefinite-lived intangible assets related to insurance licenses. The Phoenix Holdings Ltd. On July 2, 2018, Sirius Group terminated its share purchase agreement to acquire a controlling interest in The Phoenix Holdings Ltd. As a result of the termination, Sirius Group recognized an income statement charge for the $4.5 million call option it held during 2018. IMG On May 26, 2017, Sirius Group acquired 100% ownership of IMG and its subsidiaries, a leading provider of global travel medical insurance products and assistance services. The purchase of IMG was undertaken to expand on Sirius Group's existing Global Accident and Health ("Global A&H") platform and to accelerate the growth strategy of the Global A&H international insurance business, to add service fee revenues to Sirius Group's existing risk-transfer based insurance revenues, and to gain access to IMG's distribution networks and client base. Total consideration consisted of $250.8 million of cash, $100.0 million of Series A redeemable preference shares that are convertible into common shares (as explained further below), and up to $50.0 million of contingent consideration ("IMG Earnout"), payable in Series A redeemable preference shares, which was stated as $43.1 million at fair value at acquisition date, resulting in a total enterprise value of $393.9 million . Sirius Group assumed certain IMG debt of $129.5 million ("Debt Assumption"), reducing its cash consideration by that amount and resulting in a total equity consideration of $264.4 million . Concurrently with the transaction, IMG's subsidiary International Medical Group – Stop-Loss, Inc. ("IMG – Stop Loss") was sold to Certus Management Group, Inc. ("Certus"). As part of the sale of IMG – Stop Loss, Sirius Group issued a secured promissory note of $9.0 million to Certus. The following table summarizes the fair value of net assets acquired and allocation of purchase price of IMG, measured as of the acquisition date: (Millions) Total Useful Life Purchase price Cash paid $ 250.8 Series A redeemable preference shares 100.0 Contingent consideration 43.1 Total enterprise value 393.9 Less: Debt assumed (129.5 ) Total purchase price (a) $ 264.4 Assets acquired Total investments $ 41.0 Cash 10.5 Accrued investment income 0.2 Insurance and reinsurance premiums receivable 1.6 Deferred acquisition costs 2.9 Other assets 12.9 Intangible asset – distribution relationships 91.0 13.0 years Intangible asset – customer relationships 17.0 12.5 years Intangible asset – trade names 27.0 Intangible asset – technology 10.0 5.0 years Total assets acquired 214.1 Liabilities assumed Loss and loss adjustment expense reserves 14.3 Unearned insurance and reinsurance premiums 9.8 Deferred tax liability 55.9 Debt 129.5 Other liabilities 18.2 Total liabilities assumed 227.7 Net assets acquired (b) (13.6 ) Goodwill (a)-(b) $ 278.0 The goodwill balance is primarily attributed to IMG's assembled workforce and access to the supplemental healthcare and medical travel insurance market. None of the goodwill recognized is expected to be deductible for income tax purposes. The IMG Earnout is payable, if earnings before interest expense, taxes, depreciation and amortization ("EBITDA") of IMG exceed amounts defined in the purchase agreement for each year during the three year period ending December 31, 2019. As part of the Series A preference shares redemption agreement, the parties agreed that any remaining contingent consideration in respect of the IMG acquisition, will be paid in cash, not in Series A redeemable preference shares, following the redemption, as previously contemplated in the agreement in respect of the IMG acquisition. During the years ended December 31, 2019 and 2018, the Company paid $6.9 million and $3.5 million , respectively, to IMGAH for the contingent payment for the 2018 and 2017 calendar years, respectively. At December 31, 2019, and 2018, the IMG Earnout liability was remeasured at a fair value of $18.4 million and $19.9 million , respectively, and is reflected within Other liabilities. As a result of the remeasurement of the IMG Earnout, Sirius Group has recognized $(5.5) million , $6.1 million and $13.6 million , respectively, in Revaluation of contingent consideration. During 2019, Sirius Group obtained $163 million, or 9% , of its gross written premiums through IMG. During 2018 and 2017 , Sirius Group received 7% and 11% of its gross written premiums through IMG, respectively. During 2017, IMG's revenues and net income after acquisition, inclusive of intangible asset amortization expenses, were $79.6 million and $13.3 million , respectively. Series A Redeemable Preference Shares As a part of the IMG acquisition, Sirius Group issued Series A redeemable preference shares, with 150,000 shares authorized and 100,000 issued at issuance date, with liquidation preference of $1,000 per preference share ("Liquidation Preference"). Up to 50,000 Series A redeemable preference shares were available pursuant to the IMG Earnout. The Series A redeemable preference shares participated in dividends on an as-converted basis with common shares and other shares junior to the Series A redeemable preference shares. On November 5, 2018, the Company, redeemed all of the outstanding Series A redeemable preference shares, which were held by IMGAH, for $95.0 million in cash. Effective as of the completion of the redemption, the parties terminated the registration rights agreement and the shareholder's agreement between the Company and IMGAH. The Liquidation Preference of the Series A redeemable preference shares was reflected as Mezzanine equity in the balance sheet as at December 31, 2017. It was not subject to fair value or remeasurement, except for accrued dividends. Supplemental Pro Forma Information The following table presents unaudited pro forma consolidated information for the years ended December 31, 2017 and 2016 and assumes the IMG acquisition occurred on January 1, 2016. The pro forma financial information is presented for informational purposes only and does not necessarily reflect the results that would have occurred had the acquisition taken place on January 1, 2016, nor is it necessarily indicative of future results. It does not consider the impact of possible revenue enhancements, expense efficiencies, or synergies that may result from the acquisition of IMG. ​ Unaudited Pro Forma for the Years Ended December 31, (Millions) 2017 2016 Total revenues $ 1,176.8 $ 1,096.0 Net income $ (173.2 ) $ (4.6 ) Armada On April 3, 2017, Sirius Group purchased 100% of Armada and its subsidiaries from Armada Enterprises LLC ("Seller"). Armada is an insurance services and health care technology business that creates specialty employee benefit products and serves to strengthen health care coverage and access. The purchase of Armada was undertaken to expand and accelerate the growth of Sirius Group's Global A&H platform in the United States, to diversify Sirius Group's revenues to include fee based revenues, and to gain access to Armada's distribution networks. Total consideration for the acquisition consisted of (1) the purchase of 50% of Armada by Sirius Group for $123.4 million , and (2) the redemption by Armada of the remaining 50% held by Seller for a redemption price based on a three years contingent earn-out mechanism that could result in an additional payment to Seller of up to $125.0 million ("Armada Earnout"), with fair value of $79.1 million at acquisition date, resulting in a total enterprise value of $202.5 million . The following table summarizes the fair value of net assets acquired and allocation of purchase price of Armada, measured as of the acquisition date: (Millions) Total Useful Life Purchase price Cash paid $ 123.4 ​ Contingent consideration 79.1 Total purchase price (a) $ 202.5 Assets acquired Restricted cash $ 10.4 ​ Other assets 1.2 ​ Intangible asset – distribution relationships 60.0 22.5 years Intangible asset – trade name 16.0 7.5 years Intangible asset – technology 5.5 9.0 years Total assets acquired 93.1 ​ Liabilities assumed Other liabilities 13.3 ​ Total liabilities assumed 13.3 ​ Net assets acquired (b) 79.8 ​ Goodwill (a)-(b) $ 122.7 ​ The goodwill balance is primarily attributed to Armada's assembled workforce and access to the supplemental healthcare insurance market, and additional synergies to be realized in the future. The goodwill recognized is expected to be deductible for income tax purposes in the future. The contingent consideration is payable if EBITDA of Armada exceeds amounts defined in the redemption agreement. The Armada Earnout can be settled in the Company's common shares, subject to certain criteria. The Armada Earnout is subject to fair value measurement, which is a component of net income and reflected in Revaluation of contingent consideration. In December 2017, Sirius Group settled approximately 82% of the Armada Earnout with the Seller for $30.6 million . At December 31, 2017 , the remaining Armada Earnout liability was remeasured at a fair value of $13.3 million and is reflected in Other liabilities. As a result of the settlement and remeasurement of the Armada Earnout, Sirius Group recorded a $35.2 million gain in Revaluation of contingent consideration in 2017. During 2019, the Company did not pay any of the Armada Earnout. During 2018, the Company paid $0.9 million of the Armada Earnout. At December 31, 2019 and 2018, the Armada Earnout was remeasured at a fair value of $9.7 million and $8.9 million , respectively, and is reflected within Other liabilities. As a result of the remeasurement of the Armada Earnout, Sirius Group has recognized $(0.8) million and $3.5 million , respectively, in Revaluation of contingent consideration during the years ended December 31, 2019 and 2018. During 2017, Armada's revenues and net income after acquisitions, inclusive of intangible asset amortization expenses, were $24.7 million and $9.7 million , respectively. Supplemental Pro Forma Information The following table presents unaudited pro forma consolidated information for the years ended December 31, 2017 and 2016 and assumes the Armada acquisition occurred on January 1, 2016. The pro forma financial information is presented for informational purposes only and does not necessarily reflect the results that would have occurred had the acquisition taken place on January 1, 2016, nor is it necessarily indicative of future results. It does not consider the impact of possible revenue enhancements, expense efficiencies, or synergies that may result from the acquisition of Armada. Unaudited Pro Forma for the Years Ended December 31, (Millions) 2017 2016 Total revenues $ 1,144.6 $ 1,032.6 Net income $ (155.1 ) $ 45.9

Segment information

Segment information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment information	Segment information On December 31, 2019, Sirius Group completed an internal reorganization and beginning on January 1, 2020, Sirius Group's reportable segments consist of four reportable segments – Global Reinsurance, Global Accident & Health ("Global A&H"), U.S. Specialty, and Runoff & Other. The accounting policies of the reportable segments are the same as those used for the preparation of the Company's consolidated financial statements. The Company's Global Reinsurance, Global A&H, U.S. Specialty, and Runoff & Other reportable segments each have managers who are responsible for the overall profitability of their respective segments and who are directly accountable to the Company's chief operating decision maker, the Chief Executive Officer ("CEO") of the Company. The CEO assesses segment operating performance, allocates capital, and makes resource allocation decisions based on Technical profit (loss), Underwriting profit (loss), and Underwriting profit (loss), including net service fee revenue. Segment results are shown prior to corporate eliminations. Corporate eliminations are shown to reconcile to consolidated Technical profit (loss), consolidated Underwriting profit (loss) and consolidated Underwriting profit (loss), including net service fee revenue. Sirius Group does not allocate its assets by segment, with the exception of goodwill and intangible assets, and, accordingly, investment income is not allocated to each segment. The internal reorganization had no impact to the allocation of goodwill and intangible assets to the Global A&H segment. Where applicable, all prior periods presented have been revised to conform to this new presentation. Global Reinsurance Global Reinsurance consists of Sirius Group's underwriting lines of business that offer Other Property, Property Catastrophe Excess Reinsurance, Agriculture Reinsurance, Aviation & Space, Marine & Energy, Trade Credit, Contingency, and Casualty Reinsurance: Other Property —Sirius Group participates in the broker market for property reinsurance treaties written on a proportional and excess of loss basis. For Sirius Group's international business, the book consists of treaty, written on both a proportional and excess of loss basis, facultative, and primary business, primarily in Europe, Asia and Latin America. In the United States, the book predominantly centers on significant participations on proportional and excess of loss treaties mostly in the excess and surplus lines segment of the market. Property Catastrophe Excess Reinsurance —Property catastrophe excess of loss reinsurance treaties cover losses from catastrophic events. Sirius Group writes a worldwide book with the largest concentration of exposure in Europe and the United States. The U.S. book written in Bermuda has a national account focus supporting principally the lower and/or middle layers of large capacity programs. Additionally, Stockholm writes a U.S. book mainly consisting of select small regional and standard lines carriers. The exposures written in the international book are diversified across many countries, regions, perils and layers. Agriculture Reinsurance —Sirius Group provides stop-loss reinsurance coverage to companies writing U.S. government-sponsored multi-peril crop insurance ("MPCI"). Sirius Group's participation is net of the government's stop-loss reinsurance protection. Sirius Group also provides coverage for crop-hail and certain named perils when bundled with MPCI business. Sirius Group also writes agriculture business outside of the United States. Aviation & Space —Sirius Group provides aviation insurance that covers loss of or damage to an aircraft and the aircraft operations' liability to passengers, cargo and hull as well as to third parties. Additionally, liability arising out of non-aircraft operations such as hangars, airports and aircraft products can be covered. Space insurance primarily covers loss of or damage to a satellite during launch and in orbit. The book consists of treaty, written on both a proportional and excess of loss basis, facultative, and primary business. Marine & Energy —Sirius Group provides marine & energy reinsurance, primarily written on an excess of loss and proportional basis. Coverage offered includes damage to ships and goods in transit, marine liability lines, and offshore energy industry insurance. Sirius Group also writes yacht business, both on reinsurance and a primary basis. The marine & energy portfolio is diversified across many countries and regions. Trade Credit —Sirius Group writes credit and bond reinsurance worldwide. The bulk of the business is traditional short-term commercial credit insurance, covering pre-agreed domestic and export sales of goods and services with typical coverage periods of 60 to 120 days . Losses under these policies are correlated to adverse changes in a respective country's gross national product. Contingency —Sirius Group underwrote a contingency insurance book primarily for event cancellation and non-appearance. Additionally, coverage for probability based risks with prize redemption was also offered. The contingency insurance business was exited in 2018; however, Sirius Group continues to offer this class on a treaty reinsurance basis on a selective basis for a few key clients. Casualty Reinsurance —Sirius Group underwrites a cross section of all casualty lines, including general liability, umbrella, auto, workers compensation, professional liability, and other specialty classes, written on a proportional and excess of loss basis. Global A&H Global A&H consists of Sirius Group’s insurance and reinsurance business, and the managing general underwriting (“MGU”) units (which include ArmadaCorp Capital, LLC ("Armada") and International Medical Group, Inc. ("IMG")). Armada’s products are offered in the United States while IMG and the insurance and reinsurance business write accident and health products on a worldwide basis: Accident and Health insurance and reinsurance —Sirius Group is an insurer of accident and health business in the United States and internationally, on either an admitted or surplus lines basis, as well as a reinsurer of medical expense, travel and personal accident on a treaty or facultative basis worldwide. The MGU unit writes health insurance business worldwide through IMG and within the United States via Armada. U.S. Specialty U.S. Specialty consists of Sirius Group's specialty insurance product offerings, which currently includes Environmental, Surety, and Workers’ Compensation. Environmental underwrites a pure environmental insurance book in the United States consisting of four core products that revolve around pollution coverage, which are premises pollution liability, contractor's pollution liability, contractor's pollution and professional liability. Surety underwrote commercial surety bonds, including non-construction contract bonds, in a broad range of business segments in the United States. In April 2020, the Company decided to exit the Surety business due to competitive market conditions in that business line and recent economic downturn which presented new risks and challenges for this line of business. Workers' Compensation , is a state-mandated insurance program that provides medical, disability, survivor, burial, and rehabilitation benefits to employees who are injured or killed due to a work-related injury or illness. Runoff & Other Runoff & Other includes the results of Sirius Global Solutions Holding Company ("Sirius Global Solutions"), which specializes in the acquisition and management of runoff liabilities for insurance and reinsurance companies, both in the United States and internationally, as well as asbestos risks, environmental risks and other long-tailed liability exposures. The following tables summarize the segment results for the years ended December 31, 2019 , 2018 , and 2017 : For the year ended December 31, 2019 (Millions) Global Reinsurance Global A&H U.S. Specialty Runoff & Other Corporate Elimination Total Gross written premiums $ 1,238.8 $ 593.4 $ 66.3 $ 4.2 $ — $ 1,902.7 Net written premiums $ 987.9 $ 458.1 $ 54.1 $ 2.5 $ — $ 1,502.6 Net earned insurance and reinsurance premiums $ 966.5 $ 443.3 $ 29.6 $ 2.2 $ — $ 1,441.6 Loss and allocated LAE (1) (830.6 ) (271.3 ) (23.7 ) (1.8 ) — (1,127.4 ) Insurance and reinsurance acquisition expenses (199.7 ) (125.8 ) (6.4 ) (2.9 ) 46.1 (288.7 ) Technical profit (loss) (63.8 ) 46.2 (0.5 ) (2.5 ) 46.1 25.5 Unallocated LAE (2) (20.3 ) (7.4 ) (0.4 ) (1.0 ) (13.8 ) (42.9 ) Other underwriting expenses (84.5 ) (23.7 ) (10.6 ) (5.9 ) (13.5 ) (138.2 ) Underwriting (loss) income (168.6 ) 15.1 (11.5 ) (9.4 ) 18.8 (155.6 ) Service fee revenue (3) — 124.2 — — (49.6 ) 74.6 Managing general underwriter unallocated LAE (4) — (17.3 ) — — 17.3 — Managing general underwriter other underwriting expenses (5) — (13.5 ) — — 13.5 — General and administrative expenses, MGU + Runoff & Other (6) — (66.9 ) — (3.7 ) — (70.6 ) Underwriting (loss) income, including net service fee income (168.6 ) 41.6 (11.5 ) (13.1 ) — (151.6 ) Net investment income 84.7 Net realized investment gains (losses) 56.7 Net unrealized investment gains (losses) 80.6 Net foreign exchange gains 7.7 Revaluation of contingent consideration (6.3 ) Other revenue (7) (19.5 ) General and administrative expenses (8) (39.2 ) Intangible asset amortization expenses (15.8 ) Interest expense on debt (31.0 ) Pre-tax income (loss) $ (33.7 ) Underwriting Ratios Loss ratio 88.0 % 62.9 % 81.4 % NM NM 81.2 % Acquisition expense ratio 20.7 % 28.4 % 21.6 % NM NM 20.0 % Other underwriting expense ratio 8.7 % 5.3 % 35.8 % NM NM 9.6 % Combined ratio (9) 117.4 % 96.6 % 138.8 % NM NM 110.8 % Goodwill and intangible assets (10) $ — $ 572.5 $ — $ 8.1 $ — $ 580.6 (1) Loss and allocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (2) Unallocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (3) Service fee revenue is part of Other revenue on the Consolidated Statements of (Loss) (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss) Income). (4) Managing general underwriter unallocated LAE represents IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the claims process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (5) Managing general underwriter other underwriting expenses represent IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the underwriting process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (6) General and administrative expenses, MGU + Runoff & Other is part of General and administrative expenses on the Consolidated Statements of (Loss) (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (7) Other revenue is presented net of Service fee revenue and is comprised mainly of the right of indemnification and gains (losses) from derivatives (see Note 13 ), (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss)). (8) General and administrative expenses are presented net of General and administrative expenses, MGU + Runoff & Other (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (9) Ratios considered not meaningful ("NM") to Runoff & Other and Corporate Elimination. (10) Sirius Group does not allocate its assets by segment, with the exception of Goodwill and Intangible assets. ​ For the year ended December 31, 2018 (Millions) Global Global U.S. Specialty Runoff & Other Corporate Total Gross written premiums $ 1,268.1 $ 500.6 $ 19.4 $ 32.9 $ — $ 1,821.0 Net written premiums $ 934.6 $ 379.8 $ 13.1 $ 29.6 $ — $ 1,357.1 Net earned insurance and reinsurance premiums $ 870.5 $ 357.6 $ 5.0 $ 29.2 $ — $ 1,262.3 Loss and allocated LAE (1) (658.8 ) (189.0 ) (2.3 ) (13.0 ) — (863.1 ) Insurance and reinsurance acquisition expenses (185.3 ) (109.7 ) (1.3 ) (2.8 ) 43.7 (255.4 ) Technical (loss) profit 26.4 58.9 1.4 13.4 43.7 143.8 Unallocated LAE (2) (16.4 ) (5.9 ) — (1.6 ) (13.0 ) (36.9 ) Other underwriting expenses (87.7 ) (27.4 ) (8.7 ) (6.3 ) (16.1 ) (146.2 ) Underwriting (loss) income (77.7 ) 25.6 (7.3 ) 5.5 14.6 (39.3 ) Service fee revenue (3) — 115.7 — — (44.7 ) 71.0 Managing general underwriter unallocated LAE (4) — (14.0 ) — — 14.0 — Managing general underwriter other underwriting expenses (5) — (16.1 ) — — 16.1 — General and administrative expenses, MGU + Runoff & Other (6) — (53.6 ) — (3.1 ) — (56.7 ) Underwriting (loss) income, including net service fee income (77.7 ) 57.6 (7.3 ) 2.4 — (25.0 ) Net investment income 71.4 Net realized investment gains (losses) 2.3 Net unrealized investment gains (losses) (23.2 ) Net foreign exchange gains 22.7 Revaluation of contingent consideration 9.6 Other revenue (7) 41.7 General and administrative expenses (8) (21.2 ) Intangible asset amortization expenses (15.8 ) Impairment of intangible assets (8.0 ) Interest expense on debt (30.8 ) Pre-tax income (loss) $ 23.7 Underwriting Ratios Loss ratio 77.6 % 54.5 % 46.0 % NM NM 71.3 % Acquisition expense ratio 21.3 % 30.7 % 26.0 % NM NM 20.2 % Other underwriting expense ratio 10.1 % 7.7 % 174.0 % NM NM 11.6 % Combined ratio (9) 109.0 % 92.9 % 246.0 % NM NM 103.1 % Goodwill and intangible assets (10) $ — $ 588.1 $ — $ 8.1 $ — $ 596.2 (1) Loss and allocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (2) Unallocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (3) Service fee revenue is part of Other revenue on the Consolidated Statements of (Loss) (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss) Income). (4) Managing general underwriter unallocated LAE represents IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the claims process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (5) Managing general underwriter other underwriting expenses represent IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the underwriting process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (6) General and administrative expenses, MGU + Runoff & Other is part of General and administrative expenses on the Consolidated Statements of (Loss) (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (7) Other revenue is presented net of Service fee revenue and is comprised mainly of the right of indemnification, gains (losses) from derivatives (see Note 13 ), and the termination of the call option to purchase The Phoenix Holdings, Ltd. (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss)). (8) General and administrative expenses are presented net of General and administrative expenses, MGU + Runoff & Other (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (9) Ratios considered not meaningful ("NM") to Runoff & Other and Corporate Elimination. (10) Sirius Group does not allocate its assets by segment, with the exception of Goodwill and Intangible assets. For the year ended December 31, 2017 (Millions) Global Global U.S. Specialty Runoff & Other Corporate Total Gross written premiums $ 950.2 $ 494.6 $ — $ (5.5 ) $ — $ 1,439.3 Net written premiums $ 749.2 $ 341.5 $ — $ (0.5 ) $ — $ 1,090.2 Net earned insurance and reinsurance premiums $ 727.6 $ 306.8 $ — $ 0.9 $ — $ 1,035.3 Loss and allocated LAE (1) (599.1 ) (175.0 ) — (11.0 ) — (785.1 ) Insurance and reinsurance acquisition expenses (154.0 ) (89.6 ) — 3.5 42.9 (197.2 ) Technical (loss) profit (25.5 ) 42.2 — (6.6 ) 42.9 53.0 Unallocated LAE (2) (18.2 ) (4.8 ) — (3.1 ) — (26.1 ) Other underwriting expenses (79.8 ) (23.4 ) — (2.9 ) — (106.1 ) Underwriting (loss) income (123.5 ) 14.0 — (12.6 ) 42.9 (79.2 ) Service fee revenue (3) — 65.9 — — (42.9 ) 23.0 Managing general underwriter unallocated LAE (4) — — — — — — Managing general underwriter other underwriting expenses (5) — — — — — — General and administrative expenses, MGU + Runoff & Other (6) — (44.8 ) — (4.0 ) — (48.8 ) Underwriting (loss) income, including net service fee income (123.5 ) 35.1 — (16.6 ) — (105.0 ) Net investment income 56.8 Net realized investment gains (losses) (27.2 ) Net unrealized investment gains (losses) (10.5 ) Net foreign exchange gains 9.2 Revaluation of contingent consideration 48.8 Other revenue (7) (1.3 ) General and administrative expenses (8) (43.1 ) Intangible asset amortization expenses (10.2 ) Impairment of intangible assets (5.0 ) Interest expense on debt (22.4 ) Pre-tax income (loss) $ (109.9 ) Underwriting Ratios Loss ratio 84.8 % 58.6 % — % NM NM 78.4 % Acquisition expense ratio 21.2 % 29.2 % — % NM NM 19.0 % Other underwriting expense ratio 11.0 % 7.6 % — % NM NM 10.2 % Combined ratio (9) 117.0 % 95.4 % — % NM NM 107.6 % Goodwill and intangible assets (10) $ — $ 612.3 $ — $ 5.0 $ — $ 617.3 (1) Loss and allocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (2) Unallocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (3) Service fee revenue is part of Other revenue on the Consolidated Statements of (Loss) (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss) Income). (4) Managing general underwriter unallocated LAE represents IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the claims process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (5) Managing general underwriter other underwriting expenses represent IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the underwriting process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (6) General and administrative expenses, MGU + Runoff & Other is part of General and administrative expenses on the Consolidated Statements of (Loss) (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (7) Other revenue is presented net of Service fee revenue and is comprised mainly of gains (losses) from derivatives (see Note 13 ) (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss)). (8) General and administrative expenses are presented net of General and administrative expenses, MGU + Runoff & Other (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (9) Ratios considered not meaningful ("NM") to Runoff & Other and Corporate Elimination. (10) Sirius Group does not allocate its assets by segment, with the exception of Goodwill and Intangible assets. The following tables provide summary information regarding net premiums written by client location and underwriting location by reportable segment for the years ended December 31, 2019 , 2018 , and 2017 : For the year ended December 31, 2019 (Millions) Global Global U.S. Specialty Runoff & Other Total Net written premiums by client location: United States $ 480.2 $ 386.2 $ 54.1 $ 1.8 $ 922.3 Europe 245.3 23.5 — 0.1 268.9 Canada, the Caribbean, Bermuda and Latin America 90.0 12.4 — 0.1 102.5 Asia and Other 172.4 36.0 — 0.5 208.9 Total net written premium by client location $ 987.9 $ 458.1 $ 54.1 $ 2.5 $ 1,502.6 Net written premiums by underwriting location: United States $ 33.4 $ 170.3 $ 43.8 $ 1.8 $ 249.3 Europe 488.4 249.9 10.3 0.2 748.8 Canada, the Caribbean, Bermuda and Latin America 413.8 37.1 — — 450.9 Asia and Other 52.3 0.8 — 0.5 53.6 Total written premiums by underwriting location $ 987.9 $ 458.1 $ 54.1 $ 2.5 $ 1,502.6 For the year ended December 31, 2018 (Millions) Global Global U.S. Specialty Runoff Total Net written premiums by client location: United States $ 444.7 $ 307.7 $ 13.1 $ 29.2 $ 794.7 Europe 246.1 30.4 — — 276.5 Canada, the Caribbean, Bermuda and Latin America 91.1 12.5 — — 103.6 Asia and Other 152.7 29.2 — 0.4 182.3 Total net written premium by client location $ 934.6 $ 379.8 $ 13.1 $ 29.6 $ 1,357.1 Net written premiums by underwriting location: United States $ 33.5 $ 109.5 $ 7.9 $ 29.2 $ 180.1 Europe 462.0 224.9 5.2 — 692.1 Canada, the Caribbean, Bermuda and Latin America 389.1 44.7 — — 433.8 Asia and Other 50.0 0.7 — 0.4 51.1 Total written premiums by underwriting location $ 934.6 $ 379.8 $ 13.1 $ 29.6 $ 1,357.1 For the year ended December 31, 2017 (Millions) Global Global U.S. Specialty Runoff Total Net written premiums by client location: United States $ 279.8 $ 284.5 $ — $ (1.2 ) $ 563.1 Europe 234.1 28.2 — — 262.3 Canada, the Caribbean, Bermuda and Latin America 101.7 9.5 — 0.2 111.4 Asia and Other 133.6 19.3 — 0.5 153.4 Total net written premium by client location $ 749.2 $ 341.5 $ — $ (0.5 ) $ 1,090.2 Net written premiums by underwriting location: United States $ 53.4 $ 98.2 $ — $ (1.1 ) $ 150.5 Europe 386.9 196.4 — — 583.3 Canada, the Caribbean, Bermuda and Latin America 269.1 46.4 — — 315.5 Asia and Other 39.8 0.5 — 0.6 40.9 Total written premiums by underwriting location $ 749.2 $ 341.5 $ — $ (0.5 ) $ 1,090.2

Reserves for unpaid losses and

Reserves for unpaid losses and loss adjustment expenses	12 Months Ended
	Dec. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract]
Reserves for unpaid losses and loss adjustment expenses	Reserves for unpaid losses and loss adjustment expenses Sirius Group establishes loss and LAE reserves that are estimates of future amounts needed to pay claims and related expenses for events that have already occurred. Sirius Group also obtains reinsurance whereby another reinsurer contractually agrees to indemnify Sirius Group for all or a portion of the reinsurance risks underwritten by Sirius Group. Such arrangements, where one reinsurer provides reinsurance to another reinsurer, are usually referred to as "retrocessional reinsurance" arrangements. Sirius Group establishes estimates of amounts recoverable from retrocessional reinsurance in a manner consistent with the loss and LAE liability associated with reinsurance contracts offered to its customers (the "ceding companies"), net of an allowance for uncollectible amounts. Net reinsurance loss reserves represent loss and LAE reserves reduced by retrocessional reinsurance recoverable on unpaid losses. In addition to those factors which give rise to inherent uncertainties in establishing loss and LAE reserves, the inherent uncertainties of estimating such reserves are even greater for the reinsurer, due primarily to: (1) the claim-tail for reinsurers and insurers working through MGUs being further extended because claims are first reported to either the original primary insurance company or the MGU and then through one or more intermediaries to reinsurers, (2) the diversity of loss development patterns among different types of reinsurance treaties, facultative contracts or direct insurance contracts, (3) the necessary reliance on the ceding companies, intermediaries, and MGUs for information regarding reported claims and (4) the differing reserving practices among ceding companies and MGUs. As with insurance reserves, the process of estimating reinsurance reserves involves a considerable degree of judgment by management and, as of any given date, is inherently uncertain. Based on the above, such uncertainty may be larger relative to the reserves for a company that principally writes reinsurance compared to an insurance company, and certainty may take a longer time to emerge. Upon notification of a loss from an insured (typically a ceding company), Sirius Group establishes case reserves, including LAE reserves, based upon Sirius Group's share of the amount of reserves reported by the insured and Sirius Group's independent evaluation of the loss. In cases where available information indicates that reserves reported by a ceding company are inadequate or excessive, Sirius Group establishes case reserves or incurred but not reported ("IBNR") in excess of or below its share of the reserves reported by the ceding company. Also, in certain instances, Sirius Group may decide not to establish case reserves or IBNR, when the information available indicates that reserves established by ceding companies are not adequately supported. In addition, specific claim information reported by insureds or obtained through claim audits can alert management to emerging trends such as changing legal interpretations of coverage and liability, claims from unexpected sources or classes of business, and significant changes in the frequency or severity of individual claims where customary. Generally, ceding company audits are not customary outside the United States. This information is often used to supplement estimates of IBNR. Generally, initial actuarial estimates of IBNR reserves not related to a specific event are based on the loss ratio method applied to each class of business. Sirius Group regularly reviews the adequacy of its recorded reserves by using a variety of generally accepted actuarial methods, including historical incurred and paid loss development methods. Estimates of the initial expected ultimate losses involve management judgment and are based on historical information for that class of business, which includes loss ratios, market conditions, changes in pricing and conditions, underwriting changes, changes in claims emergence, and other factors that may influence expected ultimate losses. If actual loss activity differs substantially from expectations, an adjustment to recorded reserves may be warranted. As time passes, loss reserve estimates for a given year will rely more on actual loss activity and historical patterns than on initial loss ratio assumptions. The actuarial methods are used to calculate a point estimate of loss and LAE reserves for each company within Sirius Group. These point estimates are then aggregated to produce an actuarial point estimate for Sirius Group. Once a point estimate is established, Sirius Group's actuaries estimate loss reserve ranges to measure the sensitivity of the actuarial assumptions used to set the point estimates. These ranges are calculated from historical variations in loss ratios, payment, and reporting patterns by class and type of business. Management then establishes an estimate for the carried loss and LAE reserves shown in the financial statement. The management selection is within the range of loss reserve estimates provided by Sirius Group's actuaries. Loss and Loss Adjustment Expense Reserve Summary The following table summarizes the loss and LAE reserve activities of Sirius Group for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 Gross beginning balance $ 2,016.7 $ 1,898.5 $ 1,620.1 Less beginning reinsurance recoverable on unpaid losses (350.2 ) (319.7 ) (291.5 ) Net loss and LAE reserve balance 1,666.5 1,578.8 1,328.6 Loss and LAE reserves acquired (1) — 0.2 14.3 Losses and LAE incurred relating to: Current year losses 1,066.5 907.3 811.8 Prior years losses 103.8 (7.3 ) (0.6 ) Total net incurred losses and LAE 1,170.3 900.0 811.2 Accretion of fair value adjustment to net loss and LAE reserves 0.1 0.1 0.1 Foreign currency translation adjustment to net loss and LAE reserves (4.4 ) (20.9 ) 36.8 Loss and LAE paid relating to: Current year losses 251.3 251.4 222.8 Prior years losses 660.0 540.3 389.5 Total loss and LAE payments 911.3 791.7 612.3 Net ending balance 1,921.2 1,666.5 1,578.8 Plus ending reinsurance recoverable on unpaid losses 410.3 350.2 319.7 Gross ending balance $ 2,331.5 $ 2,016.7 $ 1,898.5 (1) Loss and LAE reserves acquired in 2018 relate to Sirius Group's purchase of Cedar; 2017 relate to Sirius Group's purchase of IMG. Loss and LAE development - 2019 During the year ended December 31, 2019 , Sirius Group had net unfavorable prior year loss reserve development of $103.8 million . Increases in loss reserve estimates were recorded in Global Reinsurance ( $103.6 million ) primarily attributable to prior year catastrophe events, including Typhoon Jebi and Hurricanes Michael, Florence, and Irma, and unfavorable loss reserve development in Casualty Reinsurance ( $13 million ) due to early reporting of large claims coupled with steady reporting of less severe claims. Loss and LAE development - 2018 During the year ended December 31, 2018 , Sirius Group had net favorable prior year loss reserve development of $7.3 million. During 2018 , Sirius Group strengthened its Global Reinsurance loss reserves by $25.3 million in Other Property ( $34.9 million) and Property Catastrophe Excess ( $13.2 million), resulting from higher than expected loss reporting from recent accident years, including $21.4 million from Hurricanes Harvey, Irma, and Maria, partially offset by favorable loss reserve development in Aviation & Space ( $7.9 million) and Marine ( $6.8 million). The net favorable prior year loss reserve development of $17.6 million for Runoff & Other included reductions in World Trade Center claims in response to revised information received by the Company and runoff Casualty reserves. Global A&H recorded $15.0 million of net favorable loss reserve development due to lower than expected claims activity. Loss and LAE development - 2017 During the year ended December 31, 2017 , Sirius Group had net favorable prior year loss reserve development of $0.6 million. During 2017 , Sirius Group strengthened its asbestos loss reserves by $59.0 million, which was offset by reductions of other runoff claims reserves of $45.7 million, which is reflected in the Runoff & Other segment. Global Reinsurance had net favorable prior year loss development of $9.9 million, which reflects favorable development for Marine ( $5.4 million), Trade credit ( $4.2 million), Aviation & Space ( $1.7 million), and Contingency ( $0.8 million). Fair value adjustment to loss and LAE reserves In connection with purchase accounting for acquisitions, Sirius Group is required to adjust loss and LAE reserves and the related reinsurance recoverables to fair value on their respective acquired balance sheets. The net reduction to loss and LAE reserves is being recognized through an income statement charge ratably with and over the period the claims are settled and is recorded within General and administrative expenses. Sirius Group recognized $0.1 million of such charges during the years ended December 31, 2019 , 2018 , and 2017 , respectively. As of December 31, 2019 , the pre-tax un-accreted adjustment was $0.7 million . Asbestos and Environmental Loss and Loss Adjustment Expense Reserve Activity In the Runoff & Other segment, Sirius Group's reserves include provisions made for claims that assert damages from asbestos and environmental ("A&E") related exposures primarily at Sirius America. Asbestos claims relate primarily to injuries asserted by those who came in contact with asbestos or products containing asbestos. Environmental claims relate primarily to pollution and related clean-up cost obligations, particularly as mandated by U.S. federal and state environmental protection agencies. In addition to the factors described above regarding the reserving process, Sirius Group estimates its A&E reserves based upon, among other factors, facts surrounding reported cases and exposures to claims, such as policy limits and deductibles, current law, past and projected claim activity, and past settlement values for similar claims, as well as analysis of industry studies and events, such as recent settlements and asbestos-related bankruptcies. The cost of administering A&E claims, which is an important factor in estimating loss reserves, tends to be higher than in the case of non-A&E claims due to the higher legal costs typically associated with A&E claims. Sirius Group's A&E exposure is primarily from reinsurance contracts written between 1974 through 1985 by acquired companies, mainly MONY Reinsurance Company, which was acquired in 1991, and Christiania General Insurance Company, which was acquired in 1996. The exposures are mostly higher layer excess of loss treaty and facultative coverages with relatively low limits exposed for each claim. The acquisition of companies having modest portfolios of A&E exposure has been typical of several prior Sirius Global Solutions transactions and is likely to be an element of at least some future acquisitions. However, the acquisition of new A&E liabilities is undertaken only after careful due diligence and utilizing conservative reserving assumptions in relation to industry benchmarks. In the case of portfolios acquired previously by Sirius Global Solutions, the exposures arise almost entirely from old assumed reinsurance contracts having small limits of liability. During 2019 , Sirius Group did not record any asbestos-related incurred losses and LAE on its asbestos reserves. Sirius Group recorded a decrease of $6.9 million and an increase of $59.0 million of asbestos-related incurred losses and LAE on its asbestos reserves in 2018 and 2017 , respectively. The 2018 decrease was driven by favorable loss reserve development primarily due to benign claims activity on the Sirius Global Solutions portfolio. The 2017 increase was primarily a result of an in-depth analysis of Sirius Group's loss reserves undertaken in the second quarter of 2017. Sirius Group recorded $0.7 million, $4.0 million , and $6.1 million of environmental losses in 2019 , 2018 , and 2017 , respectively, on its already existing reserves. Sirius Group's net reserves for A&E losses were $187.3 million and $200.3 million as of December 31, 2019 and 2018 , respectively. Sirius Group's asbestos three-year net paid survival ratio was approximately 11.5 years and 10.2 years as of December 31, 2019 and 2018 . Sirius Group's environmental three-year net paid survival ratio was approximately 4.0 years and 4.2 years as of December 31, 2019 and 2018 , respectively. Sirius Group's reserves for A&E losses as of December 31, 2019 represent management's best estimate of its ultimate liability based on information currently available. However, as case law expands, medical and clean-up costs increase, and industry settlement practices change, Sirius Group may be subject to asbestos and environmental losses beyond currently estimated amounts. Sirius Group cannot reasonably estimate at the present time loss reserve additions arising from any such future adverse developments and cannot be sure that allocated loss reserves will be sufficient to cover additional liability arising from any such adverse developments. The following table summarizes reported A&E loss and LAE reserve activities (gross and net of reinsurance) for the years ended December 31, 2019 , 2018 , and 2017 : 2019 2018 2017 (Millions) Gross Net Gross Net Gross Net Asbestos: Beginning balance $ 236.8 $ 184.4 $ 259.2 $ 204.6 $ 187.0 $ 166.4 Incurred losses and LAE 0.1 — (6.9 ) (6.9 ) 96.9 59.0 Paid losses and LAE (12.2 ) (11.1 ) (15.5 ) (13.3 ) (24.7 ) (20.8 ) Ending balance 224.7 173.3 236.8 184.4 259.2 204.6 Environmental: Beginning balance 16.7 15.9 16.7 16.0 18.5 13.9 Incurred losses and LAE 0.7 0.7 4.0 4.0 2.9 6.1 Paid losses and LAE (2.9 ) (2.6 ) (4.0 ) (4.1 ) (4.7 ) (4.0 ) Ending balance 14.5 14.0 16.7 15.9 16.7 16.0 Total asbestos and environmental: Beginning balance 253.4 200.3 275.9 220.6 205.5 180.3 Incurred losses and LAE 0.8 0.7 (3.0 ) (2.9 ) 99.8 65.1 Paid losses and LAE (15.0 ) (13.7 ) (19.5 ) (17.4 ) (29.4 ) (24.8 ) Ending balance $ 239.2 $ 187.3 $ 253.4 $ 200.3 $ 275.9 $ 220.6 Net loss reserves by type The following tables present Sirius Group's loss and LAE reserves, net of reinsurance, by type as of December 31, 2019 and 2018 : (Millions) 2019 2018 Case Reserve $ 1,030.6 $ 924.5 IBNR Reserve 890.6 742.0 Loss and loss adjustment expense reserves, net of reinsurance $ 1,921.2 $ 1,666.5 Reconciliation of liabilities for unpaid loss and LAE The following table summarizes the ending liabilities for unpaid loss and LAE, net of reinsurance for each of Sirius Group's segments as of December 31, 2019 : (Millions) Liabilities for unpaid loss and LAE, net of reinsurance As of December 31, 2019 Unpaid and allocated LAE reserves, net of reinsurance Other Property $ 490.7 Property Catastrophe Excess Reinsurance 286.0 Agriculture Reinsurance 68.1 Global A&H 176.9 Aviation & Space 109.2 Trade Credit 46.5 Environmental 4.6 Marine & Energy 52.4 Surety 4.9 Contingency 8.3 Casualty (1) 202.0 Runoff & Other 430.6 Total unpaid and allocated LAE reserves, net of reinsurance 1,880.2 Unallocated LAE 41.0 Total unpaid loss and LAE reserves, net of reinsurance 1,921.2 Reinsurance recoverable on unpaid losses Other Property 137.3 Property Catastrophe Excess Reinsurance 60.0 Agriculture Reinsurance 2.0 Global A&H 42.9 Aviation & Space 40.3 Trade Credit 10.1 Environmental 4.6 Marine & Energy 8.7 Surety 0.5 Contingency 2.1 Casualty 1.2 Runoff & Other 100.6 Total reinsurance recoverable on unpaid losses 410.3 Total unpaid loss and LAE reserves $ 2,331.5 (1) Casualty includes both Casualty Reinsurance in the Global Reinsurance reporting segment and Workers’ Compensation in the U.S. Specialty reporting segment. Sirius Group began providing Workers’ Compensation in the U.S. Specialty reporting segment in the latter part of 2018 and of the $18.5 included in Casualty reserves from Workers’ Compensation in the U.S. Specialty reporting segment, $17.3 is from the 2019 accident year. The following table groupings, reflecting the Other Property, Property Catastrophe Excess Reinsurance, Agriculture Reinsurance, Global A&H, Aviation & Space, Trade Credit, Environmental, Marine & Energy, Surety, Contingency, Casualty Reinsurance, and Runoff & Other lines of business include three sections. The first table (top section of grouping) presents, for each of the previous 10 accident years (1) cumulative total undiscounted incurred loss and allocated LAE, net of reinsurance, as of each of the previous 10 year-end evaluations, (2) total IBNR plus expected development on reported claims as of December 31, 2019 , and (3) the cumulative number of reported claims as of December 31, 2019 . The net loss reserves for losses and loss expenses related to the acquisitions described in Note 3 have been incorporated within the ten year short duration tables on a prospective basis. Sirius Group provides treaty reinsurance for a significant portion and across all lines of its business. Sirius Group does not receive, and as such does not maintain claims count information associated with many of its reinsurance contracts, especially proportional covers. As such, Sirius Group has determined that it is impracticable to provide this information. The second table (middle section grouping) presents cumulative paid loss and allocated LAE, net of reinsurance for each of the previous 10 accident years, as of each of the previous 10 year-end evaluations. Also included in this table is a calculation of the liability for loss and allocated LAE as of December 31, 2019 which is then included in the reconciliation to the consolidated balance sheet presented above. The liability as of December 31, 2019 is calculated as the cumulative incurred loss and allocated LAE from the first table less the cumulative paid loss and allocated from the second table, plus any outstanding liabilities from accident years prior to 2010. The third table (bottom section of grouping) is supplementary information about the average historical claims duration as of December 31, 2019 . It shows the weighted average annual percentage payout of incurred loss and allocated LAE by accident year as of each age. For example, the first column is calculated as the incremental paid loss and allocated LAE in the first calendar year for each given accident year (e.g. calendar year 2010 for accident year 2010, calendar year 2011 for accident year 2011) divided by the cumulative incurred loss and allocated LAE as of December 31, 2019 for that accident year. The resulting ratios are weighted together using cumulative incurred loss and allocated LAE as of December 31, 2019 . Other Property (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 156.1 153.2 144.5 145.2 140.2 139.3 138.6 137.0 136.7 136.3 1.5 NA 2011 162.9 150.3 141.2 133.2 131.3 132.0 132.2 131.0 131.1 0.1 NA 2012 162.1 148.9 143.8 139.4 134.7 132.7 132.6 132.0 1.1 NA 2013 130.0 126.8 116.0 112.5 112.2 111.7 111.4 0.7 NA 2014 113.8 116.6 114.1 114.4 112.0 111.3 0.7 NA 2015 139.7 132.2 134.4 134.4 134.1 1.6 NA 2016 194.9 213.7 218.3 219.1 1.7 NA 2017 332.7 369.3 387.9 19.1 NA 2018 270.8 326.3 34.0 NA 2019 245.0 101.1 NA Total 1,934.5 Other Property (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 31.4 88.7 115.5 123.2 128.0 130.1 130.6 130.6 130.5 131.4 2011 26.6 79.1 102.8 115.7 121.7 124.2 126.8 126.5 127.1 2012 20.0 84.7 107.4 115.5 118.9 124.2 125.0 126.2 2013 27.2 71.4 95.4 101.9 105.2 105.8 106.3 2014 18.8 68.9 95.5 103.7 105.9 106.7 2015 30.8 93.0 114.3 123.9 127.7 2016 31.2 128.0 180.6 197.5 2017 58.2 222.4 298.6 2018 54.8 180.1 2019 46.2 Total 1,447.8 All outstanding liabilities before 2010, net of reinsurance 4.0 Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 490.7 Other Property Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 17.8 % 42.5 % 20.1 % 7.2 % 3.1 % 1.8 % 0.9 % 0.3 % 0.1 % 0.7 % Property Catastrophe Excess Reinsurance (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 136.1 131.0 131.0 130.2 122.8 121.9 121.4 120.7 121.3 127.3 0.1 NA 2011 152.6 89.7 142.7 121.4 118.0 117.2 117.1 117.2 117.2 0.2 NA 2012 145.0 57.8 51.1 49.2 49.7 44.8 45.0 46.5 0.5 NA 2013 70.3 76.5 73.5 72.9 72.1 71.8 71.4 — NA 2014 55.4 57.0 54.3 54.4 54.3 54.8 0.5 NA 2015 27.4 29.3 26.9 25.9 25.0 0.2 NA 2016 50.4 47.7 42.4 41.2 2.3 NA 2017 105.4 123.4 117.4 8.3 NA 2018 160.4 178.0 9.1 NA 2019 169.9 35.1 NA Total 948.7 Property Catastrophe Excess Reinsurance (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 49.8 90.0 102.5 107.6 111.1 113.6 117.5 117.5 118.0 119.1 2011 15.9 54.7 96.0 114.4 114.7 115.2 116.1 116.2 116.7 2012 2.8 25.8 35.4 40.0 40.9 42.7 44.0 46.1 2013 10.9 48.3 60.7 65.5 66.8 68.0 68.9 2014 9.2 35.8 41.9 47.4 49.1 51.5 2015 1.8 9.3 16.6 19.9 22.4 2016 10.4 25.7 31.7 37.0 2017 13.2 67.4 86.4 2018 2.7 115.8 2019 3.3 ​ ​ ​ ​ ​ ​ Total 667.2 All outstanding liabilities before 2010, net of reinsurance 4.5 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 286.0 Property Catastrophe Excess Reinsurance Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 12.7 % 45.7 % 19.0 % 9.8 % 2.3 % 2.0 % 1.9 % 0.7 % 0.5 % 0.8 % Agriculture Reinsurance (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 12.8 10.8 10.9 10.7 10.6 10.7 10.7 10.7 10.7 10.7 — NA 2011 21.5 21.5 21.7 21.7 21.7 21.6 21.6 21.6 21.6 — NA 2012 41.1 45.9 45.9 45.8 47.0 47.0 47.0 46.9 — NA 2013 9.1 10.8 12.9 13.0 12.8 12.8 12.8 — NA 2014 9.7 8.2 8.5 8.9 8.9 9.0 — NA 2015 7.0 9.1 9.4 9.4 9.4 — NA 2016 33.1 30.5 29.5 29.6 0.2 NA 2017 50.2 46.8 46.1 (0.4 ) NA 2018 39.1 41.3 3.3 NA 2019 71.8 46.0 NA Total 299.2 Agriculture Reinsurance (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 0.5 10.6 10.8 10.6 10.6 10.6 10.6 10.6 10.6 10.7 2011 1.0 21.3 21.6 21.6 21.6 21.6 21.6 21.6 21.6 2012 19.0 45.4 45.7 45.6 46.9 46.9 46.9 46.9 2013 7.1 10.6 12.8 13.0 12.8 12.8 12.8 2014 6.5 8.1 8.8 8.8 8.9 9.0 2015 1.5 7.7 8.9 9.2 9.2 2016 10.0 27.8 29.2 29.5 2017 9.0 43.3 46.1 2018 2.6 35.8 2019 9.5 Total 231.1 All outstanding liabilities before 2010, net of reinsurance — ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 68.1 Agriculture Reinsurance Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 22.3 % 67.5 % 4.8 % 0.4 % 1.1 % 0.1 % 0.1 % — % — % — % Global A&H (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 118.4 125.4 123.0 122.1 121.8 121.8 121.9 121.8 121.7 121.7 (0.1 ) NA 2011 161.3 176.7 172.3 171.6 171.6 171.6 171.4 171.4 171.5 0.1 NA 2012 163.4 160.1 147.8 147.1 146.9 146.7 146.6 146.5 (0.1 ) NA 2013 125.5 123.3 118.8 118.3 117.7 116.9 116.8 — NA 2014 130.8 131.9 130.3 130.3 129.4 129.4 0.1 NA 2015 152.7 148.8 145.5 144.2 143.8 0.3 NA 2016 173.3 187.1 183.0 181.5 2.5 NA 2017 176.4 172.6 165.9 1.4 NA 2018 198.3 205.5 13.4 NA 2019 271.9 89.1 NA Total 1,654.5 Global A&H (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 53.1 102.2 119.2 121.4 121.7 121.8 121.9 121.9 121.9 122.0 2011 71.2 139.2 166.1 171.1 171.5 171.6 171.6 171.6 171.7 2012 72.2 136.1 146.1 146.5 146.6 146.6 146.6 146.6 2013 54.4 103.7 114.2 115.6 116.8 116.3 116.3 2014 59.2 111.1 124.6 126.3 126.3 127.0 2015 75.4 129.8 141.2 142.8 143.1 2016 98.2 164.4 176.0 177.9 2017 61.5 150.7 163.0 2018 89.0 186.1 2019 128.7 ​ ​ ​ ​ ​ ​ ​ ​ Total 1,482.4 All outstanding liabilities before 2010, net of reinsurance 4.8 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 176.9 Global A&H Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 46.1 % 42.6 % 9.6 % 1.4 % 0.3 % 0.1 % — % — % 0.1 % — % Aviation & Space (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 42.4 47.2 46.9 44.4 42.9 42.0 41.8 41.3 41.6 41.4 (0.4 ) NA 2011 46.8 42.2 37.8 35.8 34.6 34.4 35.7 35.0 35.2 (0.2 ) NA 2012 35.6 34.3 30.2 28.2 28.4 29.5 29.5 28.5 (0.3 ) NA 2013 40.5 36.4 33.3 31.9 32.9 32.9 33.0 (0.5 ) NA 2014 37.3 39.9 36.6 35.8 35.9 33.9 (3.0 ) NA 2015 37.6 34.0 38.1 37.1 36.5 (0.9 ) NA 2016 32.0 32.5 33.5 35.8 2.9 NA 2017 33.8 42.8 44.1 1.4 NA 2018 47.9 50.5 6.7 NA 2019 60.5 39.9 NA Total 399.4 Aviation & Space (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 12.0 22.0 31.3 36.0 37.5 38.5 39.4 39.6 40.7 41.0 2011 10.1 22.6 28.5 31.4 32.6 34.0 34.7 34.6 35.5 2012 7.6 18.4 22.6 24.6 27.3 28.2 28.7 28.4 2013 13.5 19.8 24.0 26.6 28.4 29.1 30.5 2014 8.0 17.8 23.5 26.1 28.1 28.8 2015 10.5 21.0 27.0 33.4 34.9 2016 7.8 19.6 26.7 29.1 2017 9.0 23.6 32.5 2018 14.3 27.4 2019 8.3 Total 296.4 All outstanding liabilities before 2010, net of reinsurance 6.2 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 109.2 Aviation & Space Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 25.3 % 29.4 % 17.8 % 9.6 % 5.2 % 2.7 % 2.5 % (0.3 )% 2.6 % 0.4 % Trade Credit (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 13.7 12.0 9.3 9.5 9.6 9.4 9.4 9.5 9.6 9.4 (0.3 ) NA 2011 28.4 28.2 26.7 26.5 26.5 25.8 25.8 25.6 25.4 (0.3 ) NA 2012 33.6 33.9 32.2 32.4 32.0 32.0 31.7 31.3 (0.2 ) NA 2013 28.8 27.9 27.1 26.9 27.5 27.0 27.3 0.6 NA 2014 22.2 22.2 23.0 20.9 20.6 20.5 0.5 NA 2015 19.7 19.3 18.8 18.1 17.3 — NA 2016 14.9 12.9 12.3 11.4 — NA 2017 18.8 19.8 18.9 2.5 NA 2018 24.6 24.8 4.4 NA 2019 30.1 13.8 NA Total 216.4 Trade Credit (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 1.7 5.1 7.6 8.4 8.8 8.9 9.1 9.2 9.3 9.3 2011 6.4 17.1 23.1 24.3 25.2 25.5 25.2 25.3 25.3 2012 14.4 26.2 30.4 31.1 31.5 31.3 31.3 31.2 2013 11.3 19.4 22.3 23.5 23.9 24.0 24.1 2014 7.7 13.4 17.4 18.8 19.3 19.3 2015 4.5 12.0 15.4 16.4 16.3 2016 4.5 8.8 10.4 11.0 2017 3.0 8.8 12.6 2018 7.6 16.2 2019 8.8 Total 174.1 All outstanding liabilities before 2010, net of reinsurance 4.2 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 46.5 Trade Credit Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 32.3 % 35.4 % 17.6 % 4.8 % 1.8 % 0.3 % 0.1 % 0.1 % 0.3 % (0.2 )% Environmental (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 — — — — — — — — — — — NA 2011 — — — — — — — — — — NA 2012 — — — — — — — — — NA 2013 — — — — — — — — NA 2014 — — — — — — — NA 2015 — — — — — — NA 2016 — — — — — NA 2017 — — — — NA 2018 0.4 0.1 — NA 2019 4.6 0.8 NA Total 4.7 Environmental (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 — — — — — — — — — — 2011 — — — — — — — — — 2012 — — — — — — — — 2013 — — — — — — — 2014 — — — — — — 2015 — — — — — 2016 — — — — 2017 — — — 2018 — — 2019 0.1 Total 0.1 All outstanding liabilities before 2010, net of reinsurance — ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 4.6 Environmental Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 1.0 % 6.3 % — % — % — % — % — % — % — % — % Marine & Energy (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 30.5 33.3 31.0 30.7 32.1 31.7 30.4 30.2 30.0 30.0 0.1 NA 2011 36.7 33.0 30.7 31.2 32.2 31.6 31.7 31.6 32.3 (0.3 ) NA 2012 27.2 33.4 36.0 37.5 37.9 36.8 36.3 36.2 1.7 NA 2013 23.2 20.5 19.2 18.2 18.0 18.0 18.1 0.2 NA 2014 23.2 21.4 19.4 18.2 17.8 18.4 (0.3 ) NA 2015 29.3 31.0 28.9 28.4 28.3 0.2 NA 2016 28.2 29.1 28.3 28.3 0.8 NA 2017 37.2 34.8 34.6 2.2 NA 2018 23.1 25.4 3.2 NA 2019 18.8 6.7 NA Total 270.4 Marine & Energy (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 5.0 12.2 17.1 19.5 21.3 26.7 27.5 28.5 28.7 28.8 2011 4.4 14.4 21.8 25.2 28.0 28.8 29.3 29.7 30.4 2012 5.2 14.8 24.2 27.1 29.1 31.0 32.6 33.8 2013 2.9 9.3 12.6 14.0 14.4 14.9 15.1 2014 4.1 10.2 13.6 15.0 15.7 15.8 2015 4.3 11.6 21.5 25.9 26.9 2016 6.8 17.4 21.3 24.2 2017 7.2 18.1 26.1 2018 5.2 13.9 2019 3.8 Total 218.8 All outstanding liabilities before 2010, net of reinsurance 0.8 ​ Liabilities for loss and allocated loss adjustment expense

Third party reinsurance

Third party reinsurance	12 Months Ended
	Dec. 31, 2019
Reinsurance Disclosures [Abstract]
Third party reinsurance	Third party reinsurance In the normal course of business, Sirius Group seeks to protect its businesses from losses due to concentration of risk and losses arising from catastrophic events by reinsuring with third-party reinsurers. Sirius Group remains liable for risks reinsured in the event that the reinsurer does not honor its obligations under reinsurance contracts. The effects of reinsurance on Sirius Group's written and earned premiums and on losses and LAE were as follows: (Millions) 2019 2018 2017 Written premiums: Direct $ 511.2 $ 454.5 $ 450.2 Assumed 1,391.5 1,366.5 989.1 Gross written premiums 1,902.7 1,821.0 1,439.3 Ceded (400.1 ) (463.9 ) (349.1 ) Net written premiums $ 1,502.6 $ 1,357.1 $ 1,090.2 Earned premiums: Direct $ 481.0 $ 432.6 $ 405.7 Assumed 1,357.7 1,236.2 942.2 Gross earned premiums 1,838.7 1,668.8 1,347.9 Ceded (397.1 ) (406.5 ) (312.6 ) Net earned premiums $ 1,441.6 $ 1,262.3 $ 1,035.3 Losses and LAE: Direct $ 316.3 $ 260.5 $ 294.9 Assumed 1,111.4 819.1 701.3 Gross losses and LAE 1,427.7 1,079.6 996.2 Ceded (257.4 ) (179.6 ) (185.0 ) Net losses and LAE $ 1,170.3 $ 900.0 $ 811.2 Sirius Group's reinsurance protection primarily consists of pro-rata and excess of loss protections that protect all of its reportable segments. Attachment points and coverage limits vary by region around the world. Protections by reportable segment are listed below. Global Reinsurance Sirius Group's core proportional property reinsurance programs provide protection for parts of the non-proportional treaty accounts written in Europe, the Americas, Caribbean, Asia, the Middle East, and Australia. These reinsurance protections are designed to increase underwriting capacity where appropriate, and to reduce exposure both to large catastrophe losses and to a frequency of smaller loss events. Sirius Group has in place excess of loss retrocessional coverage for its worldwide earthquake related exposures. This coverage was renewed for one year at June 1, 2019, providing 50% of $40.0 million of reinsurance protection in excess of Sirius Group's retention of $35.0 million and a further of 100% of $35.0 million of coverage in excess of $75.0 million . Sirius Group periodically purchases industry loss warranties ("ILW") contracts to augment its overall retrocessional program. The following ILW contracts are currently in force: Scope Limit Trigger Expiration Date United States excluding North East, all natural perils $5.0 million $40.0 billion July 5, 2020 Sirius Group also purchases excess of loss reinsurance protection for its facultative and primary insurance property books. Almost all of Sirius Group's excess of loss reinsurance protections, excluding ILWs which tend to only cover one loss event, include provisions that reinstate coverage at a cost of 100% or more of the original reinsurance premium. The aviation & space reinsurance program is intended to reduce exposure to a frequency of small losses, a single large loss, or a combination of both. For the proportional and facultative aviation book, reinsurance protection purchased is geared to cover losses from events that cause a market loss in excess of $150.0 million up to a full policy limit of $2.0 billion . This program is in place through October 2020. For the non‑proportional book, reinsurance protection includes a 12.5% quota share treaty. In addition, the non‑proportional book is protected by ILWs totaling limits of $27.5 million . The ILWs attach at industry loss levels between $400.0 million and $800.0 million . Other lines of business within the Global Reinsurance segment are protected through various quota share and excess of loss protections. Global A&H Sirius Group has excess of loss protection covering its personal accident and life accounts written in the Stockholm, Hamburg, Liege, and Singapore branches. For primary insurance, there are account‑specific quota share and stop‑loss reinsurance protections in place of various percentages for the medical benefits and student health business. In addition to these primary insurance protections, there is an excess of loss protection of unlimited dollars in excess of $1.5 million (per person) is in place. U.S. Specialty The Workers' Compensation, Environmental, and Surety lines of business within the U.S. Specialty segment are protected through various quota share and excess of loss protections. Runoff & Other Within the Runoff & Other segment, there are multiple reinsurance protections in place, primarily excess of loss protections. Reinsurance recoverables by rating At December 31, 2019 , Sirius Group had reinsurance recoverables on paid losses of $73.9 million and reinsurance recoverables of $410.3 million on unpaid losses. At December 31, 2018 , Sirius Group had reinsurance recoverables on paid losses of $55.0 million and reinsurance recoverables of $350.2 million on unpaid losses. Because retrocessional reinsurance contracts do not relieve Sirius Group of its obligation to its insureds, the collectability of balances due from Sirius Group's reinsurers is important to its financial strength. Sirius Group monitors the financial strength and ratings of retrocessionaires on an ongoing basis. Uncollectible amounts historically have not been significant. The following tables provide a listing of Sirius Group's gross and net recoverable amounts by the reinsurer's Standard & Poor's Financial Services LLC ("Standard & Poor's") rating and the percentage of total recoverables as of December 31, 2019 and 2018 . With certain reinsurers if Standard & Poor's rating was not available, an A.M. Best rating was used. December 31, 2019 Rating (1) Gross Collateral Net % of Net Total AAA $ 3.4 $ — $ 3.4 1 % AA 117.2 14.3 102.9 42 % A 301.8 195.6 106.2 43 % BBB or lower 14.9 13.7 1.2 1 % Not rated 46.9 13.4 33.5 13 % Total $ 484.2 $ 237.0 $ 247.2 100 % (1) Standard & Poor's ratings as detailed above are: "AAA" (Extremely Strong), "AA" (Very strong), "A" (Strong), and "BBB" (Adequate). December 31, 2018 Rating (1) Gross Collateral Net % of Net Total AA $ 115.1 $ 1.5 $ 113.6 35 % A 212.9 45.4 167.5 52 % BBB or lower 19.5 13.3 6.2 2 % Not rated 57.7 23.2 34.5 11 % Total $ 405.2 $ 83.4 $ 321.8 100 % (1) Standard & Poor's ratings as detailed above are: "AA" (Very strong), "A" (Strong), and "BBB" (Adequate). The following tables provide a listing of the five highest gross recoverable amounts by reinsurer, along with percentage of total recoverable amount, the reinsurer's Standard & Poor's reinsurer rating, and the percentage that the recoverable is collateralized as of December 31, 2019 and 2018 : December 31, 2019 (Millions) Balance % of Total S&P rating % Collateralized Reinsurer: ​ ​ General Insurance Corporation of India (1) $ 143.0 30 % A- 98 % Swiss Reinsurance Companyﾠ Ltd. 44.7 9 % AA- 5 % Berkshire Hathaway,ﾠInc. 34.0 7 % AA+ 3 % Lloyd's of London 27.0 6 % A+ 30 % Argo Capital Group Ltd. 19.1 4 % A- 89 % (1) Reflects an A.M. Best rating of "A-" (Excellent). December 31, 2018 (Millions) Balance % of Total S&P rating % Collateralized Reinsurer: General Insurance Corporation of India (1) $ 82.7 20 % A- 97 % Swiss Reinsurance Company Ltd. 44.1 11 % AA- — % Berkshire Hathaway, Inc. 39.3 10 % AA+ 1 % Argo Capital Group Ltd. 16.7 4 % A- 87 % Lloyd's of London 13.4 3 % A+ 5 % (1) Reflects an A.M. Best rating of "A-" (Excellent).

Deferred acquisition costs

Deferred acquisition costs	12 Months Ended
	Dec. 31, 2019
Deferred Policy Acquisition Costs Disclosures [Abstract]
Deferred acquisition costs	Deferred acquisition costs The following table presents a rollforward of Deferred acquisition costs for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 Deferred acquisition costs - balance, beginning of the year $ 141.6 $ 120.9 $ 84.7 Acquisition costs deferred (1) 221.6 202.6 220.7 Amortization expense (214.4 ) (180.4 ) (186.7 ) Other, including foreign exchange (0.6 ) (1.5 ) 2.2 Deferred acquisition costs – balance, end of the year $ 148.2 $ 141.6 $ 120.9 (1) 2017 amount includes $2.9 from Acquisition of IMG. (See Note 3 .)

Investment securities

Investment securities	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investment securities	Investment securities Net Investment Income Sirius Group's net investment income is comprised primarily of interest income along with associated amortization of premium and accretion of discount on Sirius Group's fixed maturity investments, dividend income from its equity investments, and interest income from its short-term investments. Net investment income for the years ended December 31, 2019 , 2018 , and 2017 consisted of the following: (Millions) 2019 2018 2017 Fixed maturity investments $ 52.1 $ 53.2 $ 51.5 Short-term investments 15.8 5.1 1.5 Equity securities 15.2 16.5 5.1 Other long-term investments 14.2 8.4 8.5 Interest on funds held under reinsurance treaties — (0.5 ) — Total investment income 97.3 82.7 66.6 Investment expenses (12.6 ) (11.3 ) (9.8 ) Net investment income $ 84.7 $ 71.4 $ 56.8 Net Realized and Unrealized Investment Gains (Losses) Net realized and unrealized investment gains (losses) for the years ended December 31, 2019 , 2018 , and 2017 consisted of the following: (Millions) 2019 2018 2017 Gross realized gains $ 99.3 $ 42.3 $ 24.4 Gross realized (losses) (42.6 ) (40.0 ) (51.6 ) Net realized gains (losses) on investments (1) 56.7 2.3 (27.2 ) Net unrealized gains (losses) on investments (2) 80.6 (23.2 ) (10.5 ) Net realized and unrealized investment gains (losses) on investments $ 137.3 $ (20.9 ) $ (37.7 ) (1) Includes $ 50.4 , $17.3 , and $(19.1) of realized gains (losses) due to foreign currency during 2019 , 2018 , and 2017 , respectively. (2) Includes $(5.7) , $35.7 , and $(51.7) of unrealized (losses) gains due to foreign currency during 2019 , 2018 , and 2017 , respectively. Net realized investment gains (losses) Net realized investment gains (losses) for the years ended December 31, 2019 , 2018 , and 2017 consisted of the following: (Millions) 2019 2018 2017 Fixed maturity investments $ 33.7 $ 3.6 $ (19.1 ) Equity securities 9.4 (6.4 ) 0.1 Short-term investments 14.8 — — Derivative instruments (2.5 ) — — Other long-term investments 1.3 5.1 (8.2 ) Net realized investment gains (losses) $ 56.7 $ 2.3 $ (27.2 ) Net unrealized investment gains (losses) The following table summarizes the net unrealized investment gains (losses) and changes in fair value for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 Fixed maturity investments $ 24.1 $ 14.1 $ (41.3 ) Equity securities 51.4 (51.1 ) 25.2 Short-term investments (5.2 ) — — Derivative instruments (0.5 ) — — Other long-term investments 10.8 13.8 5.6 Net unrealized investment gains (losses) $ 80.6 $ (23.2 ) $ (10.5 ) The following table summarizes the amount of total gains (losses) included in earnings attributable to unrealized investment gains (losses) for Level 3 investments for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 Fixed maturity investments $ — $ (6.1 ) $ (0.2 ) Equity securities — — 0.1 Other long-term investments 15.9 4.0 (0.6 ) Total unrealized investment gains (losses) - Level 3 investments $ 15.9 $ (2.1 ) $ (0.7 ) Investment Holdings Fixed maturity investments The cost or amortized cost, gross unrealized investment gains (losses), net foreign currency gains (losses), and fair value of Sirius Group's fixed maturity investments as of December 31, 2019 and 2018 , were as follows: 2019 (Millions) Cost or amortized cost Gross unrealized gains Gross unrealized losses Net foreign currency gains (losses) Fair value Asset-backed securities $ 489.4 $ 1.4 $ (3.9 ) $ (0.1 ) $ 486.8 Corporate debt securities 458.6 5.2 (1.2 ) 11.5 474.1 Residential mortgage-backed securities 426.2 10.5 (1.4 ) 3.6 438.9 U.S. government and government agency 111.5 0.7 (0.4 ) (1.3 ) 110.5 Commercial mortgage-backed securities 88.5 0.9 (0.6 ) 0.2 89.0 Non-U.S. government and government agency 63.7 — (0.7 ) — 63.0 Preferred stocks 17.0 — — — 17.0 U.S. States, municipalities and political subdivision 1.7 — — — 1.7 Total fixed maturity investments $ 1,656.6 $ 18.7 $ (8.2 ) $ 13.9 $ 1,681.0 2018 (Millions) Cost or amortized cost Gross unrealized gains Gross unrealized losses Net foreign currency gains (losses) Fair value Asset-backed securities $ 496.3 $ 0.1 $ (3.8 ) $ 1.9 $ 494.5 Corporate debt securities 694.1 1.4 (7.3 ) 7.6 695.8 Residential mortgage-backed securities 413.0 1.7 (7.1 ) 5.9 413.5 U.S. government and government agency 163.9 0.3 (0.5 ) 4.2 167.9 Commercial mortgage-backed securities 117.7 0.2 (2.7 ) 0.7 115.9 Non-U.S. government and government agency 50.6 — (0.2 ) (0.1 ) 50.3 Preferred stocks 14.5 0.6 (6.8 ) 0.2 8.5 U.S. States, municipalities and political subdivision 2.8 — — — 2.8 Total fixed maturity investments $ 1,952.9 $ 4.3 $ (28.4 ) $ 20.4 $ 1,949.2 The weighted average duration of Sirius Group's fixed income portfolio as of December 31, 2019 was approximately 1.6 years , including short-term investments, and approximately 2.5 years excluding short-term investments. The cost or amortized cost and fair value of Sirius Group's fixed maturity investments as of December 31, 2019 and 2018 are presented below by contractual maturity. Actual maturities could differ from contractual maturities because borrowers may have the right to call or prepay certain obligations with or without call or prepayment penalties. 2019 2018 (Millions) Cost or amortized cost Fair value Cost or amortized cost Fair value Due in one year or less $ 85.0 $ 88.4 $ 249.6 $ 254.6 Due after one year through five years 479.1 490.3 635.6 636.4 Due after five years through ten years 46.3 46.0 26.2 25.7 Due after ten years 25.1 24.6 0.1 0.1 Mortgage-backed and asset-backed securities 1,004.1 1,014.7 1,026.9 1,023.9 Preferred stocks 17.0 17.0 14.5 8.5 Total $ 1,656.6 $ 1,681.0 $ 1,952.9 $ 1,949.2 The following table summarizes the ratings and fair value of fixed maturity investments held in Sirius Group's investment portfolio as of December 31, 2019 and 2018 : (Millions) 2019 2018 AAA $ 559.8 $ 602.0 AA 724.3 818.0 A 219.0 290.5 BBB 95.8 167.4 Other 82.1 71.3 Total fixed maturity investments (1) $ 1,681.0 $ 1,949.2 (1) Credit ratings are assigned based on the following hierarchy: 1) Standard & Poor's and 2) Moody's Investor Service. As of December 31, 2019 , the above totals included $43.3 million of sub-prime securities. Of this total, $21.7 million was rated AAA, $18.4 million rated AA, $3.1 million rated A, and $0.1 million classified as other. As of December 31, 2018 , the above included $42.6 million of sub-prime securities. Of this total, $17.1 million was rated AAA, $9.8 million rated AA, $6.0 million rated A, $4.7 million rated BBB and $5.0 million classified as other. Mortgage-backed, Asset-backed Securities Sirius Group purchases commercial mortgage-backed securities ("CMBS") and residential mortgage-backed securities ("RMBS") and asset-backed securities with the goal of maximizing risk adjusted returns in the context of a diversified portfolio. Sirius Group considers sub-prime securities as those that have underlying loan pools that exhibit weak credit characteristics, or those that are issued from dedicated sub-prime shelves or dedicated second-lien shelf registrations (i.e., Sirius Group considers investments backed primarily by second-liens to be sub-prime risks). Given the tranched nature of mortgage-backed and asset-backed securities, Sirius Group relies primarily on rating agency credit ratings (i.e., S&P and Moody's) to evaluate credit worthiness of these securities and to a lesser extent on credit scores such as FICO. The following table summarizes the total mortgage and asset-backed securities held at fair value in Sirius Group's investment portfolio as of December 31, 2019 and 2018 : (Millions) 2019 2018 Mortgage-backed securities: Agency: Federal national mortgage association $ 235.9 $ 185.0 Federal home loan mortgage corporation 165.0 166.9 Government national mortgage association 52.2 59.4 Total agency (1) 453.1 411.3 Non-agency: Commercial 60.9 85.5 Residential 13.9 32.6 Total non-agency 74.8 118.1 Total mortgage-backed securities 527.9 529.4 Asset-backed securities: Collateralized loan obligations 417.0 373.0 Vehicle receivables 32.9 63.8 Credit card receivables 5.7 10.7 Other 31.2 47.0 Total asset-backed securities 486.8 494.5 Total mortgage and asset-backed securities (2) $ 1,014.7 $ 1,023.9 (1) Represents publicly traded mortgage-backed securities which carry the full faith and credit guaranty of the U.S. government (i.e., GNMA) or are guaranteed by a government-sponsored entity (i.e., FNMA, FHLMC). (2) As of December 31, 2019 and 2018 , all mortgage- and asset-backed securities held by Sirius Group were classified as Level 2 investments. Equity securities and Other long-term investments The cost or amortized cost, gross unrealized investment gains and losses, net foreign currency gains and losses, and fair values of Sirius Group's equity securities and other long-term investments as of December 31, 2019 and 2018 , were as follows: 2019 (Millions) Cost or amortized cost Gross unrealized gains Gross unrealized losses Net foreign currency gains Fair value Equity securities $ 379.2 $ 55.6 $ (37.3 ) $ 7.7 $ 405.2 Other long-term investments $ 315.4 $ 49.9 $ (29.3 ) $ 10.8 $ 346.8 2018 (Millions) Cost or amortized cost Gross unrealized gains Gross unrealized losses Net foreign currency gains Fair value Equity securities $ 409.4 $ 17.8 $ (50.8 ) $ 3.6 $ 380.0 Other long-term investments $ 337.6 $ 32.6 $ (13.5 ) $ 8.3 $ 365.0 Equity securities at fair value consisted of the following as of December 31, 2019 and 2018 : (Millions) 2019 2018 Fixed income mutual funds $ 175.3 $ 157.7 Common stocks 228.1 222.3 Other equity securities 1.8 — Total Equity securities $ 405.2 $ 380.0 Other long-term investments at fair value consisted of the following as of December 31, 2019 and 2018 : (Millions) 2019 2018 Hedge funds and private equity funds $ 269.0 $ 301.4 Limited liability companies and private equity securities 77.8 63.6 Total Other long-term investments $ 346.8 $ 365.0 Hedge Funds and Private Equity Funds Sirius Group holds investments in hedge funds and private equity funds, which are included in other long-term investments. The fair value of these investments has been estimated using the net asset value of the funds. As of December 31, 2019 , Sirius Group held investments in 9 hedge funds and 29 private equity funds. The largest investment in a single fund was $51.6 million as of December 31, 2019 and $54.8 million as of December 31, 2018 . The following table summarizes investments in hedge funds and private equity interests by investment objective and sector as of December 31, 2019 and 2018 : 2019 2018 (Millions) Fair value Unfunded commitments Fair value Unfunded commitments Hedge funds: Long/short multi-sector $ 53.0 $ — $ 41.0 $ — Distressed mortgage credit 51.6 — 54.8 — Private credit 21.5 — 20.0 — Other 1.4 — 2.5 — Total hedge funds 127.5 — 118.3 — Private equity funds: Energy infrastructure & services 53.6 34.6 93.7 54.2 Multi-sector 8.7 7.8 9.0 0.7 Healthcare 25.9 10.4 31.7 15.6 Life settlement 23.9 — 23.7 — Manufacturing/Industrial 27.6 3.9 23.6 10.4 Private equity secondaries 0.6 0.8 1.1 1.1 Real estate — — 0.3 — Other 1.2 2.6 — — Total private equity funds 141.5 60.1 183.1 82.0 Total hedge and private equity funds included in Other long-term investments $ 269.0 $ 60.1 $ 301.4 $ 82.0 Redemption of investments in certain hedge funds is subject to restrictions including lock-up periods where no redemptions or withdrawals are allowed, restrictions on redemption frequency, and advance notice periods for redemptions. Amounts requested for redemptions remain subject to market fluctuations until the redemption effective date, which generally falls at the end of the defined redemption period. The following summarizes the December 31, 2019 fair value of hedge funds subject to restrictions on redemption frequency and advance notice period requirements for investments in active hedge funds: Notice Period Redemption Frequency (Millions) 30-59 days notice 60-89 days notice 90-119 days notice 120+ days notice Total Monthly $ — $ 36.2 $ — $ — $ 36.2 Quarterly 0.8 — — — 0.8 Semi-annual — 0.3 — — 0.3 Annual — 16.8 51.9 21.5 90.2 Total $ 0.8 $ 53.3 $ 51.9 $ 21.5 $ 127.5 Certain of the hedge fund and private equity fund investments in which Sirius Group is invested are no longer active and are in the process of disposing of their underlying investments. Distributions from such funds are remitted to investors as the fund's underlying investments are liquidated. As of December 31, 2019 , no distributions were outstanding from these investments. Investments in private equity funds are generally subject to a "lock-up" period during which investors may not request a redemption. Distributions prior to the expected termination date of the fund may be limited to dividends or proceeds arising from the liquidation of the fund's underlying investments. In addition, certain private equity funds provide an option to extend the lock-up period at either the sole discretion of the fund manager or upon agreement between the fund and the investors. As of December 31, 2019 , investments in private equity funds were subject to lock-up periods as follows: (Millions) 1 – 3 years 3 – 5 years 5 – 10 years Total Private Equity Funds – expected lock up period remaining $ 4.7 $ 1.4 $ 135.4 $ 141.5 Investments Held on Deposit or as Collateral As of December 31, 2019 and 2018 , investments of $1,309.5 million and $792.4 million , respectively, were held in trusts required to be maintained in relation to various reinsurance agreements. Sirius Group's consolidated reinsurance operations are required to maintain deposits with certain insurance regulatory agencies in order to maintain their insurance licenses. The fair value of such deposits which are included within total investments totaled $1,315.5 million and $801.2 million as of December 31, 2019 and 2018 , respectively. As of December 31, 2019 , Sirius Group held $0.2 million of collateral in the form short-term investments associated with Interest Rate Cap agreements. (See Note 13 .) Unsettled investment purchases and sales As of December 31, 2019 and 2018 , Sirius Group reported $2.3 million and $3.2 million , respectively, in Accounts payable on unsettled investment purchases. As of December 31, 2019 and 2018 , Sirius Group reported $6.7 million and $5.0 million , respectively, in Accounts receivable on unsettled investment sales.

Fair value measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements Fair value measurements Fair value measurements are categorized into a hierarchy that distinguishes between inputs based on market data from independent sources ("observable inputs") and a reporting entity's internal assumptions based upon the best information available when external market data is limited or unavailable ("unobservable inputs"). Quoted prices in active markets for identical assets or liabilities have the highest priority ("Level 1"), followed by observable inputs other than quoted prices, including prices for similar but not identical assets or liabilities ("Level 2"), and unobservable inputs, including the reporting entity's estimates of the assumptions that market participants would use, having the lowest priority ("Level 3"). The availability of observable inputs can vary from financial instrument to financial instrument and is affected by a wide variety factors including, for example, the type of financial instrument, whether the financial instrument is new and not yet established in the marketplace, and other characteristics particular to the instrument. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires significantly more judgment. Accordingly, the degree of judgment exercised by management in determining fair value is greatest for instruments categorized in Level 3. In periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This may lead the Company to change the selection of the valuation technique (for example, from market to cash flow approach) or to use multiple valuation techniques to estimate the fair value of a financial instrument. These circumstances could cause an instrument to be reclassified between levels within fair value hierarchy. Investments valued using Level 1 inputs include fixed maturity investments, primarily investments in U.S. Treasuries Bills and Notes, equity securities, and short-term investments. Investments valued using Level 2 inputs are primarily comprised of fixed maturity investments, which have been disaggregated into classes, including U.S. government and government agency, corporate debt securities, mortgage-backed and asset-backed securities, non-U.S. government and government agency, U.S. state and municipalities and political sub division and preferred stocks. Investments valued using Level 2 inputs also include certain ETFs that track U.S. stock indices such as the S&P 500 but are traded on foreign exchanges. Fair value estimates for investments that trade infrequently and have few or no observable market prices are classified as Level 3 measurements. Sirius Group determines when transfers between levels have occurred as of the beginning of the period. Valuation techniques Sirius Group uses outside pricing services to assist in determining fair values for its investments. For investments in active markets, Sirius Group uses the quoted market prices provided by outside pricing services to determine fair value. The outside pricing services Sirius Group uses have indicated that they will only provide prices where observable inputs are available. In circumstances where quoted market prices are unavailable or are not considered reasonable, Sirius Group estimates the fair value using industry standard pricing models and observable inputs such as benchmark yields, reported trades, broker-dealer quotes, issuer spreads, benchmark securities, bids, offers, prepayment speeds, reference data including research publications, and other relevant inputs. Given that many fixed maturity investments do not trade on a daily basis, the outside pricing services evaluate a wide range of fixed maturity investments by regularly drawing parallels from recent trades and quotes of comparable securities with similar features. The characteristics used to identify comparable fixed maturity investments vary by asset type and take into account market convention. The valuation process above is generally applicable to all of Sirius Group's fixed maturity investments. The techniques and inputs specific to asset classes within Sirius Group's fixed maturity investments for Level 2 securities that use observable inputs are as follows: U.S. government and government agency U.S. government and government agency securities consist primarily of debt securities issued by the U.S. Treasury and mortgage pass-through agencies such as the Federal National Mortgage Association, the Federal Home Loan Mortgage Corporation and the Government National Mortgage Association. Fixed maturity investments included in U.S. government and government agency securities are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources and integrate other observations from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The fair value of each security is individually computed using analytical models which incorporate option adjusted spreads and other daily interest rate data. Non-U.S. government and government agency Non-U.S. government and government agency securities consist of debt securities issued by non-U.S. governments and their agencies along with supranational organizations (also known as sovereign debt securities). Securities held in these sectors are primarily priced by pricing services who employ proprietary discounted cash flow models to value the securities. Key quantitative inputs for these models are daily observed benchmark curves for treasury, swap, and high issuance credits. The pricing services then apply a credit spread for each security which is developed by in-depth and real time market analysis. For securities in which trade volume is low, the pricing services utilize data from more frequently traded securities with similar attributes. These models may also be supplemented by daily market and credit research for international markets. Corporate debt securities Corporate debt securities consist primarily of investment-grade debt of a wide variety of U.S. and non-U.S. corporate issuers and industries. The corporate fixed maturity investments are primarily priced by pricing services. When evaluating these securities, the pricing services gather information from market sources regarding the issuer of the security and obtain credit data, as well as other observations, from markets and sector news. Evaluations are updated by obtaining broker dealer quotes and other market information including actual trade volumes, when available. The pricing services also consider the specific terms and conditions of the securities, including any specific features which may influence risk. Mortgage-backed and asset-backed securities The fair value of mortgage and asset-backed securities is primarily priced by pricing services using a pricing model that uses information from market sources and leveraging similar securities. Key inputs include benchmark yields, reported trades, underlying tranche cash flow data, collateral performance, plus new issue data, as well as broker-dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including issuer, vintage, loan type, collateral attributes, prepayment speeds, default rates, recovery rates, cash flow stress testing, credit quality ratings, and market research publications. U.S. states, municipalities, and political subdivisions The U.S. states, municipalities, and political subdivisions portfolio contains debt securities issued by U.S. domiciled state and municipal entities. These securities are generally priced by independent pricing services using the techniques for U.S. government and government agency securities. Preferred stocks The fair value of preferred stocks is generally priced by independent pricing services using an evaluated pricing model that calculates the appropriate spread over a comparable security for each issue. Key inputs include exchange prices (underlying and common stock of same issuer), benchmark yields, reported trades, broker-dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data including sector, coupon, credit quality ratings, duration, credit enhancements, early redemption features, and market research publications. Level 3 Investments Level 3 valuations are generated from techniques that use assumptions not observable in the market. These unobservable assumptions reflect Sirius Group's assumptions, that market participants would use in valuing the investment. Generally, certain securities may start out as Level 3 when they are originally issued but as observable inputs become available in the market, they may be reclassified to Level 2. Sirius Group employs a number of procedures to assess the reasonableness of the fair value measurements for its other long-term investments, including obtaining and reviewing the audited annual financial statements of hedge funds and private equity funds and periodically discussing each fund's pricing with the fund manager. However, since the fund managers do not provide sufficient information to evaluate the pricing inputs and methods for each underlying investment, the inputs are considered to be unobservable. The fair values of Sirius Group's investments in private equity securities and private debt instruments have been classified as Level 3 measurements. They are carried at fair value and are initially valued based on transaction price and their valuation is subsequently estimated based on available evidence such as a market transaction in similar instruments and other financial information for the issuer. Investments measured using Net Asset Value The fair value of Sirius Group's investments in hedge funds and private equity funds has been determined using net asset value. The hedge fund's administrator provides quarterly updates of fair value in the form of Sirius Group's proportional interest in the underlying fund's net asset value (collectively "NAV"), which is deemed to approximate fair value, generally with a three month delay in valuation. The fair value of investment in hedge funds is measured using the NAV practical expedient and therefore has been not categorized within the fair value hierarchy. The private equity funds provide quarterly or semi-annual partnership capital statements with a three or six month delay which are used as a basis for valuation. These private equity investments vary in investment strategies and are not actively traded in any open markets. The fair value of these investments are measured using NAV practical expedient and therefore have not been categorized with the fair value hierarchy. Due to a lag in reporting, some of the fund managers, fund administrators, or both, are unable to provide final fund valuations as of the Company's reporting date. In these circumstances, Sirius Group estimates the return of the current period and uses all credible information available. This includes utilizing preliminary estimates reported by its fund managers and using other information that is available to Sirius Group with respect to the underlying investments, as necessary. Fair Value Measurements by Level The following tables summarize Sirius Group's financial assets and liabilities measured at fair value as of December 31, 2019 and 2018 by level: 2019 (Millions) Fair value Level 1 inputs Level 2 inputs Level 3 inputs Assets measured at fair value Fixed maturity investments: U.S. Government and government agency $ 110.5 $ 109.1 $ 1.4 $ — Corporate debt securities 474.1 — 474.1 — Asset-backed securities 486.8 — 486.8 — Residential mortgage-backed securities 438.9 — 438.9 — Commercial mortgage-backed securities 89.0 — 89.0 — Non-U.S. government and government agency 63.0 31.7 31.3 — Preferred stocks 17.0 — — 17.0 U.S. States, municipalities, and political subdivision 1.7 — 1.7 — Total fixed maturity investments 1,681.0 140.8 1,523.2 17.0 Equity securities: Fixed income mutual funds 175.3 175.3 — — Common stocks 228.1 228.1 — — Other equity securities 1.8 — 1.8 — Total equity securities 405.2 403.4 1.8 — Short-term investments 1,085.2 1,073.7 11.5 — Other long-term investments (1) 77.8 — — 77.8 Total investments $ 3,249.2 $ 1,617.9 $ 1,536.5 $ 94.8 Loan participation 20.0 — — 20.0 Derivative instruments 11.4 1.3 — 10.1 Total assets measured at fair value $ 3,280.6 $ 1,619.2 $ 1,536.5 $ 124.9 Liabilities measured at fair value Contingent consideration liabilities $ 28.2 $ — $ — $ 28.2 Derivative instruments 9.5 0.2 — 9.3 Total liabilities measured at fair value $ 37.7 $ 0.2 $ — $ 37.5 (1) Excludes fair value of $269.0 associated with hedge funds and private equity funds which fair value is measured at net asset value using the practical expedient. 2018 (Millions) Fair value Level 1 inputs Level 2 inputs Level 3 inputs Assets measured at fair value Fixed maturity investments: U.S. Government and government agency $ 167.9 $ 164.7 $ 3.2 $ — Corporate debt securities 695.8 — 695.8 — Asset-backed securities 494.5 — 494.5 — Residential mortgage-backed securities 413.5 — 413.5 — Commercial mortgage-backed securities 115.9 — 115.9 — Non-U.S. government and government agency 50.3 42.9 7.4 — Preferred stocks 8.5 — 3.1 5.4 U.S. States, municipalities, and political subdivision 2.8 — 2.8 — Total fixed maturity investments 1,949.2 207.6 1,736.2 5.4 Equity securities: Fixed income mutual funds 157.7 157.7 — — Common stocks 222.3 222.3 — — Other equity securities — — — — Total equity securities 380.0 380.0 — — Short-term investments 715.5 679.3 36.2 — Other long-term investments (1) 63.6 — — 63.6 Total investments $ 3,108.3 $ 1,266.9 $ 1,772.4 $ 69.0 Loan participation — — — — Derivative instruments 4.1 — — 4.1 Total assets measured at fair value $ 3,112.4 $ 1,266.9 $ 1,772.4 $ 73.1 Liabilities measured at fair value Contingent consideration liabilities $ 28.8 $ — $ — $ 28.8 Derivative instruments 5.1 0.5 — 4.6 Total liabilities measured at fair value $ 33.9 $ 0.5 $ — $ 33.4 (1) Excludes fair value of $301.4 associated with hedge funds and private equity funds which fair value is measured at net asset value using the practical expedient. Rollforward of Level 3 Fair Value Measurements The following tables present changes in Level 3 for financial instruments measured at fair value for the years ended December 31, 2019 and 2018 : ​ 2019 (Millions) Fixed maturities Other long-term investments (1) Loan participation Derivative instruments assets & (liabilities) Contingent consideration (liabilities) Balance at January 1, 2019 $ 5.4 $ 63.6 $ — $ (0.5 ) $ (28.8 ) Total realized and unrealized gains — 7.3 — (7.1 ) (6.3 ) Foreign currency losses through Other Comprehensive Income — (0.6 ) — — — Purchases 17.0 15.7 20.0 — — Sales/settlements (5.4 ) (8.2 ) — 8.4 6.9 Balance at December 31, 2019 $ 17.0 $ 77.8 $ 20.0 $ 0.8 $ (28.2 ) (1) Excludes fair value of $269.0 associated with hedge funds and private equity funds which fair value is measured at net asset value using the practical expedient. ​ 2018 (Millions) Fixed maturities Other long-term investments (1) Loan participation Derivative instruments assets & (liabilities) Contingent consideration (liabilities) Balance at January 1, 2018 $ 8.0 $ 64.2 $ — $ (6.1 ) $ (42.8 ) Total realized and unrealized gains (6.1 ) 6.8 — 12.0 9.6 Foreign currency losses through Other Comprehensive Income — (4.4 ) — — — Purchases 4.0 1.2 — — — Sales/settlements (0.5 ) (4.2 ) — (6.4 ) 4.4 Balance at December 31, 2018 $ 5.4 $ 63.6 $ — $ (0.5 ) $ (28.8 ) (1) Excludes fair value of $301.5 associated with hedge funds and private equity funds which fair value is measured at net asset value using the practical expedient. Fair Value Measurements – transfers between levels There were no transfers between Level 3 and Level 2 measurements for the year ended December 31, 2019 or December 31, 2018 . Significant Unobservable Inputs The table below presents information about the significant unobservable inputs used for recurring fair value measurements for certain Level 3 instruments as of December 31, 2019 and 2018 , and includes only those instruments for which information about the inputs is reasonably available to Sirius Group, such as data from independent third-party valuation service providers and from internal valuation models. (Millions) 2019 Description Valuation technique(s) Fair value Unobservable input Private equity securitiesﾠ (1) Share price of recent transaction $ 32.5 Purchase share price $ 40.6 Loan participation (1) Purchase price of recent transaction $ 20.0 Purchase price $ 20.0 Preferred stock (1) Share price of recent transaction $ 17.5 Purchase price $ 7.74 Private equity securitiesﾠ (1) Multiple of GAAP book value $ 14.2 Book value multiple 0.9 Preferred stock (1) Purchase price of recent transaction $ 12.2 Purchase price $ 12.2 Private debt instrumentﾠ (1) Purchase price of recent transaction $ 7.2 Purchase price $ 9.0 Weather derivatives (2) Third party appraisal $ 7.0 Broker quote $ 7.0 Private equity securitiesﾠ (1) Purchase price of recent transaction $ 5.1 Purchase price $ 7.74 Preferred stock (1) Purchase price of recent transaction $ 4.8 Purchase price $ 4.80 Currency forwards (2) Third party appraisal $ 2.7 Broker quote $ 2.7 Private equity securitiesﾠ (1) Purchase price of recent transaction $ 1.0 Purchase price $ 10.0 Equity warrants (2) Option pricing model $ 0.4 Strike price $ 0.2 Private equity securitiesﾠ (1) Purchase price of recent transaction $ 0.3 Purchase price $ 0.3 Currency swaps (2) Third party appraisal $ (3.6 ) Broker quote $ (3.6 ) Currency forwards (2) Third party appraisal $ (5.7 ) Broker quote $ (5.7 ) Contingent consideration External valuation model $ (28.2 ) Discounted future payments $ (28.2 ) (1) As of December 31, 2019 , each asset type consists of one security. (2) See Note 13 for discussion of derivative instruments. (Millions) 2018 Description Valuation technique(s) Fair value Unobservable input Private equity securitiesﾠ (1) Share price of recent transaction $ 32.5 Purchase share price $ 40.63 Private equity securitiesﾠ (1) Multiple of GAAP book value $ 14.7 Book value multiple 0.9 Private debt instrumentﾠ (1) Purchase price of recent transaction $ 9.0 Purchase price $ 9.0 Private debt instrumentﾠ (1) Purchase price of recent transaction $ 6.0 Purchase price $ 6.0 Preferred stock (1) Purchase price of recent transaction $ 4.6 Average share price $ 1.88 Weather derivatives (2) Third party appraisal $ 3.9 Broker quote $ 3.9 Common stock (1) Purchase price of recent transaction $ 0.9 Purchase price $ 1.88 Preferred stock (1) Share price of recent transaction $ 0.8 Purchase price $ 0.8 Common stock (1) Share price of recent transaction $ 0.3 Purchase price $ 10.0 Private debt instrumentﾠ (1) Purchase price of recent transaction $ 0.2 Purchase price $ 0.2 Interest rate cap (2) Third party appraisal $ 0.2 Broker quote $ 0.2 Currency swaps (2) Third party appraisal $ (4.6 ) Broker quote $ (4.6 ) Contingent consideration External valuation model $ (28.8 ) Discounted future payments $ (28.8 ) (1) As of December 31, 2018 , each asset type consists of one security. (2) See Note 13 for discussion of derivative instruments. Financial instruments disclosed, but not carried at fair value Sirius Group uses various financial instruments in the normal course of its business. The carrying values of Cash, Accrued investment income, certain other assets, Accounts payable on unsettled investment purchases, certain other liabilities, and other financial instruments not included in the table below approximated their fair values as of December 31, 2019 and 2018 , due to their respective short maturities. As these financial instruments are not actively traded, their respective fair values are classified within Level 3. The following table includes financial instruments for which the carrying value differs from the estimated fair values as of December 31, 2019 and 2018 : 2019 2018 (Millions) Fair value (1) Carrying value Fair value (1) Carrying value Liabilities, Mezzanine equity, and Non-controlling interest: 2017 SEK Subordinated Notes $ 294.5 $ 291.2 $ 309.5 $ 303.6 2016 SIG Senior Notes $ 394.5 $ 394.0 $ 347.6 $ 393.2 Series B preference shares $ 186.4 $ 223.0 $ 191.7 $ 232.2 (1) Fair value estimated by internal pricing and considered a Level 3 measurement. Fair Value Measurements on a Non-Recurring Basis Sirius Group measures the fair value of certain assets on a non-recurring basis, generally quarterly, annually, or when events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. These include goodwill, indefinite-lived intangible assets, and long-lived assets. Sirius Group uses a variety of techniques to measure the fair value of these assets when appropriate, as described below: Goodwill and Indefinite-Lived Intangible Assets : The preliminary fair value of the goodwill and indefinite-lived intangible asset acquired as part of the acquisitions of both IMG and Armada (see Note 3 ) was determined using the income valuation and market valuation methodologies. The income approach determines value for an asset based on the present value of cash flows projected to be generated over the remaining economic life of the asset being measured. The net cash flows are discounted to present value using a discount rate that reflects the relative risk of achieving the cash flow and the time value of money. The market approach is a valuation technique that uses prices and other relevant information generated by market transactions involving identical or comparable assets or group of assets. Determining the fair value goodwill and indefinite-lived intangible assets acquired requires the exercise of significant judgment, including the amount and timing of expected future cash flows, long-term growth rates and discount rates. The cash flows employed in the valuation are based on Sirius Group's best estimates of future sales, earnings, and cash flows after considering factors such as general market conditions, changes in working capital, long term business plans, and recent operating performance. Use of different estimates and judgments could yield different results. Sirius Group tests goodwill and indefinite-lived intangible assets for impairment whenever events or changes in circumstances indicate the carrying amount may not be recoverable. When Sirius Group determines goodwill and indefinite-lived intangible assets may be impaired, Sirius Group uses techniques, including discounted expected future cash flows, to measure fair value. Sirius Group used Level 3 inputs to measure and did not record any impairments of goodwill or indefinite-lived intangible assets. Sirius Group recorded an $8.0 million and $5.0 million of impairment of Trade Names indefinite-lived intangible asset during 2018 and 2017, respectively, that was recorded in Impairment of Intangible Assets in the Consolidated Statements of (Loss). (See Note 10 ). Long-Lived Assets : Sirius Group tests its long-lived assets for impairment whenever events or changes in circumstances indicate the carrying amount of a long-lived asset may not be recoverable.

Goodwill and intangible assets

Goodwill and intangible assets	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and intangible assets	Goodwill and intangible assets Goodwill represents the excess of the amount paid to acquire subsidiaries over the fair value of identifiable net assets at the date of acquisition. Intangible assets consist primarily of distribution relationships, trade names, customer relationships, technology, and insurance licenses. Finite-life intangible assets are measured at their acquisition date fair values, are amortized over their economic lives, and presented net of accumulated amortization on the balance sheet. Goodwill is not amortized, but rather is evaluated for impairment on an annual basis, or whenever indications of potential impairment exist. In the absence of any indications of potential impairment, the evaluation of goodwill is performed during the fourth quarter of each year. Sirius Group uses widely accepted valuation techniques to determine the fair value of its reporting units used in its annual goodwill impairment analysis. Sirius Group's valuation is primarily based on qualitative and quantitative assessments regarding the fair value of the reporting unit relative to its carrying value. Sirius Group models the fair value of the reporting unit based on projected earnings and cash flows of the reporting unit. Intangible assets with indefinite lives are evaluated for impairment at least annually and when events or changes in circumstances indicate that it is more likely than not that the asset is impaired. The following table shows the change in goodwill, intangible assets with an indefinite life, and intangible assets with a finite life during the years ended December 31, 2019 and 2018 : (Millions) Goodwill Intangible assets with an indefinite life Intangible assets with a finite life Total Net balance at December 31, 2017 $ 401.0 $ 27.0 $ 189.3 $ 617.3 Additions (1) — 3.1 — 3.1 Foreign currency translation (2) (0.4 ) — — (0.4 ) Impairments (2) — (8.0 ) — (8.0 ) Amortization (2) — — (15.8 ) (15.8 ) Net balance at December 31, 2018 400.6 22.1 173.5 596.2 Additions — — — — Foreign currency translation (2) 0.2 — — 0.2 Impairments (2) — — — — Amortization (2) — — (15.8 ) (15.8 ) Net balance at December 31, 2019 $ 400.8 $ 22.1 $ 157.7 $ 580.6 (1) Additions in 2018 relate to insurance licenses allocated to the Runoff & Other segment. (2) Foreign currency translation, impairments, and amortization in 2019 and 2018 relate to Armada and IMG and are allocated to the Global A&H segment. For the year ended December 31, 2019 , Sirius Group did not recognize any impairments on Intangible assets with an indefinite life. For the year ended December 31, 2018 , Sirius Group recognized an impairment of Intangible assets with an indefinite life that related to a trade name intangible asset acquired as part of the acquisition of IMG. The impairments resulted from lower than anticipated growth when comparing the forecasted results against a reforecast of results at year end. A quantitative impairment review of the IMG trade name intangible asset was performed by applying the royalty replacement method to determine the asset's fair value as of December 31, 2019 and 2018 , respectively. Under the royalty replacement method, the fair value of IMG's trade name intangible asset was determined based on a market participant's view of the royalty that would be paid to license the right to use the trade name. This quantitative analysis incorporated several assumptions including forecasted future revenues and cash flows, estimated royalty rate, based on similar licensing transactions and market royalty rates, and discount rate, which incorporates assumptions such as weighted-average cost of capital and risk premium. As a result of the impairment testing, the carrying value of IMG's trade name intangible asset exceeded its estimated fair value in 2018 and an impairment of $8.0 million was recorded as Impairment of intangible assets on the Consolidated Statements of (Loss). The following tables presents the components of goodwill and intangible assets as of December 31, 2019 and 2018 : ​ 2019 (Millions) Gross balance Accumulated amortization Impairments Foreign currency translation Net balance Customer relationships – finite life (1) $ 17.0 $ (3.5 ) $ — $ — $ 13.5 Distribution relationships – finite life (1) 151.0 (25.5 ) — — 125.5 Goodwill – indefinite life (1) 400.7 — — 0.1 400.8 Insurance licenses – indefinite life (2) 8.1 — — — 8.1 Technology – finite life (1) 15.5 (6.9 ) — — 8.6 Trade names – finite life (1) 16.0 (5.9 ) — — 10.1 Trade names – indefinite life (1) 14.0 — — — 14.0 Net balance at December 31, 2019 $ 622.3 $ (41.8 ) $ — $ 0.1 $ 580.6 (1) Allocated to the Global A&H segment. (2) Allocated to the Runoff & Other segment. 2018 (Millions) Gross balance Accumulated amortization Impairments Foreign currency translation Net balance Customer relationships – finite life (1) $ 17.0 $ (2.2 ) $ — $ — $ 14.8 Distribution relationships – finite life (1) 151.0 (15.8 ) — — 135.2 Goodwill – indefinite life (1) 400.7 — — (0.1 ) 400.6 Insurance licenses – indefinite life (2) 8.1 — — — 8.1 Technology – finite life (1) 15.5 (4.3 ) — — 11.2 Trade names – finite life (1) 16.0 (3.7 ) — — 12.3 Trade names – indefinite life (1) 27.0 — (13.0 ) — 14.0 Net balance at December 31, 2018 $ 635.3 $ (26.0 ) $ (13.0 ) $ (0.1 ) $ 596.2 (1) Allocated to the Global A&H segment. (2) Allocated to the Runoff & Other segment . The amortization of intangibles assets for the years ended December 31, 2019 , 2018 , and 2017 was $15.8 million, $15.8 million, and $ 10.2 million, respectively. The estimated remaining amortization expense for Sirius Group's intangible assets with finite lives is as follows: (Millions) 2020 $ 15.8 2021 15.8 2022 14.6 2023 13.8 2024 13.2 2025 and thereafter 84.5 Total remaining amortization expense $ 157.7 The estimated remaining useful lives of these intangible assets range from 2.3 years to 19.9 years .

Debt and standby letters of cre

Debt and standby letters of credit facilities	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt and standby letters of credit facilities	Debt and standby letters of credit facilities Sirius Group's debt outstanding as of December 31, 2019 and 2018 consisted of the following: (Millions) December 31, 2019 Effective rate (1) December 31, 2018 Effective rate (1) 2017 SEK Subordinated Notes, at face value $ 295.0 4.0 % $ 307.6 3.8 % Unamortized issuance costs (3.8 ) (4.0 ) 2017 SEK Subordinated Notes, carrying value 291.2 303.6 2016 SIG Senior Notes, at face value 400.0 4.7 % 400.0 4.7 % Unamortized discount (2.3 ) (2.6 ) Unamortized issuance costs (3.7 ) (4.2 ) 2016 SIG Senior Notes, carrying value 394.0 393.2 Total debt $ 685.2 $ 696.8 (1) Effective rate considers the effect of the debt issuance costs. A schedule of contractual repayments of Sirius Group's debt as of December 31, 2019 follows: (Millions) December 31, 2019 Due in one year or less $ — Due in one to three years — Due in three to five years — Due after five years 695.0 Total $ 695.0 2017 SEK Subordinated Notes On September 22, 2017, Sirius Group issued floating rate callable subordinated notes denominated in Swedish kronor ("SEK") in the amount of SEK 2,750.0 million (or $346.1 million on date of issuance) at a 100% issue price ("2017 SEK Subordinated Notes"). The 2017 SEK Subordinated Notes were issued in an offering that was exempt from the registration requirements of the Securities Act of 1933. The 2017 SEK Subordinated Notes bear interest on their principal amount at a floating rate equal to the applicable Stockholm Interbank Offered Rate ("STIBOR") for the relevant interest period plus an applicable margin, payable quarterly in arrears on March 22, June 22, September 22, and December 22 in each year commencing on December 22, 2017, until maturity in September 2047. Beginning on September 22, 2022, the 2017 SEK Subordinated Notes may be redeemed, in whole or in part, at Sirius Group's option. In addition, within 90 days following the occurrence of a Specified Event (as defined below), the 2017 SEK Subordinated Notes may be redeemed, in whole but not in part, at Sirius Group's option. "Specified Event" means (a) an "Additional Amounts Event" in connection with a change in laws, rules or regulations as a result of which Sirius Group is obligated to pay additional amounts on the notes in respect of any withholding or deduction for taxes, (b) a "Tax Event" in connection with a change in laws, rules or regulations as a result of which interest on the notes is no longer fully deductible by Sirius Group for income tax purposes in the applicable jurisdiction (to the extent that such interest was so deductible as of the time of such Tax Event), (c) a "Rating Methodology Event" in connection with a change in, or clarification to, the rating methodology of Standard & Poor's or Fitch that results in a materially unfavorable capital treatment of the notes, or (d) a "Regulatory Event" in connection with a change in, or clarification to, applicable supervisory regulations that results in the notes no longer qualifying as Tier 2 Capital. Sirius Group incurred $4.6 million in expenses related to the issuance of the 2017 SEK Subordinated Notes (including SEK 27.5 million , or $3.5 million , in underwriting fees), which have been deferred and are being recognized into interest expense over the life of the 2017 SEK Subordinated Notes. A portion of the proceeds were used to fully redeem the outstanding $250.0 million Sirius International Group, Ltd. Preference Shares. (See Note 15 ). Taking into effect the amortization of all underwriting and issuance expenses, and applicable STIBOR, the 2017 SEK Subordinated Notes yielded an effective rate of approximately 4.0% and 3.8% for the years ended December 31, 2019 and 2018 , respectively. Sirius Group recorded $11.9 million , $11.7 million and $3.3 million of interest expense, inclusive of amortization of issuance costs, on the 2017 SEK Subordinated Notes for the years ended December 31, 2019 , 2018 , and 2017 , respectively. 2016 SIG Senior Notes On November 1, 2016, Sirius Group issued $400.0 million face value of senior unsecured notes ("2016 SIG Senior Notes") at an issue price of 99.209% for net proceeds of $392.4 million after taking into effect both deferrable and non-deferrable issuance costs. The SIG Senior Notes were issued in an offering that was exempt from the registration requirements of the Securities Act of 1933. The 2016 SIG Senior Notes bear an annual interest rate of 4.6% , payable semi-annually in arrears on May 1 and November 1, in each year commencing on May 1, 2017, until maturity in November 2026. Sirius Group incurred $5.1 million in expenses related to the issuance of the 2016 SIG Senior Notes (including $3.4 million in underwriting fees), which have been deferred and are being recognized into interest expense over the life of the 2016 SIG Senior Notes. Taking into effect the amortization of the original issue discount and all underwriting and issuance expenses, the 2016 SIG Senior Notes yield an effective rate of approximately 4.7% per annum. Sirius Group recorded $19.1 million of interest expense, inclusive of amortization of issuance costs on the 2016 SIG Senior Notes for each the years ended December 31, 2019 , 2018 , and 2017 . Old Lyme Note On April 25, 2017, Sirius Group made a payment of $3.8 million to retire the Old Lyme Note that was originally issued as part of the acquisition of the runoff loss reserve portfolio of Old Lyme Insurance Company Ltd. As part of the acquisition in 2011, Sirius Group entered into a five -year $2.1 million note that was subject to upward adjustments for favorable loss reserve development (up to 50.0% of $6.0 million ) and downward adjustments for any adverse loss reserve development. From inception, Sirius Group had favorable loss reserve development of $3.4 million on the Old Lyme loss reserve position that resulted in an increase of $1.7 million on the Old Lyme Note. Standby Letter of Credit Facilities On November 6, 2019, Sirius International agreed to renew two standby letter of credit facility agreements totaling $125 million to provide capital support for Lloyd's Syndicate 1945. The first letter of credit is a $90 million facility with Nordea Bank Abp, London Branch, which is issued on an unsecured basis. The second letter of credit is a $35 million facility with DNB Bank ASA, Sweden Branch, $25 million of which is issued on an unsecured basis. Each facility is renewable annually. The above referenced facilities are subject to various affirmative, negative and financial covenants that the Company considers to be customary for such borrowings, including certain minimum net worth and maximum debt to capitalization standards. Sirius International has other secured letter of credit and trust arrangements with various financial institutions to support its insurance operations. As of December 31, 2019 and 2018 , respectively, these secured letter of credit and trust arrangements were collateralized by pledged assets and assets in trust of SEK 3.4 billion and SEK 2.9 billion , or $363.3 million and $321.3 million (based on the December 31, 2019 and December 31, 2018 SEK to USD exchange rates). As of December 31, 2019 and 2018 , respectively, Sirius America's trust arrangements were collateralized by pledged assets and assets in trust of $57.7 million and $56.2 million . As of December 31, 2019 and 2018 , respectively, Sirius Bermuda Insurance Company's ("Sirius Bermuda") trust arrangements were collateralized by pledged assets and assets in trust of $784.0 million and $319.7 million . Revolving Credit Facility In February 2018, Sirius Group, through its indirectly wholly-owned subsidiary Sirius International Group, Ltd., entered into a three -year, $300 million senior unsecured revolving credit facility (the "Facility"). The Facility provides access to loans for working capital and general corporate purposes, and letters of credit to support obligations under insurance and reinsurance agreements and retrocessional agreements. The Facility is subject to various affirmative, negative and financial covenants that Sirius Group considers to be customary for such borrowings, including certain minimum net worth, maximum debt to capitalization and financial strength rating standards. As of December 31, 2019 , there were no outstanding borrowings under the Facility. Debt and Standby Letter of Credit Facility Covenants As of December 31, 2019 , Sirius Group was in compliance with all of the covenants under the 2017 SEK Subordinated Notes, the 2016 SIG Senior Notes, the Nordea Bank Finland Abp, London Branch facility, and the DNB Bank ASA, Sweden Branch facility. In addition, as of December 31, 2019 , Sirius Group was in compliance with all of the covenants under the Facility. Interest Total interest expense incurred by Sirius Group for its indebtedness was $31.0 million , $30.8 million , and $22.4 million in 2019 , 2018 , and 2017 . Total interest paid by Sirius Group for its indebtedness was $29.9 million , $30.0 million , and $22.0 million in 2019 , 2018 , and 2017 , respectively.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income taxes	Income taxes The Company and its Bermuda domiciled subsidiaries are not subject to Bermuda income tax under current Bermuda law. In the event there is a change in the current law such that taxes are imposed, the Company and its Bermuda domiciled subsidiaries would be exempt from such tax until March 31, 2035, pursuant to the Bermuda Exempted Undertakings Tax Protection Act of 1966. The Company has subsidiaries and branches that operate in various other jurisdictions around the world that are subject to tax in the jurisdictions in which they operate. The jurisdictions in which the Company's subsidiaries and branches are subject to tax are Australia, Belgium, Canada, Denmark, Germany, Gibraltar, Hong Kong (China), Ireland, Luxembourg, Malaysia, Shanghai (China), Singapore, Spain, Sweden, Switzerland, the United Kingdom, and the United States. Sirius Group's net income (loss) before income taxes for the years ended December 31, 2019 , 2018 , and 2017 was generated in the following domestic and foreign jurisdictions: (Millions) 2019 2018 2017 Domestic: ​ Bermuda $ (32.8 ) $ 62.7 $ (95.0 ) Foreign: U.S. (5.4 ) (10.1 ) (22.4 ) U.K. (29.1 ) (14.9 ) (27.0 ) Sweden (22.4 ) (74.2 ) (26.1 ) Luxembourg 56.0 60.3 43.4 Netherlands — (0.1 ) 18.2 Other — — (1.0 ) Total (loss) income before income taxes $ (33.7 ) $ 23.7 $ (109.9 ) The total income tax (expense) benefit for the years ended December 31, 2019 , 2018 , and 2017 consisted of the following: (Millions) 2019 2018 2017 Current tax (expense): U.S. Federal $ (1.6 ) $ (7.0 ) $ (0.9 ) State (2.0 ) (2.2 ) (2.0 ) Non-U.S. (1.5 ) (19.8 ) (3.6 ) Total current tax benefit (expense) (5.1 ) (29.0 ) (6.5 ) Deferred tax (expense): U.S. Federal (8.8 ) 14.3 (8.7 ) State 0.9 0.2 (2.0 ) Non-U.S. 1.1 (25.9 ) (9.2 ) Total deferred tax (expense) (6.8 ) (11.4 ) (19.9 ) Total income tax (expense) $ (11.9 ) $ (40.4 ) $ (26.4 ) Effective Rate Reconciliation A reconciliation of taxes calculated using the 21.4% Swedish statutory rate (the rate at which the majority of Sirius Group's worldwide operations are taxed) to the income tax (expense) benefit on pre-tax income follows: (Millions) 2019 2018 2017 Tax benefit (expense) at the statutory rate $ 7.2 $ (5.2 ) $ 24.2 Differences in taxes resulting from: Change in valuation allowance (20.7 ) 2.3 1.4 Non-Sweden earnings (19.6 ) 2.3 (18.4 ) Tax reserve adjustments 13.9 (42.0 ) (0.7 ) Foreign tax credits 12.2 10.8 2.2 Results from internal restructuring 7.4 (9.1 ) — Tax rate change enacted in Luxembourg (5.8 ) — 0.4 State taxes expense (1.7 ) (2.9 ) (0.7 ) Withholding taxes (1.7 ) (1.9 ) (0.8 ) Tax rate change—other (1.6 ) 0.1 (29.7 ) Tax on Safety Reserve (0.6 ) (15.3 ) — Tax rate change enacted in Sweden (0.2 ) 15.4 — Section 197 Intangible as result of internal restructuring — 6.9 — Other, net (0.7 ) (1.8 ) (4.3 ) Total income tax (expense) on pre-tax earnings $ (11.9 ) $ (40.4 ) $ (26.4 ) The non-Sweden component of pre-tax (loss) income was $(11.3) million , $97.9 million , and $(83.8) million for the years ended December 31, 2019 , 2018 , and 2017 , respectively. The TCJA includes a new BEAT provision, which is essentially a minimum tax that is potentially applicable to certain otherwise deductible payments made by U.S. entities to non-U.S. affiliates, including cross-border interest payments and reinsurance premiums. The statutory BEAT rate is 10% in 2019 -2025, and then rises to 12.5% in 2026 and thereafter. The TCJA also includes provisions for GILTI under which taxes on foreign income are imposed on the excess of a deemed return on tangible assets of certain foreign subsidiaries. Consistent with accounting guidance, Sirius Group will treat BEAT as an in period tax charge when incurred in future periods for which no deferred taxes need to be provided and has made an accounting policy election to treat GILTI taxes in a similar manner. No provision for income taxes related to BEAT or GILTI was recorded as of December 31, 2019 or December 31, 2018 . Sirius Group has capital and liquidity in many of its subsidiaries, some of which may reflect undistributed earnings. If such capital or liquidity were to be paid or distributed to the Company or Sirius Group's subsidiaries, as dividends or otherwise, they may be subject to income or withholding taxes. Sirius Group generally intends to operate, and manage its capital and liquidity, in a tax-efficient manner. However, the applicable tax laws in relevant countries are still evolving, including in response to guidance from the OECD. Accordingly, such payments or earnings may be subject to income or withholding tax in jurisdictions where they are not currently taxed or at higher rates of tax than currently taxed, and the applicable tax authorities could attempt to apply income or withholding tax to past earnings or payments. Tax Payments and Receipts Net income tax payments to national, state, and local governments totaled $9.3 million , $19.1 million , and $16.7 million for the years ended December 31, 2019 , 2018 , and 2017 , respectively. Deferred Tax Inventory Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts for tax purposes. An outline of the significant components of Sirius Group's deferred tax assets and liabilities follows: (Millions) 2019 2018 Deferred income tax assets related to: Non-U.S. net operating loss carry forwards $ 211.1 $ 249.8 Tax credit carry forwards 41.6 28.7 U.S. federal net operating loss and capital carry forwards 40.2 33.8 Loss reserve discount 6.6 7.3 Unearned premiums 4.3 3.1 Investment basis differences 3.6 — Foreign currency translation on investments and other assets 3.4 0.8 Incentive compensation and benefit accruals 2.8 1.9 Deferred Interest 2.6 2.1 Allowance for doubtful accounts 1.5 1.4 Other items 3.9 2.7 Total gross deferred income tax assets 321.6 331.6 Valuation allowance (79.8 ) (64.3 ) Total adjusted deferred tax asset 241.8 267.3 Deferred income tax liabilities related to: Safety reserve (See Note 18 ) 239.4 261.1 Intangible assets 25.7 28.7 Deferred acquisition costs 4.6 3.1 Net unrealized investment gains 3.7 0.3 Purchase Accounting 3.6 3.0 Investment basis differences — 2.4 Other items 4.0 3.6 Total deferred income tax liabilities 281.0 302.2 Net deferred tax (liability) asset $ (39.2 ) $ (34.9 ) Sirius Group's deferred tax assets are net of U.S. federal and non-U.S. valuation allowances and, to the extent they relate to non-U.S. jurisdictions, they are shown at year-end exchange rates. Of the $39.2 million net deferred tax liability as of December 31, 2019 , $25.1 million relates to net deferred tax assets in U.S. subsidiaries, $141.6 million relates to net deferred tax assets in Luxembourg subsidiaries, and $205.9 million relates to net deferred tax liabilities in Sweden subsidiaries. Net Operating Loss and Capital Loss Carryforwards Net operating loss and capital loss carryforwards as of December 31, 2019 , the expiration dates, and the deferred tax assets thereon are as follows: (Millions) 2019 United States Luxembourg Sweden U.K. Total 2019-2023 $ 1.5 $ — $ — $ — $ 1.5 2024-2038 171.4 0.1 — — 171.5 No expiration date 21.5 764.9 230.1 97.0 1,113.5 Total 194.4 765.0 230.1 97.0 1,286.5 Gross deferred tax asset 40.2 190.8 3.8 16.5 251.3 Valuation allowance — (50.2 ) — (16.5 ) (66.7 ) Net deferred tax asset $ 40.2 $ 140.6 $ 3.8 $ — $ 184.6 Sirius Group expects to utilize net operating loss carryforwards in Luxembourg of $573.3 million but does not expect to utilize the remainder as they belong to companies that are not expected to have sufficient taxable income in the future. Included in the U.S. net operating loss carryforwards are losses of $115.4 million subject to an annual limitation on utilization under Internal Revenue Code Section 382 and $11.0 million are subject to separately return limitation year ("SRLY") provisions of the consolidated return regulations. Of the Section 382 limited loss carryforwards, $9.6 million will expire between 2022 and 2025 and $94.8 million will expire between 2030 and 2032. The SRLY limited losses will expire between 2036 and 2037. Sirius Group expects to utilize all of the U.S. net operating loss carryforwards. Foreign Tax Credits As of December 31, 2019 , there are U.S. foreign tax credits carryforwards available of $16.4 million , of which an insignificant amount expires in 2020 and 2021, and the remaining will begin to expire in 2022. As of December 31, 2019 , there are alternative minimum tax credit carryforwards of $0.1 million which do not expire and are expected to become fully refundable beginning in the 2023 tax year under the TCJA. Further, there are Swedish foreign tax credits carryforwards available of $25.1 million , which Sirius Group expects to use, and will expire between 2021 and 2024 . Valuation Allowance Sirius Group records a valuation allowance against deferred tax assets if it becomes more likely than not that all or a portion of a deferred tax asset will not be realized. Changes in valuation allowances from period to period are included in income tax expense in the period of change. In determining whether or not a valuation allowance, or change therein, is warranted, Sirius Group considers factors such as prior earnings history, expected future earnings, carryback and carryforward periods, and strategies that if executed would result in the realization of a deferred tax asset. It is possible that certain planning strategies or projected earnings in certain subsidiaries may not be feasible to utilize the entire deferred tax asset, which could result in material changes to Sirius Group's deferred tax assets and tax expense. Of the $79.8 million valuation allowance as of December 31, 2019 , $50.2 million relates to net operating loss carryforwards in Luxembourg subsidiaries, $16.5 million relates primarily to net operating loss carryforward in the United Kingdom, $13.0 million relates to foreign tax credits in the United States and $0.1 million relates to net operating losses in a Belgium subsidiary. Uncertain Tax Positions Recognition of the benefit of a given tax position is based upon whether a company determines that it is more likely than not that a tax position will be sustained upon examination based upon the technical merits of the position. In evaluating the more likely than not recognition threshold, Sirius Group must presume that the tax position will be subject to examination by a taxing authority with full knowledge of all relevant information. If the recognition threshold is met, then the tax position is measured at the largest amount of benefit that is more than 50% likely of being realized upon ultimate settlement. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: (Millions) Permanent differences (1) Temporary differences (2) Interest and penalties (3) Total Balance at January 1, 2017 $ 24.2 $ 4.1 $ 0.2 $ 28.5 Changes in prior year tax positions 0.2 (0.1 ) 0.1 0.2 Tax positions taken during the current year 3.8 (2.2 ) — 1.6 Lapse in statute of limitations (0.5 ) — — (0.5 ) Settlements with tax authorities (0.3 ) — (0.2 ) (0.5 ) Balance at December 31, 2017 $ 27.4 $ 1.8 $ 0.1 $ 29.3 Changes in prior year tax positions 1.4 — 0.1 1.5 Tax positions taken during the current year 36.2 (1.7 ) — 34.5 Lapse in statute of limitations — — — — Settlements with tax authorities (0.1 ) — — (0.1 ) Balance at December 31, 2018 $ 64.9 $ 0.1 $ 0.2 $ 65.2 Changes in prior year tax positions (17.1 ) — — (17.1 ) Tax positions taken during the current year (0.5 ) — — (0.5 ) Lapse in statute of limitations (0.1 ) — — (0.1 ) Settlements with tax authorities — — — — Balance at December 31, 2019 $ 47.2 $ 0.1 $ 0.2 $ 47.5 (1) Represents the amount of unrecognized tax benefits that, if recognized, would impact the effective tax rate. (2) Represents the amount of unrecognized tax benefits that, if recognized, would create a temporary difference between the reported amount of an item in the Consolidated Balance Sheets and its tax basis. (3) Net of tax benefit. If Sirius Group determines in the future that its reserves for unrecognized tax benefits on permanent differences and interest and penalties are not needed, the reversal of $47.2 million of such reserves as of December 31, 2019 would be recorded as an income tax benefit and would impact the effective tax rate. If Sirius Group determines in the future that its reserves for unrecognized tax benefits on temporary differences are not needed, the reversal of $0.1 million of such reserves as of December 31, 2019 would not impact the effective tax rate due to deferred tax accounting but would accelerate the payment of cash to the taxing authority. Most of Sirius Group's reserves for unrecognized tax benefits on permanent differences relate to interest deductions denied by the Swedish Tax Authority ("STA"), as described further below. Sirius Group classifies all interest and penalties on unrecognized tax benefits as part of income tax expense. During the years ended December 31, 2019 , 2018 , and 2017 , Sirius Group recognized $0.0 million , $0.1 million , and $(0.1) million in interest income (expense), respectively, net of any tax benefit. The balance of accrued interest as of December 31, 2019 and 2018 is $0.2 million and $0.2 million , respectively, net of any tax benefit. Tax Examinations The STA has denied deductions claimed by two of the Company's Swedish subsidiaries in certain tax years for interest paid on intra-group debt instruments. Sirius Group has challenged the STA's denial in court based on the technical merits. In October 2018, one of the Swedish subsidiaries received an adverse decision from Sweden's Administrative Court, which Sirius Group has appealed. Sirius Group has taken into account this and other relevant developments in applicable Swedish tax law and has established a reserve for this uncertain tax position. As of December 31, 2019 , the total amount of such reserve was $45.1 million . In connection with this matter, Sirius Group has also taken into account the Stock Purchase Agreement ("SPA") by which Sirius Group was sold to CMIG International Holding Pte. Ltd. ("CMIG International") in 2016 and has recorded an indemnification asset. Pursuant to the SPA, the seller agreed to indemnify Sirius Group and the buyer for, among other things, (1) any additional tax liability in excess of Sirius Group's accounting for uncertain tax positions for tax periods prior to the sale of Sirius Group to CMIG International, and (2) an impairment in Sirius Group's net deferred tax assets resulting from a final determination by a tax authority. While Sirius Group is continuing to challenge the STA's denial based on the technical merits (including appealing the adverse court decision received in October 2018), the ultimate resolution of these tax disputes is uncertain and no assurance can be given that there will be no material changes to Sirius Group's operating results or balance sheet in connection with these uncertain tax positions or the related indemnification. With few exceptions, Sirius Group is no longer subject to U.S. federal, state or non-U.S. income tax examinations by tax authorities for years before 2015.

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives Interest Rate Cap Sirius Group entered into an interest rate swap ("Interest Rate Cap") with two financial institutions where it paid an upfront premium and in return receives a series of quarterly payments based on the 3-month London Interbank Offered Rate ("LIBOR") at the time of payment. The Interest Rate Cap does not qualify for hedge accounting. Changes in fair value are recognized as unrealized gains or losses and are presented within Other revenue. The fair value of the interest rate cap has been estimated using a non-binding single broker quote and, accordingly, has been classified as a Level 3 measurement as of December 31, 2019 and 2018 . Collateral held is recorded within short-term investments with an equal amount recognized as a liability to return collateral. Sirius Group's liability to return that collateral is based on the amounts provided by the counterparties and investment earnings thereon. As of December 31, 2019 and 2018 , Sirius Group held collateral balances of $ 0.2 million and $ 0.3 million, respectively. Foreign Currency Swaps Sirius Group executes foreign currency swaps to manage foreign currency exposure. The foreign currency swaps have not been designated or accounted for under hedge accounting. Changes in fair value are recognized as unrealized gains or losses and are presented within Net foreign exchange gains. The fair value of the foreign currency swaps has been estimated using a non-binding single broker quote and accordingly, has been classified as a Level 3 measurement as of December 31, 2019 and 2018 . Sirius Group does not provide or hold any collateral associated with the swaps. Foreign Currency Forward Sirius Group executes foreign currency forwards to manage currency exposure against a foreign currency investment. The foreign currency forwards are not designated or accounted for under hedge accounting. Changes in fair value are recognized as unrealized gains or losses and are presented within Net foreign exchange gains. The fair value of the foreign currency forwards are estimated using a single broker quote and accordingly, classified as a Level 3 measurement. Sirius Group did not provide or hold any collateral associated with the forwards. Weather Derivatives Sirius Group holds assets and assumes liabilities related to weather and weather contingent risk management products. Weather and weather contingent derivative contracts are entered into with the objective of generating profits in normal climatic conditions. Accordingly, Sirius Group's weather and weather contingent derivatives are not designed to meet the criteria for hedge accounting under GAAP. Sirius Group receives payment of premium at the contract inception in exchange for bearing the risk of variations in a quantifiable weather index. Changes in fair value are recognized as unrealized gains or losses and are presented within Other revenue. Management uses available market data and internal pricing models based upon consistent statistical methodologies to estimate the fair value. Because of the significance of the unobservable inputs used to estimate the fair value of Sirius Group's weather risk contracts, the fair value measurements of the contracts are deemed to be Level 3 measurements in the fair value hierarchy as of December 31, 2019 and 2018 . Sirius Group does not provide or hold any collateral associated with the weather derivatives. Equity Futures Contracts Sirius Group holds restricted equity warrants as part of its investment strategy. The equity warrants are not designated or accounted for under hedge accounting. Changes in fair value are presented within Net unrealized investment gains (losses). The fair value of the equity warrants is estimated using a single broker quote and accordingly, classified as a Level 3 measurement. Sirius Group did not provide or hold any collateral associated with the equity warrants. Equity Put Options Sirius Group sells equity put options as part of its investment strategy. The equity put options were not designated or accounted for under hedge accounting. Changes in fair value are presented within Net unrealized investment (losses) gains. The fair value of the equity put options is widely available and have quoted prices in active markets and accordingly, were classified as a Level 1 measurement. The following tables summarize information on the classification and amount of the fair value of derivatives not designated as hedging instruments within the Company's Consolidated Balance Sheets as of December 31, 2019 and 2018 : (Millions) 2019 2018 Derivatives not designated as hedging instruments Notional value Asset derivative at fair value (1) Liability derivative at fair value (2 ) Notional value Asset derivative at fair value (1) Liability derivative at fair value (2) Interest rate cap $ 250.0 $ — $ — $ 250.0 $ 0.2 $ — Foreign currency swaps $ 90.0 $ — $ 3.6 $ 45.0 $ — $ 4.6 Foreign currency forwards $ (30.0 ) $ 2.7 $ 5.7 $ — $ — $ — Weather derivatives $ 110.7 $ 7.0 $ — $ 150.5 $ 3.9 $ — Equity futures contracts $ 34.5 $ — $ — $ — $ — $ — Equity warrants $ 0.4 $ 0.4 $ — $ — $ — $ — Equity put options $ 31.0 $ 1.3 $ 0.2 $ 6.2 $ — $ 0.5 (1) Asset derivatives are classified within Other assets within the Company's Consolidated Balance Sheets of December 31, 2019 and 2018 . (2) Liability derivatives are classified within Other liabilities within the Company's Consolidated Balance Sheets of December 31, 2019 and 2018 . The following table summarizes information on the classification and net impact on earnings, recognized in the Company's Consolidated Statements of (Loss) relating to derivatives during the years ended December 31, 2019 , 2018 , and 2017 : (Millions) Derivatives not designated as hedging instruments Classification of gains (losses) recognized in earnings 2019 2018 2017 Interest rate cap Other revenues $ (0.2 ) $ 0.1 $ (1.5 ) Foreign currency swaps Net foreign exchange gains $ 4.2 $ 6.9 $ (11.3 ) Foreign currency forwards Net foreign exchange gains $ (10.4 ) $ — $ (0.3 ) Weather derivatives Other revenues $ (1.1 ) $ 5.2 $ (1.5 ) Equity futures contracts Net realized investment gains (losses) $ (1.7 ) $ 1.7 $ — Equity put options Net realized investment gains (losses) $ (0.8 ) $ — $ — Equity put options Net unrealized investment gains (losses) $ (0.8 ) $ — $ — Equity warrants Net unrealized investment gains (losses) $ 0.4 $ — $ —

Employee benefit plans and comp

Employee benefit plans and compensation plans	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Employee benefit plans and compensation plans	Employee benefit plans and compensation plans Employee Benefit Plans Sirius Group operates several retirement plans in accordance with the local regulations and practices. These plans cover substantially all Sirius Group employees and provide benefits to employees in event of death, disability, or retirement. Defined benefit plans Swedish and German employees of Sirius International can participate in defined benefit plans which are based on the employees' pension entitlements and length of employment. In Sweden, where a defined benefit pension plan is mandated by the government, Sirius International's employees participate in collective agreements funded by Sirius International. These collective agreements are managed by third party trustees who calculate the pension obligation, invoice Sirius International for additional funding, and invest the funds. All employees in Germany are covered by defined benefit pension plans sponsored by Sirius International called Sirius Rückversicherungs Service GmbH Pension Plan. Paid pension premiums are invested with Skandia Liv for employees in Sweden and with Allianz for employees in Germany. Skanda Liv held 94% of total plan assets in both 2019 and 2018 . Allianz held 6% of total plan assets in both 2019 and 2018 . Skandia manages the portfolio to be able to pay a guaranteed amount and a favorable return over time with the goal of getting the highest possible return along with well-balanced risk. The average return for the period 2017 through 2019 was 7.0% . The investment directive is decided by the Skandia Liv board of directors. To achieve the goals the portfolio is diversified with the asset allocation shown below. The breakdown of the investment of plan assets for the years ended December 31, 2019 and 2018 are as follows: 2019 2018 International equities 13.0 % 11.4 % Swedish equities 8.9 % 7.5 % Swedish nominal bonds 40.7 % 40.3 % Real estate 10.2 % 11.2 % Private equity 9.4 % 10.4 % Other 17.8 % 19.2 % The assumptions used to determine Swedish benefit obligations for the years ended December 31, 2019 and 2018 are as follows: 2019 2018 Discount rate 2.3 % 2.5 % Increase in compensation levels rate 3.3 % 3.2 % Turnover rate 3.0 % 3.0 % The Swedish actuaries follow the Swedish industry DUS14 mortality rate. The discount rate used to calculate the Swedish benefit obligation was derived from the expected return of an investment in Swedish covered mortgage bonds with a duration in accordance with the duration of the pension obligation. The duration of the Swedish pension liability is approximately 20 years . The assumptions used to determine German benefit obligations for the years ended December 31, 2019 and 2018 are as follows: 2019 2018 Discount rate 1.9 % 1.7 % Increase in compensation levels rate 2.0 % 2.0 % The German actuaries follow the Germany industry Richttafeln 2018 G mortality rates and standard turnover values for the years ended December 31, 2019 and 2018 . The discount rate used to calculate the German benefit obligation was derived from markets yields on high quality corporate bonds with durations consistent with plan obligations. The duration of the German pension liability is approximately 17 years . The following tables present a reconciliation of the beginning and ending funded status and the net amounts recognized for the defined benefit plans for the years ended December 31, 2019 and 2018 : (Millions) 2019 2018 Change in benefit obligation Projected benefit obligation, beginning of year $ 17.5 $ 17.4 Service cost 1.5 1.0 Interest cost 0.4 0.4 Actuarial losses 2.9 0.6 Benefit payments (1.2 ) (0.4 ) Tax payments (0.3 ) (0.2 ) Currency revaluation effect (0.6 ) (1.3 ) Projected benefit obligation, end of year 20.3 17.5 Change in plan assets Fair value of plan assets, beginning of year 16.4 16.1 Employer contributions 1.4 1.2 Benefit payments (0.4 ) (0.3 ) Interest income 1.0 0.8 Currency revaluation effect (0.6 ) (1.4 ) Fair value of plan assets, end of year 17.7 16.4 Funded status at end of year (1) $ (2.6 ) $ (1.1 ) (1) At December 31, 2019 , the Swedish plan had a funding status of $2.5 million and the German plan had a funding status of $(5.1) million. At December 31, 2018 , the Swedish plan had a funding status of $3.0 million and the German plan had a funding status of $(4.1) million. Under the Swedish plan, a 100 basis point discount rate decrease would increase the 2019 defined benefit obligation by $2.7 million , with all other items remaining the same. Under the German plan, a 50 basis point decrease in the discount rate would increase the benefit obligation by $0.7 million , with all other items remaining the same. Conversely, a 50 basis point increase in the discount rate would decrease the benefit obligation by $0.6 million . The accumulated benefit obligation for the years ended December 31, 2019 and 2018 was $20.3 million and $17.5 million , respectively. The components of net periodic pension expense for the years ended December 31, 2019 , 2018 , and 2017 are as follows: (Millions) 2019 2018 2017 Service cost $ (0.9 ) $ (1.2 ) $ (0.8 ) Interest cost 0.1 0.1 2.2 Actuarial (loss) (0.5 ) (0.8 ) (0.3 ) Net periodic pension expense $ (1.3 ) $ (1.9 ) $ 1.1 The employer benefit payments/settlements for the years ended December 31, 2019 and 2018 were $0.3 million and $0.4 million , respectively. As of December 31, 2019 , the projected benefit payments required for the defined pension benefits plans are as follows: (Millions) December 31, 2019 2020 $ 0.5 2021 0.4 2022 0.4 2023 0.4 2024 0.5 2024-2028 3.1 Total benefit payments required $ 5.3 Defined contributions plans Non-U.S. In the United Kingdom, Sirius International contributes 12% of the employee's salary. Contributed funds are invested into an annuity of the employee's choice. In Belgium, Sirius International contributes 6.5% - 8.5% of the employee's salary. Employees in Switzerland are eligible to participate in the industry-sponsored Swisscanto pension plan ("Swisscanto plan"). The Swisscanto plan is a combination of a defined contribution and a defined benefit plan. For the Swisscanto plan, Sirius International incurs 60% - 70% of the total premium charges and the employees incur the remaining 30 - 40% . As of December 31, 2019 and 2018 , the projected benefit obligation of Sirius International's various benefit plans was $20.3 million and $17.5 million , and the funded status was $(2.6) million and $(1.1) million, respectively. Sirius International recognized expenses related to these various plans of $8.3 million , $7.6 million , and $4.9 million in 2019 , 2018 , and 2017 , respectively. Sirius Bermuda sponsors defined contribution plans, which cover substantially all of the employees of Sirius Bermuda. Under these plans, Sirius Bermuda is required to contribute 10% of each participant's salary into an individual account maintained by an independent pension administrator. Employees become vested in the Sirius Bermuda contributions after two years of service. Sirius Bermuda recognized expenses of $0.6 million , $0.5 million and $ 0.4 million during the years ended December 31, 2019 and 2018 , and 2017 , respectively. U.S. Sirius International Holding Company, Inc. ("SIHC") sponsors a defined contribution plan (the "SIHC 401(k) Plan") which offers participants the ability to invest their balances in several different investment options. The SIHC 401(k) Plan provides qualifying employees with matching contributions of 100% up to the first 2% and 50% of the next 4% of salary (subject to U.S. federal limits on allowable contributions in a given year). Total expense for matching contributions to the SIHC 401(k) Plan was $0.8 million , $0.8 million , and $1.3 million in 2019 , 2018 , and 2017 , respectively. Additionally, all participants in the SIHC 401(k) Plan can earn a variable contribution of up to 7% of their salary, subject to the applicable IRS annual covered compensation limits ( $0.3 million for 2019 ) and contingent upon Sirius Group's performance. During 2019 and 2018 , there were no variable contributions to the SIHC 401(k) Plan. Total expense for variable contributions to the SIHC 401(k) Plan was $0.3 million in 2017 . IMG sponsors a 401(k) retirement savings plan (the "IMG 401(k) Plan"). IMG 401(k) Plan participants may elect to have a percentage of their salaries contributed to the IMG 401(k) Plan on a pre-tax basis subject to annual limits prescribed under the Internal Revenue Code. IMG makes safe harbor matching contributions to the IMG 401(k) Plan equal to 100% of participants' deferrals up to the first 1% of eligible compensation and 50% of participants' deferrals between 1% and 6% of eligible compensation. IMG may also elect to make discretionary contributions to the IMG 401(k) Plan which are allocated based on compensation. IMG made matching contributions to the IMG 401(k) Plan of $0.7 million and $ 0.6 million during 2019 and 2018 , respectively, and $0.3 million from the date of acquisition to December 31, 2017 . Armada maintains a qualified 401(k) plan (the "Armada 401(k) Plan"). Under provisions of the Armada 401(k) Plan, Armada may make discretionary, matching contributions. Matching contributions into the Armada 401(k) Plan totaled $0.2 million and $ 0.2 million during 2019 and 2018 , respectively, and $0.1 million from the date of acquisition to December 31, 2017 . Share-Based and Other Long-Term Incentive Compensation Plans Sirius Group's compensation plans include grants for various types of share-based and non-share-based compensation awards to key employees and directors of Sirius Group. As of December 31, 2019 , Sirius Group's share-based compensation awards consist of performance shares units, restricted share units, restricted stock and options. 2018 Omnibus Incentive Plan The 2018 Omnibus Incentive Plan ("Plan"), which governs share-based awards to be issued to employees and directors, was adopted by the Board on August 6, 2018. The total number of shares authorized to be issued under the Plan was 14,114,904 . As of December 31, 2019 , the total number of shares available for issuance under the share-based awards was 8,416,533 , including shares that remained available under 2016 Long Term Incentive Plan. 2019 Long Term Incentive Awards In 2019, the Company granted 2019 Long Term Incentive Awards ("2019 LTI") to certain employees which are comprised of Restricted Share Units ("RSUs") and Performance Share Units ("PSUs"). The PSUs provide the opportunity for the participant to receive shares of the Company's common stock based on Sirius Group achieving specified performance goals at the end of a three -year performance period. These performance goals are pre-established by the Sirius Group Compensation Committee at the grant date of the award. The actual number of PSUs earned can vary from 0% to 200% of the target depending on Sirius Group's performance against the pre-established goals. RSUs are earned based solely on continued service by the participant. Grant date fair value of the PSUs and RSUs is equal to the closing price of Sirius Group's common stock on the grant date of the award. Grant date fair value of the awards was $12.75 per unit. Supplemental Awards The Company has also granted supplemental incentive compensation awards ("Supplemental Awards") to certain members of senior management in the form of RSUs. Supplemental awards are retention-based and have no performance conditions. The units can only be settled in common shares and vest on either the second or third anniversary of the date of the grant and contain certain restrictions, related to, among other things, forfeitures in the event of termination of employment and transferability. Option to Purchase Shares A block of stock options exercisable for 1,374,945 shares was issued as part of the 2019 LTI. The options expire five years from the grant date and have a three -year service condition. The fair value of the stock options estimated on the grant date using the Black-Scholes model was determined to be $2.8 million . The exercise price of the stock options is $12.75 . The following assumptions were used to value stock options granted: Expected annual dividend yield 1.75 % Expected volatility (1) 20 % Risk-free interest rate (2) 2.51 % Expected term (3) 4 years (1) Expected volatility was estimated based on the historical volatility of the shares of a peer group of companies. (2) Risk free rate was based on US 5-year semi-annual treasury rate interest rate. (3) The Company used the simplified method for estimating the expected term. IPO Incentive Awards In connection with the Merger, the Company granted incentive compensation awards to certain members of senior management ("IPO Incentive Awards") through its 2018 Omnibus Incentive Plan. The original terms of the IPO Incentive Award required employees to purchase the Company's common stock in order to be issued corresponding PSUs. On February 27, 2019, Sirius Group modified the plan to terminate the obligation that required participants to purchase shares in order to receive the award shares. Modification applied to to all recipients of the award. PSUs vest over three years , 25% based on return of equity ("ROE") performance during each of the 2019, 2020, and 2021 fiscal years and 25% based on the average ROE performance during the 2019 through 2021 period. Payouts begin at 0% of awarded shares for a 4.5% ROE, 100% at a 9.0% ROE and 150% at a 13.5% ROE with linear interpolation in between. The employee must remain employed through the end of the applicable performance period to vest in the shares earned in that performance period. The grant date fair value of the award was equal to the closing price of Sirius Group's common stock on the grant date of the award or $12.75 per unit. Employee Share Purchase Plan Effective August 22, 2018, the Company established an ESPP which allowed all employees of the Company and its subsidiaries to purchase up to 1,000 , but no less than 100 shares of Sirius Group in connection with the transaction with Easterly. The purchase price of each common share purchased by a participant is equal to 85% of market value for the first 100 shares and 100% of market value for any additional shares purchased. Participants can either purchase the shares in cash or be issued a full-recourse promissory note by the Company, secured by the shares, payable via payroll deductions. 149,236 shares were purchased under the ESPP during 2018. No further purchases are permitted under the ESPP. Net promissory notes as of December 31, 2019 and 2018 total $0.4 million and $0.9 million, respectively. 2016 Long Term Incentive Plan Sirius Group has historically awarded long-term incentive compensation in the form of three -year, cliff-vested, performance units or phantom performance shares that can be paid in cash, or upon Sirius Group becoming public, Sirius Group common shares, at the discretion of the Compensation Committee. Performance shares compound through the end of the three -year award period based on a selection performance metrics during the period. The performance goals were determined by the Compensation Committee of the Board of Directors upon granting of awards. There was no 2019 award issued under the 2016 Long Term Incentive Plan ("2016 LTIP") as it was replaced by the 2018 Omnibus Incentive Plan on a go-forward basis. Additionally, for the two three -year performance cycles still outstanding under the legacy 2016 LTIP, now that Sirius Group's common shares are publicly traded, upon vesting of these awards, (i) each phantom performance share will be valued at the market price of a common share at the time of payout and (ii) the Compensation Committee has discretion to settle these awards in common shares rather than cash. During the year ended December 31, 2019 , Sirius Group paid $3.3 million to employees for share-based awards. No payments were made for share-based awards during the years ended December 31, 2018 and 2017 . The following tables present pre-tax and after-tax share-based compensation expense recognized under the above plans: (Millions) 2019 2018 2017 PSUs - IPO Incentive Awards (1) $ 0.7 $ 1.5 $ — PSUs - 2019 LTI 0.8 — — RSUs 5.8 — — Stock Options 0.8 — — LTIP (2)(3) (3.4 ) 1.0 — Total share-based compensation expense - pre-tax $ 4.7 $ 2.5 $ — (1) 2019 includes a reversal of 2018 accrual of $1.5 related to modification of the award. (2) Legacy 2016 LTIP includes two open cycles in 2019 and three open cycles in 2018. (3) For the year ended December 31, 2017, $3.9 of expense associated with phantom share awards has been excluded. (Millions) 2019 2018 2017 PSUs - IPO Incentive Awards (1) $ 0.6 $ 1.2 $ — PSUs - 2019 LTI 0.7 — — RSUs 4.6 — — Stock Options 0.6 — — LTIP (2)(3) (2.7 ) 0.8 — Total share-based compensation expense - after-tax $ 3.8 $ 2.0 $ — (1) 2019 includes a reversal of 2018 accrual of $1.2 related to modification of the award. (2) Legacy 2016 LTIP includes two open cycles in 2019 and three open cycles in 2018. (3) For the year ended December 31, 2017, expense associated with phantom share awards has been excluded. The following tables present unrecognized compensation cost associated with unvested awards and weighted average period over which it is expected to be recognized: (Millions) December 31, 2019 PSUs - IPO Incentive Awards PSUs - 2019 LTI RSUs Stock Options LTIP Unrecognized compensation cost related to unvested awards $ 4.0 $ 2.0 $ 11.8 $ 2.0 $ 0.7 Weighted average recognition period (years) 2.0 years 2.0 years 1.9 years 2.2 years 1.0 year The following table summarizes outstanding share-settled awards as of the end of the year ended December 31, 2019: As of and for the year ended December 31, 2019 Number of Shares PSUs - IPO Incentive Awards PSUs - 2019 LTI RSUs Stock Options LTIP (1) Unvested, beginning of the year — — — — 1,765,637 Granted (2) 756,183 408,370 1,428,185 1,374,945 — Vested — — — — 33,307 Forfeited (3) 201,020 17,234 74,333 — 861,859 Unvested, end of the year 555,163 391,136 1,353,852 1,374,945 870,471 (1) Includes 2017 and 2018 legacy LTIP award cycles. Unearned portion of the 2017 LTIP was included in forfeited shares. (2) IPO Incentive Award was included in the granted line due to its modification during 2019. (3) Shares that are unearned as a result of missing minimum performance indicators are included in forfeited shares. Non-Employee Compensation Certain non-employee independent directors received share-based compensation in the form of restricted shares which vest after one year of issuance. During 2019 and 2018 , Sirius Group granted non-employee directors 37,039 and 24,475 restricted shares, and recognized share-based compensation expense of $ 0.3 million and $0.3 million , respectively. Transaction and Retention Bonuses From time to time, the Company may issue cash-settled retention awards to its employees. In 2019, Sirius Group issued retention awards to certain key employees of the Company that will vest and be paid in equal proportions on or prior to March 15, 2020 and on or prior to March 15, 2021, subject to continued employment on the applicable vesting date. In total the retention awards issued were $10.7 million , of which, during the year ended December 31, 2019 , the Company recognized $2.1 million in General and administrative expenses. Under the SPA, bonus arrangements for certain employees of Sirius Group were granted. Certain of these bonus arrangements were paid to bonus recipients as compensation for services performed before the sale date ("transaction bonuses"). In addition, certain employees received additional bonus payments under the bonus arrangements after the 12th month and 20th month anniversary of the sale date ("retention bonuses"). Under the SPA, White Mountains agreed to pay the Company an amount equal to the transaction bonuses plus the employer-paid portion of employment or similar taxes less tax benefits attributable to the payment. In addition, White Mountains also agreed to pay the Company for the retention bonuses under the same terms as the transaction bonuses shortly after Sirius Group paid those amounts to the employees. During 2017, Sirius Group recorded $36.9 million in General and administrative expenses in connection with the transaction bonuses. The Company was paid $25.3 million and $30.5 million in 2018 , and 2017 , respectively, from its former parent for the transaction and retention bonuses after employment costs and taxes, which was recorded as Additional paid-in surplus. During 2019 , the Company was not paid any amount from its former parent for the transaction and retention bonuses. During the years ended December 31, 2018 and 2017 , Sirius Group recorded $13.3 million and $17.6 million , respectively, in General and administrative expenses in connection with these retention bonuses. In addition, for the years ended December 31, 2018 and 2017, under the SPA, White Mountains paid Sirius Group for certain incentive awards that the Company paid to its employees, with $1.4 million and $2.5 million , respectively, recorded as Additional paid-in surplus. No payment from White Mountains was received by Sirius Group for the incentive awards in 2019.

Common shareholder equity's, me

Common shareholder equity's, mezzanine equity, and non-controlling interests	12 Months Ended
	Dec. 31, 2019
Stockholders' Equity Note [Abstract]
Common shareholder's equity, mezzanine equity, and non-controlling interests	Common shareholders' equity, mezzanine equity, and non-controlling interests Common shareholder's equity The authorized share capital of the Company consists of 500,000,000 Common shares, $0.01 par value per share, and 15,000,000 Series B preference shares, $0.01 par value per share. The following table presents changes in the Company's issued and outstanding Common shares for the years ended December 31, 2019 , 2018 , and 2017 , respectively: 2019 2018 2017 Common shares: Shares issued and outstanding, beginning of year 115,151,251 120,000,000 120,000,000 Issuance of shares (See Note 3 ) 148,090 4,670,531 — Shares redeemed (See Note 3 ) — (9,519,280 ) — Shares issued and outstanding, end of year 115,299,341 115,151,251 120,000,000 Redeemed shares On November 5, 2018, the Company repurchased 9,519,280 common shares from CM Bermuda in connection with the Merger ("redeemed shares") for $164.0 million . (See Note 3 .) The redeemed shares were canceled and the cost of the redeemed shares are included as a reduction to Additional paid-in surplus. Dividends The Company did not pay any dividends during the years ended December 31, 2019 , 2018 , or 2017 . Mezzanine equity Series B Preference Shares On November 5, 2018, in connection with the closing of the Merger, Sirius Group issued 11,901,670 of the 15,000,000 authorized Series B preference shares, with a par value of $0.01 per share, as part of the Sirius Group Private Placement. (See Note 3.) The Series B preference shares rank senior to common shares with respect to dividend rights, rights of liquidation, winding-up, or dissolution of the Company and junior to all of the Company's existing and future policyholder obligations and debt obligations. Without the consent of the holders of the Series B preference shares, the Company may not issue any class or series of shares that rank senior or pari passu with the Series B preference shares as to the payment of dividends or as to distribution of assets upon any voluntary or involuntary liquidation, winding-up or dissolution of the Company, if the aggregate gross proceeds from the issuance of all such senior or pari passu shares equals or exceeds $100 million . The Company adjusts the carrying value of the Series B preference shares to equal the redemption value at the end of each reporting period. At December 31, 2019 and 2018 , the balance of the Series B preference shares was $ 223.0 million and $232.2 million, respectively. Series A Redeemable Preference Shares In connection with the acquisition of IMG, the Company issued mandatorily convertible stock in the form of Series A redeemable preference shares as a portion of the consideration paid. (See Note 3 .) The Company issued 100,000 of the 150,000 authorized Series A redeemable preference shares to the seller of IMG. Each Series A redeemable preference share has a liquidation preference per share of $1,000 . On November 5, 2018, in connection with the closing of the Merger, the Company redeemed the 100,000 outstanding shares of Series A redeemable preference shares for $95.0 million . (See Note 3 .) Sirius Group recorded a $13.8 million gain on the redemption of the Series A redeemable preference shares. Non-controlling interests Non-controlling interests consist of the ownership interests of non-controlling shareholders in consolidated entities and are presented separately on the balance sheet. At December 31, 2019 and 2018 , Sirius Group's balance sheet included $2.4 million and $1.7 million , respectively, in non-controlling interests. The following table shows the change in non-controlling interest for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) Total Non-controlling interests as of December 31, 2016 $ 251.3 Net income attributable to non-controlling interests 13.7 Dividends to non-controlling interests (14.1 ) Other, net (250.7 ) Non-controlling interests as of December 31, 2017 $ 0.2 Net income attributable to non-controlling interests 1.4 Dividends to non-controlling interests — Other, net 0.1 Non-controlling interests as of December 31, 2018 $ 1.7 Net income attributable to non-controlling interests 1.7 Dividends to non-controlling interests (1.0 ) Other, net — Non-controlling interests as of December 31, 2019 $ 2.4 SIG Preference Shares On October 25, 2017, the Company's indirect wholly-owned subsidiary, Sirius International Group, Ltd., redeemed all of its outstanding 250,000 Fixed/Floating Perpetual Non-Cumulative Preference Shares ("SIG Preference Shares"). The redemption price equaled the $1,000 liquidation preference per preference share. Sirius Group accounted for the SIG Preference Shares as a conditionally redeemable instrument within Non-controlling interests. Alstead Re As of December 31, 2019 and 2018 , Sirius Group recorded non-controlling interest of $2.3 million and $1.7 million , respectively, in Alstead Re Insurance Company ("Alstead Re"). (See Note 20 .)

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings per share	Earnings per share Basic earnings (loss) per share is computed by dividing net (loss) available to Sirius Group common shareholders by the weighted-average number of common shares outstanding during the period. Diluted earnings per share is computed by dividing net income available to Sirius Group common shareholders by the weighted-average number of common shares outstanding adjusted to give effect to potentially dilutive securities. Sirius Group has issued preference shares that qualify as participating securities which requires the application of the two-class method to compute both basic and diluted earnings per share. The two-class method is an earnings allocation formula that treats participating securities as having rights to earnings that would otherwise have been available to common shareholders. The preference shares Sirius Group has issued have no obligation to absorb losses of the Company in periods of net (loss). The following table sets forth the computation of basic and diluted earnings per common share for the years ended December 31, 2019 , 2018 , and 2017 : (Millions, except share and per share information) 2019 2018 2017 Basic earnings per share Numerator: Net (loss) $ (45.6 ) $ (16.7 ) $ (136.3 ) Less: Income attributable to non-controlling interests (1.7 ) (1.4 ) (13.7 ) Change in carrying value of SeriesﾠB preference shares 9.2 (36.4 ) — Less: Accrued dividends on SeriesﾠA redeemable preference shares — (2.6 ) (6.1 ) Add: Redemption of SeriesﾠA redeemable preference shares — 13.8 — Net (loss) attributable to Sirius Group common shareholders $ (38.1 ) $ (43.3 ) $ (156.1 ) Denominator: Weighted average shares outstanding for basic earnings per share (1)(2) 115,234,105 119,253,924 120,000,000 Basic earnings per share $ (0.33 ) $ (0.36 ) $ (1.30 ) Diluted earnings per share Numerator: Net (loss) attributable to Sirius Group common shareholders $ (38.1 ) $ (43.3 ) $ (156.1 ) Change in carrying value of Series B preference shares (9.2 ) — — Net (loss) attributable to Sirius Group common shareholders on a diluted basis $ (47.3 ) $ (43.3 ) $ (156.1 ) Denominator: Weighted average shares outstanding for basic earnings per share (1)(2) 115,234,105 119,253,924 120,000,000 Add: Series B preference shares 11,901,670 — — Weighted average shares outstanding for diluted earnings per share (1)(2) 127,135,775 119,253,924 120,000,000 Diluted earnings per share $ (0.37 ) $ (0.36 ) $ (1.30 ) (1) As of December 31, 2019 , there were a total of 17,057,249 potentially dilutive securities excluded from the calculation of Diluted earnings per share. (2) As of December 31, 2018 , there were a total of 23,433,114 potentially dilutive securities excluded from the calculation of Diluted earnings per share.As of December 31, 2017 , there were no potentially dilutive securities.

Accumulated other comprehensive

Accumulated other comprehensive (loss)	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive (loss)	Accumulated other comprehensive (loss) The changes in accumulated other comprehensive (loss), by component, for the years ended December 31, 2019 , 2018 , and 2017 are as follows: For the year ended December 31, 2019 (Millions) Foreign currency translation adjustment Total Balance, beginning of year $ (202.4 ) $ (202.4 ) Other comprehensive (loss) (35.1 ) (35.1 ) Balance, end of year $ (237.5 ) $ (237.5 ) For the year ended December 31, 2018 (Millions) Foreign currency translation adjustment Total Balance, beginning of year $ (140.5 ) $ (140.5 ) Other comprehensive (loss) (61.9 ) (61.9 ) Balance, end of year $ (202.4 ) $ (202.4 ) For the year ended December 31, 2017 (Millions) Foreign currency translation adjustment Total Balance, beginning of year $ (212.2 ) $ (212.2 ) Other comprehensive (loss) 71.7 71.7 Balance, end of year $ (140.5 ) $ (140.5 )

Statutory capital and surplus

Statutory capital and surplus	12 Months Ended
	Dec. 31, 2019
Statutory capital and surplus
Statutory capital and surplus	Statutory capital and surplus Sirius Group's insurance and reinsurance operations are subject to regulation and supervision in each of the jurisdictions where they are domiciled and licensed to conduct business. Generally, regulatory authorities have broad supervisory and administrative powers over such matters as licenses, standards of solvency, premium rates, policy forms, investments, security deposits, methods of accounting, form and content of financial statements, reserves for unpaid loss and LAE, reinsurance, minimum capital and surplus requirements, dividends and other distributions to shareholders, periodic examinations, and annual and other report filings. In general, such regulation is for the protection of policyholders rather than shareholders. Non-U.S. The Insurance Act 1978 of Bermuda and related regulations, as amended ("Insurance Act"), regulates the insurance business of Bermuda-domiciled insurers and reinsurers. The Insurance Act imposes solvency and liquidity standards on Bermuda insurance companies, as well as auditing and reporting requirements. The Bermuda Monetary Authority ("BMA"), a Solvency II-equivalent regulatory regime, has confirmed that it will act as the primary group supervisor effective July 1, 2016 and has designated Sirius Bermuda as the designated insurer. Therefore, Sirius Group is subject to the BMA's group supervision and solvency rules. Under the Insurance Act, insurers and reinsurers are required to maintain minimum statutory capital and surplus at a level equal to the greater of a minimum solvency margin ("MSM") and the Enhanced Capital Requirement ("ECR") which is established by reference to either a Bermuda Solvency Capital Requirement ("BSCR") model or an approved internal capital model. The BSCR model is a risk-based capital model that provides a method for determining an insurer's minimum required capital taking into account the risk characteristics of different aspects of the company's business. As of December 31, 2019 , the eligible capital for Sirius Group exceeded the required capital as measured by the BSCR model. Management has also evaluated the group and principal operating subsidiaries' ability to maintain adequate levels of statutory capital, liquidity, and rating agency capital and believes they will be able to do so. In performing this analysis, management has considered the most recent statutory capital position of each of the principal operating subsidiaries as well as the group overall, through its holding companies as a result of BMA group regulation. In addition, management has evaluated the ability of the holding companies to allocate capital and liquidity around the group as and when needed. Sirius Group has two Bermuda based insurance subsidiaries: Sirius Bermuda, a Class 4 insurer, and Alstead Re, a Class 3 A insurer. Each of these Bermuda insurance subsidiaries are registered under the Insurance Act and are subject to regulation and supervision of the BMA. The BSCR and actual statutory capital and surplus for Sirius Bermuda and Alstead Re as of December 31, 2019 has not been determined as of the filing of this Annual Report on Form 10-K. The BSCR for Sirius Bermuda and Alstead Re as of December 31, 2018 was $839.1 million and $2.5 million , respectively. Actual statutory capital and surplus of the Bermuda based insurance subsidiaries as of December 31, 2018 was $2.2 billion . In addition, the Bermuda based insurance subsidiaries are required to maintain a minimum liquidity ratio. As of December 31, 2019 , all liquidity ratio requirements were met. Sirius International is subject to regulation and supervision by the Swedish Financial Supervisory Authority ("SFSA"). Sirius International's total regulatory capital as of December 31, 2019 was $1.6 billion . In accordance with SFSA regulations, Sirius International holds restricted equity of $1.2 billion as a component of Swedish regulatory capital. This restricted equity cannot be paid as dividends. Under Solvency II, the SFSA also acts as the European Economic Area group supervisor, with Sirius International UK Holding Ltd. ("SIUK") serving as the highest European entity subject to the SFSA's group supervision. Solvency II regulation in Europe gives the SFSA the option to waive European-level group supervision if certain legal requirements are met. As of December 31, 2019 , the SFSA has not exercised this option. The financial services industry in the United Kingdom is dual-regulated by the Financial Conduct Authority and the Prudential Regulation Authority (collectively, the "U.K. Regulators"). The U.K. Regulators regulate insurers, insurance intermediaries and Lloyd's. The U.K. Regulators and Lloyd's have common objectives in ensuring that the Lloyd's market is appropriately regulated. Lloyd's is required to implement certain rules prescribed by the U.K. Regulators by the powers it has under the Lloyd's Act of 1982 relating to the operation of the Lloyd's market. In addition, each year the U.K. Regulators require Lloyd's to satisfy an annual solvency test that measures whether Lloyd's has sufficient assets in the aggregate to meet all the outstanding liabilities of its members. Lloyd's permits its corporate and individual members ("Members") to underwrite insurance risks through Lloyd's syndicates. Members of Lloyd's may participate in a syndicate for one or more underwriting years by providing capital to support the syndicate's underwriting. All syndicates are managed by Lloyd's approved managing agents. Managing agents receive fees and profit commissions in respect of the underwriting and administrative services they provide to the syndicates. Lloyd's prescribes, in respect of its managing agents and Members, certain minimum standards relating to their management and control, solvency and various other requirements. Sirius Group participates in the Lloyd's market through the 100% ownership of Sirius International Corporate Member Ltd., a Lloyd's corporate member, which in turn provides underwriting capacity to Syndicate 1945. Sirius Group has its own Lloyd's managing agent, Sirius International Managing Agency, which manages Syndicate 1945. Lloyd's approved net capacity for 2020 is £91.0 million , or approximately $120.0 million (based on the December 31, 2019 GBP to USD exchange rate). Stamp capacity is a measure of the amount of net premium (premiums written less acquisition costs) that a syndicate is authorized by Lloyd's to write. U.S. Sirius America and the insurance subsidiaries of Sirius Global Solutions are subject to regulation and supervision by the National Association of Insurance Commissioners ("NAIC") and the department of insurance in the state of domicile. The NAIC uses risk-based capital ("RBC") standards for U.S. property and casualty insurers as a means of monitoring certain aspects affecting the overall financial condition of insurance companies. As of December 31, 2019 , the available capital of Sirius Group's U.S. insurance and reinsurance operating subsidiaries exceeded their respective RBC requirements. Sirius America's policyholders' surplus, as reported to regulatory authorities as of December 31, 2019 and 2018 , was $522.1 million and $522.2 million . Sirius America's statutory net (loss) income for the years ended December 31, 2019 , 2018 , and 2017 was $(25.0) million , $(9.9) million , and $(6.4) million , respectively. The principal differences between Sirius America's statutory amounts and the amounts reported in accordance with GAAP include deferred acquisition costs, deferred taxes, gains recognized under retroactive reinsurance contracts, and market value adjustments for debt securities. The minimum policyholders' surplus necessary to satisfy Sirius America's regulatory requirements was $110.1 million as of December 31, 2019 , which equals the authorized control level of the NAIC risk-based capital based on Sirius America's policyholders' surplus. Oakwood Insurance Company ("Oakwood") policyholders' surplus, as reported to regulatory authorities as of December 31, 2019 and 2018 was $39.7 million and $40.5 million , respectively. Oakwood's statutory net (loss) income for the years ended December 31, 2019 , 2018 , and 2017 was $(1.0) million , $(1.1) million and $0.5 million , respectively. The minimum policyholders' surplus necessary to satisfy Oakwood's regulatory requirements was $4.1 million as of December 31, 2019 , which equals the authorized control level of the NAIC risk-based capital. During 2017, Mount Beacon was merged into Oakwood. Empire Insurance Company ("Empire") policyholders' surplus, as reported to regulatory authorities as of December 31, 2019 and 2018 was $10.8 million and $10.7 million , respectively. Empire's statutory net income (loss) for the years ended December 31, 2019 , 2018 , and 2017 was $0.2 million , $0.1 million and $(0.3) million , respectively. The minimum policyholders' surplus necessary to satisfy Empire's regulatory requirements was $8.9 million as of December 31, 2019 , and the NAIC risk-based capital authorized control level was $0.7 million . Cedar's policyholders' surplus, as reported to regulatory authorities as of each of the years ended December 31, 2019 and 2018 was $13.9 million . Cedar's statutory net income (loss) for the years ended December 31, 2019 and 2018 was $0.0 million and $ (0.6) million , respectively. The minimum policyholders' surplus necessary to satisfy Cedar's regulatory requirements was $9.8 million as of December 31, 2019 , and the NAIC risk-based capital authorized control level was $0.1 million . Dividend Capacity Sirius Group's top tier regulated insurance and reinsurance operating subsidiary is Sirius Bermuda. Sirius Bermuda's ability to pay dividends is limited under Bermuda law and regulations. Under the Insurance Act, Sirius Bermuda is restricted with respect to the payment of dividends. Sirius Bermuda is prohibited from declaring or paying in any financial year dividends of more than 25% of its total statutory capital and surplus (as shown on its previous financial year's statutory balance sheet) unless it files, at least seven days before payment of such dividends, with the BMA an affidavit stating that it will continue to meet the required margins following the declaration of those dividends. As of December 31, 2019 , Sirius Bermuda can pay approximately $523.8 million to its parent company, Sirius International Group, Ltd., during 2020 . Sirius Bermuda indirectly owns Sirius International, Sirius America, and Sirius Group's other insurance and reinsurance operating companies, each of which are limited in their ability to pay dividends by the insurance laws of their relevant jurisdictions. CMIG International, which is approximately 82% owned by China Minsheng Investment Group Corp., Ltd. ("CMIG"), indirectly holds approximately 87% of the voting and dispositive control over the Sirius Group common shares as of December 31, 2019, through CMIG International's wholly-owned Bermuda holding company, CM Bermuda Ltd. ("CM Bermuda"). During 2019, CMIG made several public announcements relating to defaults and cross-defaults on certain bonds and other debt obligations issued by certain subsidiaries of CMIG (the "CMIG Defaults"), the failure and uncertainty of CMIG's subsidiaries to repay their debt obligations as they become due and the existence of certain asset freeze orders relating to the equity interests of CMIG in certain Chinese subsidiaries not within the chain of control of Sirius Group. On May 3, 2019, in connection with the CMIG Defaults, Sirius Bermuda and Sirius Group entered into a voluntary undertaking with the BMA to provide further comfort to the BMA as the group supervisor of Sirius Group and primary regulator of Sirius Bermuda, the designated insurer for group supervisory purposes regarding the potential risks to Sirius Group in connection with the CMIG Defaults. Pursuant to the voluntary undertaking, each of Sirius Group and Sirius Bermuda have agreed, until May 3, 2020, (a) to provide ten days prior written notice to the BMA prior to declaring any dividend or capital distribution, which notice shall include an affidavit confirming that the declaration and payment of such dividend would not be in breach of (i) the provisions of section 54 of the Companies Act 1981 in the case of Sirius Bermuda, (ii) the Minimum Liquidity Ratio as defined in the Insurance Act 1978 in the case of Sirius Bermuda; and (iii) the Target Capital Level of 120% of the Enhanced Capital Requirement as defined by the Bermuda Solvency Capital Requirement promulgated by the BMA for Sirius Group and Sirius Bermuda, and a summary description of the use proceeds from such declaration or dividend or capital distribution within Sirius Group or Sirius Bermuda; (b) not to enter into any guarantees, keepwells, loans or other financial arrangements between Sirius Group and CMIG, or provide any credit support with respect to any obligations of CMIG; and (c) not to enter into any related party transaction with CMIG. During 2019 , Sirius Bermuda paid $80.0 million of dividends to its immediate parent. Sirius International has the ability to pay dividends to its immediate parent subject to the availability of unrestricted equity, calculated in accordance with the Swedish Act on Annual Accounts in Insurance Companies and the Swedish Financial Supervisory Authority (the "SFSA"). Unrestricted equity is calculated on a consolidated group account basis and on a parent account basis. Differences between the two include but are not limited to accounting for goodwill, subsidiaries (with parent accounts stated at original foreign exchange rates), taxes and pensions. Sirius International's ability to pay dividends is limited to the "lower of" unrestricted equity as calculated within the group and parent accounts. As of December 31, 2019 , Sirius International had $401.5 million (based on the December 31, 2019 SEK to USD exchange rate) of unrestricted equity on a parent account basis (the lower of the two approaches) available to pay dividends in 2020 . The amount of dividends available to be paid by Sirius International in any given year is also subject to cash flow and earnings generated by Sirius International's business, the maintenance of adequate solvency capital ratios for Sirius International and the consolidated SIUK group, as well as to dividends received from its subsidiaries. Earnings generated by Sirius International's business that are allocated to the Safety Reserve are not available to pay dividends (see " Safety Reserve " below). During 2019 , Sirius International did not declare a dividend and paid SEK 167.1 million (or $ 17.7 million on date of payment) of dividends declared prior to 2018. Under the normal course of business, Sirius America has the ability to pay dividends to its immediate parent during any twelve-month period without the prior approval of regulatory authorities in an amount set by a formula based on the lesser of net investment income, as defined by statute, or 10% of statutory surplus, in both cases as most recently reported to regulatory authorities, subject to the availability of earned surplus and subject to dividends paid in prior periods. Based on this formula, Sirius America has dividend capacity as of December 31, 2019 , without prior regulatory approval. As of December 31, 2019 , Sirius America had $522.1 million of statutory surplus and $88.8 million of earned surplus. During 2019 , Sirius America did not pay any dividends to its immediate parent. During 2019 and 2018 , the Company did not pay any dividends to its shareholders. As of December 31, 2019 , Sirius Group had $ 42.9 million of net unrestricted cash, short-term investments, and fixed maturity investments outside of its regulated and unregulated insurance and reinsurance operating subsidiaries. Capital Maintenance Effective August 27, 2019, the capital maintenance agreement between Sirius International and Sirius America, which obligated Sirius International to make contributions to Sirius America's surplus in order for Sirius America to maintain surplus equal to at least 125% of the company action level risk-based capital as defined in the National Association of Insurance Commissioners' Property/Casualty Risk-Based Capital Report was terminated. Sirius International did not make any contributions to the surplus of Sirius America up to and including the termination date. Safety Reserve Subject to certain limitations under Swedish law, Sirius International is permitted to transfer pre-tax income amounts into a reserve referred to as a "Safety Reserve." Under local statutory requirements, an amount equal to the deferred tax liability on Sirius International's Safety Reserve is included in Solvency Capital. Access to the Safety Reserve is restricted to cover insurance and reinsurance losses and to cover a breach of the Solvency Capital Requirement. Access for any other purpose requires the approval of Swedish regulatory authorities. Similar to the approach taken by Swedish regulatory authorities, most major rating agencies generally include the balance of the Safety Reserve, without any provision for deferred taxes, in Sirius International's regulatory capital when assessing Sirius International and Sirius Group's financial strength. As of December 31, 2019 , Sirius International's Safety Reserve amounted to SEK 10.2 billion, or $ 1.1 billion (based on the December 31, 2019 SEK to USD exchange rate). Under Swedish GAAP, an amount equal to the Safety Reserve, net of a related deferred tax liability established at the Swedish tax rate, is classified as common shareholders' equity. Generally, this deferred tax liability ($ 225.9 million based on the December 31, 2019 SEK to USD exchange rate) is only required to be paid by Sirius International if it fails to maintain prescribed levels of premium writings and loss reserves in future years. As a result of the indefinite deferral of these taxes, the related deferred tax liability is not taken into account by Swedish regulatory authorities for purposes of calculating Solvency Capital under Swedish insurance regulations. Pursuant to tax legislation enacted in Sweden in June 2018, the tax rate applicable to Swedish corporations decreased to 21.4% effective as of January 1, 2019, and then will further reduce to 20.6% starting in 2021. The tax legislation also introduced an annual tax on the Safety Reserve effective as of January 1, 2019. This provision adds additional taxable income for the Company annually. The calculation applies the Government Borrowing Rate (with a floor rate of +0.5%) to the Safety Reserve balance at the beginning of the year. At the current year tax rate of 21.4% the additional tax expense for 2019 is SEK 11.4 million, or $1.2 million (based on the December 31, 2019 SEK to USD exchange rate). Further, the enacted legislation also included a new provision treating an amount equal to 6% of the Safety Reserve balance as of January 1, 2021, as additional taxable income in tax year 2021 only, subject to tax at the applicable 20.6% rate. Based on this provision and Sirius International's Safety Reserve balance as of December 31, 2019 , Sirius International has recorded an additional deferred tax liability as of December 31, 2019 in the amount of SEK 131.2 million, or $13.5 million (based on the December 31, 2019 SEK to USD exchange rate).

Investments in unconsolidated e

Investments in unconsolidated entities	12 Months Ended
	Dec. 31, 2019
Investments in unconsolidated entities
Investments in unconsolidated entities	Investments in unconsolidated entities Sirius Group's investments in unconsolidated entities are included within Other long-term investments and consist of investments in common equity securities or similar instruments, which give Sirius Group the ability to exert significant influence over the investee's operating and financial policies ("equity method eligible unconsolidated entities"). Such investments may be accounted for under either the equity method or, alternatively, Sirius Group may elect to account for them under the fair value option. The following table presents the components of Other long-term investments as of December 31, 2019 and 2018 : (Millions) 2019 2018 Equity method eligible unconsolidated entities, at fair value $ 151.9 $ 169.4 Other unconsolidated investments, at fair value (1) 194.9 195.6 Total Other long-term investments (2) $ 346.8 $ 365.0 (1) Includes Other long-term investments that are not equity method eligible . (2) There were no investments accounted for using the equity method as of December 31, 2019 and 2018 . Equity method eligible unconsolidated entities, at fair value Sirius Group has elected the Fair Value Option to account for its equity method eligible investments accounted for as part of Other long-term investments for consistency of presentation with rest of its investment portfolio. The following table presents Sirius Group's investments in equity method eligible unconsolidated entities as of December 31, 2019 and 2018 : Ownership interest as of December 31, Investee 2019 2018 Instrument Held BE Reinsurance Limited 24.9 % 25.0 % Common shares BioVentures Investors (Offshore) IV ﾠLP 73.0 % 73.0 % Units Camden Partners Strategic Fund V (Cayman),ﾠ LP 39.4 % 36.4 % Units Diamond LS I LP 16.0 % 3.9 % Units Gateway Fund LP 15.0 % — % Units Monarch 12.8 % 12.8 % Units NEC Cypress BuyerﾠLLC (1) — % 13.3 % Units New Energy Capital Infrastructure Credit Fundﾠ LP 30.5 % 22.9 % Units New Energy Capital Infrastructure Offshore Credit Fundﾠ LP 30.5 % 54.9 % Units Pie Preferred Stock (2) 30.1 % — % Preferred shares Pie Series B Preferred Stock (2) 22.4 % — % Preferred shares Quintana Energy Partners 21.8 % 21.8 % Units Tuckerman Capital VﾠLP 48.3 % 47.6 % Units Tuckerman Capital V Co-Investment IﾠLP 48.1 % 47.7 % Units (1) The ownership of NEC Cypress Buyer LLC was liquidated in 2019. (2) Sirius Group holds investments in several financing instruments of Pie Insurance Holdings, Inc. The following tables present aggregated summarized financial information for Sirius Group's investments in equity method eligible unconsolidated entities: As of December 31, (Millions) 2019 2018 Balance sheet data: Total assets $ 594.5 $ 591.1 Total liabilities $ 47.6 $ 28.7 For the years ended December 31, (Millions) 2019 2018 2017 Income statement data: Revenues $ 72.7 $ 55.4 $ 60.3 Expenses $ (30.2 ) $ (25.1 ) $ (28.8 )

Variable interest entities

Variable interest entities	12 Months Ended
	Dec. 31, 2019
Variable interest entities
Variable interest entities	Variable interest entities Sirius Group consolidates the results of operations and financial position of every voting interest entity ("VOE") in which it has a controlling financial interest and VIEs in which it is considered to be the primary beneficiary. The consolidation assessment, including the determination as to whether an entity qualifies as a VOE or VIE, depends on the facts and circumstances surrounding each entity. Sirius Group has determined that Alstead Re is a VIE for which Sirius Group is the primary beneficiary and is required to consolidate it. The following table presents Alstead Re's assets and liabilities, as classified in the Consolidated Balance Sheets as of December 31, 2019 and 2018 : (Millions) 2019 2018 Assets: Fixed maturity investments $ 3.9 $ 4.0 Short-term investments 0.5 0.3 Cash 0.1 0.2 Total investments 4.5 4.5 Accrued investment income — 0.1 Insurance and reinsurance premiums receivable (0.3 ) 3.7 Funds held by ceding companies 3.4 5.2 Deferred acquisition costs 0.3 0.9 Total assets $ 7.9 $ 14.4 Liabilities Loss and loss adjustment expense reserves $ 0.5 $ 4.6 Unearned insurance and reinsurance premiums 0.6 3.7 Other liabilities 0.1 — Total liabilities $ 1.2 $ 8.3 Sirius Group is a passive investor in certain third-party-managed hedge and private equity funds, some of which are VIEs. Sirius Group is not involved in the design or establishment of these VIEs, nor does it actively participate in the management of the VIEs. The exposure to loss from these investments is limited to the carrying value of the investments at the balance sheet date. Sirius Group calculates maximum exposure to loss to be (i) the amount invested in the debt or equity of the VIE, (ii) the notional amount of VIE assets or liabilities where Sirius Group has also provided credit protection to the VIE with the VIE as the referenced obligation, and (iii) other commitments and guarantees to the VIE. Sirius Group does not have any VIEs that it sponsors nor any VIEs where it has recourse to it or has provided a guarantee to the VIE interest holders. The following table presents total assets of unconsolidated VIEs in which Sirius Group holds a variable interest, as well as the maximum exposure to loss associated with these VIEs: Maximum Exposure to Loss (Millions) Total VIE Assets On-Balance Sheet Off-Balance Sheet Total December 31, 2019 Other long-term investments (1) $ 257.8 $ 102.6 $ 16.3 $ 118.9 Total at December 31, 2019 $ 257.8 $ 102.6 $ 16.3 $ 118.9 December 31, 2018 Other long-term investments (1) $ 209.1 $ 103.1 $ 32.0 $ 135.1 Total at December 31, 2018 $ 209.1 $ 103.1 $ 32.0 $ 135.1 (1) Comprised primarily of hedge funds and private equity funds.

Transactions with related parti

Transactions with related parties	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Transactions with related parties	Transactions with related parties (Re)insurance contracts In the normal course of business, Sirius Group enters into insurance and reinsurance contracts with certain of its insurance and MGU affiliates, or their subsidiaries. During the years ended December 31, 2019 and 2018 and 2017 , these contracts with related parties resulted in gross written premiums of $88.6 million , $67.9 million and $ 3.5 million, respectively. As of December 31, 2019 and 2018 , Sirius Group had total receivables due from related parties of $16.1 million and $14.3 million , respectively. As of December 31, 2019 , Sirius Group had total payables due to related parties of $0.9 million . As of December 31, 2018 , Sirius Group did not have any payables due to related parties. Other Meyer "Sandy" Frucher is the Company's Chairman of the board of directors and was also Vice Chairman of Nasdaq, Inc. ("Nasdaq"). The Company is traded on the Nasdaq Global Select Market and has business transactions that are related to its listing on the exchange under the normal course of business. (See Note 3. ) On October, 21, 2019, Nasdaq announced Mr. Frucher will conclude his tenure as Vice Chairman of Nasdaq and will assume the role of Strategic Advisor, effective January 1, 2020.

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies Concentrations of credit risk Sirius Group underwrites a significant amount of its reinsurance business through reinsurance intermediaries that represent the ceding company. There is credit risk associated with payments of (re)insurance balances to Sirius Group in regards to these brokers' ability to fulfill their contractual obligations. These intermediaries are fairly large and well established, and there are no indications they are financially distressed. During the years ended December 31, 2019 , 2018 , and 2017 , Sirius Group received its gross reinsurance premiums written from three major, third-party reinsurance intermediaries as detailed in the following table: Gross written premium by intermediary 2019 2018 2017 AON Corporation and subsidiaries 24 % 26 % 22 % Guy Carpenter & Company and subsidiaries 24 % 26 % 25 % WT Butler and Co. Ltd. 11 % 10 % 10 % Willis Towers Watson plc and subsidiaries 10 % 8 % 8 % Total 69 % 70 % 65 % Geographic Concentration The following table shows Sirius Group's net written premiums by geographic region based on the location of the ceding company for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 United States $ 922.3 $ 794.7 $ 563.1 Europe 268.9 276.5 262.3 Canada, the Caribbean, Bermuda and Latin America 102.5 103.6 111.4 Asia and Other 208.9 182.3 153.4 Total $ 1,502.6 $ 1,357.1 $ 1,090.2 Sirius Group conducts a significant portion of its business outside of the United States. As a result, a significant portion of Sirius Group's assets, liabilities, revenues, and expenses are denominated in currencies other than the U.S. dollar and are therefore subject to foreign currency risk. Sirius Group's foreign currency risk cannot be eliminated entirely and significant changes in foreign exchange rates may adversely affect Sirius Group's results of operations and financial condition. Sirius Group's foreign operations are subject to legal, political, and operational risks that may be greater than those present in the United States. As a result, certain of Sirius Group's operations at these foreign locations could be temporarily or permanently disrupted. Lloyd's Central Fund The Lloyd's Central Fund is available to satisfy claims if a member of Lloyd's is unable to meet its obligations to policyholders. Sirius Group has an obligation to pay contributions to the Lloyd's Central Fund each year based on gross written premium. For 2020, Sirius Group estimates the Lloyd's Central Fund contributions to be $0.5 million (based on the December 31, 2019 GBP to USD exchange rate) which is 0.35% of gross written premium. The Council of Lloyd's have the power to levy an additional contribution on members if it considered necessary, and the maximum additional contribution is currently 3% of capacity. Leases Sirius Group leases office space and equipment under various noncancelable operating lease agreements. The average life of the office leases is 7 years and the equipment leases is 3 years . During the year ended December 31, 2019 , Sirius Group recognized operating lease expense $ 12.6 million, including property taxes and routine maintenance expense as well as rental expenses related to short term leases. Total rental expense for the years ended December 31, 2018 and 2017 were $ 11.7 million and $ 10.2 million, respectively. As of December 31, 2019 , Sirius Group had $ 27.4 million operating lease right-of-use assets included in Other assets. As of December 31, 2019 , Sirius Group had $ 29.3 million operating lease liability included in Other liabilities. The following table presents the lease balances within the Consolidated Balance Sheets as of December 31, 2019 : (millions) Balance Sheet Classification December 31, 2019 Operating lease right-of-use assets Other assets $ 27.4 Current lease liabilities Other liabilities $ 8.3 Non-current lease liabilities Other liabilities $ 21.0 The following table presents weighted average remaining lease term and weighted average discount rate as at December 31, 2019 : Weighted average lease term (years) as of December 31, 2019 Leased offices 7 years Leased equipment 3 years Weighted average discount rate: Leased offices 3.7 % Leased equipment 3.4 % The following table presents future annual minimum rental payments required under non-cancellable leases and the present value discount to arrive at total lease liability as of December 31, 2019 : (Millions) Future Payments 2020 $ 9.3 2021 8.0 2022 7.1 2023 4.4 2024 2.0 2025 0.6 2026 and after 0.2 Total future annual minimum rental payments as at December 31, 2019 31.6 Less: present value discount (2.3 ) Total lease liability as of December 31, 2019 $ 29.3 As of December 31, 2019 , the Company's future operating lease obligations that have not yet commenced are immaterial. Legal Proceedings Sirius Group, and the insurance and reinsurance industry in general, are routinely subject to claims related litigation and arbitration in the normal course of business, as well as litigation and arbitration that do not arise from, or are directly related to, claims activity. Sirius Group estimates of the costs of settling matters routinely encountered in claims activity are reflected in the reserves for unpaid loss and LAE. (See Note 5 .) Sirius Group considers the requirements of ASC 450, Contingencies ("ASC 450"), when evaluating its exposure to non-claims related litigation and arbitration. ASC 450 requires that accruals be established for litigation and arbitration if it is probable that a loss has been incurred and it can be reasonably estimated. ASC 450 also requires that litigation and arbitration be disclosed if it is probable that a loss has been incurred or it there is a reasonable possibility that a loss may have been incurred.

Unaudited condensed quarterly f

Unaudited condensed quarterly financial data	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Unaudited condensed quarterly financial data	Unaudited condensed quarterly financial data (Expressed in millions of U.S. dollars, except per share amounts) December 31, September 30, June 30, March 31, Unaudited Unaudited Unaudited Unaudited Total revenues $ 352.0 $ 487.4 $ 441.0 $ 439.7 Total expenses $ 506.0 $ 498.7 $ 430.7 $ 318.4 Net (loss) income attributable to Sirius Group's common shareholders $ (137.3 ) $ (2.7 ) $ 6.6 $ 95.3 Basic earnings per common share and common share equivalent $ (1.19 ) $ (0.02 ) $ 0.05 $ 0.75 Diluted earnings per common share and common share equivalent $ (1.19 ) $ (0.06 ) $ 0.05 $ 0.74 (Expressed in millions of U.S. dollars, except per share amounts) December 31, September 30, June 30, March 31, Unaudited Unaudited Unaudited Unaudited Total revenues $ 336.8 $ 351.7 $ 441.8 $ 327.5 Total expenses $ 482.3 $ 386.3 $ 292.4 $ 273.1 Net (loss) income attributable to Sirius Group's common shareholder $ (153.6 ) $ (28.0 ) $ 97.8 $ 40.5 Basic earnings per common share and common share equivalent $ (1.31 ) $ (0.23 ) $ 0.78 $ 0.32 Diluted earnings per common share and common share equivalent $ (1.31 ) $ (0.23 ) $ 0.78 $ 0.32

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent events Events subsequent to original issuance of financial statements (Unaudited) In connection with the reissuance of the financial statements, the Company has evaluated subsequent events through September 1, 2020, the date the financial statements were available to be reissued. Series B preference shareholders expense reimbursement agreement On March 27, 2020, the Company entered into an expense reimbursement agreement (the “Agreement”) with each of the holders of the Series B preference shares. Pursuant to the Agreement, the Company agreed to reimburse each of the holders of the Series B preference shares for all reasonable and documented out-of-pocket expenses incurred by them in connection with pursuing a potential negotiated transaction (a “Potential Transaction”) involving the Company or one or more of its subsidiaries on or after January 8, 2020 up to $250,000 for each holder of Series B preference shares together with its affiliates and $1,000,000 in the aggregate with any reimbursement above such amounts requiring the written consent of the Company (but excluding any expenses incurred in connection with the evaluation or enforcement of any rights or obligations of the holders of the Series B preference shares or the Company relating to the preference shares in the Company held by such Series B preference shareholders). In addition, the Company agreed to reimburse the holders of the Series B preference shares for any and all reasonable and documented out-of-pocket attorneys’ fees or other fees payable to third party advisors up to $500,000 in the aggregate to the extent arising out of any litigation, dispute, arbitration or other proceeding commencing after the date of the Agreement that is not brought or commenced by a holder of the Series B preference shares and involves the Company, such Series B preference shareholder's investment in the Company or a Potential Transaction. As of the end of the second quarter 2020, no payments have been requested or made under the Agreement. Merger Agreement with Third Point Reinsurance, Ltd. On August 6, 2020, the Company announced that it had entered into an Agreement and Plan of Merger (the “2020 Merger Agreement”), by and among the Company, Third Point Reinsurance Ltd., a Bermuda exempted company (“TPRE”), and Yoga Merger Sub Limited, a Bermuda exempted company and a wholly owned subsidiary of TPRE (“Merger Sub”). The 2020 Merger Agreement provides, among other things, that, upon the terms and subject to the conditions set forth in the 2020 Merger Agreement and a Statutory Merger Agreement to be executed by the Company, TPRE and Merger Sub (the “Statutory Merger Agreement”), Merger Sub will merge with and into the Company, with the Company surviving as a wholly owned subsidiary of TPRE (the “Merger”). The 2020 Merger Agreement, the Statutory Merger Agreement, and the consummation of the transactions contemplated by the 2020 Merger Agreement and the Statutory Merger Agreement, including the Merger (the “Transactions”), have been unanimously approved by the board of directors of each of the Company and TPRE. The consummation of the Merger is expected to occur during the first quarter of 2021, subject to the satisfaction or waiver of applicable closing conditions. Under the terms of the 2020 Merger Agreement, as of the effective time of the Merger (the “Effective Time”), each issued and outstanding common share, par value $0.01 per share, of the Company (“Company Shares”) will be converted into the right to receive, at the election of the holder thereof, (i) $9.50 in cash (the “Cash Election”), or (ii) (A) 0.743 of a common share, par value $0.10 per share, of TPRE (“TPRE Shares”) and (B) one contractual contingent value right (each, a “CVR”), which will represent the right to receive a contingent cash payment, and which, taken together with the fraction of the TPRE Share received, guarantee that on the second anniversary of the closing date of the Merger, the electing shareholder will have received equity and cash with a value of at least $13.73 per share (the “Share & CVR Election”), or (iii) (A) $0.905 in cash, (B) a number of TPRE Shares equal to the Mixed Election Common Shares Exchange Ratio (as such term is defined in the 2020 Merger Agreement), (C) a number of newly issued Series A preference shares of TPRE (“TPRE Preference Shares”) equal to the Mixed Election Preference Shares Exchange Ratio (as such term is defined in the 2020 Merger Agreement), (D) 0.190 of a warrant issued by TPRE (each, a “Warrant”) and (E) $0.905 aggregate principal amount of a right (each, an “Upside Right”) issued by TPRE (the “Mixed Election”). Elections must be made no later than ten (10) Business Days (as defined in the 2020 Merger Agreement) prior to the closing of the Transactions. Pursuant to the Company Voting and Support Agreement (as defined below), CM Bermuda, whose parent company is CMIG International, has agreed to make the Mixed Election. Holders of Company Shares who do not make an election will be deemed to have made the Share & CVR Election. No fractional TPRE Shares or TPRE Preference Shares will be issued in the Merger, and holders of Company Shares will receive cash in lieu of any fractional TPRE Shares or TPRE Preference Shares. Dissenting Company shareholders will be entitled to exercise appraisal rights under Bermuda law. The consummation of the Merger is subject to the satisfaction or waiver of certain conditions, including, among others, (i) the affirmative vote in favor of the approval of the 2020 Merger Agreement, the Merger and the Statutory Merger Agreement by the holders of a majority of the voting power of the Company Shares and the Company’s Series B preference shares, voting together as a single class, that are present (in person or by proxy) at the Company shareholder meeting called for such purpose, (ii) the affirmative vote in favor of the approval of the issuance of TPRE Shares in the Merger as contemplated by the 2020 Merger Agreement (the “TPRE Share Issuance”) by the holders of at least a majority of the voting power of TPRE Shares that are present (in person or by proxy) at the TPRE shareholder meeting called for such purpose, (iii) the expiration or termination of any applicable waiting period (together with any extensions thereof) under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (the “HSR Act”) and any other applicable antitrust laws, (iv) the receipt of certain approvals under applicable insurance laws, (v) the absence of any effective order issued by any governmental authority or court of competent jurisdiction or other legal restraint prohibiting or preventing the consummation of the Merger, (vi) in the case of each party’s obligation to effect the Merger, the absence of a material adverse effect with respect to the other party and its subsidiaries, taken as a whole, since the date of the 2020 Merger Agreement, (vii) in the case of each party’s obligation to effect the Merger, subject to certain materiality exceptions, the accuracy of the representations and warranties made by the other party, and compliance by the other party in all material respects with such party’s respective obligations under the 2020 Merger Agreement and (viii) other customary closing conditions. The 2020 Merger Agreement did not impact the Company's consolidated financial statements as of and for the year ended December 31, 2019. Transaction Matters Agreement On August 6, 2020, CM Bermuda, the Company, TPRE and CMIG International entered into a Transaction Matters Letter Agreement (the “Transaction Matters Agreement”), pursuant to which, among other things and subject to the terms and conditions thereof, the Company has agreed to pay for and reimburse CMIG International and CM Bermuda for certain legal expenses incurred by CMIG International and CM Bermuda in connection with the Transactions and the related sales process or other discussions between CMIG International, CM Bermuda and the Company occurring on or after March 6, 2020, and TPRE has agreed to assume such remaining payment obligations of the Company following the closing of the Merger. TPRE has also agreed to pay for the fees and expenses payable by CMIG International and CM Bermuda to its financial advisor, Goldman Sachs (Asia) L.L.C., relating to the Transactions. Under the terms of the Transaction Matters Agreement, the Company is not permitted to terminate or threaten to terminate the 2020 Merger Agreement following a change by the TPRE board of directors of its recommendation to TPRE’s shareholders in favor of the TPRE Share Issuance without the prior written consent of CM Bermuda and CMIG International. On August 10, 2020, the Company paid $1.9 million for certain legal expenses incurred by CM Bermuda and CMIG International in connection with the Transaction Matters Letter Agreement.

Schedule I - Summary of Investm

Schedule I - Summary of Investments - Other Than Investments in Related Parties	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Abstract]
Summary of Investments - Other Than Investments in Related Parties	Sirius International Insurance Group, Ltd. Schedule I Summary of Investments – Other Than Investments in Related Parties As at December 31, 2019 (Expressed in millions of U.S. dollars) Cost or amortized cost Fair value Amount shown on the balance sheet Corporate debt securities $ 458.6 $ 474.1 $ 474.1 Asset-backed securities 489.4 486.8 486.8 Residential mortgage-backed securities 426.2 438.9 438.9 Commercial mortgage-backed securities 88.5 89.0 89.0 U.S. government and government agency 111.5 110.5 110.5 Non-U.S. government and government agency 63.7 63.0 63.0 Preferred stocks 17.0 17.0 17.0 U.S. States, municipalities and political subdivision 1.7 1.7 1.7 Total fixed maturities $ 1,656.6 $ 1,681.0 $ 1,681.0 Total short-term investments 1,090.8 1,085.2 1,085.2 Total equity securities 379.2 405.2 405.2 Total other long-term investments 315.4 346.8 346.8 Total $ 3,442.0 $ 3,518.2 $ 3,518.2

Schedule II - Condensed Financi

Schedule II - Condensed Financial Information of Registrant	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
Schedule II - Condensed Financial Information of Registrant	Sirius International Insurance Group, Ltd. Schedule II Condensed Financial Information of Registrant Balance Sheets As at December 31, 2019 and 2018 (Expressed in millions of U.S. dollars, except share and per share information) 2019 2018 Assets Fixed maturity investments, at fair value ( Amortized cost 2019: $11.7; 2018: $2.9) $ 11.7 $ 2.8 Short-term investments, at fair value ( Amortized cost 2019: $1.2; 2018: $5.3 ) 1.2 5.3 Cash 0.2 — Total investments and cash 13.1 8.1 Investments in unconsolidated affiliates 1,846.2 1,911.2 Other assets 24.9 42.5 Total assets $ 1,884.2 $ 1,961.8 Liabilities Other liabilities $ 20.8 $ 25.1 Total liabilities 20.8 25.1 Commitments and Contingencies Mezzanine equity Series B preference shares 223.0 232.2 Total mezzanine equity 223.0 232.2 Common shareholders' equity Common shares ( shares issued and outstanding: 2019: 115,299,341; 2018: 115,151,251 ) 1.2 1.2 Additional paid-in surplus 1,098.2 1,089.1 Retained earnings 778.5 816.6 Accumulated other comprehensive (loss) (237.5 ) (202.4 ) Total common shareholders' equity 1,640.4 1,704.5 Total liabilities, mezzanine equity, and common shareholders' equity $ 1,884.2 $ 1,961.8 See Notes to Condensed Financial Information of Registrant Sirius International Insurance Group, Ltd. Schedule II Condensed Financial Information of Registrant Statements of (Loss) For the years ended December 31, 2019 , 2018 , and 2017 (Expressed in millions of U.S. dollars) 2019 2018 2017 Revenues Net investment income $ 0.4 $ 0.5 $ 0.3 Net realized investment gains — — 0.2 Net unrealized investment gains 0.1 — 12.8 Net foreign exchange (losses) — — (0.2 ) Revaluation of contingent consideration (5.5 ) 6.1 13.6 Other revenue (18.7 ) 41.4 0.9 Total revenues (23.7 ) 48.0 27.6 Expenses Other underwriting expenses — — (0.2 ) General and administrative expenses 28.7 13.6 13.0 Total expenses 28.7 13.6 12.8 (Loss) income before equity earnings of unconsolidated affiliates, net of tax (52.4 ) 34.4 14.8 Equity in earnings of unconsolidated affiliates, net of tax 5.1 (52.5 ) (164.8 ) Net (loss) attributable to Sirius Group (47.3 ) (18.1 ) (150.0 ) Change in carrying value of Series B preference shares 9.2 (36.4 ) — Less: Accrued dividends on Series A redeemable preference shares — (2.6 ) (6.1 ) Add: Redemption of Series A redeemable preference shares — 13.8 — Net (loss) attributable to Sirius Group's common shareholders $ (38.1 ) $ (43.3 ) $ (156.1 ) See Notes to Condensed Financial Information of Registrant Sirius International Insurance Group, Ltd. Schedule II Condensed Financial Information of Registrant Statements of Comprehensive (Loss) Income For the years ended December 31, 2019 , 2018 , and 2017 (Expressed in millions of U.S. dollars) 2019 2018 2017 Comprehensive (loss) Net (loss) attributable to Sirius Group $ (47.3 ) $ (18.1 ) $ (150.0 ) Other comprehensive (loss) income Change in foreign currency translation, net of tax (35.1 ) (61.9 ) 71.7 Comprehensive (loss) attributable to Sirius Group $ (82.4 ) $ (80.0 ) $ (78.3 ) See Notes to Condensed Financial Information of Registrant Sirius International Insurance Group, Ltd. Schedule II Condensed Financial Information of Registrant Statements of Cash Flows For the years ended December 31, 2019 , 2018 , and 2017 (Expressed in millions of U.S. dollars) 2019 2018 2017 Cash flows from operations: Net (loss) income attributable to Sirius Group $ (47.3 ) $ (18.1 ) $ (150.0 ) Adjustments to reconcile net income to net cash provided from (used for) operations: Equity in earnings of subsidiaries (5.1 ) 52.5 164.8 Dividends received from subsidiaries 35.0 150.0 110.0 Net realized and unrealized investment (losses) (0.1 ) — (13.0 ) Amortization of premium on fixed maturity investments — (0.3 ) (0.1 ) Share-based compensation 9.1 2.0 — Revaluation of contingent consideration 5.5 (6.1 ) (13.6 ) Other operating items: Net change in other assets and liabilities, net 14.7 (57.5 ) 12.6 Net cash provided from (used for) operations 11.8 122.5 110.7 Cash flows from investing activities: Net change in short-term investments 4.1 25.6 2.5 Sales of fixed maturities and convertible fixed maturity investments 14.1 65.9 1.1 Maturities, calls, and paydowns of fixed maturity and convertible fixed maturity investments 0.1 — — Sales of common equity securities — — 59.6 Purchases of common equity securities — — (54.4 ) Purchases of fixed maturities and convertible fixed maturity investments (23.0 ) (64.9 ) — Contributions to subsidiaries — (143.5 ) (132.7 ) Net cash (used for) provided from investing activities (4.7 ) (116.9 ) (123.9 ) Cash flows from financing activities: Payment of contingent consideration (6.9 ) (3.5 ) — Capital contribution from former parent — 1.4 13.3 Proceeds from issuance of common shares, net of expenses — 61.2 — Proceeds from issuance of Series B preference shares — 195.8 — Redemption of common shares from CM Bermuda — (164.0 ) — Return of capital to CM Bermuda — (1.6 ) — Redemption of Series A redeemable preference shares — (95.0 ) — Net cash (used for) provided from financing activities (6.9 ) (5.7 ) 13.3 Net (decrease) increase in cash during year 0.2 (0.1 ) 0.1 Cash balance at beginning of year — 0.1 — Cash balance at end of year $ 0.2 $ — $ 0.1 See Notes to Condensed Financial Information of Registrant

Schedule III - Supplementary In

Schedule III - Supplementary Insurance Information	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Abstract]
Supplementary Insurance Information	Sirius International Insurance Group, Ltd. Schedule III Supplementary Insurance Information As at and for the years ended December 31, 2019 , 2018 , and 2017 (Millions) As at and for the year ended December 31, 2019 Deferred Acquisition Costs Loss and Loss Adjustment Expense Reserves Unearned Insurance and Reinsurance Premiums Net Earned Insurance and Reinsurance Premiums Loss and Loss Adjustment Expenses Insurance and Reinsurance Acquisition Expenses Other Underwriting Expenses Net Written Insurance and Reinsurance Premiums Global Reinsurance $ 85.9 $ 1,536.5 $ 419.0 $ 966.5 $ 850.9 $ 199.7 $ 84.5 $ 987.9 Global A&H 57.2 225.1 244.6 443.3 278.7 125.8 23.7 458.1 U.S. Specialty 5.1 30.7 44.4 29.6 24.1 6.4 10.6 54.1 Runoff & Other — 539.2 — 2.2 2.8 2.9 5.9 2.5 Corporate Elimination — — — — 13.8 (46.1 ) 13.5 — Total $ 148.2 $ 2,331.5 $ 708.0 $ 1,441.6 $ 1,170.3 $ 288.7 $ 138.2 $ 1,502.6 (Millions) As at and for the year ended December 31, 2018 Deferred Acquisition Costs Loss and Loss Adjustment Expense Reserves Unearned Insurance and Reinsurance Premiums Net Earned Insurance and Reinsurance Premiums Loss and Loss Adjustment Expenses Insurance and Reinsurance Acquisition Expenses Other Underwriting Expenses Net Written Insurance and Reinsurance Premiums Global Reinsurance $ 86.7 $ 1,231.2 $ 409.7 $ 870.5 $ 675.2 $ 185.3 $ 87.7 $ 934.6 Global A&H 54.0 197.9 224.8 357.6 194.9 109.7 27.4 379.8 U.S. Specialty 0.9 2.8 12.7 5.0 2.3 1.3 8.7 13.1 Runoff & Other — 584.8 — 29.2 14.6 2.8 6.3 29.6 Corporate Elimination — — — — 13.0 (43.7 ) 16.1 — Total $ 141.6 $ 2,016.7 $ 647.2 $ 1,262.3 $ 900.0 $ 255.4 $ 146.2 $ 1,357.1 (Millions) As at and for the year ended December 31, 2017 Deferred Acquisition Costs Loss and Loss Adjustment Expense Reserves Unearned Insurance and Reinsurance Premiums Net Earned Insurance and Reinsurance Premiums Loss and Loss Adjustment Expenses Insurance and Reinsurance Acquisition Expenses Other Underwriting Expenses Net Written Insurance and Reinsurance Premiums Global Reinsurance $ 71.7 $ 1,064.1 $ 310.7 $ 727.6 $ 617.3 $ 154.0 $ 79.8 $ 749.2 Global A&H 49.1 206.2 195.8 306.8 179.8 89.6 23.4 341.5 U.S. Specialty — — — — — — — — Runoff & Other 0.1 628.2 0.3 0.9 14.1 (3.5 ) 2.9 (0.5 ) Corporate Elimination — — — — — (42.9 ) — — Total $ 120.9 $ 1,898.5 $ 506.8 $ 1,035.3 $ 811.2 $ 197.2 $ 106.1 $ 1,090.2

Schedule IV - Reinsurance

Schedule IV - Reinsurance	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Reinsurance	Sirius International Insurance Group, Ltd. Schedule IV Reinsurance For the years ended December 31, 2019 , 2018 , and 2017 (Millions) Direct gross Ceded to other companies Assumed from other companies Net amount Percentage of amount assumed to net Year ended December 31, 2019 $ 511.2 $ 400.1 $ 1,391.5 $ 1,502.6 93 % Year ended December 31, 2018 454.5 463.9 1,366.5 1,357.1 101 % Year ended December 31, 2017 450.2 349.1 989.1 1,090.2 91 %

Schedule V - Valuation and Qual

Schedule V - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	Sirius International Insurance Group, Ltd. Schedule V Valuation and Qualifying Accounts As at and for the years ended December 31, 2019 , 2018 , and 2017 (Millions) Additions (Subtractions) Balance at beginning of period Charged to costs and expenses Charged to other accounts Deductions described (1) Balance at the end of period Years ended: December 31, 2019 Reinsurance on recoverable paid losses: Allowance for reinsurance balances $ 5.7 — — — $ 5.7 Property and casualty insurance and reinsurance premiums receivable: Allowance for uncollectible accounts $ 4.3 (0.1 ) — — $ 4.2 December 31, 2018 Reinsurance on recoverable paid losses: Allowance for reinsurance balances $ 5.8 — (0.1 ) — $ 5.7 Property and casualty insurance and reinsurance premiums receivable: Allowance for uncollectible accounts $ 4.6 — (0.2 ) (0.1 ) $ 4.3 December 31, 2017 Reinsurance on recoverable paid losses: Allowance for reinsurance balances $ 5.8 — — — $ 5.8 Property and casualty insurance and reinsurance premiums receivable: Allowance for uncollectible accounts $ 5.3 (0.5 ) (0.5 ) 0.3 $ 4.6 (1) Represents net collections (charge-offs) of receivable balances and foreign currency translation.

Schedule VI - Insurance Operati

Schedule VI - Insurance Operations	12 Months Ended
	Dec. 31, 2019
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Abstract]
Insurance Operations	Sirius International Insurance Group, Ltd. Schedule VI Insurance Operations As at and for the years ended December 31, 2019 , 2018 , and 2017 (Millions) Affiliation with registrant Deferred acquisition costs Loss and loss adjustment expense reserves Unearned insurance and reinsurance premiums Net earned insurance and reinsurance premiums Net investment income Losses and loss expenses incurred related to current year Losses and loss expenses incurred related to prior year Net paid losses and loss expenses Insurance and reinsurance acquisition costs Net premiums written Consolidated Subsidiaries 2019 $ 148.2 $ 2,331.5 $ 708.0 $ 1,441.6 $ 84.7 $ 1,066.5 $ 103.8 $ 911.3 $ 288.7 $ 1,502.6 2018 $ 141.6 $ 2,016.7 $ 647.2 $ 1,262.3 $ 71.4 $ 907.3 $ (7.3 ) $ 791.7 $ 255.4 $ 1,357.1 2017 $ 120.9 $ 1,898.5 $ 506.8 $ 1,035.3 $ 56.8 $ 811.8 $ (0.6 ) $ 612.3 $ 197.2 $ 1,090.2

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The accompanying consolidated financial statements at December 31, 2019 , have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP") and the rules and regulations of the U.S. Securities and Exchange Commission ("SEC"). The accompanying consolidated financial statements present the consolidated results of operations, financial condition, and cash flows of the Company and its subsidiaries and those entities in which the Company has control and a majority economic interest as well as those variable interest entities ("VIEs") that meet the requirements for consolidation. All significant intercompany transactions have been eliminated in consolidation. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Certain amounts in the prior period financial statements have been reclassified to conform to the current presentation. Tabular dollar amounts are in millions, with the exception of share and per share amounts. All amounts are reported in U.S. dollars, except where noted otherwise.
Investment securities	Investment securities Sirius Group's invested assets consist of securities and other investments held for general investment purposes. Sirius Group's portfolio of fixed maturity investments and equity securities held for general investment purposes are classified as trading and are reported at fair value as of the balance sheet date. Changes in unrealized gains and losses are reported pre-tax in revenues. Realized investment gains and losses are accounted for using the first-in first-out method and are reported pre-tax in revenues. Premiums and discounts on all fixed maturity investments are amortized and/or accreted to income over the anticipated life of the investment and are reported in Net investment income. Sirius Group's invested assets that are measured at fair value include fixed maturity investments, common and preferred equity securities, and other long-term investments, such as interests in hedge funds and private equities. Fair value is defined as the price received to sell an asset in an orderly transaction between market participants at the measurement date reflecting the highest and best use valuation concepts. In determining its estimates of fair value, Sirius Group uses a variety of valuation approaches and inputs. Whenever possible, Sirius Group estimates fair value using valuation methods that maximize the use of quoted prices and other observable inputs.
Short-term investments	Short-term investments Short-term investments consist of money market funds, certificates of deposit and other securities which, at the time of purchase, mature or become available for use within one year. Short-term investments are carried at fair value.
Other long-term investments	Other long-term investments Other long-term investments consist primarily of hedge funds, private equity funds, other investments in limited partnerships and other private equity securities. The fair value of other long-term investments is generally based upon Sirius Group's proportionate interest in the underlying fund's net asset value, which is deemed to approximate fair value. In addition, due to a lag in reporting, some of the fund managers, fund administrators, or both, are unable to provide final fund valuations as of the Company's reporting date. In these circumstances, Sirius Group estimates the return of the current period and uses all credible information available. This includes utilizing preliminary estimates reported by its fund managers and using information that is available to Sirius Group with respect to the underlying investments, as necessary. The changes in fair value are reported in pre-tax revenues in Net unrealized investment gains (losses). Actual final fund valuations may differ from Sirius Group's estimates and these differences are recorded in the period they become known as a change in estimate. Other long-term investments also includes certain investments that are eligible for the equity method where Sirius Group has elected the fair value option under which the changes in fair value are reported in pre-tax revenues in Net unrealized investment gains (losses).
Loan participations	Loan participations Loan participations that qualify for sale accounting under the Accounting Standards Codification ("ASC") Topic 860, "Transfers and Servicing of Financial Assets", are carried at fair value. The fair value of loan participations is estimated using discounted cash flow analysis. Sirius Group includes Loan particpations in Other assets in the Consolidated Balance Sheets.
Cash	Cash Cash includes amounts on hand and demand deposits with banks and other financial institutions. Amounts presented in the statement of cash flows are shown net of balances acquired and sold in the purchase or sale of the Company's consolidated subsidiaries.
Restricted cash	Restricted cash Restricted cash represents cash and cash equivalents that Sirius Group is (a) holding for the benefit of a third party and is legally or contractually restricted as to withdrawal or usage for general corporate purposes; and (b) not replaceable by another type of asset other than cash or cash equivalents, under the terms of Sirius Group's contractual arrangements with such third parties.
Insurance and reinsurance operations	Insurance and reinsurance operations Premiums written are recognized as revenues and are earned ratably over the term of the related policy or reinsurance treaty. Premiums written include amounts reported by brokers, managing general underwriters, and ceding companies, supplemented by the Company's own estimates of premiums where reports have not been received. The determination of premium estimates requires a review of the Company's experience with the ceding companies, managing general underwriters, familiarity with each market, the timing of the reported information, an analysis and understanding of the characteristics of each class of business, and management's judgment of the impact of various factors, including premium or loss trends, on the volume of business written and ceded to the Company. On an ongoing basis, the Company's underwriters review the amounts reported by these third parties for reasonableness based on their experience and knowledge of the subject class of business, taking into account the Company's historical experience with the brokers or ceding companies. Unearned premiums represent the portion of premiums written that are applicable to future insurance or reinsurance coverage provided by policies or treaties in force. Deferred acquisition costs represent commissions, premium taxes, brokerage expenses, and other costs which are directly attributable to the successful acquisition or renewal of contracts and vary with the production of business. These costs are deferred and amortized over the period during which the premiums are earned. Amortization of Deferred acquisition costs are shown net of contractual commissions earned on reinsurance ceded within Insurance and reinsurance acquisition expenses. Deferred acquisition costs are limited to the amount expected to be recovered from future earned premiums and anticipated investment income. This limitation is referred to as a premium deficiency. A premium deficiency is recognized if the sum of expected loss and loss adjustment expenses ("LAE"), expected dividends to policyholders, unamortized acquisition costs, and maintenance costs exceeds related unearned premiums and anticipated investment income. A premium deficiency is recognized by charging any unamortized acquisition costs to expense to the extent required in order to eliminate the deficiency. If the premium deficiency exceeds unamortized acquisition costs, then a liability is accrued for the excess deficiency. Other underwriting expenses consist primarily of personnel related expenses (including salaries, benefits, and variable compensation expense) and other general operating expenses related to the underwriting operations. Losses and LAE are charged against income as incurred. Unpaid insurance loss and LAE reserves are based on estimates (generally determined by claims adjusters, legal counsel, and actuarial staff) of the ultimate costs of settling claims, including the effects of inflation and other societal and economic factors. Unpaid reinsurance loss and LAE reserves are based primarily on reports received from ceding companies and actuarial projections. Unpaid loss and LAE reserves represent management's best estimate of ultimate losses and LAE, net of estimated salvage and subrogation recoveries, if applicable. Such estimates are regularly reviewed and updated and any resulting adjustments are reflected in current operations. The process of estimating loss and LAE reserves involves a considerable degree of judgment by management and the ultimate amount of expense to be incurred could be greater or less than the amounts currently reflected in the financial statements. Sirius Group enters into ceded reinsurance contracts to protect its businesses from losses due to concentration of risk, to manage its operating leverage ratios and to limit losses arising from catastrophic events. Such reinsurance contracts are executed through excess of loss treaties and catastrophe contracts under which the reinsurer indemnifies for a specified part or all of certain types of losses over stipulated amounts arising from any one occurrence or event. Sirius Group has also entered into quota share treaties with reinsurers under which all risks meeting prescribed criteria are covered on a pro-rata basis. The amount of each risk ceded by Sirius Group is subject to maximum limits which vary by line of business and type of coverage. Although these contracts protect Sirius Group, these reinsurance arrangements do not relieve Sirius Group from its primary obligations to insureds. Amounts recoverable from reinsurers are estimated in a manner consistent with the claim liability associated with the reinsured policies. The collectability of reinsurance recoverables is subject to the solvency of the reinsurers. Sirius Group is selective in regard to its reinsurers, principally placing reinsurance with those reinsurers with a strong financial condition, industry ratings, and underwriting ability. Management monitors the financial condition and ratings of its reinsurers on an ongoing basis. Reinsurance premiums, commissions, expense reimbursements, and reserves related to reinsured business are accounted for on a basis consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Reinsurance premiums ceded are expensed over the period the reinsurance coverage is provided. Ceded unearned insurance and reinsurance premiums represent the portion of premiums ceded applicable to the unexpired term of policies in force. Funds held by ceding companies represent amounts due to Sirius Group in connection with certain assumed reinsurance agreements in which the ceding company retains a portion of the premium to provide security against future loss payments. The funds held by ceding companies are generally invested by the ceding company and a contractually agreed interest amount is credited to Sirius Group and recognized as investment income. Funds held under reinsurance treaties represent contractual payments due from Sirius Group that have been retained to secure such obligations. Accruals for contingent commission liabilities are established for reinsurance contracts that provide for the stated commission percentage to increase or decrease based on the loss experience of the contract. Changes in the estimated liability for contingent commission arrangements are recorded as Insurance and reinsurance acquisition expenses. Accruals for contingent commission liabilities are determined through the review of the contracts that have these adjustable features and are estimated based on expected loss and LAE.
Derivative financial instruments	Derivative financial instruments Sirius Group holds derivative financial instruments for both risk management and investment purposes. Sirius Group recognizes all derivatives as either assets or liabilities, measured at fair value, in the Consolidated Balance Sheets. Changes in the fair value of derivative instruments are recognized in current period pre-tax income.
Deferred software costs	Deferred software costs Sirius Group capitalizes costs related to computer software developed for internal use during the application development stage of software development projects. These costs generally consist of certain external, payroll, and payroll-related costs. Sirius Group begins amortization of these costs once the project is completed and ready for its intended use. Amortization is on a straight-line basis and over a useful life of three to five years .
Share-based compensation	Share-based compensation Share-based compensation plans are accounted for in accordance with the ASC Topic 718 "Compensation - Stock Compensation" Sirius Group recognizes the compensation expense for stock restricted share and performance share awards based on the fair value of the award on the date of grant over the requisite service period. Awards under the 2016 Long-term Incentive Plan and 2018 Omnibus Incentive Plan vest over two or three years . The Company has elected to recognize forfeitures as they occur rather than estimate service-based forfeitures over the requisite service period.
Defined benefit plans	Defined benefit plans Certain Sirius Group employees in Europe participate in defined benefit plans. The liability for the defined benefit plans that is reported on the Consolidated Balance Sheets is the current value of the defined benefit obligation at the end of the period, reduced by the fair value of the plan's managed assets, with adjustments for actuarial gains and losses. The defined benefit pension plan obligation is calculated annually by independent actuaries. The current value of the defined benefit obligation is determined through discounting of expected future cash flows, using interest rates determined by current market interest rates. The service costs and actuarial gains and losses on the defined benefit obligation and the fair value on the plan assets are recognized in the Consolidated Statements of Income.
Commission and other revenue recognition	Commission and other revenue recognition Sirius Group recognizes agent commissions and other revenues when it has fulfilled all of its obligations necessary to earn the revenue and when it can both reliably estimate the amount of revenue, net of any amounts expected to be uncollectible, and any amounts associated with expected cancellations.
Earnings per share	Earnings per share Earnings per share is reported in accordance with ASC Topic 260 Earnings per Share . Basic earnings (loss) per share is computed by dividing net (loss) available to Sirius Group common shareholders by the weighted-average number of common shares outstanding during the period. Diluted earnings per share is computed by dividing net income available to Sirius Group common shareholders by the weighted-average number of common shares outstanding adjusted to give effect to potentially dilutive securities.
Federal and foreign income taxes	Federal and foreign income taxes Certain of Sirius Group's subsidiaries file consolidated tax returns in the United States. Sirius Group has subsidiaries in various jurisdictions, including but not limited to Sweden, the United Kingdom, and Luxembourg, which are subject to applicable taxes in those jurisdictions. Deferred tax assets and liabilities are recorded when a difference between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts for tax purposes exists, and for other temporary differences. The deferred tax asset or liability is recorded based on tax rates expected to be in effect when the difference reverses. The deferred tax asset is recognized when it is more likely than not that it will be realized. The Tax Cuts and Jobs Act (the "TCJA") which was enacted into law in the U.S. in December 31, 2017 includes a new base erosion and anti-abuse tax ("BEAT"), which is essentially a minimum tax that is potentially applicable to certain otherwise deductible payments made by U.S. entities to non-U.S. affiliates, including cross-border interest payments and reinsurance premiums. The statutory BEAT rate is 10% in 2019 -2025, and then rises to 12.5% in 2026 and thereafter. The TCJA also includes provisions for Global Intangible Low-Taxed Income ("GILTI") under which taxes on foreign income are imposed on the excess of a deemed return on tangible assets of certain foreign subsidiaries. Consistent with accounting guidance, Sirius Group is treating BEAT as an in period tax charge when incurred in future periods for which no deferred taxes need to be provided and has made an accounting policy election to treat GILTI taxes in a similar manner.
Foreign currency exchange	Foreign currency exchange The U.S. dollar is the functional currency for Sirius Group's businesses except for Sirius International Insurance Corporation ("Sirius International"), Lloyd's Syndicate 1945 ("Syndicate 1945"), several subsidiaries of International Medical Group Acquisition, Inc. ("IMG"), and the Canadian reinsurance operations of Sirius America Insurance Company ("Sirius America"). Sirius Group also invests in securities denominated in foreign currencies. Assets and liabilities recorded in these foreign currencies are translated into U.S. dollars at exchange rates in effect at the balance sheet date, and revenues and expenses are converted using the average exchange rates for the period. Net foreign exchange gains and losses arising from the translation of functional currencies are reported in shareholder's equity, in Accumulated other comprehensive (loss). As of December 31, 2019 and 2018 , Sirius Group had Net unrealized foreign currency translation losses of $237.5 million and $202.4 million , respectively, recorded in Accumulated other comprehensive (loss) on its Consolidated Balance Sheets. Assets and liabilities relating to foreign operations are remeasured into the functional currency using current exchange rates; revenues and expenses are remeasured into the functional currency using the weighted average exchange rate for the period. The resulting exchange gains and losses are reported as a component of net income in the period in which they arise within Net realized investment gains (losses), Net unrealized investment gains (losses), and Net foreign exchange gains.
Goodwill and intangible assets	Goodwill and intangible assets Goodwill represents the excess of the purchase price of an acquisition over the fair value of the identifiable net assets acquired and is assigned to the applicable reporting unit at acquisition. Goodwill is evaluated for impairment on an annual basis. Sirius Group initially evaluates goodwill using a qualitative approach to determine whether it is more likely than not that the fair value of goodwill is greater than its carrying value. If the results of the qualitative evaluation indicate that it is more likely than not that the carrying value of goodwill exceeds its fair value, Sirius Group performs the quantitative test for impairment. Indefinite-lived intangible assets are evaluated for impairment similar to goodwill. Finite-lived intangible are amortized on a straight-line basis over their estimated useful lives. The amortization periods approximate the period over which Sirius Group expects to generate future net cash inflows from the use of these assets. All of these assets are subject to impairment testing for the impairment or disposal of long-lived assets when events or conditions indicate that the carrying value of an asset may not be fully recoverable from future cash flows. If goodwill or intangible assets are impaired, such assets are written down to their fair values with the related expense recorded in Sirius Group's results of operations.
Non-controlling interests	Non-controlling interests Non-controlling interests consist of the ownership interests of non-controlling shareholders in consolidated subsidiaries, and are presented separately on the balance sheet.
Mezzanine equity	Mezzanine equity In connection with significant transactions the Company has entered into, the Company has issued preference shares. (See Note 3 .) At the date of issuance, Sirius Group evaluates the conversion and redemption features associated with the preference shares in order to determine the balance sheet classification of the instrument. The preference shares are classified outside of permanent equity (as Mezzanine equity) when the preference shares are redeemable at a fixed or determinable price on a fixed or determinable date, at the option of the shareholder or upon the occurrence of an event that is not solely within the control of Sirius Group. Sirius Group accounts for the Series B preference shares outside of permanent equity as Mezzanine equity in the Consolidated Balance Sheets as the ability to settle in common shares cannot be assured.
Variable interest entities	Variable interest entities Sirius Group consolidates a VIE when it has both the power to direct the activities of the VIE that most significantly impact its economic performance and either the obligation to absorb losses or the right to receive returns from the VIE that could potentially be significant to the VIE. An entity in which Sirius Group holds a variable interest is a VIE if any of the following conditions exist: (a) the total equity investment at risk is not sufficient to permit the entity to finance its activities without additional subordinated financial support, (b) as a group, the holders of equity investment at risk lack either the direct or indirect ability through voting rights or similar rights to make decisions about an entity's activities that most significantly impact the entity's economic performance or the obligation to absorb the expected losses or right to receive the expected residual returns, or (c) the voting rights of some investors are disproportionate to their obligation to absorb the expected losses of the entity, their rights to receive the expected residual returns of the entity, or both, and substantially all of the entity's activities either involve or are conducted on behalf of an investor with disproportionately few voting rights. The primary beneficiary is defined as the variable interest holder that is determined to have the controlling financial interest as a result of having both (a) the power to direct the activities of a VIE that most significantly impact the economic performance of the VIE and (b) the obligation to absorb losses or right to receive benefits from the VIE that could potentially be significant to the VIE. At inception of the VIE, as well as following an event that requires reassessment, Sirius Group determines whether it is the primary beneficiary based on the facts and circumstances surrounding each entity.
Recent accounting pronouncements	Recently adopted changes in accounting principles Leases Effective January 1, 2019, Sirius Group adopted Accounting Standards Update ("ASU") 2016-2, Leases (Accounting Standards Codification ("ASC") 842) which requires lessees to recognize lease assets and liabilities on the balance sheet for both operating and financing leases, with the exception of leases with an original term of 12 months or less. Under previous guidance, recognition of lease assets and liabilities was not required for operating leases. The new guidance requires that lease assets and liabilities to be recognized and measured initially based on the present value of the lease payments. Sirius Group adopted the new guidance using the simplified transition option that allows companies to apply the new lease standard at the adoption date and recognize a cumulative effect adjustment to the opening balance of retained earnings in the period of adoption. Sirius Group also made the following elections: • Sirius Group elected the package of practical expedients to not reassess prior conclusions related to contracts containing leases, lease classification and initial direct costs for all leases upon transition. • Sirius Group did not elect the hindsight practical expedient upon transition, for all leases. • Sirius Group elected the short-term lease measurement and recognition exemption, resulting in lease payments being recorded as an expense on a straight-line basis over the lease term. • Sirius Group elected to include both lease and non-lease components as a single component for all leases. • Sirius Group did not elect the land easement practical expedient as it was not applicable. As a result of the adoption of the new guidance, Sirius Group recognized a lease liability of $36.8 million , which represents the present value of our remaining lease payments and a right-of-use asset of $34.4 million as of January 1, 2019. The adoption of this guidance did not materially impact our results of operations or cash flows. Due to the adoption of the standard using the retrospective cumulative-effect adjustment method, there are no changes to our previously reported results prior to January 1, 2019. Lease expense did not change materially as a result of the adoption of the new guidance. (See Note 22 .) Premium amortization on callable debt securities Effective January 1, 2019, Sirius Group adopted ASU 2017-8, Premium Amortization on Purchased Callable Debt Securities (ASC 310-20), which changes the amortization period for certain purchased callable debt securities. Under the new guidance, for investments in callable debt securities held at a premium, the premium will be amortized over the period to the earliest call date. The new guidance does not change the amortization period for callable debt securities held at a discount. The adoption of this guidance did not have a significant effect on our financial statements. Recent accounting pronouncements Credit losses In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (ASC 326), which establishes new guidance for the recognition of credit losses for financial assets measured at amortized cost. The new guidance, which applies to financial assets that have the contractual right to receive cash, including reinsurance receivables, requires reporting entities to estimate the credit losses expected over the life of a credit exposure using historical information, current information and reasonable and supportable forecasts that affect the collectability of the financial asset. The new guidance is effective for smaller reporting companies for annual and interim periods beginning after December 15, 2022. Adoption of this guidance is on a modified retrospective basis. Early adoption of the guidance is permitted. We plan to early adopt the standard on its effective date of January 1, 2020. This guidance is currently not expected to have a material impact on the consolidated financial statements. Fair Value Measurement Disclosures In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement , which modifies the disclosure requirements of fair value measurements. The new guidance is effective for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. The adoption of this guidance will not have a material impact on the consolidated financial statements.

Summary of significant accoun_3

Summary of significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of foreign currency exchange for translation of assets and liabilities	The following rates of exchange for the U.S. dollar have been used for translation of assets and liabilities for subsidiaries whose functional currency is not the U.S. dollar at December 31, 2019 and 2018 : Currency Closing Closing Swedish kronor 9.3210 8.9397 British pound 0.7568 0.7850 Euro 0.8912 0.8734 Canadian dollar 1.3003 1.3614

Significant transactions (Table

Significant transactions (Tables)	12 Months Ended
	Dec. 31, 2019
IMG
Business combination
Schedule of fair value of net assets acquired and allocation of purchase price	The following table summarizes the fair value of net assets acquired and allocation of purchase price of IMG, measured as of the acquisition date: (Millions) Total Useful Life Purchase price Cash paid $ 250.8 Series A redeemable preference shares 100.0 Contingent consideration 43.1 Total enterprise value 393.9 Less: Debt assumed (129.5 ) Total purchase price (a) $ 264.4 Assets acquired Total investments $ 41.0 Cash 10.5 Accrued investment income 0.2 Insurance and reinsurance premiums receivable 1.6 Deferred acquisition costs 2.9 Other assets 12.9 Intangible asset – distribution relationships 91.0 13.0 years Intangible asset – customer relationships 17.0 12.5 years Intangible asset – trade names 27.0 Intangible asset – technology 10.0 5.0 years Total assets acquired 214.1 Liabilities assumed Loss and loss adjustment expense reserves 14.3 Unearned insurance and reinsurance premiums 9.8 Deferred tax liability 55.9 Debt 129.5 Other liabilities 18.2 Total liabilities assumed 227.7 Net assets acquired (b) (13.6 ) Goodwill (a)-(b) $ 278.0
Schedule of supplemental pro forma information	​ Unaudited Pro Forma for the Years Ended December 31, (Millions) 2017 2016 Total revenues $ 1,176.8 $ 1,096.0 Net income $ (173.2 ) $ (4.6 )
Armada
Business combination
Schedule of fair value of net assets acquired and allocation of purchase price	The following table summarizes the fair value of net assets acquired and allocation of purchase price of Armada, measured as of the acquisition date: (Millions) Total Useful Life Purchase price Cash paid $ 123.4 ​ Contingent consideration 79.1 Total purchase price (a) $ 202.5 Assets acquired Restricted cash $ 10.4 ​ Other assets 1.2 ​ Intangible asset – distribution relationships 60.0 22.5 years Intangible asset – trade name 16.0 7.5 years Intangible asset – technology 5.5 9.0 years Total assets acquired 93.1 ​ Liabilities assumed Other liabilities 13.3 ​ Total liabilities assumed 13.3 ​ Net assets acquired (b) 79.8 ​ Goodwill (a)-(b) $ 122.7 ​
Schedule of supplemental pro forma information	Unaudited Pro Forma for the Years Ended December 31, (Millions) 2017 2016 Total revenues $ 1,144.6 $ 1,032.6 Net income $ (155.1 ) $ 45.9

Segment information (Tables)

Segment information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Summary of segment results	The following tables summarize the segment results for the years ended December 31, 2019 , 2018 , and 2017 : For the year ended December 31, 2019 (Millions) Global Reinsurance Global A&H U.S. Specialty Runoff & Other Corporate Elimination Total Gross written premiums $ 1,238.8 $ 593.4 $ 66.3 $ 4.2 $ — $ 1,902.7 Net written premiums $ 987.9 $ 458.1 $ 54.1 $ 2.5 $ — $ 1,502.6 Net earned insurance and reinsurance premiums $ 966.5 $ 443.3 $ 29.6 $ 2.2 $ — $ 1,441.6 Loss and allocated LAE (1) (830.6 ) (271.3 ) (23.7 ) (1.8 ) — (1,127.4 ) Insurance and reinsurance acquisition expenses (199.7 ) (125.8 ) (6.4 ) (2.9 ) 46.1 (288.7 ) Technical profit (loss) (63.8 ) 46.2 (0.5 ) (2.5 ) 46.1 25.5 Unallocated LAE (2) (20.3 ) (7.4 ) (0.4 ) (1.0 ) (13.8 ) (42.9 ) Other underwriting expenses (84.5 ) (23.7 ) (10.6 ) (5.9 ) (13.5 ) (138.2 ) Underwriting (loss) income (168.6 ) 15.1 (11.5 ) (9.4 ) 18.8 (155.6 ) Service fee revenue (3) — 124.2 — — (49.6 ) 74.6 Managing general underwriter unallocated LAE (4) — (17.3 ) — — 17.3 — Managing general underwriter other underwriting expenses (5) — (13.5 ) — — 13.5 — General and administrative expenses, MGU + Runoff & Other (6) — (66.9 ) — (3.7 ) — (70.6 ) Underwriting (loss) income, including net service fee income (168.6 ) 41.6 (11.5 ) (13.1 ) — (151.6 ) Net investment income 84.7 Net realized investment gains (losses) 56.7 Net unrealized investment gains (losses) 80.6 Net foreign exchange gains 7.7 Revaluation of contingent consideration (6.3 ) Other revenue (7) (19.5 ) General and administrative expenses (8) (39.2 ) Intangible asset amortization expenses (15.8 ) Interest expense on debt (31.0 ) Pre-tax income (loss) $ (33.7 ) Underwriting Ratios Loss ratio 88.0 % 62.9 % 81.4 % NM NM 81.2 % Acquisition expense ratio 20.7 % 28.4 % 21.6 % NM NM 20.0 % Other underwriting expense ratio 8.7 % 5.3 % 35.8 % NM NM 9.6 % Combined ratio (9) 117.4 % 96.6 % 138.8 % NM NM 110.8 % Goodwill and intangible assets (10) $ — $ 572.5 $ — $ 8.1 $ — $ 580.6 (1) Loss and allocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (2) Unallocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (3) Service fee revenue is part of Other revenue on the Consolidated Statements of (Loss) (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss) Income). (4) Managing general underwriter unallocated LAE represents IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the claims process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (5) Managing general underwriter other underwriting expenses represent IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the underwriting process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (6) General and administrative expenses, MGU + Runoff & Other is part of General and administrative expenses on the Consolidated Statements of (Loss) (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (7) Other revenue is presented net of Service fee revenue and is comprised mainly of the right of indemnification and gains (losses) from derivatives (see Note 13 ), (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss)). (8) General and administrative expenses are presented net of General and administrative expenses, MGU + Runoff & Other (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (9) Ratios considered not meaningful ("NM") to Runoff & Other and Corporate Elimination. (10) Sirius Group does not allocate its assets by segment, with the exception of Goodwill and Intangible assets. ​ For the year ended December 31, 2018 (Millions) Global Global U.S. Specialty Runoff & Other Corporate Total Gross written premiums $ 1,268.1 $ 500.6 $ 19.4 $ 32.9 $ — $ 1,821.0 Net written premiums $ 934.6 $ 379.8 $ 13.1 $ 29.6 $ — $ 1,357.1 Net earned insurance and reinsurance premiums $ 870.5 $ 357.6 $ 5.0 $ 29.2 $ — $ 1,262.3 Loss and allocated LAE (1) (658.8 ) (189.0 ) (2.3 ) (13.0 ) — (863.1 ) Insurance and reinsurance acquisition expenses (185.3 ) (109.7 ) (1.3 ) (2.8 ) 43.7 (255.4 ) Technical (loss) profit 26.4 58.9 1.4 13.4 43.7 143.8 Unallocated LAE (2) (16.4 ) (5.9 ) — (1.6 ) (13.0 ) (36.9 ) Other underwriting expenses (87.7 ) (27.4 ) (8.7 ) (6.3 ) (16.1 ) (146.2 ) Underwriting (loss) income (77.7 ) 25.6 (7.3 ) 5.5 14.6 (39.3 ) Service fee revenue (3) — 115.7 — — (44.7 ) 71.0 Managing general underwriter unallocated LAE (4) — (14.0 ) — — 14.0 — Managing general underwriter other underwriting expenses (5) — (16.1 ) — — 16.1 — General and administrative expenses, MGU + Runoff & Other (6) — (53.6 ) — (3.1 ) — (56.7 ) Underwriting (loss) income, including net service fee income (77.7 ) 57.6 (7.3 ) 2.4 — (25.0 ) Net investment income 71.4 Net realized investment gains (losses) 2.3 Net unrealized investment gains (losses) (23.2 ) Net foreign exchange gains 22.7 Revaluation of contingent consideration 9.6 Other revenue (7) 41.7 General and administrative expenses (8) (21.2 ) Intangible asset amortization expenses (15.8 ) Impairment of intangible assets (8.0 ) Interest expense on debt (30.8 ) Pre-tax income (loss) $ 23.7 Underwriting Ratios Loss ratio 77.6 % 54.5 % 46.0 % NM NM 71.3 % Acquisition expense ratio 21.3 % 30.7 % 26.0 % NM NM 20.2 % Other underwriting expense ratio 10.1 % 7.7 % 174.0 % NM NM 11.6 % Combined ratio (9) 109.0 % 92.9 % 246.0 % NM NM 103.1 % Goodwill and intangible assets (10) $ — $ 588.1 $ — $ 8.1 $ — $ 596.2 (1) Loss and allocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (2) Unallocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (3) Service fee revenue is part of Other revenue on the Consolidated Statements of (Loss) (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss) Income). (4) Managing general underwriter unallocated LAE represents IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the claims process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (5) Managing general underwriter other underwriting expenses represent IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the underwriting process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (6) General and administrative expenses, MGU + Runoff & Other is part of General and administrative expenses on the Consolidated Statements of (Loss) (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (7) Other revenue is presented net of Service fee revenue and is comprised mainly of the right of indemnification, gains (losses) from derivatives (see Note 13 ), and the termination of the call option to purchase The Phoenix Holdings, Ltd. (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss)). (8) General and administrative expenses are presented net of General and administrative expenses, MGU + Runoff & Other (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (9) Ratios considered not meaningful ("NM") to Runoff & Other and Corporate Elimination. (10) Sirius Group does not allocate its assets by segment, with the exception of Goodwill and Intangible assets. For the year ended December 31, 2017 (Millions) Global Global U.S. Specialty Runoff & Other Corporate Total Gross written premiums $ 950.2 $ 494.6 $ — $ (5.5 ) $ — $ 1,439.3 Net written premiums $ 749.2 $ 341.5 $ — $ (0.5 ) $ — $ 1,090.2 Net earned insurance and reinsurance premiums $ 727.6 $ 306.8 $ — $ 0.9 $ — $ 1,035.3 Loss and allocated LAE (1) (599.1 ) (175.0 ) — (11.0 ) — (785.1 ) Insurance and reinsurance acquisition expenses (154.0 ) (89.6 ) — 3.5 42.9 (197.2 ) Technical (loss) profit (25.5 ) 42.2 — (6.6 ) 42.9 53.0 Unallocated LAE (2) (18.2 ) (4.8 ) — (3.1 ) — (26.1 ) Other underwriting expenses (79.8 ) (23.4 ) — (2.9 ) — (106.1 ) Underwriting (loss) income (123.5 ) 14.0 — (12.6 ) 42.9 (79.2 ) Service fee revenue (3) — 65.9 — — (42.9 ) 23.0 Managing general underwriter unallocated LAE (4) — — — — — — Managing general underwriter other underwriting expenses (5) — — — — — — General and administrative expenses, MGU + Runoff & Other (6) — (44.8 ) — (4.0 ) — (48.8 ) Underwriting (loss) income, including net service fee income (123.5 ) 35.1 — (16.6 ) — (105.0 ) Net investment income 56.8 Net realized investment gains (losses) (27.2 ) Net unrealized investment gains (losses) (10.5 ) Net foreign exchange gains 9.2 Revaluation of contingent consideration 48.8 Other revenue (7) (1.3 ) General and administrative expenses (8) (43.1 ) Intangible asset amortization expenses (10.2 ) Impairment of intangible assets (5.0 ) Interest expense on debt (22.4 ) Pre-tax income (loss) $ (109.9 ) Underwriting Ratios Loss ratio 84.8 % 58.6 % — % NM NM 78.4 % Acquisition expense ratio 21.2 % 29.2 % — % NM NM 19.0 % Other underwriting expense ratio 11.0 % 7.6 % — % NM NM 10.2 % Combined ratio (9) 117.0 % 95.4 % — % NM NM 107.6 % Goodwill and intangible assets (10) $ — $ 612.3 $ — $ 5.0 $ — $ 617.3 (1) Loss and allocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (2) Unallocated LAE are part of Loss and loss adjustment expenses on the Consolidated Statements of (Loss) (the sum of Loss and allocated LAE and Unallocated LAE is equal to Loss and loss adjustment expenses on the Consolidated Statements of (Loss)). (3) Service fee revenue is part of Other revenue on the Consolidated Statements of (Loss) (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss) Income). (4) Managing general underwriter unallocated LAE represents IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the claims process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (5) Managing general underwriter other underwriting expenses represent IMG and Armada generated operating expenses following their integration with the Accident and Health insurance and reinsurance underwriting unit, representing costs associated with the underwriting process. In 2017, all Armada and IMG expenses were disclosed within General and administrative expenses, MGU + Runoff & Other. (6) General and administrative expenses, MGU + Runoff & Other is part of General and administrative expenses on the Consolidated Statements of (Loss) (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (7) Other revenue is presented net of Service fee revenue and is comprised mainly of gains (losses) from derivatives (see Note 13 ) (the sum of Service fee revenue and Other revenue is equal to Other revenue on the Consolidated Statements of (Loss)). (8) General and administrative expenses are presented net of General and administrative expenses, MGU + Runoff & Other (the sum of General and administrative expenses, MGU + Runoff & Other and General and administrative expenses is equal to General and administrative expenses on the Consolidated Statements of (Loss)). (9) Ratios considered not meaningful ("NM") to Runoff & Other and Corporate Elimination. (10) Sirius Group does not allocate its assets by segment, with the exception of Goodwill and Intangible assets.
Summary information regarding net premiums written by client location and underwriting location by reportable segment	The following tables provide summary information regarding net premiums written by client location and underwriting location by reportable segment for the years ended December 31, 2019 , 2018 , and 2017 : For the year ended December 31, 2019 (Millions) Global Global U.S. Specialty Runoff & Other Total Net written premiums by client location: United States $ 480.2 $ 386.2 $ 54.1 $ 1.8 $ 922.3 Europe 245.3 23.5 — 0.1 268.9 Canada, the Caribbean, Bermuda and Latin America 90.0 12.4 — 0.1 102.5 Asia and Other 172.4 36.0 — 0.5 208.9 Total net written premium by client location $ 987.9 $ 458.1 $ 54.1 $ 2.5 $ 1,502.6 Net written premiums by underwriting location: United States $ 33.4 $ 170.3 $ 43.8 $ 1.8 $ 249.3 Europe 488.4 249.9 10.3 0.2 748.8 Canada, the Caribbean, Bermuda and Latin America 413.8 37.1 — — 450.9 Asia and Other 52.3 0.8 — 0.5 53.6 Total written premiums by underwriting location $ 987.9 $ 458.1 $ 54.1 $ 2.5 $ 1,502.6 For the year ended December 31, 2018 (Millions) Global Global U.S. Specialty Runoff Total Net written premiums by client location: United States $ 444.7 $ 307.7 $ 13.1 $ 29.2 $ 794.7 Europe 246.1 30.4 — — 276.5 Canada, the Caribbean, Bermuda and Latin America 91.1 12.5 — — 103.6 Asia and Other 152.7 29.2 — 0.4 182.3 Total net written premium by client location $ 934.6 $ 379.8 $ 13.1 $ 29.6 $ 1,357.1 Net written premiums by underwriting location: United States $ 33.5 $ 109.5 $ 7.9 $ 29.2 $ 180.1 Europe 462.0 224.9 5.2 — 692.1 Canada, the Caribbean, Bermuda and Latin America 389.1 44.7 — — 433.8 Asia and Other 50.0 0.7 — 0.4 51.1 Total written premiums by underwriting location $ 934.6 $ 379.8 $ 13.1 $ 29.6 $ 1,357.1 For the year ended December 31, 2017 (Millions) Global Global U.S. Specialty Runoff Total Net written premiums by client location: United States $ 279.8 $ 284.5 $ — $ (1.2 ) $ 563.1 Europe 234.1 28.2 — — 262.3 Canada, the Caribbean, Bermuda and Latin America 101.7 9.5 — 0.2 111.4 Asia and Other 133.6 19.3 — 0.5 153.4 Total net written premium by client location $ 749.2 $ 341.5 $ — $ (0.5 ) $ 1,090.2 Net written premiums by underwriting location: United States $ 53.4 $ 98.2 $ — $ (1.1 ) $ 150.5 Europe 386.9 196.4 — — 583.3 Canada, the Caribbean, Bermuda and Latin America 269.1 46.4 — — 315.5 Asia and Other 39.8 0.5 — 0.6 40.9 Total written premiums by underwriting location $ 749.2 $ 341.5 $ — $ (0.5 ) $ 1,090.2

Reserves for unpaid losses an_2

Reserves for unpaid losses and loss adjustment expenses (Tables)	12 Months Ended
	Dec. 31, 2019
Reserves for unpaid losses and loss adjustment expenses
Summary of the loss and LAE reserve activities	The following table summarizes the loss and LAE reserve activities of Sirius Group for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 Gross beginning balance $ 2,016.7 $ 1,898.5 $ 1,620.1 Less beginning reinsurance recoverable on unpaid losses (350.2 ) (319.7 ) (291.5 ) Net loss and LAE reserve balance 1,666.5 1,578.8 1,328.6 Loss and LAE reserves acquired (1) — 0.2 14.3 Losses and LAE incurred relating to: Current year losses 1,066.5 907.3 811.8 Prior years losses 103.8 (7.3 ) (0.6 ) Total net incurred losses and LAE 1,170.3 900.0 811.2 Accretion of fair value adjustment to net loss and LAE reserves 0.1 0.1 0.1 Foreign currency translation adjustment to net loss and LAE reserves (4.4 ) (20.9 ) 36.8 Loss and LAE paid relating to: Current year losses 251.3 251.4 222.8 Prior years losses 660.0 540.3 389.5 Total loss and LAE payments 911.3 791.7 612.3 Net ending balance 1,921.2 1,666.5 1,578.8 Plus ending reinsurance recoverable on unpaid losses 410.3 350.2 319.7 Gross ending balance $ 2,331.5 $ 2,016.7 $ 1,898.5 (1) Loss and LAE reserves acquired in 2018 relate to Sirius Group's purchase of Cedar; 2017 relate to Sirius Group's purchase of IMG
Schedule of asbestos and environmental loss and loss adjustment expense reserve activity	The following table summarizes reported A&E loss and LAE reserve activities (gross and net of reinsurance) for the years ended December 31, 2019 , 2018 , and 2017 : 2019 2018 2017 (Millions) Gross Net Gross Net Gross Net Asbestos: Beginning balance $ 236.8 $ 184.4 $ 259.2 $ 204.6 $ 187.0 $ 166.4 Incurred losses and LAE 0.1 — (6.9 ) (6.9 ) 96.9 59.0 Paid losses and LAE (12.2 ) (11.1 ) (15.5 ) (13.3 ) (24.7 ) (20.8 ) Ending balance 224.7 173.3 236.8 184.4 259.2 204.6 Environmental: Beginning balance 16.7 15.9 16.7 16.0 18.5 13.9 Incurred losses and LAE 0.7 0.7 4.0 4.0 2.9 6.1 Paid losses and LAE (2.9 ) (2.6 ) (4.0 ) (4.1 ) (4.7 ) (4.0 ) Ending balance 14.5 14.0 16.7 15.9 16.7 16.0 Total asbestos and environmental: Beginning balance 253.4 200.3 275.9 220.6 205.5 180.3 Incurred losses and LAE 0.8 0.7 (3.0 ) (2.9 ) 99.8 65.1 Paid losses and LAE (15.0 ) (13.7 ) (19.5 ) (17.4 ) (29.4 ) (24.8 ) Ending balance $ 239.2 $ 187.3 $ 253.4 $ 200.3 $ 275.9 $ 220.6
Schedule of net loss reserves by type	The following tables present Sirius Group's loss and LAE reserves, net of reinsurance, by type as of December 31, 2019 and 2018 : (Millions) 2019 2018 Case Reserve $ 1,030.6 $ 924.5 IBNR Reserve 890.6 742.0 Loss and loss adjustment expense reserves, net of reinsurance $ 1,921.2 $ 1,666.5
Schedule of reconciliation of liabilities for unpaid loss and loss adjustment expense	The following table summarizes the ending liabilities for unpaid loss and LAE, net of reinsurance for each of Sirius Group's segments as of December 31, 2019 : (Millions) Liabilities for unpaid loss and LAE, net of reinsurance As of December 31, 2019 Unpaid and allocated LAE reserves, net of reinsurance Other Property $ 490.7 Property Catastrophe Excess Reinsurance 286.0 Agriculture Reinsurance 68.1 Global A&H 176.9 Aviation & Space 109.2 Trade Credit 46.5 Environmental 4.6 Marine & Energy 52.4 Surety 4.9 Contingency 8.3 Casualty (1) 202.0 Runoff & Other 430.6 Total unpaid and allocated LAE reserves, net of reinsurance 1,880.2 Unallocated LAE 41.0 Total unpaid loss and LAE reserves, net of reinsurance 1,921.2 Reinsurance recoverable on unpaid losses Other Property 137.3 Property Catastrophe Excess Reinsurance 60.0 Agriculture Reinsurance 2.0 Global A&H 42.9 Aviation & Space 40.3 Trade Credit 10.1 Environmental 4.6 Marine & Energy 8.7 Surety 0.5 Contingency 2.1 Casualty 1.2 Runoff & Other 100.6 Total reinsurance recoverable on unpaid losses 410.3 Total unpaid loss and LAE reserves $ 2,331.5 (1) Casualty includes both Casualty Reinsurance in the Global Reinsurance reporting segment and Workers’ Compensation in the U.S. Specialty reporting segment. Sirius Group began providing Workers’ Compensation in the U.S. Specialty reporting segment in the latter part of 2018 and of the $18.5 included in Casualty reserves from Workers’ Compensation in the U.S. Specialty reporting segment, $17.3 is from the 2019 accident year.
Other property
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Other Property (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 156.1 153.2 144.5 145.2 140.2 139.3 138.6 137.0 136.7 136.3 1.5 NA 2011 162.9 150.3 141.2 133.2 131.3 132.0 132.2 131.0 131.1 0.1 NA 2012 162.1 148.9 143.8 139.4 134.7 132.7 132.6 132.0 1.1 NA 2013 130.0 126.8 116.0 112.5 112.2 111.7 111.4 0.7 NA 2014 113.8 116.6 114.1 114.4 112.0 111.3 0.7 NA 2015 139.7 132.2 134.4 134.4 134.1 1.6 NA 2016 194.9 213.7 218.3 219.1 1.7 NA 2017 332.7 369.3 387.9 19.1 NA 2018 270.8 326.3 34.0 NA 2019 245.0 101.1 NA Total 1,934.5 Other Property (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 31.4 88.7 115.5 123.2 128.0 130.1 130.6 130.6 130.5 131.4 2011 26.6 79.1 102.8 115.7 121.7 124.2 126.8 126.5 127.1 2012 20.0 84.7 107.4 115.5 118.9 124.2 125.0 126.2 2013 27.2 71.4 95.4 101.9 105.2 105.8 106.3 2014 18.8 68.9 95.5 103.7 105.9 106.7 2015 30.8 93.0 114.3 123.9 127.7 2016 31.2 128.0 180.6 197.5 2017 58.2 222.4 298.6 2018 54.8 180.1 2019 46.2 Total 1,447.8 All outstanding liabilities before 2010, net of reinsurance 4.0 Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 490.7
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Other Property Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 17.8 % 42.5 % 20.1 % 7.2 % 3.1 % 1.8 % 0.9 % 0.3 % 0.1 % 0.7 %
Property Catastrophe Excess
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Property Catastrophe Excess Reinsurance (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 136.1 131.0 131.0 130.2 122.8 121.9 121.4 120.7 121.3 127.3 0.1 NA 2011 152.6 89.7 142.7 121.4 118.0 117.2 117.1 117.2 117.2 0.2 NA 2012 145.0 57.8 51.1 49.2 49.7 44.8 45.0 46.5 0.5 NA 2013 70.3 76.5 73.5 72.9 72.1 71.8 71.4 — NA 2014 55.4 57.0 54.3 54.4 54.3 54.8 0.5 NA 2015 27.4 29.3 26.9 25.9 25.0 0.2 NA 2016 50.4 47.7 42.4 41.2 2.3 NA 2017 105.4 123.4 117.4 8.3 NA 2018 160.4 178.0 9.1 NA 2019 169.9 35.1 NA Total 948.7 Property Catastrophe Excess Reinsurance (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 49.8 90.0 102.5 107.6 111.1 113.6 117.5 117.5 118.0 119.1 2011 15.9 54.7 96.0 114.4 114.7 115.2 116.1 116.2 116.7 2012 2.8 25.8 35.4 40.0 40.9 42.7 44.0 46.1 2013 10.9 48.3 60.7 65.5 66.8 68.0 68.9 2014 9.2 35.8 41.9 47.4 49.1 51.5 2015 1.8 9.3 16.6 19.9 22.4 2016 10.4 25.7 31.7 37.0 2017 13.2 67.4 86.4 2018 2.7 115.8 2019 3.3 ​ ​ ​ ​ ​ ​ Total 667.2 All outstanding liabilities before 2010, net of reinsurance 4.5 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 286.0
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Property Catastrophe Excess Reinsurance Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 12.7 % 45.7 % 19.0 % 9.8 % 2.3 % 2.0 % 1.9 % 0.7 % 0.5 % 0.8 %
Agriculture
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Agriculture Reinsurance (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 12.8 10.8 10.9 10.7 10.6 10.7 10.7 10.7 10.7 10.7 — NA 2011 21.5 21.5 21.7 21.7 21.7 21.6 21.6 21.6 21.6 — NA 2012 41.1 45.9 45.9 45.8 47.0 47.0 47.0 46.9 — NA 2013 9.1 10.8 12.9 13.0 12.8 12.8 12.8 — NA 2014 9.7 8.2 8.5 8.9 8.9 9.0 — NA 2015 7.0 9.1 9.4 9.4 9.4 — NA 2016 33.1 30.5 29.5 29.6 0.2 NA 2017 50.2 46.8 46.1 (0.4 ) NA 2018 39.1 41.3 3.3 NA 2019 71.8 46.0 NA Total 299.2 Agriculture Reinsurance (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 0.5 10.6 10.8 10.6 10.6 10.6 10.6 10.6 10.6 10.7 2011 1.0 21.3 21.6 21.6 21.6 21.6 21.6 21.6 21.6 2012 19.0 45.4 45.7 45.6 46.9 46.9 46.9 46.9 2013 7.1 10.6 12.8 13.0 12.8 12.8 12.8 2014 6.5 8.1 8.8 8.8 8.9 9.0 2015 1.5 7.7 8.9 9.2 9.2 2016 10.0 27.8 29.2 29.5 2017 9.0 43.3 46.1 2018 2.6 35.8 2019 9.5 Total 231.1 All outstanding liabilities before 2010, net of reinsurance — ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 68.1
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Agriculture Reinsurance Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 22.3 % 67.5 % 4.8 % 0.4 % 1.1 % 0.1 % 0.1 % — % — % — %
Global Accident & Health
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Global A&H (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 118.4 125.4 123.0 122.1 121.8 121.8 121.9 121.8 121.7 121.7 (0.1 ) NA 2011 161.3 176.7 172.3 171.6 171.6 171.6 171.4 171.4 171.5 0.1 NA 2012 163.4 160.1 147.8 147.1 146.9 146.7 146.6 146.5 (0.1 ) NA 2013 125.5 123.3 118.8 118.3 117.7 116.9 116.8 — NA 2014 130.8 131.9 130.3 130.3 129.4 129.4 0.1 NA 2015 152.7 148.8 145.5 144.2 143.8 0.3 NA 2016 173.3 187.1 183.0 181.5 2.5 NA 2017 176.4 172.6 165.9 1.4 NA 2018 198.3 205.5 13.4 NA 2019 271.9 89.1 NA Total 1,654.5 Global A&H (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 53.1 102.2 119.2 121.4 121.7 121.8 121.9 121.9 121.9 122.0 2011 71.2 139.2 166.1 171.1 171.5 171.6 171.6 171.6 171.7 2012 72.2 136.1 146.1 146.5 146.6 146.6 146.6 146.6 2013 54.4 103.7 114.2 115.6 116.8 116.3 116.3 2014 59.2 111.1 124.6 126.3 126.3 127.0 2015 75.4 129.8 141.2 142.8 143.1 2016 98.2 164.4 176.0 177.9 2017 61.5 150.7 163.0 2018 89.0 186.1 2019 128.7 ​ ​ ​ ​ ​ ​ ​ ​ Total 1,482.4 All outstanding liabilities before 2010, net of reinsurance 4.8 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 176.9
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Global A&H Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 46.1 % 42.6 % 9.6 % 1.4 % 0.3 % 0.1 % — % — % 0.1 % — %
Aviation & Space
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Aviation & Space (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 42.4 47.2 46.9 44.4 42.9 42.0 41.8 41.3 41.6 41.4 (0.4 ) NA 2011 46.8 42.2 37.8 35.8 34.6 34.4 35.7 35.0 35.2 (0.2 ) NA 2012 35.6 34.3 30.2 28.2 28.4 29.5 29.5 28.5 (0.3 ) NA 2013 40.5 36.4 33.3 31.9 32.9 32.9 33.0 (0.5 ) NA 2014 37.3 39.9 36.6 35.8 35.9 33.9 (3.0 ) NA 2015 37.6 34.0 38.1 37.1 36.5 (0.9 ) NA 2016 32.0 32.5 33.5 35.8 2.9 NA 2017 33.8 42.8 44.1 1.4 NA 2018 47.9 50.5 6.7 NA 2019 60.5 39.9 NA Total 399.4 Aviation & Space (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 12.0 22.0 31.3 36.0 37.5 38.5 39.4 39.6 40.7 41.0 2011 10.1 22.6 28.5 31.4 32.6 34.0 34.7 34.6 35.5 2012 7.6 18.4 22.6 24.6 27.3 28.2 28.7 28.4 2013 13.5 19.8 24.0 26.6 28.4 29.1 30.5 2014 8.0 17.8 23.5 26.1 28.1 28.8 2015 10.5 21.0 27.0 33.4 34.9 2016 7.8 19.6 26.7 29.1 2017 9.0 23.6 32.5 2018 14.3 27.4 2019 8.3 Total 296.4 All outstanding liabilities before 2010, net of reinsurance 6.2 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 109.2
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Aviation & Space Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 25.3 % 29.4 % 17.8 % 9.6 % 5.2 % 2.7 % 2.5 % (0.3 )% 2.6 % 0.4 %
Trade credit
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Trade Credit (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 13.7 12.0 9.3 9.5 9.6 9.4 9.4 9.5 9.6 9.4 (0.3 ) NA 2011 28.4 28.2 26.7 26.5 26.5 25.8 25.8 25.6 25.4 (0.3 ) NA 2012 33.6 33.9 32.2 32.4 32.0 32.0 31.7 31.3 (0.2 ) NA 2013 28.8 27.9 27.1 26.9 27.5 27.0 27.3 0.6 NA 2014 22.2 22.2 23.0 20.9 20.6 20.5 0.5 NA 2015 19.7 19.3 18.8 18.1 17.3 — NA 2016 14.9 12.9 12.3 11.4 — NA 2017 18.8 19.8 18.9 2.5 NA 2018 24.6 24.8 4.4 NA 2019 30.1 13.8 NA Total 216.4 Trade Credit (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 1.7 5.1 7.6 8.4 8.8 8.9 9.1 9.2 9.3 9.3 2011 6.4 17.1 23.1 24.3 25.2 25.5 25.2 25.3 25.3 2012 14.4 26.2 30.4 31.1 31.5 31.3 31.3 31.2 2013 11.3 19.4 22.3 23.5 23.9 24.0 24.1 2014 7.7 13.4 17.4 18.8 19.3 19.3 2015 4.5 12.0 15.4 16.4 16.3 2016 4.5 8.8 10.4 11.0 2017 3.0 8.8 12.6 2018 7.6 16.2 2019 8.8 Total 174.1 All outstanding liabilities before 2010, net of reinsurance 4.2 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 46.5
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Trade Credit Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 32.3 % 35.4 % 17.6 % 4.8 % 1.8 % 0.3 % 0.1 % 0.1 % 0.3 % (0.2 )%
Environmental
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Environmental (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 — — — — — — — — — — — NA 2011 — — — — — — — — — — NA 2012 — — — — — — — — — NA 2013 — — — — — — — — NA 2014 — — — — — — — NA 2015 — — — — — — NA 2016 — — — — — NA 2017 — — — — NA 2018 0.4 0.1 — NA 2019 4.6 0.8 NA Total 4.7 Environmental (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 — — — — — — — — — — 2011 — — — — — — — — — 2012 — — — — — — — — 2013 — — — — — — — 2014 — — — — — — 2015 — — — — — 2016 — — — — 2017 — — — 2018 — — 2019 0.1 Total 0.1 All outstanding liabilities before 2010, net of reinsurance — ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 4.6
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Environmental Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 1.0 % 6.3 % — % — % — % — % — % — % — % — %
Marine
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Marine & Energy (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 30.5 33.3 31.0 30.7 32.1 31.7 30.4 30.2 30.0 30.0 0.1 NA 2011 36.7 33.0 30.7 31.2 32.2 31.6 31.7 31.6 32.3 (0.3 ) NA 2012 27.2 33.4 36.0 37.5 37.9 36.8 36.3 36.2 1.7 NA 2013 23.2 20.5 19.2 18.2 18.0 18.0 18.1 0.2 NA 2014 23.2 21.4 19.4 18.2 17.8 18.4 (0.3 ) NA 2015 29.3 31.0 28.9 28.4 28.3 0.2 NA 2016 28.2 29.1 28.3 28.3 0.8 NA 2017 37.2 34.8 34.6 2.2 NA 2018 23.1 25.4 3.2 NA 2019 18.8 6.7 NA Total 270.4 Marine & Energy (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 5.0 12.2 17.1 19.5 21.3 26.7 27.5 28.5 28.7 28.8 2011 4.4 14.4 21.8 25.2 28.0 28.8 29.3 29.7 30.4 2012 5.2 14.8 24.2 27.1 29.1 31.0 32.6 33.8 2013 2.9 9.3 12.6 14.0 14.4 14.9 15.1 2014 4.1 10.2 13.6 15.0 15.7 15.8 2015 4.3 11.6 21.5 25.9 26.9 2016 6.8 17.4 21.3 24.2 2017 7.2 18.1 26.1 2018 5.2 13.9 2019 3.8 Total 218.8 All outstanding liabilities before 2010, net of reinsurance 0.8 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 52.4
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Marine & Energy Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 18.1 % 30.5 % 22.2 % 9.7 % 5.4 % 6.4 % 2.6 % 2.7 % 1.4 % 0.7 %
Surety
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Surety (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 0.1 0.1 0.2 0.4 0.4 0.3 0.3 0.1 0.1 0.1 0.1 NA 2011 0.3 0.5 0.6 0.6 0.4 0.4 0.2 0.2 0.2 0.2 NA 2012 0.5 0.6 0.6 0.4 0.4 0.3 0.3 0.3 0.3 NA 2013 1.0 0.9 0.7 0.5 0.7 0.9 0.8 0.2 NA 2014 1.2 1.1 1.0 1.1 1.3 1.1 0.3 NA 2015 1.0 1.2 1.0 0.8 0.7 0.3 NA 2016 — — 0.5 0.3 — NA 2017 0.6 0.4 0.4 0.3 NA 2018 0.9 1.0 0.9 NA 2019 1.2 1.2 NA Total 6.1 Surety (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 — 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 2011 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 2012 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 2013 0.1 0.1 0.2 0.3 0.5 0.6 0.6 2014 — 0.2 0.4 0.7 0.9 1.2 2015 — 0.2 0.3 0.4 0.5 2016 — — 0.3 0.3 2017 — — — 2018 — — 2019 — Total 3.1 All outstanding liabilities before 2010, net of reinsurance 1.9 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 4.9
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Surety Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 7.3 % 9.0 % 19.0 % 14.7 % 12.4 % 17.8 % 1.7 % 2.0 % 0.9 % 0.3 %
Contingency
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Contingency (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 5.5 5.9 4.5 4.4 4.2 4.1 4.1 4.1 4.1 4.1 — NA 2011 7.7 7.1 6.6 6.5 6.5 6.6 6.6 6.6 6.6 — NA 2012 9.6 8.6 8.7 8.5 8.3 8.1 8.1 8.0 — NA 2013 5.5 4.2 3.6 3.6 3.6 3.6 3.6 0.1 NA 2014 4.2 7.0 5.2 4.7 4.7 4.7 — NA 2015 9.9 9.6 9.0 8.9 8.9 0.1 NA 2016 17.6 18.0 17.0 17.3 0.2 NA 2017 9.7 10.6 11.2 0.8 NA 2018 9.4 9.0 1.4 NA 2019 3.0 1.4 NA Total 76.4 Contingency (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 1.9 3.4 3.5 3.5 3.9 4.0 4.1 4.1 4.1 4.1 2011 2.0 5.7 6.4 6.4 6.5 6.5 6.5 6.5 6.5 2012 5.3 7.1 8.5 8.4 8.3 8.1 8.1 8.1 2013 1.8 3.0 3.3 3.3 3.3 3.3 3.3 2014 1.6 3.7 4.4 4.5 4.5 4.5 2015 2.8 7.1 7.8 7.8 8.7 2016 11.6 15.2 16.0 16.8 2017 3.0 7.0 9.4 2018 1.8 6.2 2019 0.3 Total 67.9 All outstanding liabilities before 2010, net of reinsurance (0.1 ) ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 8.3
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Contingency Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 42.2 % 36.2 % 10.8 % 1.7 % 3.2 % — % 0.2 % 0.4 % 0.4 % — %
Casualty
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Casualty (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 1.7 1.5 1.6 1.4 1.1 0.9 0.6 0.6 0.5 0.5 — NA 2011 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.2 0.2 — NA 2012 0.2 0.2 0.4 0.5 0.5 0.5 0.5 0.4 — NA 2013 0.4 0.4 0.4 0.4 0.5 0.5 0.5 — NA 2014 0.4 0.4 0.5 0.5 0.5 0.6 — NA 2015 0.5 0.8 0.6 0.5 0.6 — NA 2016 0.2 0.3 0.3 0.1 — NA 2017 9.7 9.7 12.5 7.2 NA 2018 53.4 63.5 41.3 NA 2019 141.9 116.0 NA Total 220.8 Casualty (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 — — 0.1 0.1 0.2 0.4 0.3 0.4 0.4 0.3 2011 — — 0.1 0.1 0.2 0.2 0.2 0.2 0.2 2012 — — 0.1 0.2 0.1 0.2 0.2 0.3 2013 0.1 0.1 0.2 0.3 0.4 0.4 0.5 2014 0.1 0.2 0.4 0.4 0.4 0.5 2015 0.2 0.4 0.4 0.4 0.4 2016 — 0.1 0.1 0.2 2017 — 0.6 1.6 2018 2.0 8.1 2019 10.6 Total 22.7 All outstanding liabilities before 2010, net of reinsurance 3.9 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 202.0
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Casualty Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 5.9 % 9.4 % 9.5 % 11.1 % 7.3 % 10.0 % 0.6 % 13.4 % 1.0 % 0.7 %
Runoff & Other
Reserves for unpaid losses and loss adjustment expenses
Schedule of incurred losses and allocated loss adjustment expenses and cumulative paid losses and cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	Runoff & Other (Millions) Incurred losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, December 31, 2019 Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 Total IBNR liabilities plus expected development on reported claims Cumulative number of reported claims 2010 282.3 283.2 283.4 284.0 285.1 286.6 287.6 287.7 287.0 291.5 5.4 NA 2011 221.5 222.8 223.9 224.5 225.0 225.9 225.4 225.0 223.9 2.9 NA 2012 3.6 4.0 4.1 4.2 4.1 4.1 3.9 3.7 1.1 NA 2013 1.2 0.2 0.2 0.2 0.1 0.2 0.4 — NA 2014 0.2 0.2 0.3 0.4 0.5 0.5 — NA 2015 9.5 15.7 17.5 18.0 18.0 0.2 NA 2016 11.8 12.1 11.7 11.6 — NA 2017 0.6 0.7 0.7 — NA 2018 30.3 28.6 2.6 NA 2019 0.3 0.2 NA Total 579.2 Runoff & Other (Millions) Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance Year ended December 31, Accident Year 2010 Unaudited 2011 Unaudited 2012 Unaudited 2013 Unaudited 2014 Unaudited 2015 Unaudited 2016 Unaudited 2017 Unaudited 2018 Unaudited 2019 2010 160.1 263.2 265.5 269.6 272.8 276.4 278.3 280.2 280.9 281.3 2011 206.9 209.0 211.2 213.0 214.7 216.7 218.2 218.8 219.3 2012 0.3 1.3 1.8 2.2 2.4 2.4 2.5 2.7 2013 0.7 0.1 0.1 0.1 0.1 0.1 0.2 2014 — — 0.1 0.2 0.3 0.5 2015 5.2 10.0 15.3 16.6 17.3 2016 6.2 10.1 11.0 11.3 2017 0.4 0.5 0.6 2018 7.9 12.6 2019 — ​ ​ ​ ​ ​ ​ ​ ​ Total 545.8 All outstanding liabilities before 2010, net of reinsurance 397.2 ​ Liabilities for loss and allocated loss adjustment expenses, net of reinsurance 430.6
Schedule of average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance	Runoff & Other Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance Years 1 2 3 4 5 6 7 8 9 10 ​ 66.9 % 20.6 % 2.0 % 1.5 % 1.1 % 1.1 % 0.7 % 0.5 % 0.2 % 0.1 %

Third party reinsurance (Tables

Third party reinsurance (Tables)	12 Months Ended
	Dec. 31, 2019
Reinsurance Disclosures [Abstract]
Schedule of effects of reinsurance	The effects of reinsurance on Sirius Group's written and earned premiums and on losses and LAE were as follows: (Millions) 2019 2018 2017 Written premiums: Direct $ 511.2 $ 454.5 $ 450.2 Assumed 1,391.5 1,366.5 989.1 Gross written premiums 1,902.7 1,821.0 1,439.3 Ceded (400.1 ) (463.9 ) (349.1 ) Net written premiums $ 1,502.6 $ 1,357.1 $ 1,090.2 Earned premiums: Direct $ 481.0 $ 432.6 $ 405.7 Assumed 1,357.7 1,236.2 942.2 Gross earned premiums 1,838.7 1,668.8 1,347.9 Ceded (397.1 ) (406.5 ) (312.6 ) Net earned premiums $ 1,441.6 $ 1,262.3 $ 1,035.3 Losses and LAE: Direct $ 316.3 $ 260.5 $ 294.9 Assumed 1,111.4 819.1 701.3 Gross losses and LAE 1,427.7 1,079.6 996.2 Ceded (257.4 ) (179.6 ) (185.0 ) Net losses and LAE $ 1,170.3 $ 900.0 $ 811.2
Schedule of industry loss warranty contracts	The following ILW contracts are currently in force: Scope Limit Trigger Expiration Date United States excluding North East, all natural perils $5.0 million $40.0 billion July 5, 2020
Schedule of gross, net recoverable amounts and percentage of total recoverables	The following tables provide a listing of Sirius Group's gross and net recoverable amounts by the reinsurer's Standard & Poor's Financial Services LLC ("Standard & Poor's") rating and the percentage of total recoverables as of December 31, 2019 and 2018 . With certain reinsurers if Standard & Poor's rating was not available, an A.M. Best rating was used. December 31, 2019 Rating (1) Gross Collateral Net % of Net Total AAA $ 3.4 $ — $ 3.4 1 % AA 117.2 14.3 102.9 42 % A 301.8 195.6 106.2 43 % BBB or lower 14.9 13.7 1.2 1 % Not rated 46.9 13.4 33.5 13 % Total $ 484.2 $ 237.0 $ 247.2 100 % (1) Standard & Poor's ratings as detailed above are: "AAA" (Extremely Strong), "AA" (Very strong), "A" (Strong), and "BBB" (Adequate). December 31, 2018 Rating (1) Gross Collateral Net % of Net Total AA $ 115.1 $ 1.5 $ 113.6 35 % A 212.9 45.4 167.5 52 % BBB or lower 19.5 13.3 6.2 2 % Not rated 57.7 23.2 34.5 11 % Total $ 405.2 $ 83.4 $ 321.8 100 % (1) Standard & Poor's ratings as detailed above are: "AA" (Very strong), "A" (Strong), and "BBB" (Adequate).
Schedule of highest gross recoverable amounts and percentage of total recoverable amount by reinsurer	The following tables provide a listing of the five highest gross recoverable amounts by reinsurer, along with percentage of total recoverable amount, the reinsurer's Standard & Poor's reinsurer rating, and the percentage that the recoverable is collateralized as of December 31, 2019 and 2018 : December 31, 2019 (Millions) Balance % of Total S&P rating % Collateralized Reinsurer: ​ ​ General Insurance Corporation of India (1) $ 143.0 30 % A- 98 % Swiss Reinsurance Companyﾠ Ltd. 44.7 9 % AA- 5 % Berkshire Hathaway,ﾠInc. 34.0 7 % AA+ 3 % Lloyd's of London 27.0 6 % A+ 30 % Argo Capital Group Ltd. 19.1 4 % A- 89 % (1) Reflects an A.M. Best rating of "A-" (Excellent). December 31, 2018 (Millions) Balance % of Total S&P rating % Collateralized Reinsurer: General Insurance Corporation of India (1) $ 82.7 20 % A- 97 % Swiss Reinsurance Company Ltd. 44.1 11 % AA- — % Berkshire Hathaway, Inc. 39.3 10 % AA+ 1 % Argo Capital Group Ltd. 16.7 4 % A- 87 % Lloyd's of London 13.4 3 % A+ 5 % (1) Reflects an A.M. Best rating of "A-" (Excellent).

Deferred acquisition costs (Tab

Deferred acquisition costs (Tables)	12 Months Ended
	Dec. 31, 2019
Deferred Policy Acquisition Costs Disclosures [Abstract]
Schedule of deferred acquisition costs	The following table presents a rollforward of Deferred acquisition costs for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 Deferred acquisition costs - balance, beginning of the year $ 141.6 $ 120.9 $ 84.7 Acquisition costs deferred (1) 221.6 202.6 220.7 Amortization expense (214.4 ) (180.4 ) (186.7 ) Other, including foreign exchange (0.6 ) (1.5 ) 2.2 Deferred acquisition costs – balance, end of the year $ 148.2 $ 141.6 $ 120.9 (1) 2017 amount includes $2.9 from Acquisition of IMG. (See Note 3 .)

Investment securities (Tables)

Investment securities (Tables)	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Schedule of net investment income	Net investment income for the years ended December 31, 2019 , 2018 , and 2017 consisted of the following: (Millions) 2019 2018 2017 Fixed maturity investments $ 52.1 $ 53.2 $ 51.5 Short-term investments 15.8 5.1 1.5 Equity securities 15.2 16.5 5.1 Other long-term investments 14.2 8.4 8.5 Interest on funds held under reinsurance treaties — (0.5 ) — Total investment income 97.3 82.7 66.6 Investment expenses (12.6 ) (11.3 ) (9.8 ) Net investment income $ 84.7 $ 71.4 $ 56.8
Schedule of net realized and unrealized investment (losses) gains	Net realized and unrealized investment gains (losses) for the years ended December 31, 2019 , 2018 , and 2017 consisted of the following: (Millions) 2019 2018 2017 Gross realized gains $ 99.3 $ 42.3 $ 24.4 Gross realized (losses) (42.6 ) (40.0 ) (51.6 ) Net realized gains (losses) on investments (1) 56.7 2.3 (27.2 ) Net unrealized gains (losses) on investments (2) 80.6 (23.2 ) (10.5 ) Net realized and unrealized investment gains (losses) on investments $ 137.3 $ (20.9 ) $ (37.7 ) (1) Includes $ 50.4 , $17.3 , and $(19.1) of realized gains (losses) due to foreign currency during 2019 , 2018 , and 2017 , respectively. (2) Includes $(5.7) , $35.7 , and $(51.7) of unrealized (losses) gains due to foreign currency during 2019 , 2018 , and 2017 , respectively.
Schedule of net realized investment gains (losses)	Net realized investment gains (losses) for the years ended December 31, 2019 , 2018 , and 2017 consisted of the following: (Millions) 2019 2018 2017 Fixed maturity investments $ 33.7 $ 3.6 $ (19.1 ) Equity securities 9.4 (6.4 ) 0.1 Short-term investments 14.8 — — Derivative instruments (2.5 ) — — Other long-term investments 1.3 5.1 (8.2 ) Net realized investment gains (losses) $ 56.7 $ 2.3 $ (27.2 )
Schedule of net unrealized investment gains (losses)	The following table summarizes the amount of total gains (losses) included in earnings attributable to unrealized investment gains (losses) for Level 3 investments for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 Fixed maturity investments $ — $ (6.1 ) $ (0.2 ) Equity securities — — 0.1 Other long-term investments 15.9 4.0 (0.6 ) Total unrealized investment gains (losses) - Level 3 investments $ 15.9 $ (2.1 ) $ (0.7 ) The following table summarizes the net unrealized investment gains (losses) and changes in fair value for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) 2019 2018 2017 Fixed maturity investments $ 24.1 $ 14.1 $ (41.3 ) Equity securities 51.4 (51.1 ) 25.2 Short-term investments (5.2 ) — — Derivative instruments (0.5 ) — — Other long-term investments 10.8 13.8 5.6 Net unrealized investment gains (losses) $ 80.6 $ (23.2 ) $ (10.5 )
Schedule of investment securities and other long-term investments	The cost or amortized cost, gross unrealized investment gains and losses, net foreign currency gains and losses, and fair values of Sirius Group's equity securities and other long-term investments as of December 31, 2019 and 2018 , were as follows: 2019 (Millions) Cost or amortized cost Gross unrealized gains Gross unrealized losses Net foreign currency gains Fair value Equity securities $ 379.2 $ 55.6 $ (37.3 ) $ 7.7 $ 405.2 Other long-term investments $ 315.4 $ 49.9 $ (29.3 ) $ 10.8 $ 346.8 2018 (Millions) Cost or amortized cost Gross unrealized gains Gross unrealized losses Net foreign currency gains Fair value Equity securities $ 409.4 $ 17.8 $ (50.8 ) $ 3.6 $ 380.0 Other long-term investments $ 337.6 $ 32.6 $ (13.5 ) $ 8.3 $ 365.0 Equity securities at fair value consisted of the following as of December 31, 2019 and 2018 : (Millions) 2019 2018 Fixed income mutual funds $ 175.3 $ 157.7 Common stocks 228.1 222.3 Other equity securities 1.8 — Total Equity securities $ 405.2 $ 380.0 Other long-term investments at fair value consisted of the following as of December 31, 2019 and 2018 : (Millions) 2019 2018 Hedge funds and private equity funds $ 269.0 $ 301.4 Limited liability companies and private equity securities 77.8 63.6 Total Other long-term investments $ 346.8 $ 365.0 The following table summarizes the total mortgage and asset-backed securities held at fair value in Sirius Group's investment portfolio as of December 31, 2019 and 2018 : (Millions) 2019 2018 Mortgage-backed securities: Agency: Federal national mortgage association $ 235.9 $ 185.0 Federal home loan mortgage corporation 165.0 166.9 Government national mortgage association 52.2 59.4 Total agency (1) 453.1 411.3 Non-agency: Commercial 60.9 85.5 Residential 13.9 32.6 Total non-agency 74.8 118.1 Total mortgage-backed securities 527.9 529.4 Asset-backed securities: Collateralized loan obligations 417.0 373.0 Vehicle receivables 32.9 63.8 Credit card receivables 5.7 10.7 Other 31.2 47.0 Total asset-backed securities 486.8 494.5 Total mortgage and asset-backed securities (2) $ 1,014.7 $ 1,023.9 (1) Represents publicly traded mortgage-backed securities which carry the full faith and credit guaranty of the U.S. government (i.e., GNMA) or are guaranteed by a government-sponsored entity (i.e., FNMA, FHLMC). (2) As of December 31, 2019 and 2018 , all mortgage- and asset-backed securities held by Sirius Group were classified as Level 2 investments. The cost or amortized cost, gross unrealized investment gains (losses), net foreign currency gains (losses), and fair value of Sirius Group's fixed maturity investments as of December 31, 2019 and 2018 , were as follows: 2019 (Millions) Cost or amortized cost Gross unrealized gains Gross unrealized losses Net foreign currency gains (losses) Fair value Asset-backed securities $ 489.4 $ 1.4 $ (3.9 ) $ (0.1 ) $ 486.8 Corporate debt securities 458.6 5.2 (1.2 ) 11.5 474.1 Residential mortgage-backed securities 426.2 10.5 (1.4 ) 3.6 438.9 U.S. government and government agency 111.5 0.7 (0.4 ) (1.3 ) 110.5 Commercial mortgage-backed securities 88.5 0.9 (0.6 ) 0.2 89.0 Non-U.S. government and government agency 63.7 — (0.7 ) — 63.0 Preferred stocks 17.0 — — — 17.0 U.S. States, municipalities and political subdivision 1.7 — — — 1.7 Total fixed maturity investments $ 1,656.6 $ 18.7 $ (8.2 ) $ 13.9 $ 1,681.0 2018 (Millions) Cost or amortized cost Gross unrealized gains Gross unrealized losses Net foreign currency gains (losses) Fair value Asset-backed securities $ 496.3 $ 0.1 $ (3.8 ) $ 1.9 $ 494.5 Corporate debt securities 694.1 1.4 (7.3 ) 7.6 695.8 Residential mortgage-backed securities 413.0 1.7 (7.1 ) 5.9 413.5 U.S. government and government agency 163.9 0.3 (0.5 ) 4.2 167.9 Commercial mortgage-backed securities 117.7 0.2 (2.7 ) 0.7 115.9 Non-U.S. government and government agency 50.6 — (0.2 ) (0.1 ) 50.3 Preferred stocks 14.5 0.6 (6.8 ) 0.2 8.5 U.S. States, municipalities and political subdivision 2.8 — — — 2.8 Total fixed maturity investments $ 1,952.9 $ 4.3 $ (28.4 ) $ 20.4 $ 1,949.2
Schedule of fixed maturity investment by contractual maturity	2019 2018 (Millions) Cost or amortized cost Fair value Cost or amortized cost Fair value Due in one year or less $ 85.0 $ 88.4 $ 249.6 $ 254.6 Due after one year through five years 479.1 490.3 635.6 636.4 Due after five years through ten years 46.3 46.0 26.2 25.7 Due after ten years 25.1 24.6 0.1 0.1 Mortgage-backed and asset-backed securities 1,004.1 1,014.7 1,026.9 1,023.9 Preferred stocks 17.0 17.0 14.5 8.5 Total $ 1,656.6 $ 1,681.0 $ 1,952.9 $ 1,949.2
Schedule of ratings and fair value of fixed maturity investments	The following table summarizes the ratings and fair value of fixed maturity investments held in Sirius Group's investment portfolio as of December 31, 2019 and 2018 : (Millions) 2019 2018 AAA $ 559.8 $ 602.0 AA 724.3 818.0 A 219.0 290.5 BBB 95.8 167.4 Other 82.1 71.3 Total fixed maturity investments (1) $ 1,681.0 $ 1,949.2 (1) Credit ratings are assigned based on the following hierarchy: 1) Standard & Poor's and 2) Moody's Investor Service.
Summary of investment securities by investment objective and sector	The following table summarizes investments in hedge funds and private equity interests by investment objective and sector as of December 31, 2019 and 2018 : 2019 2018 (Millions) Fair value Unfunded commitments Fair value Unfunded commitments Hedge funds: Long/short multi-sector $ 53.0 $ — $ 41.0 $ — Distressed mortgage credit 51.6 — 54.8 — Private credit 21.5 — 20.0 — Other 1.4 — 2.5 — Total hedge funds 127.5 — 118.3 — Private equity funds: Energy infrastructure & services 53.6 34.6 93.7 54.2 Multi-sector 8.7 7.8 9.0 0.7 Healthcare 25.9 10.4 31.7 15.6 Life settlement 23.9 — 23.7 — Manufacturing/Industrial 27.6 3.9 23.6 10.4 Private equity secondaries 0.6 0.8 1.1 1.1 Real estate — — 0.3 — Other 1.2 2.6 — — Total private equity funds 141.5 60.1 183.1 82.0 Total hedge and private equity funds included in Other long-term investments $ 269.0 $ 60.1 $ 301.4 $ 82.0
Schedule of redemption frequency and advance notice period requirements for investments	The following summarizes the December 31, 2019 fair value of hedge funds subject to restrictions on redemption frequency and advance notice period requirements for investments in active hedge funds: Notice Period Redemption Frequency (Millions) 30-59 days notice 60-89 days notice 90-119 days notice 120+ days notice Total Monthly $ — $ 36.2 $ — $ — $ 36.2 Quarterly 0.8 — — — 0.8 Semi-annual — 0.3 — — 0.3 Annual — 16.8 51.9 21.5 90.2 Total $ 0.8 $ 53.3 $ 51.9 $ 21.5 $ 127.5
Schedule of investment securities by lock-up period.	As of December 31, 2019 , investments in private equity funds were subject to lock-up periods as follows: (Millions) 1 – 3 years 3 – 5 years 5 – 10 years Total Private Equity Funds – expected lock up period remaining $ 4.7 $ 1.4 $ 135.4 $ 141.5

Fair value measurements (Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Summary of financial assets and liabilities measured at fair value	The following tables summarize Sirius Group's financial assets and liabilities measured at fair value as of December 31, 2019 and 2018 by level: 2019 (Millions) Fair value Level 1 inputs Level 2 inputs Level 3 inputs Assets measured at fair value Fixed maturity investments: U.S. Government and government agency $ 110.5 $ 109.1 $ 1.4 $ — Corporate debt securities 474.1 — 474.1 — Asset-backed securities 486.8 — 486.8 — Residential mortgage-backed securities 438.9 — 438.9 — Commercial mortgage-backed securities 89.0 — 89.0 — Non-U.S. government and government agency 63.0 31.7 31.3 — Preferred stocks 17.0 — — 17.0 U.S. States, municipalities, and political subdivision 1.7 — 1.7 — Total fixed maturity investments 1,681.0 140.8 1,523.2 17.0 Equity securities: Fixed income mutual funds 175.3 175.3 — — Common stocks 228.1 228.1 — — Other equity securities 1.8 — 1.8 — Total equity securities 405.2 403.4 1.8 — Short-term investments 1,085.2 1,073.7 11.5 — Other long-term investments (1) 77.8 — — 77.8 Total investments $ 3,249.2 $ 1,617.9 $ 1,536.5 $ 94.8 Loan participation 20.0 — — 20.0 Derivative instruments 11.4 1.3 — 10.1 Total assets measured at fair value $ 3,280.6 $ 1,619.2 $ 1,536.5 $ 124.9 Liabilities measured at fair value Contingent consideration liabilities $ 28.2 $ — $ — $ 28.2 Derivative instruments 9.5 0.2 — 9.3 Total liabilities measured at fair value $ 37.7 $ 0.2 $ — $ 37.5 (1) Excludes fair value of $269.0 associated with hedge funds and private equity funds which fair value is measured at net asset value using the practical expedient. 2018 (Millions) Fair value Level 1 inputs Level 2 inputs Level 3 inputs Assets measured at fair value Fixed maturity investments: U.S. Government and government agency $ 167.9 $ 164.7 $ 3.2 $ — Corporate debt securities 695.8 — 695.8 — Asset-backed securities 494.5 — 494.5 — Residential mortgage-backed securities 413.5 — 413.5 — Commercial mortgage-backed securities 115.9 — 115.9 — Non-U.S. government and government agency 50.3 42.9 7.4 — Preferred stocks 8.5 — 3.1 5.4 U.S. States, municipalities, and political subdivision 2.8 — 2.8 — Total fixed maturity investments 1,949.2 207.6 1,736.2 5.4 Equity securities: Fixed income mutual funds 157.7 157.7 — — Common stocks 222.3 222.3 — — Other equity securities — — — — Total equity securities 380.0 380.0 — — Short-term investments 715.5 679.3 36.2 — Other long-term investments (1) 63.6 — — 63.6 Total investments $ 3,108.3 $ 1,266.9 $ 1,772.4 $ 69.0 Loan participation — — — — Derivative instruments 4.1 — — 4.1 Total assets measured at fair value $ 3,112.4 $ 1,266.9 $ 1,772.4 $ 73.1 Liabilities measured at fair value Contingent consideration liabilities $ 28.8 $ — $ — $ 28.8 Derivative instruments 5.1 0.5 — 4.6 Total liabilities measured at fair value $ 33.9 $ 0.5 $ — $ 33.4 (1) Excludes fair value of $301.4 associated with hedge funds and private equity funds which fair value is measured at net asset value using the practical expedient.
Rollforward of Level 3 fair value measurements	The following tables present changes in Level 3 for financial instruments measured at fair value for the years ended December 31, 2019 and 2018 : ​ 2019 (Millions) Fixed maturities Other long-term investments (1) Loan participation Derivative instruments assets & (liabilities) Contingent consideration (liabilities) Balance at January 1, 2019 $ 5.4 $ 63.6 $ — $ (0.5 ) $ (28.8 ) Total realized and unrealized gains — 7.3 — (7.1 ) (6.3 ) Foreign currency losses through Other Comprehensive Income — (0.6 ) — — — Purchases 17.0 15.7 20.0 — — Sales/settlements (5.4 ) (8.2 ) — 8.4 6.9 Balance at December 31, 2019 $ 17.0 $ 77.8 $ 20.0 $ 0.8 $ (28.2 ) (1) Excludes fair value of $269.0 associated with hedge funds and private equity funds which fair value is measured at net asset value using the practical expedient. ​ 2018 (Millions) Fixed maturities Other long-term investments (1) Loan participation Derivative instruments assets & (liabilities) Contingent consideration (liabilities) Balance at January 1, 2018 $ 8.0 $ 64.2 $ — $ (6.1 ) $ (42.8 ) Total realized and unrealized gains (6.1 ) 6.8 — 12.0 9.6 Foreign currency losses through Other Comprehensive Income — (4.4 ) — — — Purchases 4.0 1.2 — — — Sales/settlements (0.5 ) (4.2 ) — (6.4 ) 4.4 Balance at December 31, 2018 $ 5.4 $ 63.6 $ — $ (0.5 ) $ (28.8 ) (1) Excludes fair value of $301.5 associated with hedge funds and private equity funds which fair value is measured at net asset value using the practical expedient.
Schedule of significant unobservable inputs used for recurring fair value measurements for Level 3 instruments	The table below presents information about the significant unobservable inputs used for recurring fair value measurements for certain Level 3 instruments as of December 31, 2019 and 2018 , and includes only those instruments for which information about the inputs is reasonably available to Sirius Group, such as data from independent third-party valuation service providers and from internal valuation models. (Millions) 2019 Description Valuation technique(s) Fair value Unobservable input Private equity securitiesﾠ (1) Share price of recent transaction $ 32.5 Purchase share price $ 40.6 Loan participation (1) Purchase price of recent transaction $ 20.0 Purchase price $ 20.0 Preferred stock (1) Share price of recent transaction $ 17.5 Purchase price $ 7.74 Private equity securitiesﾠ (1) Multiple of GAAP book value $ 14.2 Book value multiple 0.9 Preferred stock (1) Purchase price of recent transaction $ 12.2 Purchase price $ 12.2 Private debt instrumentﾠ (1) Purchase price of recent transaction $ 7.2 Purchase price $ 9.0 Weather derivatives (2) Third party appraisal $ 7.0 Broker quote $ 7.0 Private equity securitiesﾠ (1) Purchase price of recent transaction $ 5.1 Purchase price $ 7.74 Preferred stock (1) Purchase price of recent transaction $ 4.8 Purchase price $ 4.80 Currency forwards (2) Third party appraisal $ 2.7 Broker quote $ 2.7 Private equity securitiesﾠ (1) Purchase price of recent transaction $ 1.0 Purchase price $ 10.0 Equity warrants (2) Option pricing model $ 0.4 Strike price $ 0.2 Private equity securitiesﾠ (1) Purchase price of recent transaction $ 0.3 Purchase price $ 0.3 Currency swaps (2) Third party appraisal $ (3.6 ) Broker quote $ (3.6 ) Currency forwards (2) Third party appraisal $ (5.7 ) Broker quote $ (5.7 ) Contingent consideration External valuation model $ (28.2 ) Discounted future payments $ (28.2 ) (1) As of December 31, 2019 , each asset type consists of one security. (2) See Note 13 for discussion of derivative instruments. (Millions) 2018 Description Valuation technique(s) Fair value Unobservable input Private equity securitiesﾠ (1) Share price of recent transaction $ 32.5 Purchase share price $ 40.63 Private equity securitiesﾠ (1) Multiple of GAAP book value $ 14.7 Book value multiple 0.9 Private debt instrumentﾠ (1) Purchase price of recent transaction $ 9.0 Purchase price $ 9.0 Private debt instrumentﾠ (1) Purchase price of recent transaction $ 6.0 Purchase price $ 6.0 Preferred stock (1) Purchase price of recent transaction $ 4.6 Average share price $ 1.88 Weather derivatives (2) Third party appraisal $ 3.9 Broker quote $ 3.9 Common stock (1) Purchase price of recent transaction $ 0.9 Purchase price $ 1.88 Preferred stock (1) Share price of recent transaction $ 0.8 Purchase price $ 0.8 Common stock (1) Share price of recent transaction $ 0.3 Purchase price $ 10.0 Private debt instrumentﾠ (1) Purchase price of recent transaction $ 0.2 Purchase price $ 0.2 Interest rate cap (2) Third party appraisal $ 0.2 Broker quote $ 0.2 Currency swaps (2) Third party appraisal $ (4.6 ) Broker quote $ (4.6 ) Contingent consideration External valuation model $ (28.8 ) Discounted future payments $ (28.8 ) (1) As of December 31, 2018 , each asset type consists of one security. (2) See Note 13 for discussion of derivative instruments.
Schedule of financial instruments disclosed, but not carried at fair value	The following table includes financial instruments for which the carrying value differs from the estimated fair values as of December 31, 2019 and 2018 : 2019 2018 (Millions) Fair value (1) Carrying value Fair value (1) Carrying value Liabilities, Mezzanine equity, and Non-controlling interest: 2017 SEK Subordinated Notes $ 294.5 $ 291.2 $ 309.5 $ 303.6 2016 SIG Senior Notes $ 394.5 $ 394.0 $ 347.6 $ 393.2 Series B preference shares $ 186.4 $ 223.0 $ 191.7 $ 232.2 (1) Fair value estimated by internal pricing and considered a Level 3 measurement.

Goodwill and intangible assets

Goodwill and intangible assets (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in goodwill and intangible assets	The following table shows the change in goodwill, intangible assets with an indefinite life, and intangible assets with a finite life during the years ended December 31, 2019 and 2018 : (Millions) Goodwill Intangible assets with an indefinite life Intangible assets with a finite life Total Net balance at December 31, 2017 $ 401.0 $ 27.0 $ 189.3 $ 617.3 Additions (1) — 3.1 — 3.1 Foreign currency translation (2) (0.4 ) — — (0.4 ) Impairments (2) — (8.0 ) — (8.0 ) Amortization (2) — — (15.8 ) (15.8 ) Net balance at December 31, 2018 400.6 22.1 173.5 596.2 Additions — — — — Foreign currency translation (2) 0.2 — — 0.2 Impairments (2) — — — — Amortization (2) — — (15.8 ) (15.8 ) Net balance at December 31, 2019 $ 400.8 $ 22.1 $ 157.7 $ 580.6 (1) Additions in 2018 relate to insurance licenses allocated to the Runoff & Other segment. (2) Foreign currency translation, impairments, and amortization in 2019 and 2018 relate to Armada and IMG and are allocated to the Global A&H segment.
Schedule of components of goodwill and intangible assets	The following tables presents the components of goodwill and intangible assets as of December 31, 2019 and 2018 : ​ 2019 (Millions) Gross balance Accumulated amortization Impairments Foreign currency translation Net balance Customer relationships – finite life (1) $ 17.0 $ (3.5 ) $ — $ — $ 13.5 Distribution relationships – finite life (1) 151.0 (25.5 ) — — 125.5 Goodwill – indefinite life (1) 400.7 — — 0.1 400.8 Insurance licenses – indefinite life (2) 8.1 — — — 8.1 Technology – finite life (1) 15.5 (6.9 ) — — 8.6 Trade names – finite life (1) 16.0 (5.9 ) — — 10.1 Trade names – indefinite life (1) 14.0 — — — 14.0 Net balance at December 31, 2019 $ 622.3 $ (41.8 ) $ — $ 0.1 $ 580.6 (1) Allocated to the Global A&H segment. (2) Allocated to the Runoff & Other segment. 2018 (Millions) Gross balance Accumulated amortization Impairments Foreign currency translation Net balance Customer relationships – finite life (1) $ 17.0 $ (2.2 ) $ — $ — $ 14.8 Distribution relationships – finite life (1) 151.0 (15.8 ) — — 135.2 Goodwill – indefinite life (1) 400.7 — — (0.1 ) 400.6 Insurance licenses – indefinite life (2) 8.1 — — — 8.1 Technology – finite life (1) 15.5 (4.3 ) — — 11.2 Trade names – finite life (1) 16.0 (3.7 ) — — 12.3 Trade names – indefinite life (1) 27.0 — (13.0 ) — 14.0 Net balance at December 31, 2018 $ 635.3 $ (26.0 ) $ (13.0 ) $ (0.1 ) $ 596.2 (1) Allocated to the Global A&H segment. (2) Allocated to the Runoff & Other segment .
Schedule of remaining amortization expense	The estimated remaining amortization expense for Sirius Group's intangible assets with finite lives is as follows: (Millions) 2020 $ 15.8 2021 15.8 2022 14.6 2023 13.8 2024 13.2 2025 and thereafter 84.5 Total remaining amortization expense $ 157.7

Debt and standby letters of c_2

Debt and standby letters of credit facilities (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of debt outstanding	Sirius Group's debt outstanding as of December 31, 2019 and 2018 consisted of the following: (Millions) December 31, 2019 Effective rate (1) December 31, 2018 Effective rate (1) 2017 SEK Subordinated Notes, at face value $ 295.0 4.0 % $ 307.6 3.8 % Unamortized issuance costs (3.8 ) (4.0 ) 2017 SEK Subordinated Notes, carrying value 291.2 303.6 2016 SIG Senior Notes, at face value 400.0 4.7 % 400.0 4.7 % Unamortized discount (2.3 ) (2.6 ) Unamortized issuance costs (3.7 ) (4.2 ) 2016 SIG Senior Notes, carrying value 394.0 393.2 Total debt $ 685.2 $ 696.8 (1) Effective rate considers the effect of the debt issuance costs.
Schedule of contractual repayments of debt	A schedule of contractual repayments of Sirius Group's debt as of December 31, 2019 follows: (Millions) December 31, 2019 Due in one year or less $ — Due in one to three years — Due in three to five years — Due after five years 695.0 Total $ 695.0

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of net income (loss) before income taxes	Sirius Group's net income (loss) before income taxes for the years ended December 31, 2019 , 2018 , and 2017 was generated in the following domestic and foreign jurisdictions: (Millions) 2019 2018 2017 Domestic: ​ Bermuda $ (32.8 ) $ 62.7 $ (95.0 ) Foreign: U.S. (5.4 ) (10.1 ) (22.4 ) U.K. (29.1 ) (14.9 ) (27.0 ) Sweden (22.4 ) (74.2 ) (26.1 ) Luxembourg 56.0 60.3 43.4 Netherlands — (0.1 ) 18.2 Other — — (1.0 ) Total (loss) income before income taxes $ (33.7 ) $ 23.7 $ (109.9 )
Schedule of total income tax (expense) benefit	The total income tax (expense) benefit for the years ended December 31, 2019 , 2018 , and 2017 consisted of the following: (Millions) 2019 2018 2017 Current tax (expense): U.S. Federal $ (1.6 ) $ (7.0 ) $ (0.9 ) State (2.0 ) (2.2 ) (2.0 ) Non-U.S. (1.5 ) (19.8 ) (3.6 ) Total current tax benefit (expense) (5.1 ) (29.0 ) (6.5 ) Deferred tax (expense): U.S. Federal (8.8 ) 14.3 (8.7 ) State 0.9 0.2 (2.0 ) Non-U.S. 1.1 (25.9 ) (9.2 ) Total deferred tax (expense) (6.8 ) (11.4 ) (19.9 ) Total income tax (expense) $ (11.9 ) $ (40.4 ) $ (26.4 )
Schedule of effective rate reconciliation	A reconciliation of taxes calculated using the 21.4% Swedish statutory rate (the rate at which the majority of Sirius Group's worldwide operations are taxed) to the income tax (expense) benefit on pre-tax income follows: (Millions) 2019 2018 2017 Tax benefit (expense) at the statutory rate $ 7.2 $ (5.2 ) $ 24.2 Differences in taxes resulting from: Change in valuation allowance (20.7 ) 2.3 1.4 Non-Sweden earnings (19.6 ) 2.3 (18.4 ) Tax reserve adjustments 13.9 (42.0 ) (0.7 ) Foreign tax credits 12.2 10.8 2.2 Results from internal restructuring 7.4 (9.1 ) — Tax rate change enacted in Luxembourg (5.8 ) — 0.4 State taxes expense (1.7 ) (2.9 ) (0.7 ) Withholding taxes (1.7 ) (1.9 ) (0.8 ) Tax rate change—other (1.6 ) 0.1 (29.7 ) Tax on Safety Reserve (0.6 ) (15.3 ) — Tax rate change enacted in Sweden (0.2 ) 15.4 — Section 197 Intangible as result of internal restructuring — 6.9 — Other, net (0.7 ) (1.8 ) (4.3 ) Total income tax (expense) on pre-tax earnings $ (11.9 ) $ (40.4 ) $ (26.4 )
Schedule of deferred tax assets and liabilities	An outline of the significant components of Sirius Group's deferred tax assets and liabilities follows: (Millions) 2019 2018 Deferred income tax assets related to: Non-U.S. net operating loss carry forwards $ 211.1 $ 249.8 Tax credit carry forwards 41.6 28.7 U.S. federal net operating loss and capital carry forwards 40.2 33.8 Loss reserve discount 6.6 7.3 Unearned premiums 4.3 3.1 Investment basis differences 3.6 — Foreign currency translation on investments and other assets 3.4 0.8 Incentive compensation and benefit accruals 2.8 1.9 Deferred Interest 2.6 2.1 Allowance for doubtful accounts 1.5 1.4 Other items 3.9 2.7 Total gross deferred income tax assets 321.6 331.6 Valuation allowance (79.8 ) (64.3 ) Total adjusted deferred tax asset 241.8 267.3 Deferred income tax liabilities related to: Safety reserve (See Note 18 ) 239.4 261.1 Intangible assets 25.7 28.7 Deferred acquisition costs 4.6 3.1 Net unrealized investment gains 3.7 0.3 Purchase Accounting 3.6 3.0 Investment basis differences — 2.4 Other items 4.0 3.6 Total deferred income tax liabilities 281.0 302.2 Net deferred tax (liability) asset $ (39.2 ) $ (34.9 )
Schedule of net operating loss and capital loss carryforwards	Net operating loss and capital loss carryforwards as of December 31, 2019 , the expiration dates, and the deferred tax assets thereon are as follows: (Millions) 2019 United States Luxembourg Sweden U.K. Total 2019-2023 $ 1.5 $ — $ — $ — $ 1.5 2024-2038 171.4 0.1 — — 171.5 No expiration date 21.5 764.9 230.1 97.0 1,113.5 Total 194.4 765.0 230.1 97.0 1,286.5 Gross deferred tax asset 40.2 190.8 3.8 16.5 251.3 Valuation allowance — (50.2 ) — (16.5 ) (66.7 ) Net deferred tax asset $ 40.2 $ 140.6 $ 3.8 $ — $ 184.6
Schedule of reconciliation of the beginning and ending amount of unrecognized tax benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: (Millions) Permanent differences (1) Temporary differences (2) Interest and penalties (3) Total Balance at January 1, 2017 $ 24.2 $ 4.1 $ 0.2 $ 28.5 Changes in prior year tax positions 0.2 (0.1 ) 0.1 0.2 Tax positions taken during the current year 3.8 (2.2 ) — 1.6 Lapse in statute of limitations (0.5 ) — — (0.5 ) Settlements with tax authorities (0.3 ) — (0.2 ) (0.5 ) Balance at December 31, 2017 $ 27.4 $ 1.8 $ 0.1 $ 29.3 Changes in prior year tax positions 1.4 — 0.1 1.5 Tax positions taken during the current year 36.2 (1.7 ) — 34.5 Lapse in statute of limitations — — — — Settlements with tax authorities (0.1 ) — — (0.1 ) Balance at December 31, 2018 $ 64.9 $ 0.1 $ 0.2 $ 65.2 Changes in prior year tax positions (17.1 ) — — (17.1 ) Tax positions taken during the current year (0.5 ) — — (0.5 ) Lapse in statute of limitations (0.1 ) — — (0.1 ) Settlements with tax authorities — — — — Balance at December 31, 2019 $ 47.2 $ 0.1 $ 0.2 $ 47.5 (1) Represents the amount of unrecognized tax benefits that, if recognized, would impact the effective tax rate. (2) Represents the amount of unrecognized tax benefits that, if recognized, would create a temporary difference between the reported amount of an item in the Consolidated Balance Sheets and its tax basis. (3) Net of tax benefit.

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of classification and amount of fair value of derivatives not designated as hedging instruments within Consolidated Balance Sheets	The following tables summarize information on the classification and amount of the fair value of derivatives not designated as hedging instruments within the Company's Consolidated Balance Sheets as of December 31, 2019 and 2018 : (Millions) 2019 2018 Derivatives not designated as hedging instruments Notional value Asset derivative at fair value (1) Liability derivative at fair value (2 ) Notional value Asset derivative at fair value (1) Liability derivative at fair value (2) Interest rate cap $ 250.0 $ — $ — $ 250.0 $ 0.2 $ — Foreign currency swaps $ 90.0 $ — $ 3.6 $ 45.0 $ — $ 4.6 Foreign currency forwards $ (30.0 ) $ 2.7 $ 5.7 $ — $ — $ — Weather derivatives $ 110.7 $ 7.0 $ — $ 150.5 $ 3.9 $ — Equity futures contracts $ 34.5 $ — $ — $ — $ — $ — Equity warrants $ 0.4 $ 0.4 $ — $ — $ — $ — Equity put options $ 31.0 $ 1.3 $ 0.2 $ 6.2 $ — $ 0.5 (1) Asset derivatives are classified within Other assets within the Company's Consolidated Balance Sheets of December 31, 2019 and 2018 . (2) Liability derivatives are classified within Other liabilities within the Company's Consolidated Balance Sheets of December 31, 2019 and 2018 .
Schedule of classification and net impact on earnings, recognized in Consolidated Statements of (Loss) Income relating to derivatives	The following table summarizes information on the classification and net impact on earnings, recognized in the Company's Consolidated Statements of (Loss) relating to derivatives during the years ended December 31, 2019 , 2018 , and 2017 : (Millions) Derivatives not designated as hedging instruments Classification of gains (losses) recognized in earnings 2019 2018 2017 Interest rate cap Other revenues $ (0.2 ) $ 0.1 $ (1.5 ) Foreign currency swaps Net foreign exchange gains $ 4.2 $ 6.9 $ (11.3 ) Foreign currency forwards Net foreign exchange gains $ (10.4 ) $ — $ (0.3 ) Weather derivatives Other revenues $ (1.1 ) $ 5.2 $ (1.5 ) Equity futures contracts Net realized investment gains (losses) $ (1.7 ) $ 1.7 $ — Equity put options Net realized investment gains (losses) $ (0.8 ) $ — $ — Equity put options Net unrealized investment gains (losses) $ (0.8 ) $ — $ — Equity warrants Net unrealized investment gains (losses) $ 0.4 $ — $ —

Employee benefit plans and co_2

Employee benefit plans and compensation plans (Tables)	12 Months Ended
	Dec. 31, 2019
Employee benefit plans and compensation plans
Schedule of breakdown of plan assets	The breakdown of the investment of plan assets for the years ended December 31, 2019 and 2018 are as follows: 2019 2018 International equities 13.0 % 11.4 % Swedish equities 8.9 % 7.5 % Swedish nominal bonds 40.7 % 40.3 % Real estate 10.2 % 11.2 % Private equity 9.4 % 10.4 % Other 17.8 % 19.2 %
Schedule of reconciliation of beginning and ending funded status and net amounts recognized	The following tables present a reconciliation of the beginning and ending funded status and the net amounts recognized for the defined benefit plans for the years ended December 31, 2019 and 2018 : (Millions) 2019 2018 Change in benefit obligation Projected benefit obligation, beginning of year $ 17.5 $ 17.4 Service cost 1.5 1.0 Interest cost 0.4 0.4 Actuarial losses 2.9 0.6 Benefit payments (1.2 ) (0.4 ) Tax payments (0.3 ) (0.2 ) Currency revaluation effect (0.6 ) (1.3 ) Projected benefit obligation, end of year 20.3 17.5 Change in plan assets Fair value of plan assets, beginning of year 16.4 16.1 Employer contributions 1.4 1.2 Benefit payments (0.4 ) (0.3 ) Interest income 1.0 0.8 Currency revaluation effect (0.6 ) (1.4 ) Fair value of plan assets, end of year 17.7 16.4 Funded status at end of year (1) $ (2.6 ) $ (1.1 ) (1) At December 31, 2019 , the Swedish plan had a funding status of $2.5 million and the German plan had a funding status of $(5.1) million. At December 31, 2018 , the Swedish plan had a funding status of $3.0 million and the German plan had a funding status of $(4.1) million.
Schedule of components of net periodic pension expense	The components of net periodic pension expense for the years ended December 31, 2019 , 2018 , and 2017 are as follows: (Millions) 2019 2018 2017 Service cost $ (0.9 ) $ (1.2 ) $ (0.8 ) Interest cost 0.1 0.1 2.2 Actuarial (loss) (0.5 ) (0.8 ) (0.3 ) Net periodic pension expense $ (1.3 ) $ (1.9 ) $ 1.1
Schedule of projected benefit payments required for defined pension benefit plans	As of December 31, 2019 , the projected benefit payments required for the defined pension benefits plans are as follows: (Millions) December 31, 2019 2020 $ 0.5 2021 0.4 2022 0.4 2023 0.4 2024 0.5 2024-2028 3.1 Total benefit payments required $ 5.3
Schedule of assumptions used to value stock options	The following assumptions were used to value stock options granted: Expected annual dividend yield 1.75 % Expected volatility (1) 20 % Risk-free interest rate (2) 2.51 % Expected term (3) 4 years (1) Expected volatility was estimated based on the historical volatility of the shares of a peer group of companies. (2) Risk free rate was based on US 5-year semi-annual treasury rate interest rate. (3) The Company used the simplified method for estimating the expected term.
Schedule of share-based compensation expense recognized under plans	The following tables present pre-tax and after-tax share-based compensation expense recognized under the above plans: (Millions) 2019 2018 2017 PSUs - IPO Incentive Awards (1) $ 0.7 $ 1.5 $ — PSUs - 2019 LTI 0.8 — — RSUs 5.8 — — Stock Options 0.8 — — LTIP (2)(3) (3.4 ) 1.0 — Total share-based compensation expense - pre-tax $ 4.7 $ 2.5 $ — (1) 2019 includes a reversal of 2018 accrual of $1.5 related to modification of the award. (2) Legacy 2016 LTIP includes two open cycles in 2019 and three open cycles in 2018. (3) For the year ended December 31, 2017, $3.9 of expense associated with phantom share awards has been excluded. (Millions) 2019 2018 2017 PSUs - IPO Incentive Awards (1) $ 0.6 $ 1.2 $ — PSUs - 2019 LTI 0.7 — — RSUs 4.6 — — Stock Options 0.6 — — LTIP (2)(3) (2.7 ) 0.8 — Total share-based compensation expense - after-tax $ 3.8 $ 2.0 $ — (1) 2019 includes a reversal of 2018 accrual of $1.2 related to modification of the award. (2) Legacy 2016 LTIP includes two open cycles in 2019 and three open cycles in 2018. (3) For the year ended December 31, 2017, expense associated with phantom share awards has been excluded.
Schedule of unrecognized compensation cost associated with unvested awards	The following tables present unrecognized compensation cost associated with unvested awards and weighted average period over which it is expected to be recognized: (Millions) December 31, 2019 PSUs - IPO Incentive Awards PSUs - 2019 LTI RSUs Stock Options LTIP Unrecognized compensation cost related to unvested awards $ 4.0 $ 2.0 $ 11.8 $ 2.0 $ 0.7 Weighted average recognition period (years) 2.0 years 2.0 years 1.9 years 2.2 years 1.0 year
Schedule of outstanding share-settled awards	The following table summarizes outstanding share-settled awards as of the end of the year ended December 31, 2019: As of and for the year ended December 31, 2019 Number of Shares PSUs - IPO Incentive Awards PSUs - 2019 LTI RSUs Stock Options LTIP (1) Unvested, beginning of the year — — — — 1,765,637 Granted (2) 756,183 408,370 1,428,185 1,374,945 — Vested — — — — 33,307 Forfeited (3) 201,020 17,234 74,333 — 861,859 Unvested, end of the year 555,163 391,136 1,353,852 1,374,945 870,471 (1) Includes 2017 and 2018 legacy LTIP award cycles. Unearned portion of the 2017 LTIP was included in forfeited shares. (2) IPO Incentive Award was included in the granted line due to its modification during 2019. (3) Shares that are unearned as a result of missing minimum performance indicators are included in forfeited shares.
Sweden
Employee benefit plans and compensation plans
Schedule of assumptions used to determine benefit obligations	The assumptions used to determine Swedish benefit obligations for the years ended December 31, 2019 and 2018 are as follows: 2019 2018 Discount rate 2.3 % 2.5 % Increase in compensation levels rate 3.3 % 3.2 % Turnover rate 3.0 % 3.0 %
Germany
Employee benefit plans and compensation plans
Schedule of assumptions used to determine benefit obligations	The assumptions used to determine German benefit obligations for the years ended December 31, 2019 and 2018 are as follows: 2019 2018 Discount rate 1.9 % 1.7 % Increase in compensation levels rate 2.0 % 2.0 %

Common shareholder's equity, me

Common shareholder's equity, mezzanine equity, and non-controlling interests (Tables)	12 Months Ended
	Dec. 31, 2019
Stockholders' Equity Note [Abstract]
Schedule of changes in the company's issued and outstanding common shares	The following table presents changes in the Company's issued and outstanding Common shares for the years ended December 31, 2019 , 2018 , and 2017 , respectively: 2019 2018 2017 Common shares: Shares issued and outstanding, beginning of year 115,151,251 120,000,000 120,000,000 Issuance of shares (See Note 3 ) 148,090 4,670,531 — Shares redeemed (See Note 3 ) — (9,519,280 ) — Shares issued and outstanding, end of year 115,299,341 115,151,251 120,000,000
Schedule of change in non-controlling interest	The following table shows the change in non-controlling interest for the years ended December 31, 2019 , 2018 , and 2017 : (Millions) Total Non-controlling interests as of December 31, 2016 $ 251.3 Net income attributable to non-controlling interests 13.7 Dividends to non-controlling interests (14.1 ) Other, net (250.7 ) Non-controlling interests as of December 31, 2017 $ 0.2 Net income attributable to non-controlling interests 1.4 Dividends to non-controlling interests — Other, net 0.1 Non-controlling interests as of December 31, 2018 $ 1.7 Net income attributable to non-controlling interests 1.7 Dividends to non-controlling interests (1.0 ) Other, net — Non-controlling interests as of December 31, 2019 $ 2.4

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per common share	The following table sets forth the computation of basic and diluted earnings per common share for the years ended December 31, 2019 , 2018 , and 2017 : (Millions, except share and per share information) 2019 2018 2017 Basic earnings per share Numerator: Net (loss) $ (45.6 ) $ (16.7 ) $ (136.3 ) Less: Income attributable to non-controlling interests (1.7 ) (1.4 ) (13.7 ) Change in carrying value of SeriesﾠB preference shares 9.2 (36.4 ) — Less: Accrued dividends on SeriesﾠA redeemable preference shares — (2.6 ) (6.1 ) Add: Redemption of SeriesﾠA redeemable preference shares — 13.8 — Net (loss) attributable to Sirius Group common shareholders $ (38.1 ) $ (43.3 ) $ (156.1 ) Denominator: Weighted average shares outstanding for basic earnings per share (1)(2) 115,234,105 119,253,924 120,000,000 Basic earnings per share $ (0.33 ) $ (0.36 ) $ (1.30 ) Diluted earnings per share Numerator: Net (loss) attributable to Sirius Group common shareholders $ (38.1 ) $ (43.3 ) $ (156.1 ) Change in carrying value of Series B preference shares (9.2 ) — — Net (loss) attributable to Sirius Group common shareholders on a diluted basis $ (47.3 ) $ (43.3 ) $ (156.1 ) Denominator: Weighted average shares outstanding for basic earnings per share (1)(2) 115,234,105 119,253,924 120,000,000 Add: Series B preference shares 11,901,670 — — Weighted average shares outstanding for diluted earnings per share (1)(2) 127,135,775 119,253,924 120,000,000 Diluted earnings per share $ (0.37 ) $ (0.36 ) $ (1.30 ) (1) As of December 31, 2019 , there were a total of 17,057,249 potentially dilutive securities excluded from the calculation of Diluted earnings per share. (2) As of December 31, 2018 , there were a total of 23,433,114 potentially dilutive securities excluded from the calculation of Diluted earnings per share.As of December 31, 2017 , there were no potentially dilutive securities.

Accumulated other comprehensi_2

Accumulated other comprehensive (loss) (Tables)	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of changes in accumulated other comprehensive (loss), by component	The changes in accumulated other comprehensive (loss), by component, for the years ended December 31, 2019 , 2018 , and 2017 are as follows: For the year ended December 31, 2019 (Millions) Foreign currency translation adjustment Total Balance, beginning of year $ (202.4 ) $ (202.4 ) Other comprehensive (loss) (35.1 ) (35.1 ) Balance, end of year $ (237.5 ) $ (237.5 ) For the year ended December 31, 2018 (Millions) Foreign currency translation adjustment Total Balance, beginning of year $ (140.5 ) $ (140.5 ) Other comprehensive (loss) (61.9 ) (61.9 ) Balance, end of year $ (202.4 ) $ (202.4 ) For the year ended December 31, 2017 (Millions) Foreign currency translation adjustment Total Balance, beginning of year $ (212.2 ) $ (212.2 ) Other comprehensive (loss) 71.7 71.7 Balance, end of year $ (140.5 ) $ (140.5 )

Investments in unconsolidated_2

Investments in unconsolidated entities (Tables)	12 Months Ended
	Dec. 31, 2019
Investments in unconsolidated entities
Schedule of components of Other long-term investments	The following table presents the components of Other long-term investments as of December 31, 2019 and 2018 : (Millions) 2019 2018 Equity method eligible unconsolidated entities, at fair value $ 151.9 $ 169.4 Other unconsolidated investments, at fair value (1) 194.9 195.6 Total Other long-term investments (2) $ 346.8 $ 365.0 (1) Includes Other long-term investments that are not equity method eligible . (2) There were no investments accounted for using the equity method as of December 31, 2019 and 2018 .
Schedule of investments in equity method eligible unconsolidated entities	The following table presents Sirius Group's investments in equity method eligible unconsolidated entities as of December 31, 2019 and 2018 : Ownership interest as of December 31, Investee 2019 2018 Instrument Held BE Reinsurance Limited 24.9 % 25.0 % Common shares BioVentures Investors (Offshore) IV ﾠLP 73.0 % 73.0 % Units Camden Partners Strategic Fund V (Cayman),ﾠ LP 39.4 % 36.4 % Units Diamond LS I LP 16.0 % 3.9 % Units Gateway Fund LP 15.0 % — % Units Monarch 12.8 % 12.8 % Units NEC Cypress BuyerﾠLLC (1) — % 13.3 % Units New Energy Capital Infrastructure Credit Fundﾠ LP 30.5 % 22.9 % Units New Energy Capital Infrastructure Offshore Credit Fundﾠ LP 30.5 % 54.9 % Units Pie Preferred Stock (2) 30.1 % — % Preferred shares Pie Series B Preferred Stock (2) 22.4 % — % Preferred shares Quintana Energy Partners 21.8 % 21.8 % Units Tuckerman Capital VﾠLP 48.3 % 47.6 % Units Tuckerman Capital V Co-Investment IﾠLP 48.1 % 47.7 % Units (1) The ownership of NEC Cypress Buyer LLC was liquidated in 2019. (2) Sirius Group holds investments in several financing instruments of Pie Insurance Holdings, Inc.
Schedule of summarized financial information of investments in equity method eligible unconsolidated entities	The following tables present aggregated summarized financial information for Sirius Group's investments in equity method eligible unconsolidated entities: As of December 31, (Millions) 2019 2018 Balance sheet data: Total assets $ 594.5 $ 591.1 Total liabilities $ 47.6 $ 28.7 For the years ended December 31, (Millions) 2019 2018 2017 Income statement data: Revenues $ 72.7 $ 55.4 $ 60.3 Expenses $ (30.2 ) $ (25.1 ) $ (28.8 )

Variable interest entities (Tab

Variable interest entities (Tables)	12 Months Ended
	Dec. 31, 2019
Variable interest entities
Schedule of assets and liabilities related to the consolidated VIEs	The following table presents Alstead Re's assets and liabilities, as classified in the Consolidated Balance Sheets as of December 31, 2019 and 2018 : (Millions) 2019 2018 Assets: Fixed maturity investments $ 3.9 $ 4.0 Short-term investments 0.5 0.3 Cash 0.1 0.2 Total investments 4.5 4.5 Accrued investment income — 0.1 Insurance and reinsurance premiums receivable (0.3 ) 3.7 Funds held by ceding companies 3.4 5.2 Deferred acquisition costs 0.3 0.9 Total assets $ 7.9 $ 14.4 Liabilities Loss and loss adjustment expense reserves $ 0.5 $ 4.6 Unearned insurance and reinsurance premiums 0.6 3.7 Other liabilities 0.1 — Total liabilities $ 1.2 $ 8.3
Schedule of total assets of unconsolidated VIEs	The following table presents total assets of unconsolidated VIEs in which Sirius Group holds a variable interest, as well as the maximum exposure to loss associated with these VIEs: Maximum Exposure to Loss (Millions) Total VIE Assets On-Balance Sheet Off-Balance Sheet Total December 31, 2019 Other long-term investments (1) $ 257.8 $ 102.6 $ 16.3 $ 118.9 Total at December 31, 2019 $ 257.8 $ 102.6 $ 16.3 $ 118.9 December 31, 2018 Other long-term investments (1) $ 209.1 $ 103.1 $ 32.0 $ 135.1 Total at December 31, 2018 $ 209.1 $ 103.1 $ 32.0 $ 135.1 (1) Comprised primarily of hedge funds and private equity funds.

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of gross reinsurance premiums written by intermediaries	Gross written premium by intermediary 2019 2018 2017 AON Corporation and subsidiaries 24 % 26 % 22 % Guy Carpenter & Company and subsidiaries 24 % 26 % 25 % WT Butler and Co. Ltd. 11 % 10 % 10 % Willis Towers Watson plc and subsidiaries 10 % 8 % 8 % Total 69 % 70 % 65 %
Schedule of net written premiums by geographic region	(Millions) 2019 2018 2017 United States $ 922.3 $ 794.7 $ 563.1 Europe 268.9 276.5 262.3 Canada, the Caribbean, Bermuda and Latin America 102.5 103.6 111.4 Asia and Other 208.9 182.3 153.4 Total $ 1,502.6 $ 1,357.1 $ 1,090.2
Schedule of lease balances within the Consolidated Balance Sheets	The following table presents the lease balances within the Consolidated Balance Sheets as of December 31, 2019 : (millions) Balance Sheet Classification December 31, 2019 Operating lease right-of-use assets Other assets $ 27.4 Current lease liabilities Other liabilities $ 8.3 Non-current lease liabilities Other liabilities $ 21.0
Schedule of weighted average remaining lease term and weighted average discount rate	The following table presents weighted average remaining lease term and weighted average discount rate as at December 31, 2019 : Weighted average lease term (years) as of December 31, 2019 Leased offices 7 years Leased equipment 3 years Weighted average discount rate: Leased offices 3.7 % Leased equipment 3.4 %
Schedule of future annual minimum rental payments required under non cancellable leases for office space	The following table presents future annual minimum rental payments required under non-cancellable leases and the present value discount to arrive at total lease liability as of December 31, 2019 : (Millions) Future Payments 2020 $ 9.3 2021 8.0 2022 7.1 2023 4.4 2024 2.0 2025 0.6 2026 and after 0.2 Total future annual minimum rental payments as at December 31, 2019 31.6 Less: present value discount (2.3 ) Total lease liability as of December 31, 2019 $ 29.3

Unaudited condensed quarterly_2

Unaudited condensed quarterly financial data (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of unaudited condensed quarterly financial data	(Expressed in millions of U.S. dollars, except per share amounts) December 31, September 30, June 30, March 31, Unaudited Unaudited Unaudited Unaudited Total revenues $ 352.0 $ 487.4 $ 441.0 $ 439.7 Total expenses $ 506.0 $ 498.7 $ 430.7 $ 318.4 Net (loss) income attributable to Sirius Group's common shareholders $ (137.3 ) $ (2.7 ) $ 6.6 $ 95.3 Basic earnings per common share and common share equivalent $ (1.19 ) $ (0.02 ) $ 0.05 $ 0.75 Diluted earnings per common share and common share equivalent $ (1.19 ) $ (0.06 ) $ 0.05 $ 0.74 (Expressed in millions of U.S. dollars, except per share amounts) December 31, September 30, June 30, March 31, Unaudited Unaudited Unaudited Unaudited Total revenues $ 336.8 $ 351.7 $ 441.8 $ 327.5 Total expenses $ 482.3 $ 386.3 $ 292.4 $ 273.1 Net (loss) income attributable to Sirius Group's common shareholder $ (153.6 ) $ (28.0 ) $ 97.8 $ 40.5 Basic earnings per common share and common share equivalent $ (1.31 ) $ (0.23 ) $ 0.78 $ 0.32 Diluted earnings per common share and common share equivalent $ (1.31 ) $ (0.23 ) $ 0.78 $ 0.32

Summary of significant accoun_4

Summary of significant accounting policies - Deferred software costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of significant accounting policies
Unamortized deferred software costs	$ 157.7	$ 173.5	$ 189.3
Amortization of intangible assets	$ 15.8	15.8	10.2
Minimum
Summary of significant accounting policies
Amortization straight-line basis and over useful life	2 years 3 months 18 days
Maximum
Summary of significant accounting policies
Amortization straight-line basis and over useful life	19 years 10 months 24 days
Deferred software costs
Summary of significant accounting policies
Unamortized deferred software costs	$ 6.8	9.3
Amortization of intangible assets	$ 3.6	$ 4.8	$ 4.6
Deferred software costs | Minimum
Summary of significant accounting policies
Amortization straight-line basis and over useful life	3 years
Deferred software costs | Maximum
Summary of significant accounting policies
Amortization straight-line basis and over useful life	5 years

Summary of significant accoun_5

Summary of significant accounting policies - Share-based compensation (Details)	12 Months Ended
	Dec. 31, 2019
2016 Long Term Incentive Plan
Summary of significant accounting policies
Vesting period	2 years
2018 Omnibus plan
Summary of significant accounting policies
Vesting period	3 years

Summary of significant accoun_6

Summary of significant accounting policies - Foreign currency exchange (Details) $ in Millions	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Summary of significant accounting policies
Net unrealized foreign currency translation losses	$ 237.5	$ 202.4
Swedish kronor
Summary of significant accounting policies
Currency Closing Rate	9.3210	8.9397
British pound
Summary of significant accounting policies
Currency Closing Rate	0.7568	0.7850
Euro
Summary of significant accounting policies
Currency Closing Rate	0.8912	0.8734
Canadian dollar
Summary of significant accounting policies
Currency Closing Rate	1.3003	1.3614

Summary of significant accoun_7

Summary of significant accounting policies - Recent adopted changes in accouting principle and Recent accounting pronouncements (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019
Summary of significant accounting policies
Lease liabilities	$ 29.3
Right-of-use assets	$ 27.4
ASU 2016-02
Summary of significant accounting policies
Lease liabilities		$ 36.8
Right-of-use assets		$ 34.4

Significant transactions - East

Significant transactions - Easterly Acquisition Corp., WRM America Indemnity Company, Inc. and The Phoenix Holdings Ltd. (Details) $ / shares in Units, $ in Millions	Nov. 05, 2018USD ($)$ / sharesemployee1shares	Aug. 22, 2018shares	Aug. 16, 2018USD ($)	Jul. 02, 2018USD ($)	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)shares	Nov. 16, 2018USD ($)	Nov. 02, 2018USD ($)	Sep. 30, 2018$ / shares
Significant transactions
Value of shares redeemed	$ 164
Shares issued (in shares) | shares					148,090	4,670,531	0
Total share-based compensation expense - pre-tax					$ 4.7	$ 2.5	$ 0
Stock redeemed (in shares) | shares	9,519,280				0	9,519,280	0
ESPP
Significant transactions
Minimum number of shares to be purchased (in shares) | shares		100
Maximum number of shares to be purchased (in shares) | shares		1,000
Preference Share Investors | Private Placement | Series B preference shares
Significant transactions
Share subscriptions (in shares) | shares	11,901,670
The Phoenix
Significant transactions
Charge on termination of share repurchase agreement				$ 4.5
Merger Agreement
Significant transactions
Gross proceeds	$ 226.1
Proceeds from merger, private placement and employee stock purchase plan	$ 268
Merger Agreement | Private Placement
Significant transactions
Number of times of diluted book value per share, exchange price of share	1.05
Adjusted diluted book value per share (in dollars per share) | $ / shares	17.22447
Merger Agreement | ESPP
Significant transactions
Number of times of diluted book value per share, exchange price of share	1.05
Minimum number of shares to be purchased (in shares) | shares	100
Maximum number of shares to be purchased (in shares) | shares	1,000
Loan repayment term	2 years
Number of employees that purchased shares | employee1	405
Number of common shares purchased (in shares) | shares	149,236
Total share-based compensation expense - pre-tax	$ 2.6
Merger Agreement | CM Bermuda
Significant transactions
Adjustment to consideration payable								$ 1.6
Merger related contractual costs	9
Merger related legal, advisory and other costs	$ 7.1
Merger Agreement | CM Bermuda | Common shares
Significant transactions
Reported book value per share (in dollars per share) | $ / shares										$ 16.44
Subscription Agreement | Preference Share Investors | Private Placement
Significant transactions
Warrants received (in shares) | shares	5,418,434
Exercisable period of warrants	5 years
Strike price as a percentage of the per share purchase price	125.00%
Warrant strike price per share (in dollars per share) | $ / shares	$ 21.53
Cost value of warrants	$ 9.6
Stock issuance costs	$ 2
Subscription Agreement | Preference Share Investors | Private Placement | Series B preference shares
Significant transactions
Share subscriptions (in shares) | shares	11,901,670
Value of share subscriptions	$ 195.8
Subscription Agreement | Preference Share Investors | Private Placement | Series B preference shares | Common shares
Significant transactions
Share subscriptions (in shares) | shares	1,225,954
Value of share subscriptions	$ 20.8
Redemption Agreement | CM Bermuda | Common shares
Significant transactions
Value of shares redeemed	$ 164
Stock redeemed (in shares) | shares	9,519,280
Share price (in dollars per share) | $ / shares	$ 17.22447
Redemption Agreement | IMGAH
Significant transactions
Redemption amount of preference shares	$ 95
Easterly | Merger Agreement
Significant transactions
Public shares held by Easterly's public stockholders in trust	$ 39.3								$ 149
Shares issued (in shares) | shares	2,280,241
Issuance of converted warrants (in shares) | shares	6,088,535
Easterly | Merger Agreement | Common shares
Significant transactions
Number of times of diluted book value per share, exchange price of share	1.05
Exchange ratio	0.609
Value of shares redeemed	$ 109.7
WRM America Indemnity Company, Inc.
Significant transactions
Percentage of ownership interest acquired			100.00%
Consideration			$ 16.9
Acquisition of intangible assets			$ 3.1
For the first 100 shares | ESPP
Significant transactions
Purchase price of common shares as a percentage on its market value		85.00%
For the first 100 shares | Merger Agreement | ESPP
Significant transactions
Purchase price of common shares as a percentage on its market value	85.00%
For the next 900 shares | ESPP
Significant transactions
Purchase price of common shares as a percentage on its market value		100.00%
For the next 900 shares | Merger Agreement | ESPP
Significant transactions
Purchase price of common shares as a percentage on its market value	100.00%

Significant transactions - IMG

Significant transactions - IMG Acquisition (Details) - USD ($) $ in Millions	May 26, 2017	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liabilities assumed
Goodwill		$ 400.8				$ 400.6				$ 400.8	$ 400.6	$ 401
Payment of contingent consideration										6.9	4.4	30.6
Revaluation of contingent consideration										(6.3)	9.6	48.8
Gross written premiums										1,902.7	1,821	1,439.3
Revenues		352	$ 487.4	$ 441	$ 439.7	336.8	$ 351.7	$ 441.8	$ 327.5	1,720.1	1,457.8	1,134.1
Net income										(47.3)	(18.1)	(150)
IMG
Business combination
Percentage of ownership interest acquired	100.00%
Earnout	$ 50
Purchase price
Cash paid	250.8
Series A redeemable preference shares	100
Contingent consideration	43.1	$ 18.4				$ 19.9				18.4	19.9
Total enterprise value	393.9
Less: Debt assumed	(129.5)
Total purchase price	264.4
Assets acquired
Total investments	41
Cash	10.5
Accrued investment income	0.2
Insurance and reinsurance premiums receivable	1.6
Deferred acquisition costs	2.9
Other assets	12.9
Total assets acquired	214.1
Liabilities assumed
Loss and loss adjustment expense reserves	14.3
Unearned insurance and reinsurance premiums	9.8
Deferred tax liability	55.9
Debt	129.5
Other liabilities	18.2
Total liabilities assumed	227.7
Net assets acquired	(13.6)
Goodwill	278
Goodwill recognized is expected to be deductible for income tax purposes	0
Payment of contingent consideration										6.9	3.5
Revaluation of contingent consideration										(5.5)	$ 6.1	$ 13.6
Gross written premiums										$ 163
Gross written premiums (in percent)										9.00%	7.00%	11.00%
Revenues												$ 79.6
Net income												$ 13.3
IMG | Trade Names
Assets acquired
Intangible asset – trade names	27
IMG | Distribution relationships
Assets acquired
Intangible asset	$ 91
Intangible asset useful life	13 years
IMG | Customer relationships
Assets acquired
Intangible asset	$ 17
Intangible asset useful life	12 years 6 months
IMG | Technology
Assets acquired
Intangible asset	$ 10
Intangible asset useful life	5 years
IMG | Certus
Business combination
Secured promissory note issued	$ 9

Significant transactions - IM_2

Significant transactions - IMG Acquisition - Series A Redeemable Preference Shares (Details) - IMG - Series A redeemable preference shares - USD ($) $ / shares in Units, $ in Millions	Nov. 05, 2018	May 26, 2017
Temporary Equity [Line Items]
Redeemable preferred shares authorized (in shares)		150,000
Redeemable preferred shares issued as a consideration (in shares)		100,000
Redeemable preference share liquidation preference per share (in dollars per share)		$ 1,000
Maximum redeemable preferred shares available pursuant to earnout (in shares)		50,000
Redemption of redeemable preference shares in cash	$ 95

Significant transactions - IM_3

Significant transactions - IMG Acquisition - Supplemental Pro Forma Information (Details) - IMG - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Supplemental Pro Forma Information
Total revenues	$ 1,176.8	$ 1,096
Net income	$ (173.2)	$ (4.6)

Significant transactions - Arma

Significant transactions - Armada Acquisition (Details) - USD ($) $ in Millions	Apr. 03, 2017	Dec. 31, 2017	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liabilities assumed
Goodwill		$ 401	$ 400.8				$ 400.6				$ 400.8	$ 400.6	$ 401
Earnout payment											6.9	4.4	30.6
Revaluation of contingent consideration											(6.3)	9.6	48.8
Revenues			352	$ 487.4	$ 441	$ 439.7	336.8	$ 351.7	$ 441.8	$ 327.5	1,720.1	1,457.8	1,134.1
Net income											$ (47.3)	(18.1)	(150)
Maximum
Assets acquired
Intangible asset useful life											19 years 10 months 24 days
Armada
Business combination
Percentage of ownership interest acquired	100.00%
Purchase price
Cash paid	$ 123.4
Contingent consideration	79.1	$ 13.3	$ 9.7				$ 8.9				$ 9.7	8.9	13.3
Total purchase price	202.5
Assets acquired
Restricted cash	10.4
Other assets	1.2
Total assets acquired	93.1
Liabilities assumed
Other liabilities	13.3
Total liabilities assumed	13.3
Net assets acquired	79.8
Goodwill	122.7
Earnout payment percentage		82.00%
Earnout payment		$ 30.6									0.9
Revaluation of contingent consideration											$ (0.8)	$ 3.5	35.2
Revenues													24.7
Net income													$ 9.7
Armada | Distribution relationships
Assets acquired
Intangible asset	$ 60
Intangible asset useful life	22 years 6 months
Armada | Customer relationships
Assets acquired
Intangible asset	$ 16
Intangible asset useful life	7 years 6 months
Armada | Technology
Assets acquired
Intangible asset	$ 5.5
Intangible asset useful life	9 years
First 50% acquisition of Armada
Purchase price
Total purchase price	$ 123.4
Remaining 50% acquisition of Armada
Purchase price
Contingent consideration	79.1
Remaining 50% acquisition of Armada | Maximum
Business combination
Earnout	$ 125
Remaining 50% of Armada
Business combination
Period of contingent earn-out mechanism on which the redemption price is based	3 years

Significant transactions - Ar_2

Significant transactions - Armada Acquisition - Supplemental Pro Forma Information (Details) - Armada - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Supplemental Pro Forma Information
Total revenues	$ 1,144.6	$ 1,032.6
Net income	$ (155.1)	$ 45.9

Segment information (Details)

Segment information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)segmentproduct	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Segment information
Number of reportable segments | segment	4
Number of core products | product	4
Gross written premiums	$ 1,902.7	$ 1,821	$ 1,439.3
Net written premiums	1,502.6	1,357.1	1,090.2
Net earned insurance and reinsurance premiums	1,441.6	1,262.3	1,035.3
Loss and allocated LAE	(1,127.4)	(863.1)	(785.1)
Insurance and reinsurance acquisition expenses	(288.7)	(255.4)	(197.2)
Technical profit (loss)	25.5	143.8	53
Unallocated LAE	(42.9)	(36.9)	(26.1)
Other underwriting expenses	(138.2)	(146.2)	(106.1)
Underwriting (loss) income	(155.6)	(39.3)	(79.2)
Service fee revenue	74.6	71	23
General and administrative expenses	(109.8)	(77.9)	(91.9)
Underwriting (loss) income, including net service fee income	(151.6)	(25)	(105)
Net investment income	84.7	71.4	56.8
Net realized investment gains (losses)	56.7	2.3	(27.2)
Net unrealized investment gains (losses)	80.6	(23.2)	(10.5)
Net foreign exchange gains	7.7	22.7	9.2
Revaluation of contingent consideration	(6.3)	9.6	48.8
Other revenue	(19.5)	41.7	(1.3)
General and administrative expenses	(39.2)	(21.2)	(43.1)
Intangible asset amortization expenses	(15.8)	(15.8)	(10.2)
Impairment of intangible assets	0	(8)	(5)
Interest expense on debt	(31)	(30.8)	(22.4)
Pre-tax (loss) income	$ (33.7)	$ 23.7	$ (109.9)
Underwriting Ratios
Loss ratio	81.20%	71.30%	78.40%
Acquisition expense ratio	20.00%	20.20%	19.00%
Other underwriting expense ratio	9.60%	11.60%	10.20%
Combined ratio	110.80%	103.10%	107.60%
Goodwill and intangible assets	$ 580.6	$ 596.2	$ 617.3
Managing general underwriters
Segment information
Unallocated LAE	0	0	0
Other underwriting expenses	0	0	0
General and administrative expenses	(70.6)	(56.7)	(48.8)
Corporate Elimination
Segment information
Gross written premiums	0	0	0
Net written premiums	0	0	0
Net earned insurance and reinsurance premiums	0	0	0
Loss and allocated LAE	0	0	0
Insurance and reinsurance acquisition expenses	46.1	43.7	42.9
Technical profit (loss)	46.1	43.7	42.9
Unallocated LAE	(13.8)	(13)	0
Other underwriting expenses	(13.5)	(16.1)	0
Underwriting (loss) income	18.8	14.6	42.9
Service fee revenue	(49.6)	(44.7)	(42.9)
Underwriting (loss) income, including net service fee income	0	0	0
Underwriting Ratios
Goodwill and intangible assets	0	0	0
Corporate Elimination | Managing general underwriters
Segment information
Unallocated LAE	17.3	14	0
Other underwriting expenses	13.5	16.1	0
General and administrative expenses	0	0	0
Global Reinsurance
Segment information
Net written premiums	987.9	934.6	749.2
Global Reinsurance | Reportable segments
Segment information
Gross written premiums	1,238.8	1,268.1	950.2
Net written premiums	987.9	934.6	749.2
Net earned insurance and reinsurance premiums	966.5	870.5	727.6
Loss and allocated LAE	(830.6)	(658.8)	(599.1)
Insurance and reinsurance acquisition expenses	(199.7)	(185.3)	(154)
Technical profit (loss)	(63.8)	26.4	(25.5)
Unallocated LAE	(20.3)	(16.4)	(18.2)
Other underwriting expenses	(84.5)	(87.7)	(79.8)
Underwriting (loss) income	(168.6)	(77.7)	(123.5)
Service fee revenue	0	0	0
Underwriting (loss) income, including net service fee income	$ (168.6)	$ (77.7)	$ (123.5)
Underwriting Ratios
Loss ratio	88.00%	77.60%	84.80%
Acquisition expense ratio	20.70%	21.30%	21.20%
Other underwriting expense ratio	8.70%	10.10%	11.00%
Combined ratio	117.40%	109.00%	117.00%
Goodwill and intangible assets	$ 0	$ 0	$ 0
Global Reinsurance | Reportable segments | Managing general underwriters
Segment information
Unallocated LAE	0	0	0
Other underwriting expenses	0	0	0
General and administrative expenses	0	0	0
Global A&H
Segment information
Net written premiums	458.1	379.8	341.5
Global A&H | Reportable segments
Segment information
Gross written premiums	593.4	500.6	494.6
Net written premiums	458.1	379.8	341.5
Net earned insurance and reinsurance premiums	443.3	357.6	306.8
Loss and allocated LAE	(271.3)	(189)	(175)
Insurance and reinsurance acquisition expenses	(125.8)	(109.7)	(89.6)
Technical profit (loss)	46.2	58.9	42.2
Unallocated LAE	(7.4)	(5.9)	(4.8)
Other underwriting expenses	(23.7)	(27.4)	(23.4)
Underwriting (loss) income	15.1	25.6	14
Service fee revenue	124.2	115.7	65.9
Underwriting (loss) income, including net service fee income	$ 41.6	$ 57.6	$ 35.1
Underwriting Ratios
Loss ratio	62.90%	54.50%	58.60%
Acquisition expense ratio	28.40%	30.70%	29.20%
Other underwriting expense ratio	5.30%	7.70%	7.60%
Combined ratio	96.60%	92.90%	95.40%
Goodwill and intangible assets	$ 572.5	$ 588.1	$ 612.3
Global A&H | Reportable segments | Managing general underwriters
Segment information
Unallocated LAE	(17.3)	(14)	0
Other underwriting expenses	(13.5)	(16.1)	0
General and administrative expenses	(66.9)	(53.6)	(44.8)
U.S. Specialty
Segment information
Net written premiums	54.1	13.1	0
U.S. Specialty | Reportable segments
Segment information
Gross written premiums	66.3	19.4	0
Net written premiums	54.1	13.1	0
Net earned insurance and reinsurance premiums	29.6	5	0
Loss and allocated LAE	(23.7)	(2.3)	0
Insurance and reinsurance acquisition expenses	(6.4)	(1.3)	0
Technical profit (loss)	(0.5)	1.4	0
Unallocated LAE	(0.4)	0	0
Other underwriting expenses	(10.6)	(8.7)	0
Underwriting (loss) income	(11.5)	(7.3)	0
Service fee revenue	0	0	0
Underwriting (loss) income, including net service fee income	$ (11.5)	$ (7.3)	$ 0
Underwriting Ratios
Loss ratio	81.40%	46.00%	0.00%
Acquisition expense ratio	21.60%	26.00%	0.00%
Other underwriting expense ratio	35.80%	174.00%	0.00%
Combined ratio	138.80%	246.00%	0.00%
Goodwill and intangible assets	$ 0	$ 0	$ 0
U.S. Specialty | Reportable segments | Managing general underwriters
Segment information
Unallocated LAE	0	0	0
Other underwriting expenses	0	0	0
General and administrative expenses	0	0	0
Runoff & Other
Segment information
Net written premiums	2.5	29.6	(0.5)
Runoff & Other | Reportable segments
Segment information
Gross written premiums	4.2	32.9	(5.5)
Net written premiums	2.5	29.6	(0.5)
Net earned insurance and reinsurance premiums	2.2	29.2	0.9
Loss and allocated LAE	(1.8)	(13)	(11)
Insurance and reinsurance acquisition expenses	(2.9)	(2.8)	3.5
Technical profit (loss)	(2.5)	13.4	(6.6)
Unallocated LAE	(1)	(1.6)	(3.1)
Other underwriting expenses	(5.9)	(6.3)	(2.9)
Underwriting (loss) income	(9.4)	5.5	(12.6)
Service fee revenue	0	0	0
Underwriting (loss) income, including net service fee income	(13.1)	2.4	(16.6)
Underwriting Ratios
Goodwill and intangible assets	8.1	8.1	5
Runoff & Other | Reportable segments | Managing general underwriters
Segment information
Unallocated LAE	0	0	0
Other underwriting expenses	0	0	0
General and administrative expenses	$ (3.7)	$ (3.1)	$ (4)
Minimum | Global Reinsurance | Reportable segments
Segment information
Coverage period	60 days
Maximum | Global Reinsurance | Reportable segments
Segment information
Coverage period	120 days

Segment information - Net premi

Segment information - Net premiums written by client location and underwriting location by reportable segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	$ 1,502.6	$ 1,357.1	$ 1,090.2
Client location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	922.3	794.7	563.1
Client location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	268.9	276.5	262.3
Client location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	102.5	103.6	111.4
Client location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	208.9	182.3	153.4
Underwriting location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	249.3	180.1	150.5
Underwriting location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	748.8	692.1	583.3
Underwriting location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	450.9	433.8	315.5
Underwriting location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	53.6	51.1	40.9
Global Reinsurance
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	987.9	934.6	749.2
Global Reinsurance | Client location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	480.2	444.7	279.8
Global Reinsurance | Client location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	245.3	246.1	234.1
Global Reinsurance | Client location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	90	91.1	101.7
Global Reinsurance | Client location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	172.4	152.7	133.6
Global Reinsurance | Underwriting location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	33.4	33.5	53.4
Global Reinsurance | Underwriting location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	488.4	462	386.9
Global Reinsurance | Underwriting location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	413.8	389.1	269.1
Global Reinsurance | Underwriting location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	52.3	50	39.8
Global A&H
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	458.1	379.8	341.5
Global A&H | Client location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	386.2	307.7	284.5
Global A&H | Client location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	23.5	30.4	28.2
Global A&H | Client location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	12.4	12.5	9.5
Global A&H | Client location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	36	29.2	19.3
Global A&H | Underwriting location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	170.3	109.5	98.2
Global A&H | Underwriting location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	249.9	224.9	196.4
Global A&H | Underwriting location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	37.1	44.7	46.4
Global A&H | Underwriting location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0.8	0.7	0.5
U.S. Specialty
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	54.1	13.1	0
U.S. Specialty | Client location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	54.1	13.1	0
U.S. Specialty | Client location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0	0	0
U.S. Specialty | Client location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0	0	0
U.S. Specialty | Client location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0	0	0
U.S. Specialty | Underwriting location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	43.8	7.9	0
U.S. Specialty | Underwriting location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	10.3	5.2	0
U.S. Specialty | Underwriting location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0	0	0
U.S. Specialty | Underwriting location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0	0	0
Runoff & Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	2.5	29.6	(0.5)
Runoff & Other | Client location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	1.8	29.2	(1.2)
Runoff & Other | Client location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0.1	0	0
Runoff & Other | Client location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0.1	0	0.2
Runoff & Other | Client location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0.5	0.4	0.5
Runoff & Other | Underwriting location: United States
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	1.8	29.2	(1.1)
Runoff & Other | Underwriting location: Europe
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0.2	0	0
Runoff & Other | Underwriting location: Canada, the Caribbean, Bermuda and Latin America
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	0	0	0
Runoff & Other | Underwriting location: Asia and Other
Net premiums written by client location and underwriting location by reportable segment
Net written premiums	$ 0.5	$ 0.4	$ 0.6

Reserves for unpaid losses an_3

Reserves for unpaid losses and loss adjustment expenses - Reserve Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of the loss and LAE reserve activities
Gross beginning balance	$ 2,016.7	$ 1,898.5	$ 1,620.1
Less beginning reinsurance recoverable on unpaid losses	(350.2)	(319.7)	(291.5)
Net loss and LAE reserve balance	1,666.5	1,578.8	1,328.6
Loss and LAE reserves acquired	0	0.2	14.3
Losses and LAE incurred relating to:
Current year losses	1,066.5	907.3	811.8
Prior years losses	103.8	(7.3)	(0.6)
Total net incurred losses and LAE	1,170.3	900	811.2
Accretion of fair value adjustment to net loss and LAE reserves	0.1	0.1	0.1
Foreign currency translation adjustment to net loss and LAE reserves	(4.4)	(20.9)	36.8
Loss and LAE paid relating to:
Current year losses	251.3	251.4	222.8
Prior years losses	660	540.3	389.5
Total loss and LAE payments	911.3	791.7	612.3
Net ending balance	1,921.2	1,666.5	1,578.8
Plus ending reinsurance recoverable on unpaid losses	410.3	350.2	319.7
Gross ending balance	$ 2,331.5	$ 2,016.7	$ 1,898.5

Reserves for unpaid losses an_4

Reserves for unpaid losses and loss adjustment expenses - By segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development	$ (103.8)	$ 7.3	$ 0.6
Asbestos losses	0	(6.9)	59
Accretion of fair value adjustment to net loss and LAE reserves	0.1	0.1	0.1
Pre-tax un-accreted adjustment	0.7
Global Reinsurance
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development	(103.6)	(25.3)
Other property
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development		(34.9)
Property Catastrophe Excess
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development		(13.2)
Hurricanes Harvey, Irma and Maria
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development		(21.4)
Global A&H
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development		15
U.S. Specialty
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development			(9.9)
Marine
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development		6.8	(5.4)
Trade credit
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development			(4.2)
Aviation & Space
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development		7.9	(1.7)
Contingency
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development			(0.8)
Casualty
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development	$ (13)
Runoff & Other
Reserves for unpaid losses and loss adjustment expenses
Unfavorable (favorable) loss reserve development		$ 17.6	$ (45.7)

Reserves for unpaid losses an_5

Reserves for unpaid losses and loss adjustment expenses - Asbestos and Environmental Loss and Loss Adjustment Expense Reserve Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract]
Increase (decrease) in asbestos claims reserves		$ (6.9)
Asbestos three year net paid survival ratio	11 years 6 months	10 years 2 months 12 days
Environmental three year net paid survival ratio	4 years	4 years 2 months 12 days
Asbestos, Gross:
Beginning balance, Gross	$ 236.8	$ 259.2	$ 187
Incurred losses and LAE, Gross	0.1	(6.9)	96.9
Paid losses and LAE, Gross	(12.2)	(15.5)	(24.7)
Ending balance, Gross	224.7	236.8	259.2
Asbestos, Net:
Beginning balance, Net	184.4	204.6	166.4
Incurred losses and LAE, Net	0	(6.9)	59
Paid losses and LAE, Net	(11.1)	(13.3)	(20.8)
Ending balance, Net	173.3	184.4	204.6
Environmental Claims, Gross:
Beginning balance, Gross	16.7	16.7	18.5
Incurred losses and LAE, Gross	0.7	4	2.9
Paid losses and LAE, Gross	(2.9)	(4)	(4.7)
Ending balance, Gross	14.5	16.7	16.7
Environmental Claims, Net:
Beginning balance, Net	15.9	16	13.9
Incurred losses and LAE, Net	0.7	4	6.1
Paid losses and LAE, Net	(2.6)	(4.1)	(4)
Ending balance, Net	14	15.9	16
Total asbestos and environmental, Gross:
Beginning balance, Gross	253.4	275.9	205.5
Incurred losses and LAE, Gross	0.8	(3)	99.8
Paid losses and LAE, Gross	(15)	(19.5)	(29.4)
Ending balance, Gross	239.2	253.4	275.9
Total asbestos and environmental, Net:
Beginning balance, Net	200.3	220.6	180.3
Incurred losses and LAE, Net	0.7	(2.9)	65.1
Paid losses and LAE, Net	(13.7)	(17.4)	(24.8)
Ending balance, Net	187.3	200.3	220.6
Net loss reserves by type
Case Reserve	1,030.6	924.5
IBNR Reserve	890.6	742
Loss and loss adjustment expense reserves, net of reinsurance	$ 1,921.2	$ 1,666.5	$ 1,578.8	$ 1,328.6

Reserves for unpaid losses an_6

Reserves for unpaid losses and loss adjustment expenses - Reconciliation of liabilities for unpaid loss and LAE (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	$ 1,880.2
Unallocated LAE	41
Loss and loss adjustment expense reserves, net of reinsurance	1,921.2	$ 1,666.5	$ 1,578.8	$ 1,328.6
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	410.3	350.2	319.7	291.5
Total unpaid loss and LAE reserves	2,331.5	$ 2,016.7	$ 1,898.5	$ 1,620.1
Other property
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	490.7
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	137.3
Property Catastrophe Excess
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	286
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	60
Agriculture
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	68.1
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	2
Global Accident & Health
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	176.9
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	42.9
Aviation & Space
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	109.2
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	40.3
Trade credit
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	46.5
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	10.1
Environmental
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	4.6
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	4.6
Marine
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	52.4
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	8.7
Surety
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	4.9
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	0.5
Contingency
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	8.3
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	2.1
Casualty
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	202
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	1.2
Runoff & Other
Reserves for unpaid losses and loss adjustment expenses
Total unpaid loss and LAE reserves, net of reinsurance	430.6
Reinsurance recoverable on unpaid losses
Total reinsurance recoverable on unpaid losses	100.6
U.S. Specialty
Reinsurance recoverable on unpaid losses
Workers' compensation	19
Accident Year, 2019 | U.S. Specialty
Reinsurance recoverable on unpaid losses
Workers' compensation	$ 17.3

Reserves for unpaid losses an_7

Reserves for unpaid losses and loss adjustment expenses - Claim Development (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other property
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	$ 1,934.5
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	1,447.8
All outstanding liabilities before 2010, net of reinsurance	4
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	490.7
Other property | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	136.3	$ 136.7	$ 137	$ 138.6	$ 139.3	$ 140.2	$ 145.2	$ 144.5	$ 153.2	$ 156.1
Total IBNR liabilities plus expected development on reported claims	1.5
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	131.4	130.5	130.6	130.6	130.1	128	123.2	115.5	88.7	31.4
Other property | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	131.1	131	132.2	132	131.3	133.2	141.2	150.3	162.9
Total IBNR liabilities plus expected development on reported claims	0.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	127.1	126.5	126.8	124.2	121.7	115.7	102.8	79.1	26.6
Other property | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	132	132.6	132.7	134.7	139.4	143.8	148.9	162.1
Total IBNR liabilities plus expected development on reported claims	1.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	126.2	125	124.2	118.9	115.5	107.4	84.7	20
Other property | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	111.4	111.7	112.2	112.5	116	126.8	130
Total IBNR liabilities plus expected development on reported claims	0.7
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	106.3	105.8	105.2	101.9	95.4	71.4	27.2
Other property | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	111.3	112	114.4	114.1	116.6	113.8
Total IBNR liabilities plus expected development on reported claims	0.7
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	106.7	105.9	103.7	95.5	68.9	18.8
Other property | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	134.1	134.4	134.4	132.2	139.7
Total IBNR liabilities plus expected development on reported claims	1.6
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	127.7	123.9	114.3	93	30.8
Other property | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	219.1	218.3	213.7	194.9
Total IBNR liabilities plus expected development on reported claims	1.7
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	197.5	180.6	128	31.2
Other property | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	387.9	369.3	332.7
Total IBNR liabilities plus expected development on reported claims	19.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	298.6	222.4	58.2
Other property | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	326.3	270.8
Total IBNR liabilities plus expected development on reported claims	34
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	180.1	54.8
Other property | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	245
Total IBNR liabilities plus expected development on reported claims	101.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	46.2
Property Catastrophe Excess
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	948.7
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	667.2
All outstanding liabilities before 2010, net of reinsurance	4.5
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	286
Property Catastrophe Excess | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	127.3	121.3	120.7	121.4	121.9	122.8	130.2	131	131	136.1
Total IBNR liabilities plus expected development on reported claims	0.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	119.1	118	117.5	117.5	113.6	111.1	107.6	102.5	90	49.8
Property Catastrophe Excess | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	117.2	117.2	117.1	117.2	118	121.4	142.7	89.7	152.6
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	116.7	116.2	116.1	115.2	114.7	114.4	96	54.7	15.9
Property Catastrophe Excess | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	46.5	45	44.8	49.7	49.2	51.1	57.8	145
Total IBNR liabilities plus expected development on reported claims	0.5
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	46.1	44	42.7	40.9	40	35.4	25.8	2.8
Property Catastrophe Excess | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	71.4	71.8	72.1	72.9	73.5	76.5	70.3
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	68.9	68	66.8	65.5	60.7	48.3	10.9
Property Catastrophe Excess | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	54.8	54.3	54.4	54.3	57	55.4
Total IBNR liabilities plus expected development on reported claims	0.5
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	51.5	49.1	47.4	41.9	35.8	9.2
Property Catastrophe Excess | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	25	25.9	26.9	29.3	27.4
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	22.4	19.9	16.6	9.3	1.8
Property Catastrophe Excess | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	41.2	42.4	47.7	50.4
Total IBNR liabilities plus expected development on reported claims	2.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	37	31.7	25.7	10.4
Property Catastrophe Excess | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	117.4	123.4	105.4
Total IBNR liabilities plus expected development on reported claims	8.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	86.4	67.4	13.2
Property Catastrophe Excess | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	178	160.4
Total IBNR liabilities plus expected development on reported claims	9.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	115.8	2.7
Property Catastrophe Excess | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	169.9
Total IBNR liabilities plus expected development on reported claims	35.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	3.3
Agriculture
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	299.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	231.1
All outstanding liabilities before 2010, net of reinsurance	0
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	68.1
Agriculture | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	10.7	10.7	10.7	10.7	10.7	10.6	10.7	10.9	10.8	12.8
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	10.7	10.6	10.6	10.6	10.6	10.6	10.6	10.8	10.6	0.5
Agriculture | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	21.6	21.6	21.6	21.6	21.7	21.7	21.7	21.5	21.5
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	21.6	21.6	21.6	21.6	21.6	21.6	21.6	21.3	1
Agriculture | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	46.9	47	47	47	45.8	45.9	45.9	41.1
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	46.9	46.9	46.9	46.9	45.6	45.7	45.4	19
Agriculture | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	12.8	12.8	12.8	13	12.9	10.8	9.1
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	12.8	12.8	12.8	13	12.8	10.6	7.1
Agriculture | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	9	8.9	8.9	8.5	8.2	9.7
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	9	8.9	8.8	8.8	8.1	6.5
Agriculture | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	9.4	9.4	9.4	9.1	7
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	9.2	9.2	8.9	7.7	1.5
Agriculture | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	29.6	29.5	30.5	33.1
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	29.5	29.2	27.8	10
Agriculture | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	46.1	46.8	50.2
Total IBNR liabilities plus expected development on reported claims	(0.4)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	46.1	43.3	9
Agriculture | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	41.3	39.1
Total IBNR liabilities plus expected development on reported claims	3.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	35.8	2.6
Agriculture | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	71.8
Total IBNR liabilities plus expected development on reported claims	46
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	9.5
Global Accident & Health
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	1,654.5
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	1,482.4
All outstanding liabilities before 2010, net of reinsurance	4.8
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	176.9
Global Accident & Health | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	121.7	121.7	121.8	121.9	121.8	121.8	122.1	123	125.4	118.4
Total IBNR liabilities plus expected development on reported claims	(0.1)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	122	121.9	121.9	121.9	121.8	121.7	121.4	119.2	102.2	53.1
Global Accident & Health | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	171.5	171.4	171.4	171.6	171.6	171.6	172.3	176.7	161.3
Total IBNR liabilities plus expected development on reported claims	0.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	171.7	171.6	171.6	171.6	171.5	171.1	166.1	139.2	71.2
Global Accident & Health | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	146.5	146.6	146.7	146.9	147.1	147.8	160.1	163.4
Total IBNR liabilities plus expected development on reported claims	(0.1)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	146.6	146.6	146.6	146.6	146.5	146.1	136.1	72.2
Global Accident & Health | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	116.8	116.9	117.7	118.3	118.8	123.3	125.5
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	116.3	116.3	116.8	115.6	114.2	103.7	54.4
Global Accident & Health | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	129.4	129.4	130.3	130.3	131.9	130.8
Total IBNR liabilities plus expected development on reported claims	0.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	127	126.3	126.3	124.6	111.1	59.2
Global Accident & Health | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	143.8	144.2	145.5	148.8	152.7
Total IBNR liabilities plus expected development on reported claims	0.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	143.1	142.8	141.2	129.8	75.4
Global Accident & Health | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	181.5	183	187.1	173.3
Total IBNR liabilities plus expected development on reported claims	2.5
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	177.9	176	164.4	98.2
Global Accident & Health | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	165.9	172.6	176.4
Total IBNR liabilities plus expected development on reported claims	1.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	163	150.7	61.5
Global Accident & Health | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	205.5	198.3
Total IBNR liabilities plus expected development on reported claims	13.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	186.1	89
Global Accident & Health | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	271.9
Total IBNR liabilities plus expected development on reported claims	89.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	128.7
Aviation & Space
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	399.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	296.4
All outstanding liabilities before 2010, net of reinsurance	6.2
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	109.2
Aviation & Space | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	41.4	41.6	41.3	41.8	42	42.9	44.4	46.9	47.2	42.4
Total IBNR liabilities plus expected development on reported claims	(0.4)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	41	40.7	39.6	39.4	38.5	37.5	36	31.3	22	12
Aviation & Space | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	35.2	35	35.7	34.4	34.6	35.8	37.8	42.2	46.8
Total IBNR liabilities plus expected development on reported claims	(0.2)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	35.5	34.6	34.7	34	32.6	31.4	28.5	22.6	10.1
Aviation & Space | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	28.5	29.5	29.5	28.4	28.2	30.2	34.3	35.6
Total IBNR liabilities plus expected development on reported claims	(0.3)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	28.4	28.7	28.2	27.3	24.6	22.6	18.4	7.6
Aviation & Space | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	33	32.9	32.9	31.9	33.3	36.4	40.5
Total IBNR liabilities plus expected development on reported claims	(0.5)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	30.5	29.1	28.4	26.6	24	19.8	13.5
Aviation & Space | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	33.9	35.9	35.8	36.6	39.9	37.3
Total IBNR liabilities plus expected development on reported claims	(3)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	28.8	28.1	26.1	23.5	17.8	8
Aviation & Space | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	36.5	37.1	38.1	34	37.6
Total IBNR liabilities plus expected development on reported claims	(0.9)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	34.9	33.4	27	21	10.5
Aviation & Space | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	35.8	33.5	32.5	32
Total IBNR liabilities plus expected development on reported claims	2.9
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	29.1	26.7	19.6	7.8
Aviation & Space | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	44.1	42.8	33.8
Total IBNR liabilities plus expected development on reported claims	1.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	32.5	23.6	9
Aviation & Space | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	50.5	47.9
Total IBNR liabilities plus expected development on reported claims	6.7
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	27.4	14.3
Aviation & Space | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	60.5
Total IBNR liabilities plus expected development on reported claims	39.9
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	8.3
Trade credit
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	216.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	174.1
All outstanding liabilities before 2010, net of reinsurance				4.2
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	46.5
Trade credit | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	9.4	9.6	9.5	9.4	9.4	9.6	9.5	9.3	12	13.7
Total IBNR liabilities plus expected development on reported claims	(0.3)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	9.3	9.3	9.2	9.1	8.9	8.8	8.4	7.6	5.1	1.7
Trade credit | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	25.4	25.6	25.8	25.8	26.5	26.5	26.7	28.2	28.4
Total IBNR liabilities plus expected development on reported claims	(0.3)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	25.3	25.3	25.2	25.5	25.2	24.3	23.1	17.1	6.4
Trade credit | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	31.3	31.7	32	32	32.4	32.2	33.9	33.6
Total IBNR liabilities plus expected development on reported claims	(0.2)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	31.2	31.3	31.3	31.5	31.1	30.4	26.2	14.4
Trade credit | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	27.3	27	27.5	26.9	27.1	27.9	28.8
Total IBNR liabilities plus expected development on reported claims	0.6
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	24.1	24	23.9	23.5	22.3	19.4	11.3
Trade credit | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	20.5	20.6	20.9	23	22.2	22.2
Total IBNR liabilities plus expected development on reported claims	0.5
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	19.3	19.3	18.8	17.4	13.4	7.7
Trade credit | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	17.3	18.1	18.8	19.3	19.7
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	16.3	16.4	15.4	12	4.5
Trade credit | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	11.4	12.3	12.9	14.9
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	11	10.4	8.8	4.5
Trade credit | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	18.9	19.8	18.8
Total IBNR liabilities plus expected development on reported claims	2.5
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	12.6	8.8	3
Trade credit | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	24.8	24.6
Total IBNR liabilities plus expected development on reported claims	4.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	16.2	7.6
Trade credit | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	30.1
Total IBNR liabilities plus expected development on reported claims	13.8
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	8.8
Environmental
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	4.7
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.1
All outstanding liabilities before 2010, net of reinsurance				0
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	4.6
Environmental | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0	0	0	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0	0	0	0	0
Environmental | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0	0	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0	0	0	0
Environmental | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0	0	0
Environmental | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0	0
Environmental | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0	0
Environmental | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0	0
Environmental | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0	0
Environmental | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0
Environmental | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.1	0.4
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0
Environmental | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	4.6
Total IBNR liabilities plus expected development on reported claims	0.8
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.1
Marine
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	270.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	218.8
All outstanding liabilities before 2010, net of reinsurance				0.8
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	52.4
Marine | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	30	30	30.2	30.4	31.7	32.1	30.7	31	33.3	30.5
Total IBNR liabilities plus expected development on reported claims	0.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	28.8	28.7	28.5	27.5	26.7	21.3	19.5	17.1	12.2	5
Marine | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	32.3	31.6	31.7	31.6	32.2	31.2	30.7	33	36.7
Total IBNR liabilities plus expected development on reported claims	(0.3)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	30.4	29.7	29.3	28.8	28	25.2	21.8	14.4	4.4
Marine | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	36.2	36.3	36.8	37.9	37.5	36	33.4	27.2
Total IBNR liabilities plus expected development on reported claims	1.7
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	33.8	32.6	31	29.1	27.1	24.2	14.8	5.2
Marine | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	18.1	18	18	18.2	19.2	20.5	23.2
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	15.1	14.9	14.4	14	12.6	9.3	2.9
Marine | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	18.4	17.8	18.2	19.4	21.4	23.2
Total IBNR liabilities plus expected development on reported claims	(0.3)
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	15.8	15.7	15	13.6	10.2	4.1
Marine | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	28.3	28.4	28.9	31	29.3
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	26.9	25.9	21.5	11.6	4.3
Marine | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	28.3	28.3	29.1	28.2
Total IBNR liabilities plus expected development on reported claims	0.8
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	24.2	21.3	17.4	6.8
Marine | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	34.6	34.8	37.2
Total IBNR liabilities plus expected development on reported claims	2.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	26.1	18.1	7.2
Marine | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	25.4	23.1
Total IBNR liabilities plus expected development on reported claims	3.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	13.9	5.2
Marine | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	18.8
Total IBNR liabilities plus expected development on reported claims	6.7
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	3.8
Surety
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	6.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	3.1
All outstanding liabilities before 2010, net of reinsurance				1.9
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	4.9
Surety | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.1	0.1	0.1	0.3	0.3	0.4	0.4	0.2	0.1	0.1
Total IBNR liabilities plus expected development on reported claims	0.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0
Surety | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.2	0.2	0.2	0.4	0.4	0.6	0.6	0.5	0.3
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.1
Surety | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.3	0.3	0.3	0.4	0.4	0.6	0.6	0.5
Total IBNR liabilities plus expected development on reported claims	0.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.2	0.2	0.2	0.2	0.2	0.1	0.1	0.1
Surety | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.8	0.9	0.7	0.5	0.7	0.9	1
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.6	0.6	0.5	0.3	0.2	0.1	0.1
Surety | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	1.1	1.3	1.1	1	1.1	1.2
Total IBNR liabilities plus expected development on reported claims	0.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	1.2	0.9	0.7	0.4	0.2	0
Surety | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.7	0.8	1	1.2	1
Total IBNR liabilities plus expected development on reported claims	0.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.5	0.4	0.3	0.2	0
Surety | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.3	0.5	0	0
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.3	0.3	0	0
Surety | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.4	0.4	0.6
Total IBNR liabilities plus expected development on reported claims	0.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0	0
Surety | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	1	0.9
Total IBNR liabilities plus expected development on reported claims	0.9
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0	0
Surety | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	1.2
Total IBNR liabilities plus expected development on reported claims	1.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0
Contingency
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	76.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	67.9
All outstanding liabilities before 2010, net of reinsurance				(0.1)
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	8.3
Contingency | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	4.1	4.1	4.1	4.1	4.1	4.2	4.4	4.5	5.9	5.5
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	4.1	4.1	4.1	4.1	4	3.9	3.5	3.5	3.4	1.9
Contingency | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	6.6	6.6	6.6	6.6	6.5	6.5	6.6	7.1	7.7
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	6.5	6.5	6.5	6.5	6.5	6.4	6.4	5.7	2
Contingency | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	8	8.1	8.1	8.3	8.5	8.7	8.6	9.6
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	8.1	8.1	8.1	8.3	8.4	8.5	7.1	5.3
Contingency | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	3.6	3.6	3.6	3.6	3.6	4.2	5.5
Total IBNR liabilities plus expected development on reported claims	0.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	3.3	3.3	3.3	3.3	3.3	3	1.8
Contingency | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	4.7	4.7	4.7	5.2	7	4.2
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	4.5	4.5	4.5	4.4	3.7	1.6
Contingency | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	8.9	8.9	9	9.6	9.9
Total IBNR liabilities plus expected development on reported claims	0.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	8.7	7.8	7.8	7.1	2.8
Contingency | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	17.3	17	18	17.6
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	16.8	16	15.2	11.6
Contingency | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	11.2	10.6	9.7
Total IBNR liabilities plus expected development on reported claims	0.8
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	9.4	7	3
Contingency | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	9	9.4
Total IBNR liabilities plus expected development on reported claims	1.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	6.2	1.8
Contingency | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	3
Total IBNR liabilities plus expected development on reported claims	1.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.3
Casualty
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	220.8
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	22.7
All outstanding liabilities before 2010, net of reinsurance				3.9
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	202
Casualty | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.5	0.5	0.6	0.6	0.9	1.1	1.4	1.6	1.5	1.7
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.3	0.4	0.4	0.3	0.4	0.2	0.1	0.1	0	0
Casualty | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.2	0.2	0.2	0.2	0.3	0.3	0.4	0.4	0.5
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.2	0.2	0.2	0.2	0.2	0.1	0.1	0	0
Casualty | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.4	0.5	0.5	0.5	0.5	0.4	0.2	0.2
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.3	0.2	0.2	0.1	0.2	0.1	0	0
Casualty | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.5	0.5	0.5	0.4	0.4	0.4	0.4
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.5	0.4	0.4	0.3	0.2	0.1	0.1
Casualty | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.6	0.5	0.5	0.5	0.4	0.4
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.5	0.4	0.4	0.4	0.2	0.1
Casualty | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.6	0.5	0.6	0.8	0.5
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.4	0.4	0.4	0.4	0.2
Casualty | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.1	0.3	0.3	0.2
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.2	0.1	0.1	0
Casualty | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	12.5	9.7	9.7
Total IBNR liabilities plus expected development on reported claims	7.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	1.6	0.6	0
Casualty | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	63.5	53.4
Total IBNR liabilities plus expected development on reported claims	41.3
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	8.1	2
Casualty | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	141.9
Total IBNR liabilities plus expected development on reported claims	116
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	10.6
Runoff & Other
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	579.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	545.8
All outstanding liabilities before 2010, net of reinsurance				397.2
Liabilities for loss and allocated loss adjustment expenses, net of reinsurance	430.6
Runoff & Other | Accident Year, 2010
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	291.5	287	287.7	287.6	286.6	285.1	284	283.4	283.2	282.3
Total IBNR liabilities plus expected development on reported claims	5.4
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	281.3	280.9	280.2	278.3	276.4	272.8	269.6	265.5	263.2	$ 160.1
Runoff & Other | Accident Year, 2011
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	223.9	225	225.4	225.9	225	224.5	223.9	222.8	221.5
Total IBNR liabilities plus expected development on reported claims	2.9
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	219.3	218.8	218.2	216.7	214.7	213	211.2	209	$ 206.9
Runoff & Other | Accident Year, 2012
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	3.7	3.9	4.1	4.1	4.2	4.1	4	3.6
Total IBNR liabilities plus expected development on reported claims	1.1
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	2.7	2.5	2.4	2.4	2.2	1.8	1.3	$ 0.3
Runoff & Other | Accident Year, 2013
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.4	0.2	0.1	0.2	0.2	0.2	1.2
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.2	0.1	0.1	0.1	0.1	0.1	$ 0.7
Runoff & Other | Accident Year, 2014
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.5	0.5	0.4	0.3	0.2	0.2
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.5	0.3	0.2	0.1	0	$ 0
Runoff & Other | Accident Year, 2015
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	18	18	17.5	15.7	9.5
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	17.3	16.6	15.3	10	$ 5.2
Runoff & Other | Accident Year, 2016
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	11.6	11.7	12.1	11.8
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	11.3	11	10.1	$ 6.2
Runoff & Other | Accident Year, 2017
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.7	0.7	0.6
Total IBNR liabilities plus expected development on reported claims	0
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	0.6	0.5	$ 0.4
Runoff & Other | Accident Year, 2018
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	28.6	30.3
Total IBNR liabilities plus expected development on reported claims	2.6
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	12.6	$ 7.9
Runoff & Other | Accident Year, 2019
Reserves for unpaid losses and loss adjustment expenses
Incurred losses and allocated loss adjustment expenses, net of reinsurance	0.3
Total IBNR liabilities plus expected development on reported claims	0.2
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance	$ 0

Reserves for unpaid losses an_8

Reserves for unpaid losses and loss adjustment expenses - Average Annual Percentage Payout of Incurred Losses and Allocated LAE by Age, Net of Reinsurance (Details)	Dec. 31, 2019
Other property
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	17.80%
Year 2	42.50%
Year 3	20.10%
Year 4	7.20%
Year 5	3.10%
Year 6	1.80%
Year 7	0.90%
Year 8	0.30%
Year 9	0.10%
Year 10	0.70%
Property Catastrophe Excess
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	12.70%
Year 2	45.70%
Year 3	19.00%
Year 4	9.80%
Year 5	2.30%
Year 6	2.00%
Year 7	1.90%
Year 8	0.70%
Year 9	0.50%
Year 10	0.80%
Agriculture
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	22.30%
Year 2	67.50%
Year 3	4.80%
Year 4	0.40%
Year 5	1.10%
Year 6	0.10%
Year 7	0.10%
Year 8	0.00%
Year 9	0.00%
Year 10	0.00%
Global Accident & Health
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	46.10%
Year 2	42.60%
Year 3	9.60%
Year 4	1.40%
Year 5	0.30%
Year 6	0.10%
Year 7	0.00%
Year 8	0.00%
Year 9	0.10%
Year 10	0.00%
Aviation & Space
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	25.30%
Year 2	29.40%
Year 3	17.80%
Year 4	9.60%
Year 5	5.20%
Year 6	2.70%
Year 7	2.50%
Year 8	(0.30%)
Year 9	2.60%
Year 10	0.40%
Trade credit
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	32.30%
Year 2	35.40%
Year 3	17.60%
Year 4	4.80%
Year 5	1.80%
Year 6	0.30%
Year 7	0.10%
Year 8	0.10%
Year 9	0.30%
Year 10	(0.20%)
Environmental
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	1.00%
Year 2	6.30%
Year 3	0.00%
Year 4	0.00%
Year 5	0.00%
Year 6	0.00%
Year 7	0.00%
Year 8	0.00%
Year 9	0.00%
Year 10	0.00%
Marine
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	18.10%
Year 2	30.50%
Year 3	22.20%
Year 4	9.70%
Year 5	5.40%
Year 6	6.40%
Year 7	2.60%
Year 8	2.70%
Year 9	1.40%
Year 10	0.70%
Surety
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	7.30%
Year 2	9.00%
Year 3	19.00%
Year 4	14.70%
Year 5	12.40%
Year 6	17.80%
Year 7	1.70%
Year 8	2.00%
Year 9	0.90%
Year 10	0.30%
Contingency
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	42.20%
Year 2	36.20%
Year 3	10.80%
Year 4	1.70%
Year 5	3.20%
Year 6	0.00%
Year 7	0.20%
Year 8	0.40%
Year 9	0.40%
Year 10	0.00%
Casualty
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	5.90%
Year 2	9.40%
Year 3	9.50%
Year 4	11.10%
Year 5	7.30%
Year 6	10.00%
Year 7	0.60%
Year 8	13.40%
Year 9	1.00%
Year 10	0.70%
Runoff & Other
Average annual percentage payout of incurred losses and allocated LAE by age, net of reinsurance
Year 1	66.90%
Year 2	20.60%
Year 3	2.00%
Year 4	1.50%
Year 5	1.10%
Year 6	1.10%
Year 7	0.70%
Year 8	0.50%
Year 9	0.20%
Year 10	0.10%

Third party reinsurance - The e

Third party reinsurance - The effects of reinsurance (Details) - USD ($) $ in Millions	Jun. 01, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Written premiums:
Direct		$ 511.2	$ 454.5	$ 450.2
Assumed		1,391.5	1,366.5	989.1
Gross written premiums		1,902.7	1,821	1,439.3
Ceded		(400.1)	(463.9)	(349.1)
Net written premiums		1,502.6	1,357.1	1,090.2
Earned premiums:
Direct		481	432.6	405.7
Assumed		1,357.7	1,236.2	942.2
Gross earned premiums		1,838.7	1,668.8	1,347.9
Ceded		(397.1)	(406.5)	(312.6)
Net earned premiums		1,441.6	1,262.3	1,035.3
Losses and LAE:
Direct		316.3	260.5	294.9
Assumed		1,111.4	819.1	701.3
Gross losses and LAE		1,427.7	1,079.6	996.2
Ceded		(257.4)	(179.6)	(185)
Net losses and LAE		$ 1,170.3	$ 900	$ 811.2
Excess of loss retrocessional coverage | Earthquake related property liability and casualty insurance
Losses and LAE:
Renewal term	1 year
Reinsurance protection in excess of retention	$ 40
Retention amount	35
Further reinsurance protection in excess of retention	35
Further retention amount	$ 75
Minimum | Excess of loss retrocessional coverage | Earthquake related property liability and casualty insurance
Losses and LAE:
Reinsurance protection in excess of retention (as a percent)	50.00%
Maximum | Excess of loss retrocessional coverage | Earthquake related property liability and casualty insurance
Losses and LAE:
Reinsurance protection in excess of retention (as a percent)	100.00%

Third party reinsurance - Indus

Third party reinsurance - Industry loss warranty contracts and Narrative (Details)	12 Months Ended
	Dec. 31, 2019USD ($)event	Dec. 31, 2018USD ($)
Third party reinsurance
Reinsurance recoverable on paid losses	$ 73,900,000	$ 55,000,000
Reinsurance recoverable on unpaid losses	$ 410,300,000	$ 350,200,000
Excess of loss reinsurance coverage
Third party reinsurance
Cost coverage of original insurance premium (as a percent)	100.00%
Industry loss warranty contract
Third party reinsurance
Number of loss events covered | event	1
Industry loss warranty contract | United States excluding North East | All natural perils
Third party reinsurance
Limit	$ 5,000,000
Trigger	$ 40,000,000,000
Global Reinsurance
Third party reinsurance
Quota share treaty, percentage	12.50%
Global Reinsurance | Industry loss warranty contract
Third party reinsurance
Limit	$ 27,500,000
Global Reinsurance | Minimum | Excess of loss reinsurance coverage
Third party reinsurance
Reinsurance protection in excess of retention	150,000,000
Global Reinsurance | Minimum | Industry loss warranty contract
Third party reinsurance
Reinsurance protection in excess of retention	400,000,000
Global Reinsurance | Maximum | Excess of loss reinsurance coverage
Third party reinsurance
Reinsurance protection in excess of retention	2,000,000,000
Global Reinsurance | Maximum | Industry loss warranty contract
Third party reinsurance
Reinsurance protection in excess of retention	800,000,000
Global A&H | Excess of loss reinsurance coverage
Third party reinsurance
Retention amount	$ 1,500,000

Third party reinsurance- Gross

Third party reinsurance- Gross and net recoverable amounts (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Third party reinsurance
Gross	$ 484.2	$ 405.2
Collateral	237	83.4
Net	$ 247.2	$ 321.8
Percentage of Net Total	100.00%	100.00%
AAA
Third party reinsurance
Gross	$ 3.4
Collateral	0
Net	$ 3.4
Percentage of Net Total	1.00%
AA
Third party reinsurance
Gross	$ 117.2	$ 115.1
Collateral	14.3	1.5
Net	$ 102.9	$ 113.6
Percentage of Net Total	42.00%	35.00%
A
Third party reinsurance
Gross	$ 301.8	$ 212.9
Collateral	195.6	45.4
Net	$ 106.2	$ 167.5
Percentage of Net Total	43.00%	52.00%
BBB or lower
Third party reinsurance
Gross	$ 14.9	$ 19.5
Collateral	13.7	13.3
Net	$ 1.2	$ 6.2
Percentage of Net Total	1.00%	2.00%
Not rated
Third party reinsurance
Gross	$ 46.9	$ 57.7
Collateral	13.4	23.2
Net	$ 33.5	$ 34.5
Percentage of Net Total	13.00%	11.00%

Third party reinsurance - Highe

Third party reinsurance - Highest gross recoverable amounts by reinsurer (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Third party reinsurance
Gross recoverable balance	$ 484.2	$ 405.2
General Insurance Corporation of India | A-
Third party reinsurance
Gross recoverable balance	$ 143	$ 82.7
Percentage of Total	30.00%	20.00%
Percentage Collateralized	98.00%	97.00%
Swiss Reinsurance Companyﾠ Ltd. | AA-
Third party reinsurance
Gross recoverable balance	$ 44.7	$ 44.1
Percentage of Total	9.00%	11.00%
Percentage Collateralized	5.00%	0.00%
Berkshire Hathaway,ﾠInc. | AA+
Third party reinsurance
Gross recoverable balance	$ 34	$ 39.3
Percentage of Total	7.00%	10.00%
Percentage Collateralized	3.00%	1.00%
Argo Capital Group Ltd. | A-
Third party reinsurance
Gross recoverable balance	$ 19.1	$ 16.7
Percentage of Total	4.00%	4.00%
Percentage Collateralized	89.00%	87.00%
Lloyd's of London | A
Third party reinsurance
Gross recoverable balance	$ 27	$ 13.4
Percentage of Total	6.00%	3.00%
Percentage Collateralized	30.00%	5.00%

Deferred acquisition costs (Det

Deferred acquisition costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred acquisition costs - balance, beginning of the year	$ 141.6	$ 120.9	$ 84.7
Acquisition costs deferred	221.6	202.6	220.7
Amortization expense	(214.4)	(180.4)	(186.7)
Other, including foreign exchange	(0.6)	(1.5)	2.2
Deferred acquisition costs – balance, end of the year	$ 148.2	$ 141.6	120.9
IMG
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Acquisition costs deferred			$ 2.9

Investment securities - Net Inv

Investment securities - Net Investment Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net Investment Income
Total investment income	$ 97.3	$ 82.7	$ 66.6
Interest on funds held under reinsurance treaties	0	(0.5)	0
Investment expenses	(12.6)	(11.3)	(9.8)
Net investment income	84.7	71.4	56.8
Fixed maturity investments
Net Investment Income
Total investment income	52.1	53.2	51.5
Short-term investments
Net Investment Income
Total investment income	15.8	5.1	1.5
Equity securities
Net Investment Income
Total investment income	15.2	16.5	5.1
Other long-term investments
Net Investment Income
Total investment income	$ 14.2	$ 8.4	$ 8.5

Investment securities - Net Rea

Investment securities - Net Realized and Unrealized Investment (Losses) Gains (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net Realized and Unrealized Investment (Losses) Gains
Gross realized gains	$ 99.3	$ 42.3	$ 24.4
Gross realized (losses)	(42.6)	(40)	(51.6)
Net realized gains (losses) on investments	56.7	2.3	(27.2)
Net unrealized investment gains (losses)	80.6	(23.2)	(10.5)
Net realized and unrealized investment gains (losses) on investments	137.3	(20.9)	(37.7)
Realized gains (losses) due to foreign currency	50.4	17.3	(19.1)
Unrealized gains (losses) due to foreign currency	(5.7)	35.7	(51.7)
Total unrealized investment gains (losses) - Level 3 investments	15.9	(2.1)	(0.7)
Fixed maturity investments
Net Realized and Unrealized Investment (Losses) Gains
Net realized gains (losses) on investments	33.7	3.6	(19.1)
Net unrealized investment gains (losses)	24.1	14.1	(41.3)
Total unrealized investment gains (losses) - Level 3 investments	0	(6.1)	(0.2)
Equity securities
Net Realized and Unrealized Investment (Losses) Gains
Net realized gains (losses) on investments	9.4	(6.4)	0.1
Net unrealized investment gains (losses)	51.4	(51.1)	25.2
Total unrealized investment gains (losses) - Level 3 investments	0	0	0.1
Short-term investments
Net Realized and Unrealized Investment (Losses) Gains
Net realized gains (losses) on investments	14.8	0	0
Net unrealized investment gains (losses)	(5.2)	0	0
Derivative instruments
Net Realized and Unrealized Investment (Losses) Gains
Net realized gains (losses) on investments	(2.5)	0	0
Net unrealized investment gains (losses)	(0.5)	0	0
Other long-term investments
Net Realized and Unrealized Investment (Losses) Gains
Net realized gains (losses) on investments	1.3	5.1	(8.2)
Net unrealized investment gains (losses)	10.8	13.8	5.6
Total unrealized investment gains (losses) - Level 3 investments	$ 15.9	$ 4	$ (0.6)

Investment securities - Fixed m

Investment securities - Fixed maturity investments (Details) - Fixed maturity investments - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fixed maturity investments
Cost or amortized cost	$ 1,656.6	$ 1,952.9
Gross unrealized gains	18.7	4.3
Gross unrealized losses	(8.2)	(28.4)
Net foreign currency gains (losses)	13.9	20.4
Fair value	$ 1,681	1,949.2
Weighted average duration of fixed income portfolio including short-term investments	1 year 7 months
Weighted average duration of fixed income portfolio excluding short-term investments	2 years 6 months
Cost or amortized cost
Cost or amortized cost due in one year or less	$ 85	249.6
Cost or amortized cost due after one year through five years	479.1	635.6
Cost or amortized cost due after five years through ten years	46.3	26.2
Cost or amortized cost due after ten years	25.1	0.1
Fair Value
Fair value due in one year or less	88.4	254.6
Fair value due after one year through five years	490.3	636.4
Fair value due after five years through ten years	46	25.7
Fair value due after ten years	24.6	0.1
AAA
Fixed maturity investments
Fair value	559.8	602
AA
Fixed maturity investments
Fair value	724.3	818
A
Fixed maturity investments
Fair value	219	290.5
BBB
Fixed maturity investments
Fair value	95.8	167.4
Other
Fixed maturity investments
Fair value	82.1	71.3
Asset-backed securities
Fixed maturity investments
Cost or amortized cost	489.4	496.3
Gross unrealized gains	1.4	0.1
Gross unrealized losses	(3.9)	(3.8)
Net foreign currency gains (losses)	(0.1)	1.9
Fair value	486.8	494.5
Corporate debt securities
Fixed maturity investments
Cost or amortized cost	458.6	694.1
Gross unrealized gains	5.2	1.4
Gross unrealized losses	(1.2)	(7.3)
Net foreign currency gains (losses)	11.5	7.6
Fair value	474.1	695.8
Residential mortgage-backed securities
Fixed maturity investments
Cost or amortized cost	426.2	413
Gross unrealized gains	10.5	1.7
Gross unrealized losses	(1.4)	(7.1)
Net foreign currency gains (losses)	3.6	5.9
Fair value	438.9	413.5
U.S. government and government agency
Fixed maturity investments
Cost or amortized cost	111.5	163.9
Gross unrealized gains	0.7	0.3
Gross unrealized losses	(0.4)	(0.5)
Net foreign currency gains (losses)	(1.3)	4.2
Fair value	110.5	167.9
Commercial mortgage-backed securities
Fixed maturity investments
Cost or amortized cost	88.5	117.7
Gross unrealized gains	0.9	0.2
Gross unrealized losses	(0.6)	(2.7)
Net foreign currency gains (losses)	0.2	0.7
Fair value	89	115.9
Non-U.S. government and government agency
Fixed maturity investments
Cost or amortized cost	63.7	50.6
Gross unrealized gains	0	0
Gross unrealized losses	(0.7)	(0.2)
Net foreign currency gains (losses)	0	(0.1)
Fair value	63	50.3
Preferred stocks
Fixed maturity investments
Cost or amortized cost	17	14.5
Gross unrealized gains	0	0.6
Gross unrealized losses	0	(6.8)
Net foreign currency gains (losses)	0	0.2
Fair value	17	8.5
Cost or amortized cost
Cost or amortized cost without single maturity date	17	14.5
Fair Value
Fair value without single maturity date	17	8.5
U.S. States, municipalities and political subdivision
Fixed maturity investments
Cost or amortized cost	1.7	2.8
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Net foreign currency gains (losses)	0	0
Fair value	1.7	2.8
Mortgage-backed and asset-backed securities
Cost or amortized cost
Cost or amortized cost without single maturity date	1,004.1	1,026.9
Fair Value
Fair value without single maturity date	1,014.7	1,023.9
Sub-prime securities
Fixed maturity investments
Fair value	43.3	42.6
Sub-prime securities | AAA
Fixed maturity investments
Fair value	21.7	17.1
Sub-prime securities | AA
Fixed maturity investments
Fair value	18.4	9.8
Sub-prime securities | A
Fixed maturity investments
Fair value	3.1	6
Sub-prime securities | BBB
Fixed maturity investments
Fair value		4.7
Sub-prime securities | Other
Fixed maturity investments
Fair value	$ 0.1	$ 5

Investment securities - Mortgag

Investment securities - Mortgage-backed, Asset-backed Securities (Details) - Level 2 - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Mortgage-backed and asset-backed securities
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	$ 1,014.7	$ 1,023.9
Mortgage-backed securities
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	527.9	529.4
Agency
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	453.1	411.3
Federal national mortgage association
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	235.9	185
Federal home loan mortgage corporation
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	165	166.9
Government national mortgage association
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	52.2	59.4
Non-agency
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	74.8	118.1
Commercial
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	60.9	85.5
Residential
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	13.9	32.6
Asset-backed securities
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	486.8	494.5
Collateralized loan obligations
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	417	373
Vehicle receivables
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	32.9	63.8
Credit card receivables
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	5.7	10.7
Other
Total mortgage and asset backed securities held at fair value
Total mortgage and asset-backed securities held at fair value	$ 31.2	$ 47

Investment securities - Equity

Investment securities - Equity securities and Other long-term investments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fixed income mutual funds
Equity securities and Other long-term investments
Fair value	$ 175.3	$ 157.7
Common stocks
Equity securities and Other long-term investments
Fair value	228.1	222.3
Other equity securities
Equity securities and Other long-term investments
Fair value	1.8	0
Equity securities
Equity securities and Other long-term investments
Cost or amortized cost	379.2	409.4
Gross unrealized gains	55.6	17.8
Gross unrealized losses	(37.3)	(50.8)
Net foreign currency gains	7.7	3.6
Fair value	405.2	380
Other long-term investments
Equity securities and Other long-term investments
Cost or amortized cost	315.4	337.6
Gross unrealized gains	49.9	32.6
Gross unrealized losses	(29.3)	(13.5)
Net foreign currency gains	10.8	8.3
Fair value	346.8	365
Other long-term investments | Hedge funds and private equity funds
Equity securities and Other long-term investments
Fair value	269	301.4
Other long-term investments | Limited liability companies and private equity securities
Equity securities and Other long-term investments
Fair value	$ 77.8	$ 63.6

Investment securities - Hedge F

Investment securities - Hedge Funds and Private Equity Funds (Details) - Other long-term investments $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)fund	Dec. 31, 2018USD ($)
Equity securities and Other long-term investments
Largest investment in single fund	$ 51.6	$ 54.8
Fair value	346.8	365
Hedge funds and private equity funds
Equity securities and Other long-term investments
Fair value	269	301.4
Unfunded commitments	$ 60.1	82
Hedge funds
Equity securities and Other long-term investments
Number of investment funds in which the investments are held | fund	9
Fair value	$ 127.5	118.3
Unfunded commitments	0	0
Long/short multi-sector
Equity securities and Other long-term investments
Fair value	53	41
Unfunded commitments	0	0
Distressed mortgage credit
Equity securities and Other long-term investments
Fair value	51.6	54.8
Unfunded commitments	0	0
Private credit
Equity securities and Other long-term investments
Fair value	21.5	20
Unfunded commitments	0	0
Other
Equity securities and Other long-term investments
Fair value	1.4	2.5
Unfunded commitments	$ 0	0
Private equity securities
Equity securities and Other long-term investments
Number of investment funds in which the investments are held | fund	29
Fair value	$ 141.5	183.1
Unfunded commitments	60.1	82
Energy infrastructure & services
Equity securities and Other long-term investments
Fair value	53.6	93.7
Unfunded commitments	34.6	54.2
Multi-sector
Equity securities and Other long-term investments
Fair value	8.7	9
Unfunded commitments	7.8	0.7
Healthcare
Equity securities and Other long-term investments
Fair value	25.9	31.7
Unfunded commitments	10.4	15.6
Life settlement
Equity securities and Other long-term investments
Fair value	23.9	23.7
Unfunded commitments	0	0
Manufacturing/Industrial
Equity securities and Other long-term investments
Fair value	27.6	23.6
Unfunded commitments	3.9	10.4
Private equity secondaries
Equity securities and Other long-term investments
Fair value	0.6	1.1
Unfunded commitments	0.8	1.1
Real estate
Equity securities and Other long-term investments
Fair value	0	0.3
Unfunded commitments	0	0
Other
Equity securities and Other long-term investments
Fair value	1.2	0
Unfunded commitments	$ 2.6	$ 0

Investment securities - Hedge_2

Investment securities - Hedge Funds redemption frequency and Private Equity Fund lock-up period (Details) - Other long-term investments - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Equity securities and Other long-term investments
Other long-term investments	$ 346.8	$ 365
Hedge funds
Equity securities and Other long-term investments
Other long-term investments	127.5	118.3
Outstanding distribution from investments	0	0
Hedge funds | Monthly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	36.2
Hedge funds | Quarterly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0.8
Hedge funds | Semi-annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0.3
Hedge funds | Annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	90.2
Private equity securities
Equity securities and Other long-term investments
Other long-term investments	141.5	183.1
Outstanding distribution from investments	60.1	$ 82
Private equity securities | Lock up period of 1 - 3 years
Equity securities and Other long-term investments
Other long-term investments	4.7
Private equity securities | Lock up period of 3 - 5 years
Equity securities and Other long-term investments
Other long-term investments	1.4
Private equity securities | Lock up period of 5 - 10 years
Equity securities and Other long-term investments
Other long-term investments	135.4
30-59 days notice | Hedge funds
Equity securities and Other long-term investments
Other long-term investments	0.8
30-59 days notice | Hedge funds | Monthly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
30-59 days notice | Hedge funds | Quarterly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0.8
30-59 days notice | Hedge funds | Semi-annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
30-59 days notice | Hedge funds | Annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
60-89 days notice | Hedge funds
Equity securities and Other long-term investments
Other long-term investments	53.3
60-89 days notice | Hedge funds | Monthly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	36.2
60-89 days notice | Hedge funds | Quarterly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
60-89 days notice | Hedge funds | Semi-annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0.3
60-89 days notice | Hedge funds | Annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	16.8
90-119 days notice | Hedge funds
Equity securities and Other long-term investments
Other long-term investments	51.9
90-119 days notice | Hedge funds | Monthly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
90-119 days notice | Hedge funds | Quarterly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
90-119 days notice | Hedge funds | Semi-annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
90-119 days notice | Hedge funds | Annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	51.9
120 days notice | Hedge funds
Equity securities and Other long-term investments
Other long-term investments	21.5
120 days notice | Hedge funds | Monthly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
120 days notice | Hedge funds | Quarterly Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
120 days notice | Hedge funds | Semi-annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	0
120 days notice | Hedge funds | Annual Redemption Frequency
Equity securities and Other long-term investments
Other long-term investments	$ 21.5

Investment securities - Investm

Investment securities - Investments Held on Deposit or as Collateral and Unsettled investment purchases and sales (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Marketable securities
Investments held in trusts	$ 1,309.5	$ 792.4
Investments held in trusts - fair value	1,315.5	801.2
Accounts payable
Marketable securities
Unsettled investment purchases	2.3	3.2
Accounts receivable
Marketable securities
Unsettled investment sales	6.7	5
Interest rate cap | Derivatives not designated as hedging instruments
Marketable securities
Collateral balances held	$ 0.2	$ 0

Fair value measurements - Fair

Fair value measurements - Fair Value Measurements by Level (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets measured at fair value
Fixed maturity investments	$ 1,681	$ 1,949.2
Equity securities	405.2	380
Short-term investments	1,085.2	715.5
Other long-term investments	77.8	63.6
Total investments	3,249.2	3,108.3
Derivative instruments	11.4	4.1
Total assets measured at fair value	3,280.6	3,112.4
Liabilities measured at fair value
Contingent consideration liabilities	28.2	28.8
Derivative instruments	9.5	5.1
Total liabilities measured at fair value	37.7	33.9
U.S. government and government agency
Assets measured at fair value
Fixed maturity investments	110.5	167.9
Corporate debt securities
Assets measured at fair value
Fixed maturity investments	474.1	695.8
Asset-backed securities
Assets measured at fair value
Fixed maturity investments	486.8	494.5
Residential mortgage-backed securities
Assets measured at fair value
Fixed maturity investments	438.9	413.5
Commercial mortgage-backed securities
Assets measured at fair value
Fixed maturity investments	89	115.9
Non-U.S. government and government agency
Assets measured at fair value
Fixed maturity investments	63	50.3
Preferred stocks
Assets measured at fair value
Fixed maturity investments	17	8.5
U.S. States, municipalities and political subdivision
Assets measured at fair value
Fixed maturity investments	1.7	2.8
Fixed income mutual funds
Assets measured at fair value
Equity securities	175.3	157.7
Common stocks
Assets measured at fair value
Equity securities	228.1	222.3
Other equity securities
Assets measured at fair value
Equity securities	1.8	0
Hedge funds and private equity funds
Liabilities measured at fair value
Fair value of hedges	269	301.4
Loan participation
Assets measured at fair value
Loan participation	20	0
Level 1
Assets measured at fair value
Fixed maturity investments	140.8	207.6
Equity securities	403.4	380
Short-term investments	1,073.7	679.3
Other long-term investments	0	0
Total investments	1,617.9	1,266.9
Derivative instruments	1.3	0
Total assets measured at fair value	1,619.2	1,266.9
Liabilities measured at fair value
Contingent consideration liabilities	0	0
Derivative instruments	0.2	0.5
Total liabilities measured at fair value	0.2	0.5
Level 1 | U.S. government and government agency
Assets measured at fair value
Fixed maturity investments	109.1	164.7
Level 1 | Corporate debt securities
Assets measured at fair value
Fixed maturity investments	0	0
Level 1 | Asset-backed securities
Assets measured at fair value
Fixed maturity investments	0	0
Level 1 | Residential mortgage-backed securities
Assets measured at fair value
Fixed maturity investments	0	0
Level 1 | Commercial mortgage-backed securities
Assets measured at fair value
Fixed maturity investments	0	0
Level 1 | Non-U.S. government and government agency
Assets measured at fair value
Fixed maturity investments	31.7	42.9
Level 1 | Preferred stocks
Assets measured at fair value
Fixed maturity investments	0	0
Level 1 | U.S. States, municipalities and political subdivision
Assets measured at fair value
Fixed maturity investments	0	0
Level 1 | Fixed income mutual funds
Assets measured at fair value
Equity securities	175.3	157.7
Level 1 | Common stocks
Assets measured at fair value
Equity securities	228.1	222.3
Level 1 | Other equity securities
Assets measured at fair value
Equity securities	0	0
Level 1 | Loan participation
Assets measured at fair value
Loan participation	0	0
Level 2
Assets measured at fair value
Fixed maturity investments	1,523.2	1,736.2
Equity securities	1.8	0
Short-term investments	11.5	36.2
Other long-term investments	0	0
Total investments	1,536.5	1,772.4
Derivative instruments	0	0
Total assets measured at fair value	1,536.5	1,772.4
Liabilities measured at fair value
Contingent consideration liabilities	0	0
Derivative instruments	0	0
Total liabilities measured at fair value	0	0
Level 2 | U.S. government and government agency
Assets measured at fair value
Fixed maturity investments	1.4	3.2
Level 2 | Corporate debt securities
Assets measured at fair value
Fixed maturity investments	474.1	695.8
Level 2 | Asset-backed securities
Assets measured at fair value
Fixed maturity investments	486.8	494.5
Level 2 | Residential mortgage-backed securities
Assets measured at fair value
Fixed maturity investments	438.9	413.5
Level 2 | Commercial mortgage-backed securities
Assets measured at fair value
Fixed maturity investments	89	115.9
Level 2 | Non-U.S. government and government agency
Assets measured at fair value
Fixed maturity investments	31.3	7.4
Level 2 | Preferred stocks
Assets measured at fair value
Fixed maturity investments	0	3.1
Level 2 | U.S. States, municipalities and political subdivision
Assets measured at fair value
Fixed maturity investments	1.7	2.8
Level 2 | Fixed income mutual funds
Assets measured at fair value
Equity securities	0	0
Level 2 | Common stocks
Assets measured at fair value
Equity securities	0	0
Level 2 | Other equity securities
Assets measured at fair value
Equity securities	1.8	0
Level 2 | Loan participation
Assets measured at fair value
Loan participation	0	0
Level 3
Assets measured at fair value
Fixed maturity investments	17	5.4
Equity securities	0	0
Short-term investments	0	0
Other long-term investments	77.8	63.6
Total investments	94.8	69
Derivative instruments	10.1	4.1
Total assets measured at fair value	124.9	73.1
Liabilities measured at fair value
Contingent consideration liabilities	28.2	28.8
Derivative instruments	9.3	4.6
Total liabilities measured at fair value	37.5	33.4
Level 3 | U.S. government and government agency
Assets measured at fair value
Fixed maturity investments	0	0
Level 3 | Corporate debt securities
Assets measured at fair value
Fixed maturity investments	0	0
Level 3 | Asset-backed securities
Assets measured at fair value
Fixed maturity investments	0	0
Level 3 | Residential mortgage-backed securities
Assets measured at fair value
Fixed maturity investments	0	0
Level 3 | Commercial mortgage-backed securities
Assets measured at fair value
Fixed maturity investments	0	0
Level 3 | Non-U.S. government and government agency
Assets measured at fair value
Fixed maturity investments	0	0
Level 3 | Preferred stocks
Assets measured at fair value
Fixed maturity investments	17	5.4
Level 3 | U.S. States, municipalities and political subdivision
Assets measured at fair value
Fixed maturity investments	0	0
Level 3 | Fixed income mutual funds
Assets measured at fair value
Equity securities	0	0
Level 3 | Common stocks
Assets measured at fair value
Equity securities	0	0
Level 3 | Other equity securities
Assets measured at fair value
Equity securities	0	0
Level 3 | Loan participation
Assets measured at fair value
Loan participation	$ 20	$ 0

Fair value measurements - Rollf

Fair value measurements - Rollforward of Level 3 Fair Value Measurements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Rollforward of Level 3, Derivative instruments assets & (liabilities)
Balance at beginning of the period	$ (0.5)	$ (6.1)
Total realized and unrealized gains	(7.1)	12
Purchases	0	0
Sales/settlements	8.4	(6.4)
Balance at end of the period	0.8	(0.5)
Foreign currency losses
Rollforward of Level 3, Derivative instruments assets & (liabilities)
Foreign currency losses through Other Comprehensive Income	0	0
Contingent consideration (liabilities)
Rollforward of Level 3, (liabilities)
Balance at beginning of the period	(28.8)	(42.8)
Total realized and unrealized gains	(6.3)	9.6
Foreign currency losses through Other Comprehensive Income	0	0
Purchases	0	0
Sales/settlements	6.9	4.4
Balance at end of the period	(28.2)	(28.8)
Fixed maturity investments
Rollforward of Level 3 Fair Value Measurements
Balance at beginning of the period	5.4	8
Total realized and unrealized gains	0	(6.1)
Purchases	17	4
Sales/settlements	(5.4)	(0.5)
Balance at end of the period	17	5.4
Fixed maturity investments | Foreign currency losses
Rollforward of Level 3 Fair Value Measurements
Foreign currency losses through Other Comprehensive Income	0	0
Other long-term investments
Rollforward of Level 3 Fair Value Measurements
Balance at beginning of the period	63.6	64.2
Total realized and unrealized gains	7.3	6.8
Purchases	15.7	1.2
Sales/settlements	(8.2)	(4.2)
Balance at end of the period	77.8	63.6
Other long-term investments | Foreign currency losses
Rollforward of Level 3 Fair Value Measurements
Foreign currency losses through Other Comprehensive Income	(0.6)	(4.4)
Loan participation
Rollforward of Level 3 Fair Value Measurements
Balance at beginning of the period	0	0
Total realized and unrealized gains	0	0
Purchases	20	0
Sales/settlements	0	0
Balance at end of the period	20	0
Loan participation | Foreign currency losses
Rollforward of Level 3 Fair Value Measurements
Foreign currency losses through Other Comprehensive Income	0	0
Hedge funds and private equity funds
Rollforward of Level 3, (liabilities)
Fair value of hedges	$ 269	$ 301.5

Fair value measurements - Trans

Fair value measurements - Transfers between levels (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Transfers between level 3 and level 2	$ 0	$ 0

Fair value measurements - Signi

Fair value measurements - Significant Unobservable Inputs (Details) $ in Thousands	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2018USD ($)$ / shares
Significant Unobservable Inputs
Equity securities	$ 405,200	$ 380,000
Derivative assets	11,400	4,100
Derivative liabilities	(9,500)	(5,100)
Contingent consideration	(28,200)	(28,800)
Common stocks
Significant Unobservable Inputs
Equity securities	228,100	222,300
Level 3
Significant Unobservable Inputs
Equity securities	0	0
Derivative assets	10,100	4,100
Derivative liabilities	(9,300)	(4,600)
Contingent consideration	(28,200)	(28,800)
Level 3 | Common stocks
Significant Unobservable Inputs
Equity securities	0	0
Level 3 | Share price of recent transaction | Private equity securities
Significant Unobservable Inputs
Equity securities	32,500	32,500
Level 3 | Share price of recent transaction | Preferred Stock1
Significant Unobservable Inputs
Equity securities	$ 17,500
Level 3 | Share price of recent transaction | Preferred Stock 2
Significant Unobservable Inputs
Equity securities		800
Level 3 | Share price of recent transaction | Common stocks
Significant Unobservable Inputs
Equity securities		$ 300
Level 3 | Share price of recent transaction | Purchase share price | Private equity securities
Significant Unobservable Inputs
Equity Securities, Input | $ / shares	40.6	40.63
Level 3 | Share price of recent transaction | Purchase price | Preferred Stock1
Significant Unobservable Inputs
Equity Securities, Input | $ / shares	7.74
Level 3 | Share price of recent transaction | Purchase price | Preferred Stock 2
Significant Unobservable Inputs
Equity securities measurement input		$ 800
Level 3 | Share price of recent transaction | Purchase price | Common stocks
Significant Unobservable Inputs
Equity Securities, Input | $ / shares		10
Level 3 | Multiple of GAAP book value | Private Equity Securities 1
Significant Unobservable Inputs
Equity securities	$ 14,200	$ 14,700
Level 3 | Multiple of GAAP book value | Book value multiple | Private Equity Securities 1
Significant Unobservable Inputs
Equity Securities, Input	0.9	0.9
Level 3 | Purchase price of recent transaction | Loan participation
Significant Unobservable Inputs
Equity securities	$ 20,000
Level 3 | Purchase price of recent transaction | Preferred Stock 2
Significant Unobservable Inputs
Equity securities	12,200
Level 3 | Purchase price of recent transaction | Private debt instrument
Significant Unobservable Inputs
Private debt instrument	7,200	$ 9,000
Level 3 | Purchase price of recent transaction | Private Equity Funds 3
Significant Unobservable Inputs
Equity securities	5,100
Level 3 | Purchase price of recent transaction | Preferred Stock 3
Significant Unobservable Inputs
Equity securities	4,800	4,600
Level 3 | Purchase price of recent transaction | Private Equity Securities 4
Significant Unobservable Inputs
Equity securities	1,000
Level 3 | Purchase price of recent transaction | Private Equity Securities 2
Significant Unobservable Inputs
Equity securities	300
Level 3 | Purchase price of recent transaction | Private Debt Instrument 1
Significant Unobservable Inputs
Private debt instrument		6,000
Level 3 | Purchase price of recent transaction | Common stocks
Significant Unobservable Inputs
Equity securities		900
Level 3 | Purchase price of recent transaction | Private Debt Instrument 2
Significant Unobservable Inputs
Private debt instrument		200
Level 3 | Purchase price of recent transaction | Purchase price | Preferred Stock 2
Significant Unobservable Inputs
Equity securities measurement input	12,200
Level 3 | Purchase price of recent transaction | Purchase price | Private debt instrument
Significant Unobservable Inputs
Debt securities	$ 9,000	9,000
Level 3 | Purchase price of recent transaction | Purchase price | Private Equity Funds 3
Significant Unobservable Inputs
Equity Securities, Input | $ / shares	7.74
Level 3 | Purchase price of recent transaction | Purchase price | Preferred Stock 3
Significant Unobservable Inputs
Equity securities measurement input	$ 4,800
Level 3 | Purchase price of recent transaction | Purchase price | Private Equity Securities 4
Significant Unobservable Inputs
Equity Securities, Input | $ / shares	10
Level 3 | Purchase price of recent transaction | Purchase price | Private Equity Securities 2
Significant Unobservable Inputs
Equity securities measurement input	$ 300
Level 3 | Purchase price of recent transaction | Purchase price | Private Debt Instrument 1
Significant Unobservable Inputs
Debt securities		$ 6,000
Level 3 | Purchase price of recent transaction | Purchase price | Common stocks
Significant Unobservable Inputs
Equity Securities, Input | $ / shares		1.88
Level 3 | Purchase price of recent transaction | Purchase price | Private Debt Instrument 2
Significant Unobservable Inputs
Debt securities		$ 200
Level 3 | Purchase price of recent transaction | Average share price | Preferred Stock 3
Significant Unobservable Inputs
Equity Securities, Input | $ / shares		1.88
Level 3 | Third party appraisal | Weather derivatives
Significant Unobservable Inputs
Derivative assets	7,000	$ 3,900
Level 3 | Third party appraisal | Interest rate cap
Significant Unobservable Inputs
Derivative assets		200
Level 3 | Third party appraisal | Currency swaps
Significant Unobservable Inputs
Derivative liabilities	(3,600)	(4,600)
Level 3 | Third party appraisal | Currency forwards
Significant Unobservable Inputs
Derivative liabilities	2,700
Level 3 | Third party appraisal | Currency forwards
Significant Unobservable Inputs
Derivative liabilities	(5,700)
Level 3 | Third party appraisal | Broker quote | Weather derivatives
Significant Unobservable Inputs
Derivative asset	7,000	3,900
Level 3 | Third party appraisal | Broker quote | Interest rate cap
Significant Unobservable Inputs
Derivative asset		200
Level 3 | Third party appraisal | Broker quote | Currency swaps
Significant Unobservable Inputs
Derivative assets, Input	3,600	4,600
Level 3 | Third party appraisal | Broker quote | Currency forwards
Significant Unobservable Inputs
Derivative assets, Input	2,700
Level 3 | Third party appraisal | Broker quote | Currency forwards
Significant Unobservable Inputs
Derivative assets, Input	5,700
Level 3 | Option pricing model
Significant Unobservable Inputs
Equity securities	400
Level 3 | Option pricing model | Strike price
Significant Unobservable Inputs
Equity securities measurement input	200
Level 3 | External valuation model
Significant Unobservable Inputs
Contingent consideration	(28,200)	(28,800)
Level 3 | External valuation model | Discounted future payments
Significant Unobservable Inputs
Contingent consideration, Input	$ (28,200)	$ (28,800)

Fair value measurements - Finan

Fair value measurements - Financial instruments disclosed, but not carried at fair value (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financial instruments not carried at fair value
Debt	$ 685.2	$ 696.8
2017 SEK Subordinated Notes
Financial instruments not carried at fair value
Debt	291.2	303.6
2016 SIG Senior Notes
Financial instruments not carried at fair value
Debt	394	393.2
Fair Value | Level 3 | Series B preference shares
Financial instruments not carried at fair value
Redeemable preference shares	186.4	191.7
Fair Value | Level 3 | 2017 SEK Subordinated Notes
Financial instruments not carried at fair value
Debt	294.5	309.5
Fair Value | Level 3 | 2016 SIG Senior Notes
Financial instruments not carried at fair value
Debt	394.5	347.6
Carrying Value | Series B preference shares
Financial instruments not carried at fair value
Redeemable preference shares	223	232.2
Carrying Value | 2017 SEK Subordinated Notes
Financial instruments not carried at fair value
Debt	291.2	303.6
Carrying Value | 2016 SIG Senior Notes
Financial instruments not carried at fair value
Debt	$ 394	$ 393.2

Fair value measurements - Fai_2

Fair value measurements - Fair Value Measurements on a Non-Recurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurements on a Non-Recurring Basis
Impairment of indefinite-lived intangible asset excluding goodwill	$ 0	$ 8
Trade Names
Fair Value Measurements on a Non-Recurring Basis
Impairment of indefinite-lived intangible asset excluding goodwill	$ 0	13
Trade Names | Impairment of Intangible Assets
Fair Value Measurements on a Non-Recurring Basis
Impairment of indefinite-lived intangible asset excluding goodwill		$ 8	$ 5

Goodwill and intangible asset_2

Goodwill and intangible assets - Change in goodwill, intangible assets with an indefinite life and with a finite life (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill
Balance at the beginning of the period	$ 400.6	$ 401
Additions	0	0
Foreign currency translation	0.2	(0.4)
Impairments	0	0
Balance at the end of the period	400.8	400.6	$ 401
Intangible assets with an indefinite life
Balance at the beginning of the period	22.1	27
Additions	0	3.1
Foreign currency translation	0	0
Impairments	0	(8)
Balance at the end of the period	22.1	22.1	27
Intangible assets with a finite life
Balance at the beginning of the period	173.5	189.3
Additions	0	0
Foreign currency translation	0	0
Impairments	0	0
Balance at the end of the period	157.7	173.5	189.3
Balance at the beginning of the period	596.2	617.3
Additions	0	3.1
Foreign currency translation	0.2	(0.4)
Impairments	0	(8)
Amortization of Intangible Assets	(15.8)	(15.8)	(10.2)
Balance at the end of the period	$ 580.6	$ 596.2	$ 617.3

Goodwill and intangible asset_3

Goodwill and intangible assets - Components of goodwill and intangible assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite lived intangible Asset
Accumulated Amortization	$ (41.8)	$ (26)
Impairments	0	0
Foreign currency translation	0	0
Net Balance	157.7	173.5	$ 189.3
Goodwill
Gross Balance	400.7	400.7
Impairments	0	0
Foreign currency translation	0.1	(0.1)
Net Balance	400.8	400.6	401
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross Balance	22.1	22.1	27
Impairments	0	(8)
Foreign currency translation	0	0
Gross carrying amount of intangible assets	622.3	635.3
Impairment of intangible assets	0	(13)
Foreign currency translation including goodwill	0.1	(0.1)
Net carrying amount of intangible assets	580.6	596.2	617.3
Amortization of intangible assets	15.8	15.8	$ 10.2
Insurance licenses
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross Balance	8.1	8.1
Impairments	0	0
Foreign currency translation	0	0
Net Balance	8.1	8.1
Trade Names
Indefinite-lived Intangible Assets (Excluding Goodwill) [Abstract]
Gross Balance	14	27
Impairments	0	(13)
Net Balance	14	14
Customer relationships
Finite lived intangible Asset
Gross Balance	17	17
Accumulated Amortization	(3.5)	(2.2)
Impairments	0	0
Foreign currency translation	0	0
Net Balance	13.5	14.8
Distribution relationships
Finite lived intangible Asset
Gross Balance	151	151
Accumulated Amortization	(25.5)	(15.8)
Impairments	0	0
Foreign currency translation	0	0
Net Balance	125.5	135.2
Technology
Finite lived intangible Asset
Gross Balance	15.5	15.5
Accumulated Amortization	(6.9)	(4.3)
Impairments	0	0
Foreign currency translation	0	0
Net Balance	8.6	11.2
Trade Names
Finite lived intangible Asset
Gross Balance	16	16
Accumulated Amortization	(5.9)	(3.7)
Impairments	0	0
Foreign currency translation	0	0
Net Balance	$ 10.1	$ 12.3

Goodwill and intangible asset_4

Goodwill and intangible assets - Estimation of remaining amortization expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortization of intangible assets
2020	$ 15.8
2021	15.8
2022	14.6
2023	13.8
2024	13.2
2025 and thereafter	84.5
Total remaining amortization expense	$ 157.7	$ 173.5	$ 189.3
Minimum
Amortization of intangible assets
Intangible asset useful life	2 years 3 months 18 days
Maximum
Amortization of intangible assets
Intangible asset useful life	19 years 10 months 24 days

Debt and standby letters of c_3

Debt and standby letters of credit facilities (Details) kr in Millions, $ in Millions	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 22, 2017USD ($)	Sep. 22, 2017SEK (kr)	Nov. 01, 2016USD ($)
Debt and standby letters of credit facilities
Long-term debt, total	$ 685.2	$ 696.8
2017 SEK Subordinated Notes
Debt and standby letters of credit facilities
Debt, at face value	295	307.6	$ 346.1	kr 2,750
Unamortized issuance costs	(3.8)	(4)
Long-term debt, total	$ 291.2	$ 303.6
Effective rate	4.00%	3.80%
2016 SIG Senior Notes
Debt and standby letters of credit facilities
Debt, at face value	$ 400	$ 400			$ 400
Unamortized discount	(2.3)	(2.6)
Unamortized issuance costs	(3.7)	(4.2)
Long-term debt, total	$ 394	$ 393.2
Effective rate	4.70%	4.70%

Debt and standby letters of c_4

Debt and standby letters of credit facilities - Schedule of contractual repayments (Details) $ in Millions	Dec. 31, 2019USD ($)
Debt Disclosure [Abstract]
Due in one year or less	$ 0
Due in one to three years	0
Due in three to five years	0
Due after five years	695
Total	$ 695

Debt and standby letters of c_5

Debt and standby letters of credit facilities - 2017 SEK Subordinated Notes and 2016 SIG Senior Notes (Details) kr in Millions, $ in Millions	Nov. 05, 2018USD ($)	Sep. 22, 2017USD ($)	Sep. 22, 2017SEK (kr)	Nov. 01, 2016USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 22, 2017SEK (kr)
Debt and standby letters of credit facilities
Outstanding preference shares redeemed	$ 164
Interest expense on debt					$ 31	$ 30.8	$ 22.4
2017 SEK Subordinated Notes
Debt and standby letters of credit facilities
Debt notes issued		$ 346.1			$ 295	$ 307.6		kr 2,750
Issue price (as a percent)		100.00%	100.00%
Term of redemption following occurrence of Specified Event		90 days	90 days
Debt issuance costs		$ 4.6
Underwriting fees		$ 3.5	kr 27.5
Annual interest rate (as a percent)					4.00%	3.80%
Interest expense on debt					$ 11.9	$ 11.7	3.3
Effective rate					4.00%	3.80%
2016 SIG Senior Notes
Debt and standby letters of credit facilities
Debt notes issued				$ 400	$ 400	$ 400
Issue price (as a percent)				99.209%
Debt issuance costs				$ 5.1
Underwriting fees				$ 3.4
Annual interest rate (as a percent)				4.60%
Interest expense on debt					$ 19.1	$ 19.1	$ 19.1
Net proceeds				$ 392.4
Effective rate					4.70%	4.70%
Preferred stocks | Sirius International Group, Ltd | 2017 SEK Subordinated Notes
Debt and standby letters of credit facilities
Outstanding preference shares redeemed					$ 250

Debt and standby letters of c_6

Debt and standby letters of credit facilities - 2007 SIG Senior Notes and Old Lyme Note (Details) - USD ($) $ in Millions	Apr. 25, 2017	Dec. 31, 2011	Dec. 31, 2019	Dec. 31, 2018
Debt and standby letters of credit facilities
Debt			$ 685.2	$ 696.8
Old Lyme Note
Debt and standby letters of credit facilities
Payment made on retirements	$ 3.8
Term of credit facility		5 years
Debt		$ 2.1
Percentage of principal amount of debt subject to upward or downward adjustments		50.00%
Principal amount of debt subject to upward or downward adjustment		$ 6
Amount of debt available for loss reserve development		3.4
Amount of debt available for loss reserve position		$ 1.7

Debt and standby letters of c_7

Debt and standby letters of credit facilities - Standby Letter of Credit Facilities (Details) kr in Billions	Dec. 31, 2019USD ($)	Dec. 31, 2019SEK (kr)	Nov. 06, 2019USD ($)letter_of_credit	Dec. 31, 2018USD ($)	Dec. 31, 2018SEK (kr)
Standby Letter of Credit Facilities
Number of standby letter of credit agreements renewed | letter_of_credit			2
Other Secured Letter of Credit and Trust Arrangement | Sirius America Insurance Company
Standby Letter of Credit Facilities
Secured letter of credit and trust arrangements were collateralized by pledged assets and assets in trust	$ 57,700,000			$ 56,200,000
Other Secured Letter of Credit and Trust Arrangement | Sirius Bermuda Insurance Company Ltd.
Standby Letter of Credit Facilities
Secured letter of credit and trust arrangements were collateralized by pledged assets and assets in trust	784,000,000			319,700,000
Sirius International | Nordea Bank London Abp
Standby Letter of Credit Facilities
Borrowing capacity			$ 90,000,000
Sirius International | DNB Bank ASA Sweden Branch
Standby Letter of Credit Facilities
Borrowing capacity			35,000,000
Sirius International | Standby Letters of Credit
Standby Letter of Credit Facilities
Borrowing capacity			125,000,000
Sirius International | Unsecured Standby Letters of Credit | DNB Bank ASA Sweden Branch
Standby Letter of Credit Facilities
Borrowing capacity			$ 25,000,000
Sirius International | Other Secured Letter of Credit and Trust Arrangement
Standby Letter of Credit Facilities
Secured letter of credit and trust arrangements were collateralized by pledged assets and assets in trust	$ 363,300,000	kr 3.4		$ 321,300,000	kr 2.9

Debt and standby letters of c_8

Debt and standby letters of credit facilities - Revolving Credit Facility (Details) - Revolving Credit Facility - USD ($) $ in Millions	1 Months Ended
	Feb. 28, 2018	Dec. 31, 2019
Line of Credit Facility [Line Items]
Term of credit facility	3 years
Borrowing capacity	$ 300
Outstanding amount		$ 0

Debt and standby letters of c_9

Debt and standby letters of credit facilities - Interest (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Total interest expense incurred	$ 31	$ 30.8	$ 22.4
Total interest paid	$ 29.9	$ 30	$ 22

Income taxes - Net income (loss

Income taxes - Net income (loss) before income taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net income (loss) before income taxes
Pre-tax (loss) income	$ (33.7)	$ 23.7	$ (109.9)
Bermuda
Net income (loss) before income taxes
Income (loss) before income taxes, Domestic	(32.8)	62.7	(95)
U.S.
Net income (loss) before income taxes
Income (loss) before income taxes, Foreign	(5.4)	(10.1)	(22.4)
U.K.
Net income (loss) before income taxes
Income (loss) before income taxes, Foreign	(29.1)	(14.9)	(27)
Sweden
Net income (loss) before income taxes
Income (loss) before income taxes, Foreign	(22.4)	(74.2)	(26.1)
Luxembourg
Net income (loss) before income taxes
Income (loss) before income taxes, Foreign	56	60.3	43.4
Netherlands
Net income (loss) before income taxes
Income (loss) before income taxes, Foreign	0	(0.1)	18.2
Other
Net income (loss) before income taxes
Income (loss) before income taxes, Foreign	$ 0	$ 0	$ (1)

Income taxes - Total income tax

Income taxes - Total income tax (expense) benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current tax (expense):
U.S. Federal	$ (1.6)	$ (7)	$ (0.9)
State	(2)	(2.2)	(2)
Non-U.S.	(1.5)	(19.8)	(3.6)
Total current tax benefit (expense)	(5.1)	(29)	(6.5)
Deferred tax (expense):
U.S. Federal	(8.8)	14.3	(8.7)
State	0.9	0.2	(2)
Non-U.S.	1.1	(25.9)	(9.2)
Total deferred tax (expense) benefit	(6.8)	(11.4)	(19.9)
Total income tax (expense) on pre-tax earnings	$ (11.9)	$ (40.4)	$ (26.4)

Income taxes - Effective Rate R

Income taxes - Effective Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Rate Reconciliation
Tax benefit (expense) at the statutory rate	$ 7.2	$ (5.2)	$ 24.2
Differences in taxes resulting from:
Change in valuation allowance	(20.7)	2.3	1.4
Tax reserve adjustments	13.9	(42)	(0.7)
Foreign tax credits	12.2	10.8	2.2
Results from internal restructuring	7.4	(9.1)	0
State taxes expense	(1.7)	(2.9)	(0.7)
Withholding taxes	(1.7)	(1.9)	(0.8)
Tax on Safety Reserve	(0.6)	(15.3)	0
Section 197 Intangible as result of internal restructuring	0	6.9	0
Other, net	(0.7)	(1.8)	(4.3)
Total income tax (expense) on pre-tax earnings	(11.9)	(40.4)	(26.4)
Pre-tax (loss) income	$ (33.7)	23.7	(109.9)
Swedish Tax Authority
Effective Rate Reconciliation
Statutory tax rate (as a percent)	21.40%
Non-Sweden
Differences in taxes resulting from:
Non-Sweden earnings	$ (19.6)	2.3	(18.4)
Pre-tax (loss) income	(11.3)	97.9	(83.8)
Luxembourg
Differences in taxes resulting from:
Tax rate change	(5.8)	0	0.4
Other
Differences in taxes resulting from:
Tax rate change	(1.6)	0.1	(29.7)
Sweden
Differences in taxes resulting from:
Tax rate change	$ (0.2)	$ 15.4	$ 0

Income taxes - Tax Cuts and Job

Income taxes - Tax Cuts and Jobs Act and Tax Payments and Receipts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net income tax payments	$ 9.3	$ 19.1	$ 16.7

Income taxes - Deferred Tax Inv

Income taxes - Deferred Tax Inventory (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred income tax assets related to:
Non-U.S. net operating loss carry forwards	$ 211.1	$ 249.8
Tax credit carry forwards	41.6	28.7
U.S. federal net operating loss and capital carry forwards	40.2	33.8
Loss reserve discount	6.6	7.3
Unearned premiums	4.3	3.1
Investment basis differences	3.6	0
Foreign currency translation on investments and other assets	3.4	0.8
Incentive compensation and benefit accruals	2.8	1.9
Deferred Interest	2.6	2.1
Allowance for doubtful accounts	1.5	1.4
Other items	3.9	2.7
Total gross deferred income tax assets	321.6	331.6
Valuation allowance	(79.8)	(64.3)
Total adjusted deferred tax asset	241.8	267.3
Deferred income tax liabilities related to:
Safety reserve	239.4	261.1
Intangible assets	25.7	28.7
Deferred acquisition costs	4.6	3.1
Net unrealized investment gains	3.7	0.3
Purchase Accounting	3.6	3
Investment basis differences	0	2.4
Other items	4	3.6
Total deferred income tax liabilities	281	302.2
Deferred tax liability	(39.2)	$ (34.9)
U.S. subsidiaries
Deferred income tax liabilities related to:
Deferred tax liability	(25.1)
Luxembourg subsidiaries
Deferred income tax liabilities related to:
Deferred tax liability	(141.6)
Sweden subsidiaries
Deferred income tax liabilities related to:
Deferred tax liability	$ (205.9)

Income taxes - Net Operating Lo

Income taxes - Net Operating Loss and Capital Loss Carryforwards (Details) $ in Millions	Dec. 31, 2019USD ($)
Net Operating Loss and Capital Loss Carryforwards
Total	$ 1,286.5
Gross deferred tax asset	251.3
Valuation allowance	(66.7)
Net deferred tax asset	184.6
Operating loss carryforward subject to annual limitation	115.4
Operating loss carryforward subject to SRLY provisions	11
Valuation allowance	79.8
U.S.
Net Operating Loss and Capital Loss Carryforwards
Total	194.4
Gross deferred tax asset	40.2
Valuation allowance	0
Net deferred tax asset	40.2
Valuation allowance	13
Luxembourg
Net Operating Loss and Capital Loss Carryforwards
Total	765
Gross deferred tax asset	190.8
Valuation allowance	(50.2)
Net deferred tax asset	140.6
Operating loss carryforwards	573.3
Valuation allowance	50.2
Sweden
Net Operating Loss and Capital Loss Carryforwards
Total	230.1
Gross deferred tax asset	3.8
Valuation allowance	0
Net deferred tax asset	3.8
U.K.
Net Operating Loss and Capital Loss Carryforwards
Total	97
Gross deferred tax asset	16.5
Valuation allowance	(16.5)
Net deferred tax asset	0
Valuation allowance	16.5
Belgium
Net Operating Loss and Capital Loss Carryforwards
Valuation allowance	0.1
2019-2023
Net Operating Loss and Capital Loss Carryforwards
Total	1.5
2019-2023 | U.S.
Net Operating Loss and Capital Loss Carryforwards
Total	1.5
2019-2023 | Luxembourg
Net Operating Loss and Capital Loss Carryforwards
Total	0
2019-2023 | Sweden
Net Operating Loss and Capital Loss Carryforwards
Total	0
2019-2023 | U.K.
Net Operating Loss and Capital Loss Carryforwards
Total	0
2024-2038
Net Operating Loss and Capital Loss Carryforwards
Total	171.5
2024-2038 | U.S.
Net Operating Loss and Capital Loss Carryforwards
Total	171.4
2024-2038 | Luxembourg
Net Operating Loss and Capital Loss Carryforwards
Total	0.1
2024-2038 | Sweden
Net Operating Loss and Capital Loss Carryforwards
Total	0
2024-2038 | U.K.
Net Operating Loss and Capital Loss Carryforwards
Total	0
No expiration date
Net Operating Loss and Capital Loss Carryforwards
Total	1,113.5
No expiration date | U.S.
Net Operating Loss and Capital Loss Carryforwards
Total	21.5
No expiration date | Luxembourg
Net Operating Loss and Capital Loss Carryforwards
Total	764.9
No expiration date | Sweden
Net Operating Loss and Capital Loss Carryforwards
Total	230.1
No expiration date | U.K.
Net Operating Loss and Capital Loss Carryforwards
Total	97
Expire in between 2022 to 2025
Net Operating Loss and Capital Loss Carryforwards
Operating loss carryforward subject to annual limitation	9.6
Expire in between 2030 to 2032
Net Operating Loss and Capital Loss Carryforwards
Operating loss carryforward subject to annual limitation	94.8
Expires in 2020 and 2021 | U.S.
Net Operating Loss and Capital Loss Carryforwards
Operating loss carryforwards	16.4
Refundable in 2023
Net Operating Loss and Capital Loss Carryforwards
Operating loss carryforwards	0.1
Expire in between 2021 to 2024 | Sweden
Net Operating Loss and Capital Loss Carryforwards
Operating loss carryforwards	$ 25.1

Income taxes - Uncertain Tax Po

Income taxes - Uncertain Tax Positions (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)subsidiary1	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Permanent differences
Balance at the beginning of the year	$ 64.9	$ 27.4	$ 24.2
Changes in prior year tax positions	(17.1)	1.4	0.2
Tax positions taken during the current year	(0.5)	36.2	3.8
Lapse in statute of limitations	(0.1)	0	(0.5)
Settlements with tax authorities	0	(0.1)	(0.3)
Balance at the end of the year	47.2	64.9	27.4
Temporary differences
Balance at the beginning of the year	0.1	1.8	4.1
Changes in prior year tax positions	0	0	(0.1)
Tax positions taken during the current year	0	(1.7)	(2.2)
Lapse in statute of limitations	0	0	0
Settlements with tax authorities	0	0	0
Balance at the end of the year	0.1	0.1	1.8
Interest and penalties
Balance at the beginning of the year	0.2	0.1	0.2
Changes in prior year tax positions	0	0.1	0.1
Tax positions taken during the current year	0	0	0
Lapse in statute of limitations	0	0	0
Settlements with tax authorities	0	0	(0.2)
Balance at the end of the year	0.2	0.2	0.1
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Unrecognized Tax Benefits, Beginning Balance	65.2	29.3	28.5
Changes in prior year tax positions		1.5	0.2
Changes in prior year tax positions	(17.1)
Tax positions taken during the current year		34.5	1.6
Tax positions taken during the current year	(0.5)
Lapse in statute of limitations	(0.1)	0	(0.5)
Settlements with tax authorities	0	(0.1)	(0.5)
Unrecognized Tax Benefits, Ending Balance	47.5	65.2	29.3
Reversal of reserves for unrecognized tax benefits on permanent differences and interest and penalties	47.2
Reversal of reserves for unrecognized tax benefits on temporary differences	0.1
Interest income (expense)	0	0.1	$ (0.1)
Accrued interest	$ 0.2	$ 0.2
Number of subsidiaries claimed deductions for interest paid on intra-group debt instruments | subsidiary1	2
Swedish Tax Authority | Sweden subsidiaries
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Reserve attributable to uncertain tax positions	$ 45.1

Derivatives - Interest Rate Cap

Derivatives - Interest Rate Cap (Details) - Interest rate cap $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)financial_institution	Dec. 31, 2018USD ($)
Derivatives
Number of financial institutions entered into derivative contracts | financial_institution	2
Derivatives not designated as hedging instruments
Derivatives
Collateral balances held | $	$ 0.2	$ 0

Derivatives - Classification an

Derivatives - Classification and Fair Value of Derivatives in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivatives
Derivative assets	$ 11.4	$ 4.1
Derivative liabilities	9.5	5.1
Interest rate cap | Derivatives not designated as hedging instruments
Derivatives
Notional Value	250	250
Interest rate cap | Derivatives not designated as hedging instruments | Other assets
Derivatives
Derivative assets	0	0.2
Interest rate cap | Derivatives not designated as hedging instruments | Other liabilities
Derivatives
Derivative liabilities	0	0
Foreign currency swaps | Derivatives not designated as hedging instruments
Derivatives
Notional Value	90	45
Foreign currency swaps | Derivatives not designated as hedging instruments | Other assets
Derivatives
Derivative assets	0	0
Foreign currency swaps | Derivatives not designated as hedging instruments | Other liabilities
Derivatives
Derivative liabilities	3.6	4.6
Foreign currency forwards | Derivatives not designated as hedging instruments
Derivatives
Notional Value	30	0
Foreign currency forwards | Derivatives not designated as hedging instruments | Other assets
Derivatives
Derivative assets	2.7	0
Foreign currency forwards | Derivatives not designated as hedging instruments | Other liabilities
Derivatives
Derivative liabilities	5.7	0
Weather derivatives | Derivatives not designated as hedging instruments
Derivatives
Notional Value	110.7	150.5
Weather derivatives | Derivatives not designated as hedging instruments | Other assets
Derivatives
Derivative assets	7	3.9
Weather derivatives | Derivatives not designated as hedging instruments | Other liabilities
Derivatives
Derivative liabilities	0	0
Equity futures contracts | Derivatives not designated as hedging instruments
Derivatives
Notional Value	34.5	0
Equity futures contracts | Derivatives not designated as hedging instruments | Other assets
Derivatives
Derivative assets	0	0
Equity futures contracts | Derivatives not designated as hedging instruments | Other liabilities
Derivatives
Derivative liabilities	0	0
Equity warrants | Derivatives not designated as hedging instruments
Derivatives
Notional Value	0.4	0
Equity warrants | Derivatives not designated as hedging instruments | Other assets
Derivatives
Derivative assets	0.4	0
Equity warrants | Derivatives not designated as hedging instruments | Other liabilities
Derivatives
Derivative liabilities	0	0
Equity put options | Derivatives not designated as hedging instruments
Derivatives
Notional Value	31	6.2
Equity put options | Derivatives not designated as hedging instruments | Other assets
Derivatives
Derivative assets	1.3	0
Equity put options | Derivatives not designated as hedging instruments | Other liabilities
Derivatives
Derivative liabilities	$ 0.2	$ 0.5

Derivatives - Classification _2

Derivatives - Classification and Fair Value of Derivatives in Consolidated of (Loss) Income Statements (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest rate cap | Other revenues
Derivatives
Gains (losses) recognized in earnings	$ (0.2)	$ 0.1	$ (1.5)
Foreign currency swaps | Net foreign exchange gains
Derivatives
Gains (losses) recognized in earnings	4.2	6.9	(11.3)
Foreign currency forwards | Net foreign exchange gains
Derivatives
Gains (losses) recognized in earnings	(10.4)	0	(0.3)
Weather derivatives | Other revenues
Derivatives
Gains (losses) recognized in earnings	(1.1)	5.2	(1.5)
Equity futures contracts | Net realized investment gains (losses)
Derivatives
Gains (losses) recognized in earnings	(1.7)	1.7	0
Equity put options | Net realized investment gains (losses)
Derivatives
Gains (losses) recognized in earnings	(0.8)	0	0
Equity put options | Net unrealized investment gains (losses)
Derivatives
Gains (losses) recognized in earnings	(0.8)	0	0
Equity warrants | Net unrealized investment gains (losses)
Derivatives
Gains (losses) recognized in earnings	$ 0.4	$ 0	$ 0

Employee benefit plans and co_3

Employee benefit plans and compensation plans - Defined benefit plans (Details)	36 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Employee benefit plans and compensation plans
Average return on plan assets	7.00%
Sweden
Employee benefit plans and compensation plans
Percentage of total plan assets	94.00%	94.00%
Germany
Employee benefit plans and compensation plans
Percentage of total plan assets	6.00%	6.00%

Employee benefit plans and co_4

Employee benefit plans and compensation plans - Defined benefit plans - Plan Assets (Details)	Dec. 31, 2019	Dec. 31, 2018
International equities
Employee benefit plans and compensation plans
Percentage of plan assets	13.00%	11.40%
Swedish equities
Employee benefit plans and compensation plans
Percentage of plan assets	8.90%	7.50%
Swedish nominal bonds
Employee benefit plans and compensation plans
Percentage of plan assets	40.70%	40.30%
Real estate
Employee benefit plans and compensation plans
Percentage of plan assets	10.20%	11.20%
Private equity
Employee benefit plans and compensation plans
Percentage of plan assets	9.40%	10.40%
Other
Employee benefit plans and compensation plans
Percentage of plan assets	17.80%	19.20%

Employee benefit plans and co_5

Employee benefit plans and compensation plans - Defined benefit plans - Obligations (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Sweden
Employee benefit plans and compensation plans
Discount rate	2.30%	2.50%
Increase in compensation levels rate	3.30%	3.20%
Turnover rate	3.00%	3.00%
Additional information
Pension liability (in years)	20 years
Germany
Employee benefit plans and compensation plans
Discount rate	1.90%	1.70%
Increase in compensation levels rate	2.00%	2.00%
Additional information
Pension liability (in years)	17 years

Employee benefit plans and co_6

Employee benefit plans and compensation plans - Defined benefit plans - Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined benefit plans
Change in benefit obligation
Projected benefit obligation, beginning of year	$ 17.5	$ 17.4
Service cost	1.5	1
Interest cost	0.4	0.4
Actuarial losses	2.9	0.6
Benefit payments	(1.2)	(0.4)
Tax payments	(0.3)	(0.2)
Currency revaluation effect	(0.6)	(1.3)
Projected benefit obligation, end of year	20.3	17.5	$ 17.4
Change in plan assets
Fair value of plan assets, beginning of year	16.4	16.1
Employer contributions	1.4	1.2
Benefit payments	(0.4)	(0.3)
Interest income	1	0.8
Currency revaluation effect	(0.6)	(1.4)
Fair value of plan assets, end of year	17.7	16.4	16.1
Funded status at the end of year	(2.6)	(1.1)
Foreign Plan | Defined benefit plans
Change in benefit obligation
Actuarial losses	(0.5)	(0.8)	$ (0.3)
Sweden
Change in plan assets
Funded status at the end of year	2.5	3
Germany
Change in plan assets
Funded status at the end of year	$ (5.1)	$ (4.1)

Employee benefit plans and co_7

Employee benefit plans and compensation plans - Defined benefit plans - Additional information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Sweden
Employee benefit plans and compensation plans
Increase in the defined benefit obligation related to a 100 basis point decrease in the discount rate	$ 2.7
Germany
Employee benefit plans and compensation plans
Increase in the defined benefit obligation related to a 50 basis point decrease in the discount rate	0.7
Decrease in the defined benefit obligation related to a 50 basis point increase in the discount rate	0.6
Defined benefit plans
Employee benefit plans and compensation plans
Accumulated benefit obligation	$ 20.3	$ 17.5	$ 17.4

Employee benefit plans and co_8

Employee benefit plans and compensation plans - Defined benefit plans - Expense (Details) - Defined benefit plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee benefit plans and compensation plans
Actuarial (loss)	$ 2.9	$ 0.6
Foreign Plan
Employee benefit plans and compensation plans
Service cost	(0.9)	(1.2)	$ (0.8)
Interest cost	0.1	0.1	2.2
Actuarial (loss)	(0.5)	(0.8)	(0.3)
Net periodic pension expense	$ (1.3)	$ (1.9)	$ 1.1

Employee benefit plans and co_9

Employee benefit plans and compensation plans - Defined benefit plans - Payments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Employer benefit payments/settlements	$ 0.3	$ 0.4
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2020	0.5
2021	0.4
2022	0.4
2023	0.4
2024	0.5
2024 -2028	3.1
Total benefit payments required	$ 5.3

Employee benefit plans and c_10

Employee benefit plans and compensation plans - Defined contribution plans - Non U.S and U.S. (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined contribution plans
Benefit plan expenses recognized		$ 8.3	$ 7.6	$ 4.9
SIHC 401(k) Plan
Defined contribution plans
Employer match, first level, percent		100.00%
Percentage of salary matched, first level, percent		2.00%
Employer match, second level, percent		50.00%
Percentage of salary matched, second level, percent		4.00%
Matching contribution expense		$ 0.8	0.8	1.3
Variable contribution as percentage of salary		7.00%
IRS annual covered compensation limit		$ 0.3
Variable contribution expense				0.3
IMG 401(k) Plan
Defined contribution plans
Employer match, first level, percent		100.00%
Percentage of salary matched, first level, percent		1.00%
Employer match, second level, percent		50.00%
Matching contribution expense	$ 0.3	$ 0.7	0.6
Armada 401(k) Plan
Defined contribution plans
Discretionary matching contributions	$ 0.1	$ 0.2	0.2
Minimum | IMG 401(k) Plan
Defined contribution plans
Percentage of salary matched, second level, percent		1.00%
Maximum | IMG 401(k) Plan
Defined contribution plans
Percentage of salary matched, second level, percent		6.00%
UNITED KINGDOM
Defined contribution plans
Employer contribution as percentage of employees' salary		12.00%
Belgium | Minimum
Defined contribution plans
Employer contribution as percentage of employees' salary		6.50%
Belgium | Maximum
Defined contribution plans
Employer contribution as percentage of employees' salary		8.50%
Bermuda
Defined contribution plans
Employer contribution as percentage of employees' salary		10.00%
Employee vesting period		2 years
Bermuda | Sirius Bermuda Insurance Company Ltd.
Defined contribution plans
Benefit plan expenses recognized		$ 0.6	$ 0.5	$ 0.4
Swisscanto plan | Switzerland | Minimum
Defined contribution plans
Employer share of total premium charges incurred, percent		60.00%
Employee share of total premium charges incurred, percent		30.00%
Swisscanto plan | Switzerland | Maximum
Defined contribution plans
Employer share of total premium charges incurred, percent		70.00%
Employee share of total premium charges incurred, percent		40.00%

Employee benefit plans and c_11

Employee benefit plans and compensation plans - Share-Based and Other Long-Term Incentive Compensation Plans (Details) - USD ($) $ / shares in Units, $ in Millions	Aug. 22, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Aug. 06, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance under the plan (in shares)		8,416,533
Payments for share-based awards		$ 3.3	$ 0	$ 0
Total share-based compensation expense - pre-tax		$ 4.7	$ 2.5	0
Non-employee independent directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		1 year
Shares granted (in shares)		37,039	24,475
Total share-based compensation expense - pre-tax		$ 0.3
2018 Omnibus plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized to be issued (in shares)					14,114,904
Vesting period		3 years
2016 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		2 years
Shares granted (in shares)		0
Total share-based compensation expense - pre-tax		$ (3.4)	$ 1	0
PSUs | 2018 Omnibus plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value (in dollars per share)		$ 12.75
Shares granted (in shares)		756,183
Total share-based compensation expense - pre-tax		$ 0.7	1.5	0
PSUs | Long Term Incentive Plan 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
PSUs | 2019 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Grant date fair value (in dollars per share)		$ 12.75
Shares granted (in shares)		408,370
Total share-based compensation expense - pre-tax		$ 0.8	0	0
PSUs | 2019 Long Term Incentive Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		0.00%
PSUs | 2019 Long Term Incentive Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		200.00%
PSUs | 2016 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)		1,428,185
Total share-based compensation expense - pre-tax		$ 5.8	0	0
RSUs | 2019 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value (in dollars per share)		$ 12.75
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected annual dividend yield		1.75%
Expected volatility		20.00%
Risk-free interest rate		2.51%
Expected term		4 years
Total share-based compensation expense - pre-tax		$ 0.8	$ 0	$ 0
Stock Options | 2019 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Shares issued (in shares)		1,374,945
Expiration period		5 years
Fair value of stock options		$ 2.8
Exercise price (in dollars per share)		$ 12.75
IPO Incentive Awards | 2018 Omnibus plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of years over which shares to be purchased		3 years
IPO Incentive Awards | 2018 Omnibus plan | 2019 ROE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
IPO Incentive Awards | 2018 Omnibus plan | 2020 ROE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
IPO Incentive Awards | 2018 Omnibus plan | 2021 ROE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
IPO Incentive Awards | 2018 Omnibus plan | 2019-2021 Average ROE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)		0	149,236
Maximum number of shares to be purchased (in shares)	1,000
Minimum number of shares to be purchased (in shares)	100
Net promissory notes		$ 0.4	$ 0.9
9.0% ROE | IPO Incentive Awards | 2018 Omnibus plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payout as percentage of awarded shares		100.00%
13.5% ROE | IPO Incentive Awards | 2018 Omnibus plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payout as percentage of awarded shares		150.00%
For the first 100 shares | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common shares as a percentage on its market value	85.00%
For the next 900 shares | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common shares as a percentage on its market value	100.00%

Employee benefit plans and c_12

Employee benefit plans and compensation plans Employee benefit plans and compensation plans - Pre-tax and after-tax share-based compensation expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense - pre-tax	$ 4.7	$ 2.5	$ 0
Total share-based compensation expense - after-tax	3.8	2	0
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense - pre-tax	5.8	0	0
Total share-based compensation expense - after-tax	4.6	0	0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense - pre-tax	0.8	0	0
Total share-based compensation expense - after-tax	0.6	0	0
Phantom share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense - pre-tax			3.9
2018 Omnibus plan | PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense - pre-tax	0.7	1.5	0
Modification of award, pre tax	1.5
Total share-based compensation expense - after-tax	0.6	1.2	0
Modification of award, after tax	1.2
2019 Long Term Incentive Plan | PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense - pre-tax	0.8	0	0
Total share-based compensation expense - after-tax	0.7	0	0
2016 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense - pre-tax	(3.4)	1	0
Total share-based compensation expense - after-tax	$ (2.7)	$ 0.8	$ 0

Employee benefit plans and c_13

Employee benefit plans and compensation plans Employee benefit plans and compensation plans - Unrecognized compensation cost (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
2016 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested awards	$ 0.7
Weighted average recognition period (years)	1 year
PSUs | 2018 Omnibus plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested awards	$ 4
Weighted average recognition period (years)	2 years
PSUs | 2019 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested awards	$ 2
Weighted average recognition period (years)	2 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested awards	$ 11.8
Weighted average recognition period (years)	1 year 10 months 24 days
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested awards	$ 2
Weighted average recognition period (years)	2 years 2 months 12 days

Employee benefit plans and c_14

Employee benefit plans and compensation plans Employee benefit plans and compensation plans - Outstanding share-settled awards (Details)	12 Months Ended
	Dec. 31, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning of the year (in shares)	0
Granted (in shares)	1,374,945
Vested (in shares)	0
Forfeited (in shares)	0
Unvested, end of the year (in shares)	1,374,945
2016 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning of the year (in shares)	1,765,637
Granted (in shares)	0
Vested (in shares)	33,307
Forfeited (in shares)	861,859
Unvested, end of the year (in shares)	870,471
PSUs | 2018 Omnibus plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning of the year (in shares)	0
Granted (in shares)	756,183
Vested (in shares)	0
Forfeited (in shares)	201,020
Unvested, end of the year (in shares)	555,163
PSUs | 2019 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning of the year (in shares)	0
Granted (in shares)	408,370
Vested (in shares)	0
Forfeited (in shares)	17,234
Unvested, end of the year (in shares)	391,136
RSUs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning of the year (in shares)	0
Granted (in shares)	1,428,185
Vested (in shares)	0
Forfeited (in shares)	74,333
Unvested, end of the year (in shares)	1,353,852

Employee benefit plans and c_15

Employee benefit plans and compensation plans - Transaction and retention bonuses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Transaction bonuses recognized			$ 36.9
Amount received from former parent for transaction and retention bonuses		$ 25.3	30.5
Retention bonuses recorded		13.3	17.6
2016 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of incentive awards paid to employees received from White Mountains		$ 1.4	$ 2.5
Retention awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Retention awards issued	$ 10.7
Retention awards recognized	$ 2.1

Common shareholder's equity, _2

Common shareholder's equity, mezzanine equity, and non controlling interests - Common shareholder (Details) - USD ($)	Nov. 05, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Common shareholder
Common shares authorized (in shares)		500,000,000
Common shares par value (in dollars per share)		$ 0.01
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued beginning of the year (in shares)		115,151,251	120,000,000	120,000,000
Shares outstanding beginning of the year (in shares)		115,151,251	120,000,000
Issuance of shares (in shares)		148,090	4,670,531	0
Shares redeemed (in shares)	(9,519,280)	0	(9,519,280)	0
Shares issued end of the year (in shares)		115,299,341	115,151,251	120,000,000
Shares outstanding end of the year (in shares)		115,299,341	115,151,251	120,000,000
Common dividends paid		$ 0	$ 0	$ 0
Value of shares redeemed	$ 164,000,000
Series B preference shares
Common shareholder
Preferred shares authorized (in shares)	15,000,000	15,000,000
Preferred shares par value (in dollars per share)	$ 0.01	$ 0.01

Common shareholder's equity, _3

Common shareholder's equity, mezzanine equity, and non controlling interests - Mezzanine equity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Nov. 05, 2018
Mezzanine equity
Redeemable preference shares with accrued dividend carrying value	$ 223	$ 232.2
Series B preference shares
Mezzanine equity
Preferred shares authorized (in shares)	15,000,000		15,000,000
Preferred shares par value (in dollars per share)	$ 0.01		$ 0.01
Preferential rights, Minimum gross proceeds from the issuance of senior or pari passu shares	$ 100
Redeemable preference shares with accrued dividend carrying value	$ 223	$ 232.2
Series B preference shares | Private Placement | Preference Share Investors
Mezzanine equity
Share subscriptions (in shares)			11,901,670
Series A redeemable preference shares
Mezzanine equity
Redeemable preference shares outstanding (in shares)			100,000
Redemption amount of preference shares			$ 95
Gain on redemption of preference shares			$ 13.8
Series A redeemable preference shares | IMGAH
Mezzanine equity
Preferred shares authorized (in shares)	150,000
Number of convertible preferred shares issued as a consideration (in shares)	100,000
Redeemable preference share liquidation preference per share (in dollars per share)	$ 1,000

Common shareholder's equity, _4

Common shareholder's equity, mezzanine equity, and non controlling interests - Non-controlling interests (Details) - USD ($) $ / shares in Units, $ in Millions	Nov. 05, 2018	Oct. 25, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in non-controlling interest
Balance at beginning			$ 1.7	$ 0.2	$ 251.3
Net income attributable to non-controlling interests			1.7	1.4	13.7
Dividends to non-controlling interests			(1)	0	(14.1)
Other, net			0	0.1	(250.7)
Balance at end			$ 2.4	$ 1.7	$ 0.2
Stock redeemed (in shares)	9,519,280		0	9,519,280	0
Perpetual Non-Cumulative Preferred Shares | Sirius International Group, Ltd
Change in non-controlling interest
Stock redeemed (in shares)		250,000
Preferred stock redemption price per share (In dollars per share)		$ 1,000
Alstead Re
Change in non-controlling interest
Balance at beginning			$ 1.7
Balance at end			$ 2.3	$ 1.7

Earnings per share (Details)

Earnings per share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net (loss)									$ (45.6)	$ (16.7)	$ (136.3)
Less: Income attributable to non-controlling interests									(1.7)	(1.4)	(13.7)
Change in carrying value of Series B preference shares									9.2	(36.4)	0
Less: Accrued dividends on Series A redeemable preference shares									0	(2.6)	(6.1)
Add: Redemption of SeriesﾠA redeemable preference shares									0	13.8	0
Net (loss) attributable to Sirius Group common shareholders									(38.1)	(43.3)	(156.1)
Change in carrying value of Series B preference shares									(9.2)	0	0
Net (loss) attributable to Sirius Group common shareholders on a diluted basis									$ (47.3)	$ (43.3)	$ (156.1)
Denominator:
Weighted average shares outstanding for basic earnings per share (in shares)									115,234,105	119,253,924	120,000,000
Add: Series B preference shares (in shares)									11,901,670	0	0
Weighted average shares outstanding for diluted earnings per share (in shares)									127,135,775	119,253,924	120,000,000
Earnings per share
Basic earnings per share (in dollars per share)	$ (1.19)	$ (0.02)	$ 0.05	$ 0.75	$ (1.31)	$ (0.23)	$ 0.78	$ 0.32	$ (0.33)	$ (0.36)	$ (1.30)
Diluted earnings per share (in dollars per share)	$ (1.19)	$ (0.06)	$ 0.05	$ 0.74	$ (1.31)	$ (0.23)	$ 0.78	$ 0.32	$ (0.37)	$ (0.36)	$ (1.30)
Potentially dilutive securities (in shares)									17,057,249	23,433,114	0

Accumulated other comprehensi_3

Accumulated other comprehensive (loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated other comprehensive (loss)
Balance at beginning of year	$ 1,706.2	$ 1,917.2
Other comprehensive (loss)	(35.1)	(61.9)	$ 71.7
Balance at end of year	1,642.8	1,706.2	1,917.2
Accumulated other comprehensive (loss)
Accumulated other comprehensive (loss)
Balance at beginning of year	(202.4)	(140.5)	(212.2)
Other comprehensive (loss)	(35.1)	(61.9)	71.7
Balance at end of year	(237.5)	(202.4)	(140.5)
Foreign currency translation adjustment
Accumulated other comprehensive (loss)
Balance at beginning of year	(202.4)	(140.5)	(212.2)
Other comprehensive (loss)	(35.1)	(61.9)	71.7
Balance at end of year	$ (237.5)	$ (202.4)	$ (140.5)

Statutory capital and surplus -

Statutory capital and surplus - Non U.S. and U.S. (Details) £ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)subsidiary1	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2019GBP (£)subsidiary1
Sirius Bermuda
Statutory and capital surplus
Ownership percentage	87.00%			87.00%
Bermuda
Statutory and capital surplus
Number of subsidiaries | subsidiary1	2			2
Actual statutory capital and surplus		$ 2,200
Bermuda | Sirius Bermuda
Statutory and capital surplus
Solvency Capital Requirement		839.1
Bermuda | Alstead Re
Statutory and capital surplus
Solvency Capital Requirement		2.5
Sweden
Statutory and capital surplus
Solvency Capital Requirement	$ 1,200
Actual statutory capital and surplus	$ 1,600
U.K. | Sirius International Corporate Member Ltd
Statutory and capital surplus
Ownership percentage	100.00%			100.00%
Lloyd's approved net capacity	$ 120			£ 91
U.S. | Sirius America
Statutory and capital surplus
Actual statutory capital and surplus	522.1	522.2
Statutory net (loss) income	(25)	(9.9)	$ (6.4)
NAIC risk based capital authorized control level	110.1
U.S. | Oakwood
Statutory and capital surplus
Actual statutory capital and surplus	39.7	40.5
Statutory net (loss) income	(1)	(1.1)	0.5
NAIC risk based capital authorized control level	4.1
U.S. | Empire
Statutory and capital surplus
Solvency Capital Requirement	8.9
Actual statutory capital and surplus	10.8	10.7
Statutory net (loss) income	0.2	0.1	$ (0.3)
NAIC risk based capital authorized control level	0.7
U.S. | WRM America
Statutory and capital surplus
Solvency Capital Requirement	9.8
Actual statutory capital and surplus	13.9	13.9
Statutory net (loss) income	0	$ (0.6)
NAIC risk based capital authorized control level	$ 0.1

Statutory capital and surplus_2

Statutory capital and surplus - Dividend Capacity, Capital Maintenance and Safety Reserve (Details) kr in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2019USD ($)	Dec. 31, 2019SEK (kr)	Dec. 31, 2018USD ($)	Dec. 31, 2019SEK (kr)
Dividend Capacity
Dividend declaration notice period		10 days	10 days
Target capital level		120.00%			120.00%
Dividends paid to shareholders		$ 0		$ 0
Net unrestricted cash, short term investments, and fixed maturity investments		42.9
Safety Reserve
Deferred tax liability		$ 281		302.2
Swedish Tax Authority
Safety Reserve
Statutory tax rate (as a percent)		21.40%	21.40%
Additional tax expense		$ 1.2	kr 11.4
Deferred tax liability		$ 13.5			kr 131.2
Sirius Bermuda
Dividend Capacity
Percentage of regulatory capital available for distribution without prior approval of regulatory authorities		25.00%	25.00%
Minimum number of days before, capital to be transferred		7 days	7 days
Amount available for dividend payments		$ 523.8
Ownership percentage		87.00%			87.00%
Dividends paid		$ 80
Sirius International
Dividend Capacity
Amount available for dividend payments		$ 401.5
Ownership percentage		82.00%			82.00%
Dividends paid		$ 17.7	kr 167.1
Safety Reserve
Safety reserve		1,100			kr 10,200
Amount equal to the deferred tax liability on the safety reserve that is included in solvency capital		$ 225.9
Sirius America
Dividend Capacity
Percentage of statutory surplus available for dividend payments without regulatory approval		10.00%	10.00%
Earned surplus		$ 88.8
Capital Maintenance
Statutory risk-based capital required, percent		125.00%			125.00%
U.S. | Sirius America
Dividend Capacity
Actual statutory capital and surplus		$ 522.1		$ 522.2
Scenario, Forecast | Swedish Tax Authority
Safety Reserve
Statutory tax rate (as a percent)	20.60%

Investments in unconsolidated_3

Investments in unconsolidated entities - Other long-term investments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Investments in unconsolidated entities
Other long-term investments	$ 346.8	$ 365
Investments in unconsolidated entities
Investments in unconsolidated entities
Other long-term investments	346.8	365
Equity method investments	0	0
Investments in unconsolidated entities | Equity method eligible unconsolidated entities, at fair value
Investments in unconsolidated entities
Other long-term investments	151.9	169.4
Investments in unconsolidated entities | Other unconsolidated investments, at fair value
Investments in unconsolidated entities
Other long-term investments	$ 194.9	$ 195.6

Investments in unconsolidated_4

Investments in unconsolidated entities - Equity method unconsolidated entities (Details) - Investments in unconsolidated entities - Equity method eligible unconsolidated entities, at fair value	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
BE Reinsurance Limited
Investments in unconsolidated entities
Ownership interest	24.90%	25.00%
BioVentures Investors (Offshore) IV ﾠLP
Investments in unconsolidated entities
Ownership interest	73.00%	73.00%
Camden Partners Strategic Fund V (Cayman),ﾠ LP
Investments in unconsolidated entities
Ownership interest	39.40%	36.40%
Diamond LS I LP
Investments in unconsolidated entities
Ownership interest	16.00%	3.90%
Gateway Fund LP
Investments in unconsolidated entities
Ownership interest	15.00%	0.00%
Monarch
Investments in unconsolidated entities
Ownership interest	12.80%	12.80%
NEC Cypress Buyer LLC
Investments in unconsolidated entities
Ownership interest	0.00%	13.30%
New Energy Capital Infrastructure Credit Fundﾠ LP
Investments in unconsolidated entities
Ownership interest	30.50%	22.90%
New Energy Capital Infrastructure Offshore Credit Fundﾠ LP
Investments in unconsolidated entities
Ownership interest	30.50%	54.90%
Pie Preferred Stock
Investments in unconsolidated entities
Ownership interest	30.10%	0.00%
Pie Series B Preferred Stock
Investments in unconsolidated entities
Ownership interest	22.40%	0.00%
Quintana Energy Partners
Investments in unconsolidated entities
Ownership interest	21.80%	21.80%
Tuckerman Capital VﾠLP
Investments in unconsolidated entities
Ownership interest	48.30%	47.60%
Tuckerman Capital V Co-Investment IﾠLP
Investments in unconsolidated entities
Ownership interest	48.10%	47.70%

Investments in unconsolidated_5

Investments in unconsolidated entities - Summarized Financial Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance sheet data:
Total assets	$ 6,413.8				$ 6,007.7				$ 6,413.8	$ 6,007.7
Total liabilities	4,548				4,069.3				4,548	4,069.3
Income statement data:
Revenues	352	$ 487.4	$ 441	$ 439.7	336.8	$ 351.7	$ 441.8	$ 327.5	1,720.1	1,457.8	$ 1,134.1
Expenses	(506)	$ (498.7)	$ (430.7)	$ (318.4)	(482.3)	$ (386.3)	$ (292.4)	$ (273.1)	(1,753.8)	(1,434.1)	(1,244)
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Balance sheet data:
Total assets	594.5				591.1				594.5	591.1
Total liabilities	$ 47.6				$ 28.7				47.6	28.7
Income statement data:
Revenues									72.7	55.4	60.3
Expenses									$ (30.2)	$ (25.1)	$ (28.8)

Variable interest entities - Al

Variable interest entities - Alstead Re Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets:
Fixed maturity investments	$ 1,681	$ 1,949.2
Short-term investments	1,085.2	715.5
Cash	136.3	119.4
Accrued investment income	11.2	14.1
Insurance and reinsurance premiums receivable	730.1	630.6
Funds held by ceding companies	293.9	186.8
Deferred acquisition costs	148.2	141.6	$ 120.9	$ 84.7
Total assets	6,413.8	6,007.7
Liabilities
Total unpaid loss and LAE reserves	2,331.5	2,016.7	$ 1,898.5	$ 1,620.1
Unearned insurance and reinsurance premiums	708	647.2
Other liabilities	201.3	150.5
Total liabilities	4,548	4,069.3
VIEs
Liabilities
Other liabilities	0.1	0
Alstead Re
Assets:
Fixed maturity investments	3.9	4
Short-term investments	0.5	0.3
Cash	0.1	0.2
Total investments	4.5	4.5
Accrued investment income	0	0.1
Insurance and reinsurance premiums receivable	(0.3)	3.7
Funds held by ceding companies	3.4	5.2
Deferred acquisition costs	0.3	0.9
Total assets	7.9	14.4
Liabilities
Total unpaid loss and LAE reserves	0.5	4.6
Unearned insurance and reinsurance premiums	0.6	3.7
Total liabilities	$ 1.2	$ 8.3

Variable interest entities - Un

Variable interest entities - Unconsolidated VIE (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Variable interest entities
Other long-term investments	$ 346.8	$ 365
Total assets	6,413.8	6,007.7
Unconsolidated VIE
Variable interest entities
Other long-term investments	257.8	209.1
Total assets	257.8	209.1
On-Balance Sheet
Variable interest entities
Other long term investments	102.6	103.1
Total assets	102.6	103.1
Off-Balance Sheet
Variable interest entities
Other long term investments	16.3	32
Total assets	16.3	32
Other long-term investments
Variable interest entities
Other long term investments	118.9	135.1
Total assets	$ 118.9	$ 135.1

Transactions with related par_2

Transactions with related parties (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Transactions with related parties
Gross written premiums	$ 1,902.7	$ 1,821	$ 1,439.3
Receivables due from affiliates	16.1	14.3
Payables due to affiliates	0.9	0
Insurance and MGU affiliates, or their subsidiaries
Transactions with related parties
Gross written premiums	$ 88.6	$ 67.9	$ 3.5

Commitments and contingencies -

Commitments and contingencies - Gross reinsurance premiums written (Details) - intermediary	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gross written premium by intermediary
Number of reinsurance intermediaries	3	3	3
Gross written premium by intermediary	69.00%	70.00%	65.00%
AON Corporation and subsidiaries
Gross written premium by intermediary
Gross written premium by intermediary	24.00%	26.00%	22.00%
Guy Carpenter & Company and subsidiaries
Gross written premium by intermediary
Gross written premium by intermediary	24.00%	26.00%	25.00%
WT Butler and Co. Ltd.
Gross written premium by intermediary
Gross written premium by intermediary	11.00%	10.00%	10.00%
Willis Towers Watson plc and subsidiaries
Gross written premium by intermediary
Gross written premium by intermediary	10.00%	8.00%	8.00%

Commitments and contingencies_2

Commitments and contingencies - Geographic Concentration (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Third party reinsurance
Net written premiums	$ 1,502.6	$ 1,357.1	$ 1,090.2
U.S.
Third party reinsurance
Net written premiums	922.3	794.7	563.1
Europe
Third party reinsurance
Net written premiums	268.9	276.5	262.3
Canada, the Caribbean, Bermuda and Latin America
Third party reinsurance
Net written premiums	102.5	103.6	111.4
Asia and Other
Third party reinsurance
Net written premiums	$ 208.9	$ 182.3	$ 153.4

Commitments and contingencies_3

Commitments and contingencies - Lloyd's Central Fund (Details) - Lloyd's Central Fund $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Gross written premium by intermediary
Contribution to Lloyd's Central Fund	$ 0.5
Contribution to Lloyd's Central Fund as percent of gross written premium	0.35%
Maximum additional contribution that may be levied, as a percentage of capacity.	3.00%

Commitments and contingencies_4

Commitments and contingencies - Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases
Operating lease expense	$ 12.6
Rent expense		$ 11.7	$ 10.2
Operating lease right-of-use assets	27.4
Lease liabilities	$ 29.3
Leased offices
Leases
Weighted average lease term (years)	7 years
Leased equipment
Leases
Weighted average lease term (years)	3 years

Commitments and contingencies_5

Commitments and contingencies - Lease balances (Details) $ in Millions	Dec. 31, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Operating lease right-of-use assets	$ 27.4
Current lease liabilities	8.3
Non-current lease liabilities	$ 21

Commitments and contingencies_6

Commitments and contingencies - Weighted average remaining lease term and weighted average discount rate (Details)	Dec. 31, 2019
Leased offices
Property, Plant and Equipment [Line Items]
Weighted average lease term (years)	7 years
Weighted average discount rate:	3.70%
Leased equipment
Property, Plant and Equipment [Line Items]
Weighted average lease term (years)	3 years
Weighted average discount rate:	3.40%

Commitments and contingencies_7

Commitments and contingencies - Future annual minimum rental payments (Details) $ in Millions	Dec. 31, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
2020	$ 9.3
2021	8
2022	7.1
2023	4.4
2024	2
2025	0.6
2026 and after	0.2
Total future annual minimum rental payments as of December 31, 2019	31.6
Less: present value discount	(2.3)
Lease liability	$ 29.3

Unaudited condensed quarterly_3

Unaudited condensed quarterly financial data (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 352	$ 487.4	$ 441	$ 439.7	$ 336.8	$ 351.7	$ 441.8	$ 327.5	$ 1,720.1	$ 1,457.8	$ 1,134.1
Total expenses	506	498.7	430.7	318.4	482.3	386.3	292.4	273.1	1,753.8	1,434.1	1,244
Net (loss) attributable to Sirius Group's common shareholders	$ (137.3)	$ (2.7)	$ 6.6	$ 95.3	$ (153.6)	$ (28)	$ 97.8	$ 40.5	$ (38.1)	$ (43.3)	$ (156.1)
Basic earnings per common share and common share equivalent (in dollars per share)	$ (1.19)	$ (0.02)	$ 0.05	$ 0.75	$ (1.31)	$ (0.23)	$ 0.78	$ 0.32	$ (0.33)	$ (0.36)	$ (1.30)
Diluted earnings per common share and common share equivalent (in dollars per share)	$ (1.19)	$ (0.06)	$ 0.05	$ 0.74	$ (1.31)	$ (0.23)	$ 0.78	$ 0.32	$ (0.37)	$ (0.36)	$ (1.30)

Subsequent Events (Details)

Subsequent Events (Details)	Aug. 10, 2020USD ($)	Mar. 27, 2020USD ($)	Aug. 06, 2020contingent_value_right$ / sharesshares	Dec. 31, 2019$ / shares
Subsequent Event [Line Items]
Common shares par value (in dollars per share)				$ 0.01
Subsequent event
Subsequent Event [Line Items]
Payments for legal expenses | $	$ 2,000,000
Merger Agreement | Subsequent event
Subsequent Event [Line Items]
Right to receive in cash (in dollars per share)			$ 9.50
TPRE Shares | Subsequent event
Subsequent Event [Line Items]
Right to receive in cash (in dollars per share)			$ 0.905
Warrants issued (in shares) | shares			0.190
Value of warrants (in dollars per share)			$ 0.905
TPRE Shares | Merger Agreement | Subsequent event
Subsequent Event [Line Items]
Common shares par value (in dollars per share)			$ 0.10
Right to receive common stock (in shares) | shares			0.743
Number of CVRs | contingent_value_right			1
Right to receive cash and equity (in dollars per share)			$ 13.73
Holder's Of Series B Preference Shares | Expense Reimbursement | Subsequent event
Subsequent Event [Line Items]
Related party transaction | $		$ 250,000
Holder's Of Series B Preference Shares | Expense Reimbursement Requiring Written Consent | Subsequent event
Subsequent Event [Line Items]
Related party transaction | $		1,000,000
Holder's Of Series B Preference Shares | Other Professional Fees Reimbursement | Subsequent event
Subsequent Event [Line Items]
Related party transaction | $		$ 500,000

Schedule I - Summary of Inves_2

Schedule I - Summary of Investments - Other Than Investments in Related Parties (Details) $ in Millions	Dec. 31, 2019USD ($)
Summary of investments - other than investments in related parties
Cost or amortized cost	$ 3,442
Fair value	3,518.2
Amount shown on the balance sheet	3,518.2
Fixed maturity investments
Summary of investments - other than investments in related parties
Cost or amortized cost	1,656.6
Fair value	1,681
Amount shown on the balance sheet	1,681
Corporate debt securities
Summary of investments - other than investments in related parties
Cost or amortized cost	458.6
Fair value	474.1
Amount shown on the balance sheet	474.1
Asset-backed securities
Summary of investments - other than investments in related parties
Cost or amortized cost	489.4
Fair value	486.8
Amount shown on the balance sheet	486.8
Residential mortgage-backed securities
Summary of investments - other than investments in related parties
Cost or amortized cost	426.2
Fair value	438.9
Amount shown on the balance sheet	438.9
Commercial mortgage-backed securities
Summary of investments - other than investments in related parties
Cost or amortized cost	88.5
Fair value	89
Amount shown on the balance sheet	89
U.S. government and government agency
Summary of investments - other than investments in related parties
Cost or amortized cost	111.5
Fair value	110.5
Amount shown on the balance sheet	110.5
Non-U.S. government and government agency
Summary of investments - other than investments in related parties
Cost or amortized cost	63.7
Fair value	63
Amount shown on the balance sheet	63
Preferred stocks
Summary of investments - other than investments in related parties
Cost or amortized cost	17
Fair value	17
Amount shown on the balance sheet	17
U.S. States, municipalities and political subdivision
Summary of investments - other than investments in related parties
Cost or amortized cost	1.7
Fair value	1.7
Amount shown on the balance sheet	1.7
Short-term investments
Summary of investments - other than investments in related parties
Cost or amortized cost	1,090.8
Fair value	1,085.2
Amount shown on the balance sheet	1,085.2
Total equity securities
Summary of investments - other than investments in related parties
Cost or amortized cost	379.2
Fair value	405.2
Amount shown on the balance sheet	405.2
Other long-term investments
Summary of investments - other than investments in related parties
Cost or amortized cost	315.4
Fair value	346.8
Amount shown on the balance sheet	$ 346.8

Schedule II - Condensed Finan_2

Schedule II - Condensed Financial Information of Registrant - Balance Sheets (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Apr. 27, 2016
Assets
Fixed maturity investments	$ 1,681,000,000	$ 1,949,200,000
Short-term investments	1,085,200,000	715,500,000
Cash	136,300,000	119,400,000
Other assets	161,400,000	124,000,000
Total assets	6,413,800,000	6,007,700,000
Liabilities
Other liabilities	201,300,000	150,500,000
Total liabilities	4,548,000,000	4,069,300,000
Commitments and Contingencies
Mezzanine equity
Series B preference shares	223,000,000	232,200,000
Total mezzanine equity	223,000,000	232,200,000
Common shareholders' equity
Common shares (shares issued and outstanding, 2019: 115,299,341, 2018: 115,151,251)	1,200,000	1,200,000
Additional paid-in surplus	1,098,200,000	1,089,100,000
Retained earnings	778,500,000	816,600,000
Accumulated other comprehensive (loss)	(237,500,000)	(202,400,000)
Total common shareholders' equity	1,640,400,000	1,704,500,000
Total liabilities, mezzanine equity, and equity	6,413,800,000	6,007,700,000
Balance Sheet (Parenthetical)
Fixed maturity investments, trading, amortized cost	1,656,600,000	1,952,900,000
Short-term investments, amortized cost	$ 1,090,800,000	$ 716,100,000
Common shares issued (in shares)	115,299,341	115,151,251	120,000,000	120,000,000
Common shares outstanding (in shares)	115,299,341	115,151,251	120,000,000		120,000,000
Registrant
Assets
Fixed maturity investments	$ 11,700,000	$ 2,800,000
Short-term investments	1,200,000	5,300,000
Cash	200,000	0
Total investments and cash	13,100,000	8,100,000
Investments in unconsolidated affiliates	1,846,200,000	1,911,200,000
Other assets	24,900,000	42,500,000
Total assets	1,884,200,000	1,961,800,000
Liabilities
Other liabilities	20,800,000	25,100,000
Total liabilities	20,800,000	25,100,000
Commitments and Contingencies
Mezzanine equity
Series B preference shares	223,000,000	232,200,000
Total mezzanine equity	223,000,000	232,200,000
Common shareholders' equity
Common shares (shares issued and outstanding, 2019: 115,299,341, 2018: 115,151,251)	1,200,000	1,200,000
Additional paid-in surplus	1,098,200,000	1,089,100,000
Retained earnings	778,500,000	816,600,000
Accumulated other comprehensive (loss)	(237,500,000)	(202,400,000)
Total common shareholders' equity	1,640,400,000	1,704,500,000
Total liabilities, mezzanine equity, and equity	1,884,200,000	1,961,800,000
Balance Sheet (Parenthetical)
Fixed maturity investments, trading, amortized cost	11,700,000	2,900,000
Short-term investments, amortized cost	$ 1.2	$ 5.3

Schedule II - Condensed Finan_3

Schedule II - Condensed Financial Information of Registrant - Statements of (Loss) Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Net investment income									$ 84.7	$ 71.4	$ 56.8
Net realized investment gains									56.7	2.3	(27.2)
Net unrealized investment gains (losses)									80.6	(23.2)	(10.5)
Net foreign exchange (losses)									7.7	22.7	9.2
Revaluation of contingent consideration									(6.3)	9.6	48.8
Other revenue									55.1	112.7	21.7
Total revenues	$ 352	$ 487.4	$ 441	$ 439.7	$ 336.8	$ 351.7	$ 441.8	$ 327.5	1,720.1	1,457.8	1,134.1
Expenses
Other underwriting expenses									138.2	146.2	106.1
General and administrative expenses									109.8	77.9	91.9
Total expenses	506	498.7	430.7	318.4	482.3	386.3	292.4	273.1	1,753.8	1,434.1	1,244
Net (loss) attributable to Sirius Group									(47.3)	(18.1)	(150)
Change in carrying value of Series B preference shares									9.2	(36.4)	0
Less: Accrued dividends on Series A redeemable preference shares									0	(2.6)	(6.1)
Add: Redemption of Series A redeemable preference shares									0	13.8	0
Net (loss) attributable to Sirius Group's common shareholders	$ (137.3)	$ (2.7)	$ 6.6	$ 95.3	$ (153.6)	$ (28)	$ 97.8	$ 40.5	(38.1)	(43.3)	(156.1)
Registrant
Revenues
Net investment income									0.4	0.5	0.3
Net realized investment gains									0	0	0.2
Net unrealized investment gains (losses)									0.1	0	12.8
Net foreign exchange (losses)									0	0	(0.2)
Revaluation of contingent consideration									(5.5)	6.1	13.6
Other revenue									(18.7)	41.4	0.9
Total revenues									(23.7)	48	27.6
Expenses
Other underwriting expenses									0	0	(0.2)
General and administrative expenses									28.7	13.6	13
Total expenses									28.7	13.6	12.8
(Loss) income before equity earnings of unconsolidated affiliates, net of tax									(52.4)	34.4	14.8
Equity in earnings of unconsolidated affiliates, net of tax									5.1	(52.5)	(164.8)
Net (loss) attributable to Sirius Group									(47.3)	(18.1)	(150)
Change in carrying value of Series B preference shares									9.2	(36.4)	0
Less: Accrued dividends on Series A redeemable preference shares									0	(2.6)	(6.1)
Add: Redemption of Series A redeemable preference shares									0	13.8	0
Net (loss) attributable to Sirius Group's common shareholders									$ (38.1)	$ (43.3)	$ (156.1)

Schedule II - Condensed Finan_4

Schedule II - Condensed Financial Information of Registrant - Statements of Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net (loss) attributable to Sirius Group	$ (47.3)	$ (18.1)	$ (150)
Other comprehensive (loss) income
Change in foreign currency translation, net of tax	(35.1)	(61.9)	71.7
Comprehensive (loss) attributable to Sirius Group	(82.4)	(80)	(78.3)
Registrant
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net (loss) attributable to Sirius Group	(47.3)	(18.1)	(150)
Other comprehensive (loss) income
Change in foreign currency translation, net of tax	(35.1)	(61.9)	71.7
Comprehensive (loss) attributable to Sirius Group	$ (82.4)	$ (80)	$ (78.3)

Schedule II - Condensed Finan_5

Schedule II - Condensed Financial Information of Registrant - Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operations:
Net (loss) income attributable to Sirius Group	$ (45.6)	$ (16.7)	$ (136.3)
Adjustments to reconcile net (loss) to net cash provided from (used for) operations:
Net realized and unrealized investment gains	(137.3)	20.9	37.7
Amortization of premium on fixed maturity investments	(5.9)	5.8	16.6
Share-based Payment Arrangement, Noncash Expense	9.1	2	0
Revaluation of contingent consideration	6.3	(9.6)	(48.8)
Other operating items:
Net change in other assets and liabilities, net	61.8	(89.2)	(50.3)
Net cash provided from (used for) operations	109.8	108	(36)
Cash flows from investing activities:
Net change in short-term investments	(362.3)	(90.1)	(1)
Sales of fixed maturities and convertible fixed maturity investments	573.3	1,373.1	1,422.4
Maturities, calls, and paydowns of fixed maturity and convertible fixed maturity investments	407.7	102.7	292.2
Sales of common equity securities	369.3	353.1	87.6
Purchases of common equity securities	(336.9)	(505.7)	(222.3)
Purchases of fixed maturities and convertible fixed maturity investments	(726.7)	(1,321.3)	(1,018.5)
Net cash (used for) provided from investing activities	(77.7)	(189.9)	66
Cash flows from financing activities:
Payment of contingent consideration	(6.9)	(4.4)	(30.6)
Capital contribution from former parent	0	1.4	13.3
Proceeds from issuance of common shares, net of expenses	0	61.2	0
Proceeds from issuance of Series B preference shares	0	195.8	0
Redemption of common shares from CM Bermuda	0	(164)	0
Return of capital to CM Bermuda	0	(1.6)	0
Redemption of Series A redeemable preference shares	0	(95)	0
Net cash (used for) provided from financing activities	(8)	(6.6)	53.6
Net increase (decrease) in cash during year	18.4	(98.4)	93.5
Cash and restricted cash balance at beginning of year	132.2	230.6	137.1
Cash and restricted cash balance at end of year	150.6	132.2	230.6
Registrant
Cash flows from operations:
Net (loss) income attributable to Sirius Group	(47.3)	(18.1)	(150)
Adjustments to reconcile net (loss) to net cash provided from (used for) operations:
Equity in earnings of subsidiaries	(5.1)	52.5	164.8
Dividends received from subsidiaries	35	150	110
Net realized and unrealized investment gains	(0.1)	0	(13)
Amortization of premium on fixed maturity investments	0	(0.3)	(0.1)
Share-based Payment Arrangement, Noncash Expense	9.1	2	0
Revaluation of contingent consideration	5.5	(6.1)	(13.6)
Other operating items:
Net change in other assets and liabilities, net	14.7	(57.5)	12.6
Net cash provided from (used for) operations	11.8	122.5	110.7
Cash flows from investing activities:
Net change in short-term investments	4.1	25.6	2.5
Sales of fixed maturities and convertible fixed maturity investments	14.1	65.9	1.1
Maturities, calls, and paydowns of fixed maturity and convertible fixed maturity investments	0.1	0	0
Sales of common equity securities	0	0	59.6
Purchases of common equity securities	0	0	(54.4)
Purchases of fixed maturities and convertible fixed maturity investments	(23)	(64.9)	0
Contributions to subsidiaries	0	(143.5)	(132.7)
Net cash (used for) provided from investing activities	(4.7)	(116.9)	(123.9)
Cash flows from financing activities:
Payment of contingent consideration	(6.9)	(3.5)	0
Capital contribution from former parent	0	1.4	13.3
Proceeds from issuance of common shares, net of expenses	0	61.2	0
Proceeds from issuance of Series B preference shares	0	195.8	0
Redemption of common shares from CM Bermuda	0	(164)	0
Return of capital to CM Bermuda	0	(1.6)	0
Redemption of Series A redeemable preference shares	0	(95)	0
Net cash (used for) provided from financing activities	(6.9)	(5.7)	13.3
Net increase (decrease) in cash during year	0.2	(0.1)	0.1
Cash and restricted cash balance at beginning of year	0	0.1	0
Cash and restricted cash balance at end of year	$ 0.2	$ 0	$ 0.1

Schedule III - Supplementary _2

Schedule III - Supplementary Insurance Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplementary Insurance Information
Deferred Acquisition Costs	$ 148.2	$ 141.6	$ 120.9
Loss and Loss Adjustment Expense Reserves	2,331.5	2,016.7	1,898.5
Unearned Insurance and Reinsurance Premiums	708	647.2	506.8
Net Earned Insurance and Reinsurance Premiums	1,441.6	1,262.3	1,035.3
Loss and Loss Adjustment Expenses	1,170.3	900	811.2
Insurance and Reinsurance Acquisition Expenses	288.7	255.4	197.2
Other Underwriting Expenses	138.2	146.2	106.1
Net Written Insurance and Reinsurance Premiums	1,502.6	1,357.1	1,090.2
Corporate Elimination
Supplementary Insurance Information
Deferred Acquisition Costs	0	0	0
Loss and Loss Adjustment Expense Reserves	0	0	0
Unearned Insurance and Reinsurance Premiums	0	0	0
Net Earned Insurance and Reinsurance Premiums	0	0	0
Loss and Loss Adjustment Expenses	13.8	13	0
Insurance and Reinsurance Acquisition Expenses	(46.1)	(43.7)	(42.9)
Other Underwriting Expenses	13.5	16.1	0
Net Written Insurance and Reinsurance Premiums	0	0	0
Global Reinsurance | Reportable segments
Supplementary Insurance Information
Deferred Acquisition Costs	85.9	86.7	71.7
Loss and Loss Adjustment Expense Reserves	1,536.5	1,231.2	1,064.1
Unearned Insurance and Reinsurance Premiums	419	409.7	310.7
Net Earned Insurance and Reinsurance Premiums	966.5	870.5	727.6
Loss and Loss Adjustment Expenses	850.9	675.2	617.3
Insurance and Reinsurance Acquisition Expenses	199.7	185.3	154
Other Underwriting Expenses	84.5	87.7	79.8
Net Written Insurance and Reinsurance Premiums	987.9	934.6	749.2
Global A&H | Reportable segments
Supplementary Insurance Information
Deferred Acquisition Costs	57.2	54	49.1
Loss and Loss Adjustment Expense Reserves	225.1	197.9	206.2
Unearned Insurance and Reinsurance Premiums	244.6	224.8	195.8
Net Earned Insurance and Reinsurance Premiums	443.3	357.6	306.8
Loss and Loss Adjustment Expenses	278.7	194.9	179.8
Insurance and Reinsurance Acquisition Expenses	125.8	109.7	89.6
Other Underwriting Expenses	23.7	27.4	23.4
Net Written Insurance and Reinsurance Premiums	458.1	379.8	341.5
U.S. Specialty | Reportable segments
Supplementary Insurance Information
Deferred Acquisition Costs	5.1	0.9	0
Loss and Loss Adjustment Expense Reserves	30.7	2.8	0
Unearned Insurance and Reinsurance Premiums	44.4	12.7	0
Net Earned Insurance and Reinsurance Premiums	29.6	5	0
Loss and Loss Adjustment Expenses	24.1	2.3	0
Insurance and Reinsurance Acquisition Expenses	6.4	1.3	0
Other Underwriting Expenses	10.6	8.7	0
Net Written Insurance and Reinsurance Premiums	54.1	13.1	0
Runoff & Other | Reportable segments
Supplementary Insurance Information
Deferred Acquisition Costs	0	0	0.1
Loss and Loss Adjustment Expense Reserves	539.2	584.8	628.2
Unearned Insurance and Reinsurance Premiums	0	0	0.3
Net Earned Insurance and Reinsurance Premiums	2.2	29.2	0.9
Loss and Loss Adjustment Expenses	2.8	14.6	14.1
Insurance and Reinsurance Acquisition Expenses	2.9	2.8	(3.5)
Other Underwriting Expenses	5.9	6.3	2.9
Net Written Insurance and Reinsurance Premiums	$ 2.5	$ 29.6	$ (0.5)

Schedule IV - Reinsurance (Deta

Schedule IV - Reinsurance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Direct gross	$ 511.2	$ 454.5	$ 450.2
Ceded to other companies	400.1	463.9	349.1
Assumed from other companies	1,391.5	1,366.5	989.1
Net amount	$ 1,502.6	$ 1,357.1	$ 1,090.2
Percentage of amount assumed to net	93.00%	101.00%	91.00%

Schedule V - Valuation and Qu_2

Schedule V - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for reinsurance balances
Valuation and Qualifying Accounts
Balance at beginning of period	$ 5.7	$ 5.8	$ 5.8
Charged to costs and expenses	0	0	0
Charged to other accounts	0	(0.1)	0
Deductions described	0	0	0
Balance at the end of period	5.7	5.7	5.8
Allowance for uncollectible accounts
Valuation and Qualifying Accounts
Balance at beginning of period	4.3	4.6	5.3
Charged to costs and expenses	(0.1)	0	(0.5)
Charged to other accounts	0	(0.2)	(0.5)
Deductions described	0	(0.1)	(0.3)
Balance at the end of period	$ 4.2	$ 4.3	$ 4.6

Schedule VI - Insurance Opera_2

Schedule VI - Insurance Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Abstract]
Deferred Acquisition Costs	$ 148.2	$ 141.6	$ 120.9
Loss and Loss Adjustment Expense Reserves	2,331.5	2,016.7	1,898.5
Unearned Insurance and Reinsurance Premiums	708	647.2	506.8
Net Earned Insurance and Reinsurance Premiums	1,441.6	1,262.3	1,035.3
Net investment income	84.7	71.4	56.8
Losses and loss expenses incurred related to prior year	1,066.5	907.3	811.8
Losses and loss expenses incurred related to prior year	103.8	(7.3)	(0.6)
Net paid losses and loss expenses	911.3	791.7	612.3
Insurance and Reinsurance Acquisition Expenses	288.7	255.4	197.2
Net premiums written	$ 1,502.6	$ 1,357.1	$ 1,090.2