Employers (EIG) 10-Q 26 Apr 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2024	Apr. 23, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-33245
Entity Registrant Name	EMPLOYERS HOLDINGS, INC.
Entity Incorporation, State or Country Code	NV
Entity Tax Identification Number	04-3850065
Entity Address, Address Line One	2340 Corporate Circle, Suite 200
Entity Address, City or Town	Henderson,
Entity Address, State or Province	NV
Entity Address, Postal Zip Code	89074
City Area Code	888
Local Phone Number	682-6671
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	EIG
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		25,343,504
Entity Central Index Key	0001379041
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Investments:
Fixed maturity securities at fair value (amortized cost $2,139.7 at March 31, 2024 and $2,048.0 at December 31, 2023, less CECL allowance of $3.2 at March 31, 2024 and $2.7 at December 31, 2023)	$ 2,013.8	$ 1,936.3
Equity securities at fair value (cost $125.9 at March 31, 2024 and $125.9 at December 31, 2023)	224.3	211.2
Equity securities at cost	6	6
Other invested assets (cost $88.9 at March 31, 2024 and $82.5 at December 31, 2023)	97.6	91.5
Short-term investments at fair value (amortized cost $38.2 at March 31, 2024 and $33.1 at December 31, 2023)	38.2	33.1
Total investments	2,379.9	2,278.1
Cash and cash equivalents	114.2	226.4
Restricted Cash and Cash Equivalents	0.2	0.2
Accrued investment income	16.5	16.3
Premiums receivable (less CECL allowance of $19.7 at March 31, 2024 and $17.9 at December 31, 2023)	380.4	359.4
Reinsurance recoverable for:
Paid losses	6.7	6.3
Unpaid losses (less CECL allowance of $0.9 at March 31, 2024 and $0.9 at December 31, 2023)	423.1	427.5
Deferred policy acquisition costs	59.4	55.6
Deferred income tax asset, net	42.1	43.4
Property and equipment, net	6.6	6.5
Operating lease right-of-use assets	4.7	5.1
Intangible assets, net	13.6	13.6
Goodwill	36.2	36.2
Contingent commission receivable—LPT Agreement	14.4	14.2
Cloud computing arrangements	25.2	28
Other assets	39.6	33.6
Total assets	3,562.8	3,550.4
Liabilities and stockholders’ equity
Unpaid losses and loss adjustment expenses	1,874.5	1,884.5
Unearned premiums	402.3	379.7
Commissions and premium taxes payable	60.9	66
Accounts payable and accrued expenses	18.2	26.1
Deferred reinsurance gain—LPT Agreement	97.2	99.2
Operating lease liability	5.5	5.9
Non-cancellable obligations	14.1	17
Other liabilities	71.2	58.1
Total liabilities	2,543.9	2,536.5
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.01 par value; 150,000,000 shares authorized; 58,152,792 and 58,055,968 shares issued and 25,343,504 and 25,369,753 shares outstanding at March 31, 2024 and December 31, 2023, respectively	0.6	0.6
Preferred stock, $0.01 par value; 25,000,000 shares authorized; none issued	0	0
Additional paid-in capital	419.5	419.8
Retained earnings	1,405.4	1,384.3
Accumulated other comprehensive loss, net of tax	(96.9)	(86)
Treasury stock, at cost (32,809,288 shares at March 31, 2024 and 32,686,215 shares at December 31, 2023)	(709.7)	(704.8)
Total stockholders’ equity	1,018.9	1,013.9
Total liabilities and stockholders’ equity	$ 3,562.8	$ 3,550.4

Consolidated Balance Sheets Con

Consolidated Balance Sheets Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Available for sale:
Debt securities, available-for-sale, amortized cost	$ 2,139.7	$ 2,048
Debt Securities, Available-for-sale, Allowance for Credit Loss	3.2	2.7
Equity Securities, FV-NI, Cost	125.9	125.9
Other Investments and Securities, at Cost	88.9	82.5
Available for sale, short-term investments, at amortized cost	38.2	33.1
Accounts Receivable, Allowance for Credit Loss, Current	19.7	17.9
Reinsurance recoverables on unpaid losses, allowance	$ 0.9	$ 0.9
Stockholders' equity
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	58,152,792	58,055,968
Common stock, shares outstanding (in shares)	25,343,504	25,369,753
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Treasury stock, at cost (in shares)	32,809,288	32,686,215

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Net premiums earned	$ 184.9	$ 172.7
Net investment income	26.8	27.6
Net realized and unrealized (losses) gains on investments	11.4	6.4
Other income (loss)	0	(0.2)
Total revenues	223.1	206.5
Expenses
Losses and loss adjustment expenses	116.5	107.4
Commission expense	25.5	23.4
Underwriting and general and administrative expenses	45.8	44.4
Interest and financing expenses	0	2.3
Total expenses	187.8	177.5
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest, Total	35.3	29
Income tax expense	7	5.4
Net Income	28.3	23.6
Comprehensive (loss) income
Unrealized AFS investment (losses) gains arising during the period, net of tax benefit (expense) of $3.0 and $(6.0) for the three months ended March 31, 2024 and 2023, respectively	(11.6)	22.5
Reclassification adjustment for realized AFS investment losses in net income, net of tax benefit of $(0.2) and $(0.3) for the three months ended March 31, 2024 and 2023, respectively	0.7	1.3
Other comprehensive (loss) income, net of tax	(10.9)	23.8
Total Comprehensive income	$ 17.4	$ 47.4
Earnings per common share (Note 13):
Basic	$ 1.12	$ 0.87
Diluted	1.11	0.86
Cash dividends declared per common share and eligible plan awards	$ 0.28	$ 0.26

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement Parenthetical [Abstract]
OCI, Debt Securities, Available-for-Sale, Gain (Loss), before Adjustment, Tax	$ 3	$ (6)
Other comprehensive income (loss), reclassification adjustment for sale of securities included in net income, tax	$ (0.2)	$ (0.3)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders Equity Statement - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income, Net	Treasury Stock, Common
Stockholders' equity, shares at Dec. 31, 2022		57,876,287
Stockholders' equity, value at Dec. 31, 2022	$ 944.2	$ 0.6	$ 414.6	$ 1,295.6	$ (138.9)	$ (627.7)
Stock-based obligations, shares		0
Stock-based obligations, value	$ 1.8	$ 0	1.8	0	0	0
Stock-options exercised, shares	23,500	23,500
Stock-options exercised, value	$ 0.6	$ 0	0.6	0	0	0
Vesting of RSUs and PSUs, net of shares withheld to satisfy minimum tax withholding, shares		85,602
Vesting of RSUs and PSUs, net of shares withheld to satisfy minimum tax withholding, value	(1.4)	$ 0	(1.4)	0	0	0
Acquisition of common stock, shares		0
Acquisition of common stock, value	(11.4)	$ 0	0	0	0	(11.4)
Dividends declared, shares		0
Dividends declared, value	(7.1)	$ 0	0	(7.1)	0	0
Net income	23.6	0	0	23.6	0	0
Change in net unrealized gains in investments, net of tax	23.8	$ 0	0	0	23.8	0
Stockholders' equity, shares at Mar. 31, 2023		57,985,389
Stockholders' equity, value at Mar. 31, 2023	974.1	$ 0.6	415.6	1,312.1	(115.1)	(639.1)
Other comprehensive income (loss), unrealized holding gain (loss) on securities arising during period, tax	(6.3)
Stockholders' equity, shares at Dec. 31, 2022		57,876,287
Stockholders' equity, value at Dec. 31, 2022	$ 944.2	$ 0.6	414.6	1,295.6	(138.9)	(627.7)
Stock-options exercised, shares	23,500
Stockholders' equity, shares at Dec. 31, 2023	58,055,968	58,055,968
Stockholders' equity, value at Dec. 31, 2023	$ 1,013.9	$ 0.6	419.8	1,384.3	(86)	(704.8)
Stock-based obligations, shares		0
Stock-based obligations, value	1.4	$ 0	1.4	0	0	0
Vesting of RSUs and PSUs, net of shares withheld to satisfy minimum tax withholding, shares		96,824
Vesting of RSUs and PSUs, net of shares withheld to satisfy minimum tax withholding, value	(1.7)	$ 0	(1.7)	0	0	0
Acquisition of common stock, shares		0
Acquisition of common stock, value	(4.9)	$ 0	0	0	0	(4.9)
Dividends declared, shares		0
Dividends declared, value	(7.2)	$ 0	0	(7.2)	0	0
Net income	28.3	0	0	28.3	0	0
Change in net unrealized gains in investments, net of tax	$ (10.9)	$ 0	0	0	(10.9)	0
Stockholders' equity, shares at Mar. 31, 2024	58,152,792	58,152,792
Stockholders' equity, value at Mar. 31, 2024	$ 1,018.9	$ 0.6	$ 419.5	$ 1,405.4	$ (96.9)	$ (709.7)
Other comprehensive income (loss), unrealized holding gain (loss) on securities arising during period, tax	$ 2.8

Consolidated Statements of St_2

Consolidated Statements of Stockholders Equity (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Stockholders' Equity [Abstract]
Change in net unrealized (losses) gains on investments, net of tax	$ 2.8	$ (6.3)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Operating activities
Net income	$ 28.3	$ 23.6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1	1.1
Stock-based compensation	1.5	1.8
Amortization of cloud computing arrangements	2.8	4.3	$ 16.7
Amortization of premium on investments, net	(0.3)	0.8
Allowance for expected credit losses	1.8	1.2
Deferred income tax (benefit) expense	4.1	2.8
Net realized and unrealized gains on investments	(11.4)	(6.4)
Change in operating assets and liabilities:
Premiums receivable	(22.8)	(21.4)
Reinsurance recoverable on paid and unpaid losses	4	4.7
Cloud computing arrangements	0	(1.4)
Operating lease right-of-use assets	0.4	0.7
Current federal income taxes	2.5	2.6
Unpaid losses and loss adjustment expenses	(10)	(7)
Unearned premiums	22.6	20.4
Accounts payable, accrued expenses and other liabilities	(3.6)	(6.4)
Deferred reinsurance gain—LPT Agreement	(2)	(2)
Contingent commission receivable—LPT Agreement	(0.2)	0
Operating lease liabilities	(0.4)	(0.8)
Non-cancellable obligations	(2.9)	(2.6)
Other	(14.8)	(11.7)
Net cash provided by operating activities	0.6	4.3
Investing activities
Purchases of fixed maturity securities	(169)	(106.7)
Payments to Acquire Equity Securities, FV-NI	(5.8)	(12.3)
Purchases of short-term investments	(17.7)	(10.5)
Purchases of other invested assets	(6.4)	(11.5)
Proceeds from sale of fixed maturity securities	32	44.8
Proceeds from Sale of Equity Securities, FV-NI	5.5	12
Proceeds from maturities and redemptions of fixed maturity securities	45	27.5
Proceeds from maturities of short-term investments	12.7	71
Net change in unsettled investment purchases and sales	7.3	(1)
Capital expenditures and other	(1.3)	(0.5)
Net cash (used in) provided by investing activities	(97.7)	12.8
Financing activities
Acquisition of common stock	(5.6)	(11.1)
Cash transactions related to stock-based compensation	(1.7)	(0.8)
Dividends paid to stockholders	(7.8)	(7.6)
Financing cash flows from finance leases	0	(0.1)
Net cash used in financing activities	(15.1)	(19.6)
Net decrease in cash, cash equivalents and restricted cash	(112.2)	(2.5)
Cash, cash equivalents, restricted cash and restricted cash equivalents at the beginning of the period	226.6	89.4	89.4
Cash, cash equivalents, restricted cash and restricted cash equivalents at the end of the period	114.4	86.9	226.6
Cash and cash equivalents	114.2		226.4
Restricted Cash and Cash Equivalents	0.2		0.2
Total cash, cash equivalents, restricted cash	$ 114.4	$ 86.9	$ 226.6

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Description and Basis of Presentation	Basis of Presentation and Summary of Operations Employers Holdings, Inc. (EHI) is a Nevada holding company. Through its wholly owned insurance subsidiaries, Employers Insurance Company of Nevada (EICN), Employers Compensation Insurance Company (ECIC), Employers Preferred Insurance Company (EPIC), Employers Assurance Company (EAC), and Cerity Insurance Company (CIC), EHI is engaged in the commercial property and casualty insurance industry, specializing in workers’ compensation products and services. Unless otherwise indicated, all references to the “Company” refer to EHI, together with its subsidiaries. In 1999, the Nevada State Industrial Insurance System (the Fund) entered into a retroactive 100% quota share reinsurance agreement (the LPT Agreement) through a loss portfolio transfer transaction with third party reinsurers. The LPT Agreement commenced on June 30, 1999 and will remain in effect until: (i) all claims under the covered policies have closed; (ii) the LPT Agreement is commuted or terminated, upon the mutual agreement of the parties; or (iii) the reinsurers’ aggregate maximum limit of liability is exhausted, whichever occurs first. The LPT Agreement does not provide for any additional termination terms. On January 1, 2000, EICN assumed all of the assets, liabilities and operations of the Fund, including the Fund’s rights and obligations associated with the LPT Agreement (See Note 9). The Company accounts for the LPT Agreement as retroactive reinsurance. Upon entry into the LPT Agreement, an initial deferred reinsurance gain (the Deferred Gain) was recorded as a liability on the Company’s Consolidated Balance Sheets. The Company is also entitled to receive a contingent profit commission under the LPT Agreement through June 30, 2024. The contingent profit commission is estimated based on both actual paid results to date and projections of expected paid losses under the LPT Agreement and is recorded as an asset on the Company’s Consolidated Balance Sheets. The Contingent Commission receivable at March 31, 2024 was $14.4 million. The accompanying consolidated financial statements have been prepared in accordance with United States (U.S.) generally accepted accounting principles (GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities Exchange Act of 1934 (Exchange Act), as amended. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal, recurring adjustments) necessary for a fair presentation of the Company’s consolidated financial position and results of operations for the periods presented have been included. The results of operations for an interim period are not necessarily indicative of the results for an entire year. These financial statements have been prepared consistent with the accounting policies described in the Company’s Form 10-K for the year ended December 31, 2023 (Annual Report). The Company operates as a single operating segment, Insurance Operations , through its wholly owned subsidiaries. The Company considers an operating segment to be any component of its business whose operating results are regularly reviewed by the Company's chief operating decision maker (CODM) to make decisions about resources to be allocated to the segment and assess its performance based on discrete financial information. Prior to December 31, 2023, the Company operated through two reportable segments: Employers and Cerity . All periods prior to December 31, 2023 have been conformed to the current presentation. Detailed financial information about the Company's single operating segment is presented in Note 14. Use of Estimates The preparation of the consolidated 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 at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. As a result, actual results could differ from these estimates. The most significant areas that require management judgment are the estimate of unpaid losses and loss adjustment expenses (LAE), evaluation of reinsurance recoverables, recognition of premium revenue, recoverability of deferred income taxes, and valuation of investments.

New Accounting Standards

New Accounting Standards	3 Months Ended
	Mar. 31, 2024
New Accounting Standards [Abstract]
New Accounting Standards	New Accounting Standards Recently Issued Accounting Standards In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280). The amendments in this update improve disclosures about reportable segments and provide more detailed information about a reportable segment's expenses. Specifically, the amendments in this update include disclosures on an annual and interim basis, significant segment expenses that are regularly provided to the CODM, an amount for other segment items by reportable segment and a description on their composition, all annual disclosures about a reportable segment's profit or loss and assets to be required on an interim basis, the measures the CODM uses in assessing performance and allocating resources, and the title and position of the CODM. Additionally, a single reporting segment is subject to all disclosures in this amendment along with existing segment disclosures within Topic 280. This update is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The Company will adopt this standard when it becomes effective. Recently Adopted Accounting Standards In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740). This update requires public business entities to annually disclose specific categories within the income tax rate reconciliation, and provide additional information for reconciling items that meet a certain quantitative threshold. Additionally, the amendments in this update require entities to disclose certain information about income taxes paid, income tax disaggregation, disclosures around unrecognized tax benefits, and the removal of disclosures related to temporary differences surrounding deferred tax liabilities to enhance the transparency and decision usefulness of income tax disclosures. This update is effective for fiscal years beginning after December 15, 2024 and early adoption is permitted for financial statements that have not been issued. The Company elected to early adopt this update as of December 31, 2023, and the impact of this standard was not material to its consolidated financial condition or results of operations. In March 2020, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2020-04, Reference Rate Reform (Topic 848) . This update provided optional transition guidance to ease the potential accounting burden associated with transitioning away from the London Interbank Offered Rate (LIBOR), with optional expedients and exceptions related to the application of US GAAP to contracts, hedging relationships and other transactions affected by reference rate reform. Companies can elect to adopt this ASU through December 31, 2024. The Company determined that there was no impact of LIBOR transitioning on its existing contracts and investments.

Valuation of Financial Instrume

Valuation of Financial Instruments	3 Months Ended
	Mar. 31, 2024
Fair Value of Financial Instruments [Abstract]
Fair Value of Financial Instruments	Valuation of Financial Instruments Financial Instruments Carried at Fair Value The carrying value and the estimated fair value of the Company’s financial instruments at fair value were as follows: March 31, 2024 December 31, 2023 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value (in millions) Financial assets Total investments at fair value $ 2,276.3 $ 2,276.3 $ 2,180.6 $ 2,180.6 Cash and cash equivalents 114.2 114.2 226.4 226.4 Restricted cash and cash equivalents 0.2 0.2 0.2 0.2 Assets and liabilities recorded at fair value on the Company’s Consolidated Balance Sheets are categorized based upon the levels of judgment associated with the inputs used to measure their fair value. Level inputs are defined as follows: • Level 1 - Inputs are unadjusted quoted market prices for identical assets or liabilities in active markets at the measurement date. • Level 2 - Inputs other than Level 1 prices that are observable for similar assets or liabilities through corroboration with market data at the measurement date. • Level 3 - Inputs that are unobservable that reflect management’s best estimate of what willing market participants would use in pricing the assets or liabilities at the measurement date. The Company uses third party pricing services to assist with its investment accounting function. The ultimate pricing source varies depending on the investment security and pricing service used, but investment securities valued on the basis of observable inputs (Levels 1 and 2) are generally assigned values on the basis of actual transactions. Securities valued on the basis of pricing models with significant unobservable inputs or non-binding broker quotes are classified as Level 3. The Company performs quarterly analyses on the prices it receives from third parties to determine whether the prices are reasonable estimates of fair value, including confirming the fair values of these securities through observable market prices using an alternative pricing source, as it is ultimately management’s responsibility to ensure that the fair values reflected in the Company’s consolidated financial statements are appropriate. If differences are noted in these analyses, the Company may obtain additional information from other pricing services to validate the quoted price. The Company bases all of its estimates of fair value for assets on the bid prices, when available, as they represent what a third-party market participant would be willing to pay in an arm’s length transaction. For securities not actively traded, third party pricing services may use quoted market prices of similar instruments or discounted cash flow analyses, incorporating inputs that are currently observable in the markets for similar securities. Inputs that are often used in the valuation methodologies include, but are not limited to, broker quotes, benchmark yields, credit spreads, default rates, and prepayment speed assumptions. There were no material adjustments to the valuation methodology utilized by third party pricing services as of March 31, 2024 and December 31, 2023. These methods of valuation only produce an estimate of fair value if there is objectively verifiable information to produce a valuation. If objectively verifiable information is not available, the Company would be required to produce an estimate of fair value using some of the same methodologies, making assumptions for market-based inputs that are unavailable. As of March 31, 2024, the Company held $47.5 million of fixed maturity securities at fair value that were designated Level 3. These private placement securities were designated as Level 3 securities d ue to the limited amount of observable market information available. The following table presents the Company’s investments at fair value and the corresponding fair value measurements. March 31, 2024 December 31, 2023 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 (in millions) Fixed maturity securities: U.S. Treasuries $ — $ 63.0 $ — $ — $ 58.4 $ — U.S. Agencies — 2.1 — — 2.1 — States and municipalities — 199.8 — — 210.2 — Corporate securities — 905.5 34.0 — 863.7 32.1 Residential mortgage-backed securities — 370.0 — — 362.2 — Commercial mortgage-backed securities — 63.2 — — 63.8 — Asset-backed securities — 163.2 13.5 — 113.9 14.1 Collateralized loan obligations — 72.8 — — 91.5 — Foreign government securities — 10.0 — — 10.4 — Other securities — 116.7 — — 113.9 — Total fixed maturity securities $ — $ 1,966.3 $ 47.5 $ — $ 1,890.1 $ 46.2 Equity securities at fair value: Industrial and miscellaneous $ 195.3 $ — $ — $ 181.7 $ — $ — Other 29.0 — — 29.5 — — Total equity securities at fair value $ 224.3 $ — $ — $ 211.2 $ — $ — Short-term investments $ 16.5 $ 21.7 $ — $ 17.6 $ 15.5 $ — Total investments at fair value $ 240.8 $ 1,988.0 $ 47.5 $ 228.8 $ 1,905.6 $ 46.2 Financial Instruments Carried at Cost All of the Company's insurance subsidiaries are members of the Federal Home Loan Bank of San Francisco (FHLB). Members are required to purchase stock in the FHLB in addition to maintaining collateral deposits that back any funds advanced and standby letters of credit issued (See Note 10). The Company’s investment in FHLB stock is recorded at cost, which approximates fair value, as purchases and sales of these securities are at par value with the issuer. FHLB stock is considered a restricted security and is periodically evaluated by the Company for impairment based on the estimated ultimate recovery of par value. Financial Instruments Carried at Net Asset Value The Company has investments in private equity limited partnership interests that are included in Other invested assets on the Company’s Consolidated Balance Sheets. These investments do not have readily determinable fair values and are carried at net asset value (NAV) and therefore are excluded from the fair value hierarchy. The Company initially estimates the value of these investments using the transaction price. In subsequent periods, the Company measures these investments using NAV per share provided quarterly by the general partner, based on financial statements that are audited annually. These investments are generally not redeemable by the investees and cannot be sold without approval of the general partner. These investments have a fund term of 3 to 12 years, subject to two or three one Additionally, certain cash equivalents, principally money market securities, are measured using NAV, which approximates fair value. The following table presents cash and investments carried at NAV on the Company’s Consolidated Balance Sheets. March 31, 2024 December 31, 2023 (in millions) Cash equivalents carried at NAV $ 104.3 $ 197.2 Other invested assets carried at NAV 97.6 91.5 The following table provides a reconciliation of the beginning and ending balances that are measured using Level 3 inputs. Three Months Ended March 31, 2024 2023 (in millions) Balance at the beginning of the year $ 46.2 $ 24.2 Purchases 1.5 1.5 Unrealized (losses) gains included in comprehensive (loss) income (0.2) 0.2 Balance at end of period $ 47.5 $ 25.9

Investments

Investments	3 Months Ended
	Mar. 31, 2024
Investments [Abstract]
Investments	Investments The amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of the Company’s available-for-sale (AFS) investments were as follows: Amortized Allowance for Current Expected Credit Losses Gross Gross Estimated (in millions) At March 31, 2024 Fixed maturity securities U.S. Treasuries $ 65.6 $ — $ 0.3 $ (2.9) $ 63.0 U.S. Agencies 2.2 — — (0.1) 2.1 States and municipalities 202.8 — 2.4 (5.4) 199.8 Corporate securities 1,003.5 (2.2) 5.4 (67.2) 939.5 Residential mortgage-backed securities 413.0 — 0.6 (43.6) 370.0 Commercial mortgage-backed securities 69.7 (0.3) — (6.2) 63.2 Asset-backed securities 180.3 — 1.1 (4.7) 176.7 Collateralized loan obligations 73.0 — — (0.2) 72.8 Foreign government securities 12.7 — — (2.7) 10.0 Other securities (1) 116.9 (0.7) 0.9 (0.4) 116.7 Total fixed maturity securities $ 2,139.7 $ (3.2) $ 10.7 $ (133.4) $ 2,013.8 Short-term investments 38.2 — — — 38.2 Total AFS investments $ 2,177.9 $ (3.2) $ 10.7 $ (133.4) $ 2,052.0 At December 31, 2023 Fixed maturity securities U.S. Treasuries $ 60.3 $ — $ 0.6 $ (2.5) $ 58.4 U.S. Agencies 2.2 — — (0.1) 2.1 States and municipalities 212.3 — 3.1 (5.2) 210.2 Corporate securities 952.8 (2.1) 8.3 (63.2) 895.8 Residential mortgage-backed securities 399.3 — 0.9 (38.0) 362.2 Commercial mortgage-backed securities 70.2 — — (6.4) 63.8 Asset-backed securities 131.8 — 1.0 (4.8) 128.0 Collateralized loan obligations 92.2 — — (0.7) 91.5 Foreign government securities 12.7 — — (2.3) 10.4 Other securities (1) 114.2 (0.6) 1.0 (0.7) 113.9 Total fixed maturity securities $ 2,048.0 $ (2.7) $ 14.9 $ (123.9) $ 1,936.3 Short-term investments 33.1 — — — 33.1 Total AFS investments $ 2,081.1 $ (2.7) $ 14.9 $ (123.9) $ 1,969.4 (1) Other securities within fixed maturity securities consist of bank loans, which are classified as AFS and reported at fair value. The cost and estimated fair value of the Company’s equity securities recorded at fair value at March 31, 2024 and December 31, 2023 were as follows: Cost Estimated Fair Value (in millions) At March 31, 2024 Equity securities at fair value Industrial and miscellaneous $ 105.1 $ 195.3 Other 20.8 29.0 Total equity securities at fair value $ 125.9 $ 224.3 At December 31, 2023 Equity securities at fair value Industrial and miscellaneous $ 104.4 $ 181.7 Other 21.5 29.5 Total equity securities at fair value $ 125.9 $ 211.2 The Company had Other invested assets totaling $97.6 million and $91.5 million (initial cost of $88.9 million and $82.5 million) at March 31, 2024 and December 31, 2023, respectively, consisting of private equity limited partnerships, which are carried at NAV based on information provided by the general partner. These investments are non-redeemable until conversion and are periodically evaluated by the Company for impairment based on the ultimate recovery of the investment. Changes in the value of these investments are recorded through Net realized and unrealized gains (losses) on the Company’s Consolidated Statements of Comprehensive Income (Loss). The amortized cost and estimated fair value of the Company’s fixed maturity securities at March 31, 2024, by contractual maturity, are shown below. Expected maturities differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Cost Estimated Fair Value (in millions) Due in one year or less $ 20.6 $ 20.3 Due after one year through five years 651.8 630.3 Due after five years through ten years 642.6 599.2 Due after ten years 88.7 81.3 Mortgage and asset-backed securities 736.0 682.7 Total $ 2,139.7 $ 2,013.8 The following is a summary of AFS investments that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 months or greater in each case as of March 31, 2024 and December 31, 2023. March 31, 2024 December 31, 2023 Estimated Fair Value Gross Number of Issues Estimated Fair Value Gross Number of Issues (dollars in millions) Less than 12 months: Fixed maturity securities U.S. Treasuries $ 19.0 $ (0.3) 8 $ 11.9 $ (0.1) 5 States and municipalities 42.2 (0.7) 16 39.5 (0.3) 15 Corporate securities 60.2 (0.6) 23 26.1 (0.8) 13 Residential mortgage-backed securities 21.5 (0.3) 20 15.8 (0.2) 15 Asset-backed securities 55.1 (0.2) 24 24.0 (0.1) 15 Collateralized loan obligations 32.6 (0.1) 8 — — — Other securities 14.9 (0.2) 81 12.6 (0.1) 70 Total fixed maturity securities 245.5 (2.4) 180 129.9 (1.6) 133 Total less than 12 months $ 245.5 $ (2.4) 180 $ 129.9 $ (1.6) 133 12 months or greater: Fixed maturity securities U.S. Treasuries $ 23.5 $ (2.6) 7 $ 23.7 $ (2.4) 7 U.S. Agencies 2.2 (0.1) 1 2.2 (0.1) 1 States and municipalities 71.9 (4.7) 33 73.5 (4.9) 32 Corporate securities 695.6 (66.6) 328 684.5 (62.4) 331 Residential mortgage-backed securities 301.7 (43.3) 230 306.6 (37.8) 228 Commercial mortgage-backed securities 52.4 (6.2) 24 53.0 (6.4) 24 Asset-backed securities 46.6 (4.5) 30 47.0 (4.7) 29 Collateralized loan obligations 7.4 (0.1) 4 80.5 (0.7) 21 Foreign government securities 10.0 (2.7) 2 10.4 (2.3) 2 Other securities 7.1 (0.2) 42 10.2 (0.6) 58 Total fixed maturity securities 1,218.4 (131.0) 701 1,291.6 (122.3) 733 Total 12 months or greater $ 1,218.4 $ (131.0) 701 $ 1,291.6 $ (122.3) 733 As of March 31, 2024 and December 31, 2023, the Company had an allowance for current expected credit losses (CECL) on AFS debt securities of $3.2 million and $2.7 million, respectively (See Note 5). Those fixed maturity securities whose total fair value was less than amortized cost at each of March 31, 2024 and December 31, 2023, were those in which the Company had no intent, need or requirement to sell at an amount less than their amortized cost. Realized gains and losses on investments include the gain or loss on a security at the time of sale compared to its original or adjusted cost (equity securities and other invested assets) or amortized cost (fixed maturity securities). Realized losses on fixed maturity securities are also recognized when securities are written down as a result of an other-than-temporary impairment or for unfavorable changes in CECL. Reversals of previously recognized realized losses on fixed maturity securities can also result when securities are written up for favorable changes in CECL. Net realized gains and losses on investments and the change in unrealized gains and losses on the Company’s investments recorded at fair value are determined on a specific-identification basis and were as follows: Gross Realized Gains Gross Realized Losses Net Increase in CECL Allowance Change in Net Unrealized Gains (Losses) Changes in Fair Value Reflected in Earnings Changes in Fair Value Reflected in AOCI (1) , before tax (in millions) Three Months Ended March 31, 2024 Fixed maturity securities 0.1 $ (0.5) $ (0.5) $ (13.7) $ (0.9) $ (13.7) Equity securities 0.1 (0.5) — 13.1 12.7 — Other invested assets — — — (0.4) (0.4) — Total investments $ 0.2 $ (1.0) $ (0.5) $ (1.0) $ 11.4 $ (13.7) Three Months Ended March 31, 2023 Fixed maturity securities $ 0.4 $ (0.6) $ (1.4) $ 30.1 $ (1.6) $ 30.1 Equity securities 0.1 (1.3) — 7.9 6.7 — Other invested assets — — — 1.3 1.3 — Total investments $ 0.5 $ (1.9) $ (1.4) $ 39.3 $ 6.4 $ 30.1 (1) AOCI means Accumulated other comprehensive income or loss Proceeds from sales of fixed maturity securities were $32.0 million for the three months ended March 31, 2024, compared to $44.8 million for the three months ended March 31, 2023. Net investment income was as follows: Three Months Ended March 31, 2024 2023 (in millions) Fixed maturity securities $ 22.3 $ 23.7 Equity securities 1.6 1.8 Other invested assets 1.1 0.9 Short-term investments 0.5 1.2 Cash equivalents and restricted cash 2.3 0.9 Gross investment income 27.8 28.5 Investment expenses (1.0) (0.9) Net investment income $ 26.8 $ 27.6 The Company is required by various state laws and regulations to support, through securities on deposit or otherwise, its outstanding loss reserves in certain states in which it does business. These laws and regulations govern not only the amount but also the types of securities that are eligible for deposit. As of March 31, 2024 and December 31, 2023, securities having a fair value of $760.6 million and $748.1 million, respectively, were on deposit. Additionally, standby letters of credit from the FHLB were in place in lieu of $70.0 million of securities on deposit as of both March 31, 2024 and December 31, 2023 (See Note 10).

Current Expected Credit Losses

Current Expected Credit Losses	3 Months Ended
	Mar. 31, 2024
Credit Loss [Abstract]
Credit Losses	Current Expected Credit Losses Premiums Receivable Premiums receivable balances are all due within one year. The Company currently determines the allowance for premiums receivable based on an internal aging schedule using collectability and historical payment patterns, as well as current and expected future market conditions to determine the appropriateness of the allowance. Historical payment patterns and future market conditions provide the basis for the estimation along with similar risk characteristics and the Company's business strategy, which have not changed significantly over time. Changes in the allowance for CECL are recorded through underwriting and general and administrative expenses. The table below shows the changes in CECL on premiums receivable. Three Months Ended March 31, 2024 2023 (in millions) Beginning balance of CECL on premiums receivable $ 17.9 $ 12.8 Net change in CECL provision 5.9 3.3 Write-offs charged against CECL (1.9) (0.7) Recoveries collected (2.2) (1.4) Ending balance of CECL on premiums receivable $ 19.7 $ 14.0 Reinsurance Recoverable In assessing an allowance for reinsurance assets, which includes reinsurance recoverables and contingent commission receivables, the Company considers historical information, financial strength of reinsurers, collateralization amounts, and ratings to determine the appropriateness of the allowance. Historically, the Company has not experienced a credit loss from reinsurance transactions. In assessing future default, the Company evaluated the CECL allowance under the ratings-based method using the A.M. Best's Average Cumulative Net Impairment Rates. Reinsurer ratings are also assessed through this process. Changes in the allowance for CECL are recorded through underwriting and general and administrative expenses. The table below shows the changes in CECL on reinsurance recoverables. Three Months Ended March 31, 2024 2023 (in millions) Beginning balance of CECL on reinsurance recoverables $ 0.9 $ 0.9 Net change in CECL provision — — Ending balance of CECL on reinsurance recoverables $ 0.9 $ 0.9 Investments The Company assesses all AFS debt securities in an unrealized loss position for CECL. The Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria is met, the security's amortized cost basis is written down to its fair value. For AFS debt securities that do not meet either criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. Any impairment that has not been recorded through an allowance for credit losses is recognized in Accumulated other comprehensive loss on the Company's Consolidated Balance Sheets. Changes in the allowance for CECL are recorded through realized capital losses. As of March 31, 2024, the Company established an aggregate allowance for CECL in the amount of $3.2 million. For the Company’s investments in fixed maturity debt securities, the allowance for CECL was determined by: (i) observing the credit characteristics of those debt securities that may have demonstrated a credit loss as of that date and by comparing the present value of cash flows expected to be collected to its amortized cost basis; and (ii) observing the credit characteristics of those debt securities that are expected to demonstrate a credit loss in the future by comparing the present value of cash flows expected to be collected to its amortized cost basis. The expected present value of cash flows are calculated using scenario based credit loss models derived from the discounted cash flows under the Comprehensive Capital Analysis Review framework, which is adopted by the Federal Reserve. As of March 31, 2024, the Company did not intend to sell any of its AFS debt securities in which its amortized cost exceeded its fair value. Accrued interest receivable on AFS debt securities totaled $16.5 million at March 31, 2024 and is excluded from the estimate of credit losses based on historically timely payments. The table below shows the changes in the allowance for CECL on AFS securities. Three Months Ended March 31, 2024 2023 (in millions) Beginning balance of CECL on AFS securities $ 2.7 $ 4.5 Net change in CECL provision 0.6 2.0 Reductions in allowance from disposals (0.1) (0.2) Recoveries of amounts previously written off — (0.4) Ending balance of CECL on AFS securities $ 3.2 $ 5.9

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Disclosure [Text Block]	Property and Equipment Property and equipment consists of the following: As of March 31, As of December 31, 2024 2023 (in millions) Furniture and equipment $ 1.8 $ 1.8 Leasehold improvements 0.5 0.5 Computers and software 42.2 45.7 Automobiles 0.6 0.6 Property and equipment, gross 45.1 48.6 Accumulated depreciation (38.5) (42.1) Property and equipment, net $ 6.6 $ 6.5 Depreciation expenses related to property and equipment for the three months ended March 31, 2024 were $1.0 million and $4.8 million for the year ended December 31, 2023. Internally developed software costs that were capitalized were $0.6 million during the three months ended March 31, 2024 and $1.8 million during the year ended December 31, 2023. Cloud Computing Arrangements The Company’s capitalized costs associated with cloud computing arrangements totaled $25.2 million and $28.0 million, which were comprised of service contract fees and implementation costs associated with hosting arrangements as of March 31, 2024 and December 31, 2023, respectively. Total amortization for hosting arrangements was $2.8 million for the three months ended March 31, 2024 and $16.7 million for the year ended December 31, 2023. Leases The Company determines if an arrangement is a lease at the inception of the transaction. Operating leases for offices are presented as a right-of-use asset (ROU asset) and lease liability on the Company’s Consolidated Balance Sheets. Financing leases for automobiles are included in property and equipment and other liabilities on the Company’s Consolidated Balance Sheets. ROU assets represent the right to use an underlying asset for the lease term and the lease liability represents the obligation to make lease payments arising from the lease transaction. Operating lease ROU assets and liabilities are recognized at the commencement date based on the present value of the lease payments over the lease term. The Company uses collateralized incremental borrowing rates to determine the present value of lease payments. The ROU assets also include lease payments less any lease incentives within a lease agreement. The Company’s lease terms may include options to extend or terminate a lease. Lease expense for lease payments is recognized on a straight-line basis over the lease term. As of March 31, 2024, the Company’s operating leases have remaining terms of one Components of lease expense were as follows: Three Months Ended March 31, 2024 2023 (in millions) Operating lease expense $ 0.3 $ 0.6 Finance lease expense — 0.1 Total lease expense $ 0.3 $ 0.7 As of March 31, 2024 , the weighted average remaining lease term for o perating leases was 3.8 years and for finance leases was 1.7 years. The weighted average dis cou nt rate was 1.3% and 7.4% for operating and finance leases, respectively . Maturities of lease liabilities were as follows: As of March 31, 2024 Operating Leases Finance Leases (in millions) 2024 $ 1.3 $ 0.1 2025 1.5 0.1 2026 1.2 — 2027 1.2 — 2028 0.4 — Thereafter — — Total lease payments 5.6 0.2 Less: imputed interest (0.1) — Total $ 5.5 $ 0.2 Supplemental balance sheet information related to leases was as follows: As of March 31, As of December 31, 2024 2023 (in millions) Operating leases: Operating lease right-of-use asset $ 4.7 $ 5.1 Operating lease liability 5.5 5.9 Finance leases: Property and equipment, gross 0.6 0.6 Accumulated depreciation (0.4) (0.4) Property and equipment, net 0.2 0.2 Other liabilities $ 0.2 $ 0.2 Supplemental cash flow information related to leases was as follows: Three Months Ended March 31, 2024 2023 (in millions) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows used for operating leases $ 0.3 $ 0.6 Financing cash flows used for finance leases — 0.1

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Taxes [Abstract]
Income Taxes	Income Taxes The Company’s effective tax rate for the three months ended March 31, 2024 was 19.8% and the Company’s effective tax rate for the three months ended March 31, 2023 was 18.6%. The effective rates during each of the periods presented included income tax benefits and exclusions associated with tax-advantaged investment income, LPT adjustments, and deferred gain amortization. The Inflation Reduction Act of 2022 added a new IRC section, Section 4501, that imposes a 1% excise tax on stock repurchases on publicly traded companies that occurred after December 31, 2022. The Company's excise tax obligation is $0.7 million at March 31, 2024, which is included in treasury stock, on its Consolidated Balance Sheets.

Liability for Unpaid Losses and

Liability for Unpaid Losses and Loss Adjustment Expenses	3 Months Ended
	Mar. 31, 2024
Liability for Unpaid Losses and Loss Adjustment Expenses [Abstract]
Liability for Unpaid Losses and Loss Adjustment Expenses	Liability for Unpaid Losses and Loss Adjustment Expenses The following table represents a reconciliation of changes in the liability for unpaid losses and LAE. Three Months Ended March 31, 2024 2023 (in millions) Unpaid losses and LAE at beginning of period $ 1,884.5 $ 1,960.7 Less reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE 428.4 445.4 Net unpaid losses and LAE at beginning of period 1,456.1 1,515.3 Losses and LAE, net of reinsurance, incurred during the period related to: Current period 118.7 109.6 Prior periods (0.1) (0.2) Total net losses and LAE incurred during the period 118.6 109.4 Paid losses and LAE, net of reinsurance, related to: Current period 6.8 5.6 Prior periods 117.4 105.7 Total net paid losses and LAE during the period 124.2 111.3 Ending unpaid losses and LAE, net of reinsurance 1,450.5 1,513.4 Reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE 424.0 440.3 Unpaid losses and LAE at end of period $ 1,874.5 $ 1,953.7 Total net losses and LAE included in the above table exclude amortization of the deferred reinsurance gain—LPT Agreement and LPT Contingent Commission Adjustments, which totaled $2.1 million and $2.0 million for the three months ended March 31, 2024 and 2023, respectively (see Note 9). The change in incurred losses and LAE attributable to prior periods for the three months ended March 31, 2024 and 2023, included $0.1 million and $0.2 million of net favorable loss reserve development on the Company's assigned risk business, respectively. For each of the three months ended March 31, 2024 and 2023, the Company did not recognize any prior accident year loss reserve development on its voluntary risk business. These determinations were made in light of: (i) a full actuarial study not being performed during the periods; and (ii) the amount of indicated net prior year loss reserve development was consistent with our expectations.

LPT Agreement

LPT Agreement	3 Months Ended
	Mar. 31, 2024
LPT Agreement [Abstract]
LPT Agreement	LPT Agreement The Company is party to the LPT Agreement under which $1.5 billion in liabilities for losses and LAE related to claims incurred by the Fund prior to July 1, 1995 were reinsured for consideration of $775.0 million. The LPT Agreement provides coverage up to $2.0 billion. The Company records its estimate of contingent profit commission in the accompanying Consolidated Balance Sheets as Contingent commission receivable–LPT Agreement and a corresponding liability is recorded in the accompanying Consolidated Balance Sheets in Deferred reinsurance gain–LPT Agreement. The Deferred Gain is being amortized using the recovery method. Amortization is determined by the proportion of actual reinsurance recoveries to total estimated recoveries over the life of the LPT Agreement, except for the contingent profit commission, which is amortized through June 30, 2024, the date through which the Company is entitled to receive a contingent profit commission under the LPT Agreement. The amortization is recorded in losses and LAE incurred in the accompanying Consolidated Statements of Comprehensive Income (Loss). Any adjustments to the Deferred Gain are recorded in losses and LAE incurred in the accompanying Consolidated Statements of Comprehensive Income (Loss). The Company amortized $1.9 million and $2.0 million of the Deferred Gain for the three months ended March 31, 2024 and 2023, respectively. The remaining Deferred Gain was $97.2 million and $99.2 million as of March 31, 2024 and December 31, 2023, respectively. Additionally, the Company recognized $0.2 million of favorable LPT Contingent Commission Adjustments as of March 31, 2024. The estimated remaining liabilities subject to the LPT Agreement were $287.1 million and $291.7 million as of March 31, 2024 and December 31, 2023, respectively. Losses and LAE paid with respect to the LPT Agreement totaled $882.2 million and $877.6 million from inception through March 31, 2024 and December 31, 2023, respectively.

Notes Payable

Notes Payable	3 Months Ended
	Mar. 31, 2024
Notes Payable [Abstract]
Debt Disclosure [Text Block]	Financing Arrangements All of the Company's insurance subsidiaries are members of the FHLB. Membership allows the insurance subsidiaries access to collateralized advances, which may be used to support and enhance liquidity management. The amount of advances that may be taken is dependent on statutory admitted assets on a per company basis. FHLB membership also allows the Company’s insurance subsidiaries access to standby letters of credit (Letter of Credit Agreements). Letter of Credit Agreements may only be used to satisfy, in whole or in part, insurance deposit requirements with the State of California and must be fully secured with eligible collateral at all times. Letter of Credit Agreements are subject to annual maintenance charges and a fee of 15 basis points on issued amounts. As of both March 31, 2024 and December 31, 2023, letters of credit totaling $70.0 million, were issued in lieu of securities on deposit with the State of California under these Letter of Credit Agreements. The Letter of Credit Agreements currently in effect expire on March 31, 2025, and will remain evergreen with automatic one-year extensions unless the FHLB notifies the beneficiary at least 60 days prior to the then applicable expiration date of its election not to renew. As of March 31, 2024 and December 31, 2023, investment securities having a fair value of $275.1 million and $286.4 million, respectively, were pledged to the FHLB by the Company’s insurance subsidiaries in support of the collateralized advance facility and the Letter of Credit Agreements.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2024
Accumulated Other Comprehensive Income [Abstract]
Accumulated Other Comprehensive Income, Net	Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is comprised of unrealized gains and losses on investments classified as AFS, net of deferred taxes. The following table summarizes the components of accumulated other comprehensive loss: March 31, 2024 December 31, 2023 (in millions) Net unrealized losses on investments, before taxes $ (122.6) $ (108.9) Deferred tax benefit on net unrealized losses 25.7 22.9 Total accumulated other comprehensive loss $ (96.9) $ (86.0)

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2024
Stock-Based Compensation [Abstract]
Stock-Based compensation	Stock-Based Compensation The Company awarded restricted stock units (RSUs) and performance share units (PSUs) to certain employees and non-employee Directors of the Company as follows: Number Awarded Weighted Average Fair Value on Date of Grant Aggregate Fair Value on Date of Grant (in millions) February 2024 RSUs (1) 61,280 46.36 2.8 PSUs (2) 77,360 46.36 3.6 March 2024 RSUs (1) 4,712 45.00 0.2 (1) These RSUs were awarded to certain employees of the Company on two separate dates and all vest 25% on March 15, 2025 and each of the subsequent three anniversaries of that date. (2) These PSUs were awarded to certain employees of the Company and have a performance period of three years. The PSU awards are subject to certain performance goals with payouts that range from 0% to 250% of the target awards. The value shown in the table represents the aggregate number of PSUs awarded at the target level. Employees who are awarded RSUs and PSUs are entitled to receive dividend equivalents for eligible awards, payable in cash, when and if, the underlying award vests and becomes payable. If the underlying award does not vest or is forfeited, dividend equivalents with respect to the underlying award fail to become payable and are forfeited. RSUs and PSUs are subject to accelerated vesting in certain circumstances, including but not limited to: death, disability, retirement, or in connection with a change of control of the Company. As of March 31, 2024, the Company no longer had any stock options outstanding. During the three months ended March 31, 2023, and the year ended December 31, 2023, there were 23,500 stock options exercised. As of March 31, 2024, the Company had 240,365 RSUs, and 208,015 PSUs (based on the target achievement for the PSUs awarded) outstanding.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Common Share Basic earnings per share is computed by dividing net income by the weighted average number of common shares outstanding for the period. Diluted earnings per share reflects the potential dilutive impact of all common stock equivalents on earnings per share. Diluted earnings per share includes common shares assumed issued under the “treasury stock method,” which reflects the potential dilution that would occur if outstanding RSUs and PSUs vested. No outstanding PSUs and RSUs are considered in the Company’s diluted earnings per share computations in any period that involves a net loss because their inclusion would be anti-dilutive. Employees who are awarded RSUs and PSUs are entitled to receive dividend equivalents for eligible awards, payable in cash, when and if, the underlying award vests and becomes payable. Therefore, these awards are not considered participating securities for the purposes of determining earnings per share. The following table presents the net income and the weighted average number of shares outstanding used in the earnings per common share calculations. Three Months Ended March 31, 2024 2023 (in millions, except share data) Net income $ 28.3 $ 23.6 Weighted average number of shares outstanding—basic 25,345,942 27,176,823 Effect of dilutive securities: PSUs 115,021 141,246 Stock options — 8,286 RSUs 75,008 66,323 Potential dilutive shares 190,029 215,855 Weighted average number of shares outstanding—diluted 25,535,971 27,392,678

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
Segment Reporting Disclosure [Text Block]	Segment Reporting The Company operates as a single reportable segment, Insurance Operations , through its wholly owned subsidiaries. In the fourth quarter of 2023, the Company developed and executed an integration plan to consolidate its previously segregated direct-to-consumer operations (Cerity) into the Company's mainstream operations, while retaining its digital distribution capabilities. The integration plan, which will allow the Company to operate more efficiently and generate cost savings, resulted in a change in the composition of our reportable segments by eliminating any distinction for reporting purposes, including stand-alone financial statements, among our former segments, which were: Employers and Cerity . The Insurance Operations segment represents the traditional business offered through its agents, including business originated from the Company's strategic partnerships and alliances and also direct-to-customer business. The following table summarizes the Company's written premium and components of net income. The prior period has been conformed to current presentation. Insurance Operations Total (in millions) Three Months Ended March 31, 2024 Gross premiums written $ 210.9 $ 210.9 Net premiums written 209.1 209.1 Net premiums earned 184.9 184.9 Net investment income 26.8 26.8 Net realized and unrealized gains on investments 11.4 11.4 Total revenues 223.1 223.1 Losses and loss adjustment expenses 116.5 116.5 Commission expense 25.5 25.5 Underwriting and general and administrative expenses 45.8 45.8 Total expenses 187.8 187.8 Net income before income taxes 35.3 35.3 Income tax expense 7.0 7.0 Net income $ 28.3 $ 28.3 Three Months Ended March 31, 2023 Gross premiums written $ 194.9 $ 194.9 Net premiums written 193.1 193.1 Net premiums earned 172.7 172.7 Net investment income 27.6 27.6 Net realized and unrealized gains on investments 6.4 6.4 Other (loss) income (0.2) (0.2) Total revenues 206.5 206.5 Losses and loss adjustment expenses 107.4 107.4 Commission expense 23.4 23.4 Underwriting and general and administrative expenses 44.4 44.4 Interest and financing expenses 2.3 2.3 Total expenses 177.5 177.5 Net income before income taxes 29.0 29.0 Income tax expense 5.4 5.4 Net income $ 23.6 $ 23.6 Entity-Wide Disclosures The Company operates solely within the U.S. and does not have revenue from transactions with a single policyholder accounting for 10% or more of its revenues. In-force premiums represent the estimated annual premium on all policies that are active and in-force on such date. More specifically, in-force premiums include policy endorsements but exclude estimated final audit premiums. When adjusting for estimated final audit premium, our total in-force premiums were $757.5 million, $737.5 million, $667.6 million, and $654.9 million as of March 31, 2024, December 31, 2023, March 31, 2023, and December 31, 2022, respectively. The Company's management focuses on in-force premium because it represents premium that is available for renewal in the future. The following table shows our in-force premiums, in-force premiums including estimated final audit premium, and number of policies in-force for each of our largest states and all other states combined for the periods presented: March 31, 2024 December 31, 2023 March 31, 2023 December 31, 2022 State In-force Premiums Policies In-force Premiums Policies In-force Policies In-force Policies (dollars in millions) California $ 320.1 43,832 $ 311.5 43,353 $ 282.9 42,908 $ 279.7 42,876 Florida 57.5 10,277 56.6 10,008 50.5 9,560 49.4 9,417 New York 33.6 7,679 31.9 7,603 28.5 7,478 27.3 7,497 Other (43 states and D.C.) 301.6 65,696 294.6 65,445 269.0 62,738 266.1 61,566 Total in-force $ 712.8 127,484 $ 694.6 126,409 $ 630.9 122,684 $ 622.5 121,356 Estimated audit premium 44.7 — 42.9 — 36.7 — 32.4 — Total in-force, including $ 757.5 127,484 $ 737.5 126,409 $ 667.6 122,684 $ 654.9 121,356

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net income	$ 28.3	$ 23.6

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Item 5. Other Information Rule 10b5-1 Trading Plans During the three months ended March 31, 2024, no director or officer of the Company adopted or terminated a "Rule 10b5-1 trading arrangement" or "non-Rule 10b5-1 trading arrangement," as each such term is defined in Item 408(a) of Regulation S-K.
Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false

Valuation of Financial Instru_2

Valuation of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value of Financial Instruments [Abstract]
Estimated fair value of financial instruments table	The carrying value and the estimated fair value of the Company’s financial instruments at fair value were as follows: March 31, 2024 December 31, 2023 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value (in millions) Financial assets Total investments at fair value $ 2,276.3 $ 2,276.3 $ 2,180.6 $ 2,180.6 Cash and cash equivalents 114.2 114.2 226.4 226.4 Restricted cash and cash equivalents 0.2 0.2 0.2 0.2
Fair value, assets and liabilities measured on recurring basis table	The following table presents the Company’s investments at fair value and the corresponding fair value measurements. March 31, 2024 December 31, 2023 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 (in millions) Fixed maturity securities: U.S. Treasuries $ — $ 63.0 $ — $ — $ 58.4 $ — U.S. Agencies — 2.1 — — 2.1 — States and municipalities — 199.8 — — 210.2 — Corporate securities — 905.5 34.0 — 863.7 32.1 Residential mortgage-backed securities — 370.0 — — 362.2 — Commercial mortgage-backed securities — 63.2 — — 63.8 — Asset-backed securities — 163.2 13.5 — 113.9 14.1 Collateralized loan obligations — 72.8 — — 91.5 — Foreign government securities — 10.0 — — 10.4 — Other securities — 116.7 — — 113.9 — Total fixed maturity securities $ — $ 1,966.3 $ 47.5 $ — $ 1,890.1 $ 46.2 Equity securities at fair value: Industrial and miscellaneous $ 195.3 $ — $ — $ 181.7 $ — $ — Other 29.0 — — 29.5 — — Total equity securities at fair value $ 224.3 $ — $ — $ 211.2 $ — $ — Short-term investments $ 16.5 $ 21.7 $ — $ 17.6 $ 15.5 $ — Total investments at fair value $ 240.8 $ 1,988.0 $ 47.5 $ 228.8 $ 1,905.6 $ 46.2
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table Text Block]	Financial Instruments Carried at Net Asset Value The Company has investments in private equity limited partnership interests that are included in Other invested assets on the Company’s Consolidated Balance Sheets. These investments do not have readily determinable fair values and are carried at net asset value (NAV) and therefore are excluded from the fair value hierarchy. The Company initially estimates the value of these investments using the transaction price. In subsequent periods, the Company measures these investments using NAV per share provided quarterly by the general partner, based on financial statements that are audited annually. These investments are generally not redeemable by the investees and cannot be sold without approval of the general partner. These investments have a fund term of 3 to 12 years, subject to two or three one Additionally, certain cash equivalents, principally money market securities, are measured using NAV, which approximates fair value. The following table presents cash and investments carried at NAV on the Company’s Consolidated Balance Sheets. March 31, 2024 December 31, 2023 (in millions) Cash equivalents carried at NAV $ 104.3 $ 197.2 Other invested assets carried at NAV 97.6 91.5
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following table provides a reconciliation of the beginning and ending balances that are measured using Level 3 inputs. Three Months Ended March 31, 2024 2023 (in millions) Balance at the beginning of the year $ 46.2 $ 24.2 Purchases 1.5 1.5 Unrealized (losses) gains included in comprehensive (loss) income (0.2) 0.2 Balance at end of period $ 47.5 $ 25.9

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2024
Investments [Abstract]
Debt Securities, Available-for-sale	The amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of the Company’s available-for-sale (AFS) investments were as follows: Amortized Allowance for Current Expected Credit Losses Gross Gross Estimated (in millions) At March 31, 2024 Fixed maturity securities U.S. Treasuries $ 65.6 $ — $ 0.3 $ (2.9) $ 63.0 U.S. Agencies 2.2 — — (0.1) 2.1 States and municipalities 202.8 — 2.4 (5.4) 199.8 Corporate securities 1,003.5 (2.2) 5.4 (67.2) 939.5 Residential mortgage-backed securities 413.0 — 0.6 (43.6) 370.0 Commercial mortgage-backed securities 69.7 (0.3) — (6.2) 63.2 Asset-backed securities 180.3 — 1.1 (4.7) 176.7 Collateralized loan obligations 73.0 — — (0.2) 72.8 Foreign government securities 12.7 — — (2.7) 10.0 Other securities (1) 116.9 (0.7) 0.9 (0.4) 116.7 Total fixed maturity securities $ 2,139.7 $ (3.2) $ 10.7 $ (133.4) $ 2,013.8 Short-term investments 38.2 — — — 38.2 Total AFS investments $ 2,177.9 $ (3.2) $ 10.7 $ (133.4) $ 2,052.0 At December 31, 2023 Fixed maturity securities U.S. Treasuries $ 60.3 $ — $ 0.6 $ (2.5) $ 58.4 U.S. Agencies 2.2 — — (0.1) 2.1 States and municipalities 212.3 — 3.1 (5.2) 210.2 Corporate securities 952.8 (2.1) 8.3 (63.2) 895.8 Residential mortgage-backed securities 399.3 — 0.9 (38.0) 362.2 Commercial mortgage-backed securities 70.2 — — (6.4) 63.8 Asset-backed securities 131.8 — 1.0 (4.8) 128.0 Collateralized loan obligations 92.2 — — (0.7) 91.5 Foreign government securities 12.7 — — (2.3) 10.4 Other securities (1) 114.2 (0.6) 1.0 (0.7) 113.9 Total fixed maturity securities $ 2,048.0 $ (2.7) $ 14.9 $ (123.9) $ 1,936.3 Short-term investments 33.1 — — — 33.1 Total AFS investments $ 2,081.1 $ (2.7) $ 14.9 $ (123.9) $ 1,969.4 (1) Other securities within fixed maturity securities consist of bank loans, which are classified as AFS and reported at fair value.
Equity securities table	The cost and estimated fair value of the Company’s equity securities recorded at fair value at March 31, 2024 and December 31, 2023 were as follows: Cost Estimated Fair Value (in millions) At March 31, 2024 Equity securities at fair value Industrial and miscellaneous $ 105.1 $ 195.3 Other 20.8 29.0 Total equity securities at fair value $ 125.9 $ 224.3 At December 31, 2023 Equity securities at fair value Industrial and miscellaneous $ 104.4 $ 181.7 Other 21.5 29.5 Total equity securities at fair value $ 125.9 $ 211.2
Other invested assets	The Company had Other invested assets totaling $97.6 million and $91.5 million (initial cost of $88.9 million and $82.5 million) at March 31, 2024 and December 31, 2023, respectively, consisting of private equity limited partnerships, which are carried at NAV based on information provided by the general partner. These investments are non-redeemable until conversion and are periodically evaluated by the Company for impairment based on the ultimate recovery of the investment. Changes in the value of these investments are recorded through Net realized and unrealized gains (losses) on the Company’s Consolidated Statements of Comprehensive Income (Loss).
Investments classified by contractual maturity date table	The amortized cost and estimated fair value of the Company’s fixed maturity securities at March 31, 2024, by contractual maturity, are shown below. Expected maturities differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Cost Estimated Fair Value (in millions) Due in one year or less $ 20.6 $ 20.3 Due after one year through five years 651.8 630.3 Due after five years through ten years 642.6 599.2 Due after ten years 88.7 81.3 Mortgage and asset-backed securities 736.0 682.7 Total $ 2,139.7 $ 2,013.8
Unrealized loss on investments table	The following is a summary of AFS investments that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 months or greater in each case as of March 31, 2024 and December 31, 2023. March 31, 2024 December 31, 2023 Estimated Fair Value Gross Number of Issues Estimated Fair Value Gross Number of Issues (dollars in millions) Less than 12 months: Fixed maturity securities U.S. Treasuries $ 19.0 $ (0.3) 8 $ 11.9 $ (0.1) 5 States and municipalities 42.2 (0.7) 16 39.5 (0.3) 15 Corporate securities 60.2 (0.6) 23 26.1 (0.8) 13 Residential mortgage-backed securities 21.5 (0.3) 20 15.8 (0.2) 15 Asset-backed securities 55.1 (0.2) 24 24.0 (0.1) 15 Collateralized loan obligations 32.6 (0.1) 8 — — — Other securities 14.9 (0.2) 81 12.6 (0.1) 70 Total fixed maturity securities 245.5 (2.4) 180 129.9 (1.6) 133 Total less than 12 months $ 245.5 $ (2.4) 180 $ 129.9 $ (1.6) 133 12 months or greater: Fixed maturity securities U.S. Treasuries $ 23.5 $ (2.6) 7 $ 23.7 $ (2.4) 7 U.S. Agencies 2.2 (0.1) 1 2.2 (0.1) 1 States and municipalities 71.9 (4.7) 33 73.5 (4.9) 32 Corporate securities 695.6 (66.6) 328 684.5 (62.4) 331 Residential mortgage-backed securities 301.7 (43.3) 230 306.6 (37.8) 228 Commercial mortgage-backed securities 52.4 (6.2) 24 53.0 (6.4) 24 Asset-backed securities 46.6 (4.5) 30 47.0 (4.7) 29 Collateralized loan obligations 7.4 (0.1) 4 80.5 (0.7) 21 Foreign government securities 10.0 (2.7) 2 10.4 (2.3) 2 Other securities 7.1 (0.2) 42 10.2 (0.6) 58 Total fixed maturity securities 1,218.4 (131.0) 701 1,291.6 (122.3) 733 Total 12 months or greater $ 1,218.4 $ (131.0) 701 $ 1,291.6 $ (122.3) 733
Unrealized gain (loss) on investments	Net realized gains and losses on investments and the change in unrealized gains and losses on the Company’s investments recorded at fair value are determined on a specific-identification basis and were as follows: Gross Realized Gains Gross Realized Losses Net Increase in CECL Allowance Change in Net Unrealized Gains (Losses) Changes in Fair Value Reflected in Earnings Changes in Fair Value Reflected in AOCI (1) , before tax (in millions) Three Months Ended March 31, 2024 Fixed maturity securities 0.1 $ (0.5) $ (0.5) $ (13.7) $ (0.9) $ (13.7) Equity securities 0.1 (0.5) — 13.1 12.7 — Other invested assets — — — (0.4) (0.4) — Total investments $ 0.2 $ (1.0) $ (0.5) $ (1.0) $ 11.4 $ (13.7) Three Months Ended March 31, 2023 Fixed maturity securities $ 0.4 $ (0.6) $ (1.4) $ 30.1 $ (1.6) $ 30.1 Equity securities 0.1 (1.3) — 7.9 6.7 — Other invested assets — — — 1.3 1.3 — Total investments $ 0.5 $ (1.9) $ (1.4) $ 39.3 $ 6.4 $ 30.1
Investment income table	Net investment income was as follows: Three Months Ended March 31, 2024 2023 (in millions) Fixed maturity securities $ 22.3 $ 23.7 Equity securities 1.6 1.8 Other invested assets 1.1 0.9 Short-term investments 0.5 1.2 Cash equivalents and restricted cash 2.3 0.9 Gross investment income 27.8 28.5 Investment expenses (1.0) (0.9) Net investment income $ 26.8 $ 27.6

Current Expected Credit Losses

Current Expected Credit Losses (Tables)	3 Months Ended
	Mar. 31, 2024
Credit Loss [Abstract]
Premium Receivable, Allowance for Credit Loss [Table Text Block]	The table below shows the changes in CECL on premiums receivable. Three Months Ended March 31, 2024 2023 (in millions) Beginning balance of CECL on premiums receivable $ 17.9 $ 12.8 Net change in CECL provision 5.9 3.3 Write-offs charged against CECL (1.9) (0.7) Recoveries collected (2.2) (1.4) Ending balance of CECL on premiums receivable $ 19.7 $ 14.0
Reinsurance Recoverable, Allowance for Credit Loss [Table Text Block]	The table below shows the changes in CECL on reinsurance recoverables. Three Months Ended March 31, 2024 2023 (in millions) Beginning balance of CECL on reinsurance recoverables $ 0.9 $ 0.9 Net change in CECL provision — — Ending balance of CECL on reinsurance recoverables $ 0.9 $ 0.9
Debt Securities, Available-for-sale, Allowance for Credit Loss [Table Text Block]	The table below shows the changes in the allowance for CECL on AFS securities. Three Months Ended March 31, 2024 2023 (in millions) Beginning balance of CECL on AFS securities $ 2.7 $ 4.5 Net change in CECL provision 0.6 2.0 Reductions in allowance from disposals (0.1) (0.2) Recoveries of amounts previously written off — (0.4) Ending balance of CECL on AFS securities $ 3.2 $ 5.9

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property and Equipment [Table Text Block]	Property and equipment consists of the following: As of March 31, As of December 31, 2024 2023 (in millions) Furniture and equipment $ 1.8 $ 1.8 Leasehold improvements 0.5 0.5 Computers and software 42.2 45.7 Automobiles 0.6 0.6 Property and equipment, gross 45.1 48.6 Accumulated depreciation (38.5) (42.1) Property and equipment, net $ 6.6 $ 6.5
Lease, Cost [Table Text Block]	Components of lease expense were as follows: Three Months Ended March 31, 2024 2023 (in millions) Operating lease expense $ 0.3 $ 0.6 Finance lease expense — 0.1 Total lease expense $ 0.3 $ 0.7
Lessee, Operating and Finance Lease Liability Maturity [Table Text Block]	Maturities of lease liabilities were as follows: As of March 31, 2024 Operating Leases Finance Leases (in millions) 2024 $ 1.3 $ 0.1 2025 1.5 0.1 2026 1.2 — 2027 1.2 — 2028 0.4 — Thereafter — — Total lease payments 5.6 0.2 Less: imputed interest (0.1) — Total $ 5.5 $ 0.2
Supplemental Balance Sheet Information related to Leases [Table Text Block]	Supplemental balance sheet information related to leases was as follows: As of March 31, As of December 31, 2024 2023 (in millions) Operating leases: Operating lease right-of-use asset $ 4.7 $ 5.1 Operating lease liability 5.5 5.9 Finance leases: Property and equipment, gross 0.6 0.6 Accumulated depreciation (0.4) (0.4) Property and equipment, net 0.2 0.2 Other liabilities $ 0.2 $ 0.2
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	Supplemental cash flow information related to leases was as follows: Three Months Ended March 31, 2024 2023 (in millions) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows used for operating leases $ 0.3 $ 0.6 Financing cash flows used for finance leases — 0.1

Liability for Unpaid Losses a_2

Liability for Unpaid Losses and Loss Adjustment Expenses (Tables)	3 Months Ended
	Mar. 31, 2024
Liability for Unpaid Losses and Loss Adjustment Expenses [Abstract]
Changes in the liability for unpaid losses and LAE table	The following table represents a reconciliation of changes in the liability for unpaid losses and LAE. Three Months Ended March 31, 2024 2023 (in millions) Unpaid losses and LAE at beginning of period $ 1,884.5 $ 1,960.7 Less reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE 428.4 445.4 Net unpaid losses and LAE at beginning of period 1,456.1 1,515.3 Losses and LAE, net of reinsurance, incurred during the period related to: Current period 118.7 109.6 Prior periods (0.1) (0.2) Total net losses and LAE incurred during the period 118.6 109.4 Paid losses and LAE, net of reinsurance, related to: Current period 6.8 5.6 Prior periods 117.4 105.7 Total net paid losses and LAE during the period 124.2 111.3 Ending unpaid losses and LAE, net of reinsurance 1,450.5 1,513.4 Reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE 424.0 440.3 Unpaid losses and LAE at end of period $ 1,874.5 $ 1,953.7

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2024
Accumulated Other Comprehensive Income [Abstract]
Schedule of accumulated other comprehensive income (loss) table	The following table summarizes the components of accumulated other comprehensive loss: March 31, 2024 December 31, 2023 (in millions) Net unrealized losses on investments, before taxes $ (122.6) $ (108.9) Deferred tax benefit on net unrealized losses 25.7 22.9 Total accumulated other comprehensive loss $ (96.9) $ (86.0)

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Stock-Based Compensation [Abstract]
Share-based compensation arrangements by share-based payment award table	The Company awarded restricted stock units (RSUs) and performance share units (PSUs) to certain employees and non-employee Directors of the Company as follows: Number Awarded Weighted Average Fair Value on Date of Grant Aggregate Fair Value on Date of Grant (in millions) February 2024 RSUs (1) 61,280 46.36 2.8 PSUs (2) 77,360 46.36 3.6 March 2024 RSUs (1) 4,712 45.00 0.2 (1) These RSUs were awarded to certain employees of the Company on two separate dates and all vest 25% on March 15, 2025 and each of the subsequent three anniversaries of that date. (2) These PSUs were awarded to certain employees of the Company and have a performance period of three years. The PSU awards are subject to certain performance goals with payouts that range from 0% to 250% of the target awards. The value shown in the table represents the aggregate number of PSUs awarded at the target level.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net income and weighted average common shares outstanding used in earnings per share calculations table	The following table presents the net income and the weighted average number of shares outstanding used in the earnings per common share calculations. Three Months Ended March 31, 2024 2023 (in millions, except share data) Net income $ 28.3 $ 23.6 Weighted average number of shares outstanding—basic 25,345,942 27,176,823 Effect of dilutive securities: PSUs 115,021 141,246 Stock options — 8,286 RSUs 75,008 66,323 Potential dilutive shares 190,029 215,855 Weighted average number of shares outstanding—diluted 25,535,971 27,392,678

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2024
Net Income before income taxes by segment [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Insurance Operations Total (in millions) Three Months Ended March 31, 2024 Gross premiums written $ 210.9 $ 210.9 Net premiums written 209.1 209.1 Net premiums earned 184.9 184.9 Net investment income 26.8 26.8 Net realized and unrealized gains on investments 11.4 11.4 Total revenues 223.1 223.1 Losses and loss adjustment expenses 116.5 116.5 Commission expense 25.5 25.5 Underwriting and general and administrative expenses 45.8 45.8 Total expenses 187.8 187.8 Net income before income taxes 35.3 35.3 Income tax expense 7.0 7.0 Net income $ 28.3 $ 28.3 Three Months Ended March 31, 2023 Gross premiums written $ 194.9 $ 194.9 Net premiums written 193.1 193.1 Net premiums earned 172.7 172.7 Net investment income 27.6 27.6 Net realized and unrealized gains on investments 6.4 6.4 Other (loss) income (0.2) (0.2) Total revenues 206.5 206.5 Losses and loss adjustment expenses 107.4 107.4 Commission expense 23.4 23.4 Underwriting and general and administrative expenses 44.4 44.4 Interest and financing expenses 2.3 2.3 Total expenses 177.5 177.5 Net income before income taxes 29.0 29.0 Income tax expense 5.4 5.4 Net income $ 23.6 $ 23.6
Revenue from External Customers by Geographic Areas [Table Text Block]	March 31, 2024 December 31, 2023 March 31, 2023 December 31, 2022 State In-force Premiums Policies In-force Premiums Policies In-force Policies In-force Policies (dollars in millions) California $ 320.1 43,832 $ 311.5 43,353 $ 282.9 42,908 $ 279.7 42,876 Florida 57.5 10,277 56.6 10,008 50.5 9,560 49.4 9,417 New York 33.6 7,679 31.9 7,603 28.5 7,478 27.3 7,497 Other (43 states and D.C.) 301.6 65,696 294.6 65,445 269.0 62,738 266.1 61,566 Total in-force $ 712.8 127,484 $ 694.6 126,409 $ 630.9 122,684 $ 622.5 121,356 Estimated audit premium 44.7 — 42.9 — 36.7 — 32.4 — Total in-force, including $ 757.5 127,484 $ 737.5 126,409 $ 667.6 122,684 $ 654.9 121,356

Basis of Presentation (Details)

Basis of Presentation (Details)	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reinsurance Quota Share, Percentage	100%

Fair Value of Financial Instrum

Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	$ 2,276.3	$ 2,180.6
Total Investments at fair value, estimated fair value	2,276.3	2,180.6
Cash and cash equivalents	114.2	226.4
Cash and cash equivalents, estimated fair value	114.2	226.4
Restricted Cash and Cash Equivalents	0.2	0.2
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Restricted Cash and Cash Equivalents	$ 0.2	$ 0.2

Fair Value of Financial Instr_2

Fair Value of Financial Instruments, Fair Value Inputs (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	$ 2,013.8	$ 1,936.3
Equity securities at fair value (cost $125.9 at March 31, 2024 and $125.9 at December 31, 2023)	224.3	211.2
Equity Securities, FV-NI	224.3	211.2
Short-term investments at fair value (amortized cost $38.2 at March 31, 2024 and $33.1 at December 31, 2023)	38.2	33.1
Investments	2,379.9	2,278.1
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	224.3	211.2
Short-term investments at fair value (amortized cost $38.2 at March 31, 2024 and $33.1 at December 31, 2023)	16.5	17.6
Investments	240.8	228.8
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	0	0
Short-term investments at fair value (amortized cost $38.2 at March 31, 2024 and $33.1 at December 31, 2023)	21.7	15.5
Investments	1,988	1,905.6
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	0	0
Short-term investments at fair value (amortized cost $38.2 at March 31, 2024 and $33.1 at December 31, 2023)	0	0
Investments	47.5	46.2
Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	1,966.3	1,890.1
Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	47.5	46.2
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	63	58.4
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	63	58.4
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
US Government Agencies Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	2.1	2.1
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	2.1	2.1
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
US States and Political Subdivisions Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	199.8	210.2
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	199.8	210.2
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	939.5	895.8
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	905.5	863.7
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	34	32.1
Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	370	362.2
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	370	362.2
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	63.2	63.8
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	63.2	63.8
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	176.7	128
Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	163.2	113.9
Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	13.5	14.1
Foreign Government Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	10	10.4
Foreign Government Debt | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Foreign Government Debt | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	10	10.4
Foreign Government Debt | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Collateralized Loan Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	72.8	91.5
Collateralized Loan Obligations [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Collateralized Loan Obligations [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	72.8	91.5
Collateralized Loan Obligations [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Other Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	116.7	113.9
Other Debt Obligations [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Other Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	116.7	113.9
Other Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturity securities, fair value	0	0
Industrial and Miscellaneous [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	195.3	181.7
Industrial and Miscellaneous [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	195.3	181.7
Industrial and Miscellaneous [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	0	0
Industrial and Miscellaneous [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities at fair value (cost $125.9 at March 31, 2024 and $125.9 at December 31, 2023)		0
Equity Securities, FV-NI	0
Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	29	29.5
Other [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	29	29.5
Other [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	0	0
Other [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	$ 0	$ 0

Valuation of Financial Instru_3

Valuation of Financial Instruments Investments at NAV (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Investments at NAV [Abstract]
Fair value investments entities that calculate net asset value per share liquidating investment original expected lives increments	1 year
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 19
Cash Equivalents Measured at Net Asset Value	104.3	$ 197.2
Other invested assets at NAV	$ 97.6	$ 91.5
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value investments entities that calculate net asset value per share liquidating investment original expected lives increments	1 year
Maximum [Member]
Investments at NAV [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	12 years
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	12 years
Minimum [Member]
Investments at NAV [Abstract]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	3 years
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	3 years

Fair Value Measures nd Disclosu

Fair Value Measures nd Disclosures on recurring basis, unobservable inputs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	$ 1.5	$ 1.5
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	(0.2)	0.2
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 47.5	$ 25.9	$ 46.2	$ 24.2

Investments Available for Sale

Investments Available for Sale Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	$ 2,139.7	$ 2,048
Debt securities, available-for-sale, gross unrealized gain	10.7	14.9
Debt securities, available-for-sale, gross unrealized loss	(133.4)	(123.9)
Fixed maturity securities, fair value	2,013.8	1,936.3
Total AFS, amortized cost	2,177.9	2,081.1
Total AFS, gross unrealized gain	10.7	14.9
Total AFS, gross unrealized loss	133.4	123.9
Short-term investments at fair value (amortized cost $38.2 at March 31, 2024 and $33.1 at December 31, 2023)	38.2	33.1
Total AFS investments	2,052	1,969.4
Debt Securities, Available-for-sale, Allowance for Credit Loss	(3.2)	(2.7)	$ (5.9)	$ (4.5)
Other invested assets (cost $88.9 at March 31, 2024 and $82.5 at December 31, 2023)	97.6	91.5
Other invested assets at NAV	97.6	91.5
Investment Owned, at Cost	88.9	82.5
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	65.6	60.3
Debt securities, available-for-sale, gross unrealized gain	0.3	0.6
Debt securities, available-for-sale, gross unrealized loss	(2.9)	(2.5)
Fixed maturity securities, fair value	63	58.4
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	2.2	2.2
Debt securities, available-for-sale, gross unrealized gain	0	0
Debt securities, available-for-sale, gross unrealized loss	(0.1)	(0.1)
Fixed maturity securities, fair value	2.1	2.1
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	202.8	212.3
Debt securities, available-for-sale, gross unrealized gain	2.4	3.1
Debt securities, available-for-sale, gross unrealized loss	(5.4)	(5.2)
Fixed maturity securities, fair value	199.8	210.2
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	1,003.5	952.8
Debt securities, available-for-sale, gross unrealized gain	5.4	8.3
Debt securities, available-for-sale, gross unrealized loss	(67.2)	(63.2)
Fixed maturity securities, fair value	939.5	895.8
Debt Securities, Available-for-sale, Allowance for Credit Loss	(2.2)	(2.1)
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	413	399.3
Debt securities, available-for-sale, gross unrealized gain	0.6	0.9
Debt securities, available-for-sale, gross unrealized loss	(43.6)	(38)
Fixed maturity securities, fair value	370	362.2
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	69.7	70.2
Debt securities, available-for-sale, gross unrealized gain	0	0
Debt securities, available-for-sale, gross unrealized loss	(6.2)	(6.4)
Fixed maturity securities, fair value	63.2	63.8
Debt Securities, Available-for-sale, Allowance for Credit Loss	(0.3)	0
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	180.3	131.8
Debt securities, available-for-sale, gross unrealized gain	1.1	1
Debt securities, available-for-sale, gross unrealized loss	(4.7)	(4.8)
Fixed maturity securities, fair value	176.7	128
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Foreign Government Debt
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	12.7	12.7
Debt securities, available-for-sale, gross unrealized gain	0	0
Debt securities, available-for-sale, gross unrealized loss	(2.7)	(2.3)
Fixed maturity securities, fair value	10	10.4
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Collateralized Loan Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	73	92.2
Debt securities, available-for-sale, gross unrealized gain	0	0
Debt securities, available-for-sale, gross unrealized loss	(0.2)	(0.7)
Fixed maturity securities, fair value	72.8	91.5
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Other Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, amortized cost	116.9	114.2
Debt securities, available-for-sale, gross unrealized gain	0.9	1
Debt securities, available-for-sale, gross unrealized loss	(0.4)	(0.7)
Fixed maturity securities, fair value	116.7	113.9
Debt Securities, Available-for-sale, Allowance for Credit Loss	(0.7)	(0.6)
Short-term Investments [Member]
Debt Securities, Available-for-sale [Line Items]
Total AFS, amortized cost	38.2	33.1
Total AFS, gross unrealized gain	0	0
Total AFS, gross unrealized loss	0	0
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 0	$ 0

Investments Equity Securities (

Investments Equity Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Schedule of Equity Securities and Other [Line Items]
Equity Securities, FV-NI, Cost	$ 125.9	$ 125.9
Equity Securities, FV-NI	224.3	211.2
Industrial and Miscellaneous [Member]
Schedule of Equity Securities and Other [Line Items]
Equity Securities, FV-NI, Cost	105.1	104.4
Equity Securities, FV-NI	195.3	181.7
Other [Member]
Schedule of Equity Securities and Other [Line Items]
Equity Securities, FV-NI, Cost	20.8	21.5
Equity Securities, FV-NI	$ 29	$ 29.5

Investments Other Invested Asse

Investments Other Invested Assets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Other Invest Assets [Abstract]
Other invested assets at NAV	$ 97.6	$ 91.5
Investment Owned, at Cost	88.9	82.5
Total other invested assets	$ 97.6	$ 91.5

Investments, Amortized Cost and

Investments, Amortized Cost and Estimated Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Amortized Cost
Due in one year or less, amortized cost	$ 20.6
Due after one year through five years, amortized cost	651.8
Due after five years through ten years, amortized cost	642.6
Due after ten years, amortized cost	88.7
Mortgage and asset-backed securities, amortized cost	736
Debt securities, available-for-sale, amortized cost	2,139.7	$ 2,048
Estimated Fair Value
Due in one year or less, fair value	20.3
Due after one year through five years, fair value	630.3
Due after five years through ten years, fair value	599.2
Due after ten years, fair value	81.3
Mortgage and asset-backed securities, fair value	682.7
Total, fair value	$ 2,013.8	$ 1,936.3

Investments, Continuous Loss Po

Investments, Continuous Loss Position (Details) $ in Millions	Mar. 31, 2024 USD ($) shares shares	Dec. 31, 2023 USD ($) shares
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 245.5	$ 129.9
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,218.4	1,291.6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2.4)	(1.6)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (131)	$ (122.3)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	180	133
Debt Securities, number of issues in loss position, 12 months or greater	701	733
Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 245.5	$ 129.9
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,218.4	1,291.6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2.4)	(1.6)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (131)	$ (122.3)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	180	133
Debt Securities, number of issues in loss position, 12 months or greater | shares	701	733
US Treasury Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 19	$ 11.9
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	23.5	23.7
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.3)	(0.1)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (2.6)	$ (2.4)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	8	5
Debt Securities, number of issues in loss position, 12 months or greater	7	7
US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 2.2	$ 2.2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (0.1)	$ (0.1)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, 12 months or greater	1	1
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 42.2	$ 39.5
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	71.9	73.5
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.7)	(0.3)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (4.7)	$ (4.9)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	16	15
Debt Securities, number of issues in loss position, 12 months or greater	33	32
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 60.2	$ 26.1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	695.6	684.5
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.6)	(0.8)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (66.6)	$ (62.4)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	23	13
Debt Securities, number of issues in loss position, 12 months or greater	328	331
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 21.5	$ 15.8
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	301.7	306.6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.3)	(0.2)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (43.3)	$ (37.8)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	20	15
Debt Securities, number of issues in loss position, 12 months or greater	230	228
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 52.4	$ 53
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (6.2)	$ (6.4)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, 12 months or greater	24	24
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 55.1	$ 24
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	46.6	47
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.2)	(0.1)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (4.5)	$ (4.7)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	24	15
Debt Securities, number of issues in loss position, 12 months or greater	30	29
Collateralized Loan Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 32.6	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	7.4	80.5
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.1)	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (0.1)	$ (0.7)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	8	0
Debt Securities, number of issues in loss position, 12 months or greater | shares	4	21
Foreign Government Debt
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 10	$ 10.4
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (2.7)	$ (2.3)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, 12 months or greater | shares	2	2
Other Debt Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 14.9	$ 12.6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	7.1	10.2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.2)	(0.1)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (0.2)	$ (0.6)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Debt Securities, number of issues in loss position, less than 12 months | shares	81	70
Debt Securities, number of issues in loss position, 12 months or greater | shares	42	58

Investments Investments, Net Re

Investments Investments, Net Realized Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Equity securities:
Equity Securities, FV-NI, Realized Gain	$ 0.1	$ 0.1
Equity Securities, FV-NI, Realized Loss	0.5	1.3
Equity Securities, FV-NI, Unrealized Gain (Loss)	13.1	7.9
AFS, change in unrealized gains (losses)
AFS, change unrealized gains (losses) on fixed maturity and equity securities reflected in AOCI	(13.7)	30.1
AFS, net realized gains (losses)
Net realized and unrealized (losses) gains on investments	11.4	6.4
Total gross realized gains	0.2	0.5
Investments, Gross Realized Losses	(1)	(1.9)
Total change in net unrealized gains (losses)	(1)	39.3
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Proceeds from sale of fixed maturity securities	32	44.8
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease), Total	0.6	2
Debt Securities [Member]
AFS, change in unrealized gains (losses)
AFS, change unrealized gains (losses) on fixed maturity and equity securities reflected in AOCI	(13.7)	30.1
AFS, net realized gains (losses)
Net realized and unrealized (losses) gains on investments	(0.9)	(1.6)
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease), Total	0.5	1.4
Debt Securities, Available-for-sale, Realized Loss	0.5	0.6
Debt Securities, Available-for-sale, Realized Gain	0.1	0.4
Equity Securities [Member]
AFS, change in unrealized gains (losses)
AFS, change unrealized gains (losses) on fixed maturity and equity securities reflected in AOCI	0	0
AFS, net realized gains (losses)
Net realized and unrealized (losses) gains on investments	12.7	6.7
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease), Total	0	0
Other Investments [Member]
AFS, change in unrealized gains (losses)
AFS, change unrealized gains (losses) on fixed maturity and equity securities reflected in AOCI	0	0
AFS, net realized gains (losses)
Net realized and unrealized (losses) gains on investments	(0.4)	1.3
Debt Securities, Available-for-sale, Unrealized Gain (Loss) [Abstract]
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease), Total	0	0
Gain on Sale of Investments	0	0
Loss on Sale of Investments	0	0
Unrealized Gain (Loss) on Investments	$ (0.4)	$ 1.3

Net Investment Income (Details)

Net Investment Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 27.8	$ 28.5
Investment expenses	1	0.9
Net investment income	26.8	27.6
Debt Securities [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	22.3	23.7
Equity Securities [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	1.6	1.8
Other Investments [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	1.1	0.9
Short-term Investments [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	0.5	1.2
Cash and Cash Equivalents [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	$ 2.3	$ 0.9

Investments Investments, Held i

Investments Investments, Held in Trust or on Deposit (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Line of Credit Facility [Line Items]
Other invested assets (cost $88.9 at March 31, 2024 and $82.5 at December 31, 2023)	$ 97.6	$ 91.5
Deposit Assets [Abstract]
Investments	2,379.9	2,278.1
Assets Held-in-trust [Abstract]
Funds Held under Reinsurance Agreements, Asset	3	3
Federal Home Loan Bank [Member]
Deposit Assets [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity	70	70
Required by various state laws and regulations to hold securities or letters of credit in depository account [Member]
Deposit Assets [Abstract]
Investments	$ 760.6	$ 748.1

Current Expected Credit Losse_2

Current Expected Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Current Expected Credit Losses [Abstract]
Premium Receivable, Allowance for Credit Loss	$ 19.7	$ 14	$ 17.9	$ 12.8
Premium Receivable, Allowance for Credit Loss, Period Increase (Decrease)	5.9	3.3
Premium Receivable, Allowance for Credit Loss, Writeoff	(1.9)	(0.7)
Premium Receivable, Allowance for Credit Loss, Recovery	(2.2)	(1.4)
Reinsurance recoverables on unpaid losses, allowance	0.9	0.9	0.9	0.9
Reinsurance Recoverable, Allowance for Credit Loss, Period Increase (Decrease)	0	0
Debt Securities, Available-for-sale, Allowance for Credit Loss	3.2	5.9	2.7	$ 4.5
Debt Securities, Available-for-sale, Allowance for Credit Loss, Securities Sold	(0.1)	(0.2)
Debt Securities, Available-for-sale, Allowance for Credit Loss, Recovery	0	(0.4)
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease)	0.6	$ 2
Accrued investment income	$ 16.5		$ 16.3

Property and Equipment Property

Property and Equipment Property and Equipment (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Property and Equipment [Line Items]
Property and equipment, gross	$ 45.1		$ 48.6
Accumulated depreciation, depletion and amortization, property and equipment	(38.5)		(42.1)
Property and equipment, net	6.6		6.5
Utilities operating expense, depreciation and amortization	1		4.8
Payments to develop software	0.6		1.8
Cloud computing arrangements	25.2		28
Amortization of cloud computing arrangements	2.8	$ 4.3	16.7
Furniture and equipment
Property and Equipment [Line Items]
Property and equipment, gross	1.8		1.8
Leasehold improvements
Property and Equipment [Line Items]
Property and equipment, gross	0.5		0.5
Computer and software
Property and Equipment [Line Items]
Property and equipment, gross	42.2		45.7
Automobiles
Property and Equipment [Line Items]
Property and equipment, gross	$ 0.6		$ 0.6

Property and Equipment Leases (

Property and Equipment Leases (Details)	Mar. 31, 2024
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, operating lease, remaining lease term	1 year
Lessee, Finance Lease, Term of Contract	1 year
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, operating lease, remaining lease term	5 years
Lessee, operating lease, renewal term	5 years

Property and Equipment Leases,

Property and Equipment Leases, Components of Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Components of Lease Expense [Abstract]
Operating Lease, Cost	$ 0.3	$ 0.6
Finance lease expense	0	0.1
Total lease expense	$ 0.3	$ 0.7

Property and Equipment Leases_2

Property and Equipment Leases, Maturities of Lease Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Lessee, operating lease liabilities due
Operating lease liabilities due next twelve months	$ 1.3
Operating lease liabilities due year two	1.5
Operating lease liabilities due year three	1.2
Operating lease liabilities due year four	1.2
Operating lease liabilities due year five	0.4
Operating lease liabilities due after year five	0
Operating lease liabilities due	5.6
Less: inputed interest, Operating lease liability	(0.1)
Operating lease liability	$ 5.5	$ 5.9
Operating lease, weighted average remaining lease term	3 years 9 months 18 days
Operating lease, weighted average discount rate, percent	1.30%
Lessee, finance lease liabilities due
Finance lease liabilities due next twelve months	$ 0.1
Finance lease liabilities due year two	0.1
Finance lease liabilities due year three	0
Finance lease liabilities due year four	0
Finance lease liabilities due year five	0
Finance lease liabilities due after year five	0
Finance lease liabilities due	0.2
Less: inputed interest, finance lease	0
Finance lease, liability	$ 0.2	$ 0.2
Finance lease, weighted average remaining lease term	1 year 8 months 12 days
Finance lease, weighted average discount rate, percent	7.40%

Property and Equipment Leases_3

Property and Equipment Leases, Supplement Balance Sheet Information (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 4.7	$ 5.1
Operating lease liability	5.5	5.9
Property and equipment, gross	45.1	48.6
Accumulated depreciation, depletion and amortization, property and equipment	(38.5)	(42.1)
Property and equipment, net	6.6	6.5
Other liabilities	71.2	58.1
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization	0.6	0.6
Finance Lease, Right-of-Use Asset, Accumulated Amortization	0.4	0.4
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	0.2	0.2
Finance lease, liability	$ 0.2	$ 0.2

Property and Equipment Leases_4

Property and Equipment Leases, Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Leases, Supplement Balance Sheet Information [Abstract]
Operating cash flows from operating leases	$ 0.3	$ 0.6
Financing cash flows from finance leases	$ 0	$ 0.1

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Income tax expense	$ 7	$ 5.4
Effective tax rate	19.80%	18.60%
Taxes Payable	$ 0.7

Liability for Unpaid Losses a_3

Liability for Unpaid Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Unpaid losses and LAE at beginning of period	$ 1,884.5	$ 1,960.7
Less reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE	428.4	445.4
Net unpaid losses and LAE at beginning of period	1,456.1	1,515.3
Losses and LAE, net of reinsurance, incurred during the period related to:
Current period	118.7	109.6
Prior periods	0.1	0.2
Total net losses and LAE incurred during the period	118.6	109.4
Deduct payments for losses and LAE, net of reinsurance, related to:
Current period	6.8	5.6
Prior periods	117.4	105.7
Total net paid losses and LAE during the period	124.2	111.3
Ending unpaid losses and LAE, net of reinsurance	1,450.5	1,513.4
Reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE	424	440.3
Unpaid losses and LAE at end of period	1,874.5	1,953.7
Impact of the LPT Agreement	2.1	2
Involuntary Assigned Risk Business [Member]
Losses and LAE, net of reinsurance, incurred during the period related to:
Prior periods	$ (0.1)	$ (0.2)

LPT Agreement (Details)

LPT Agreement (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Reinsurance Agreement [Line Items]
Liabilities for the incurred but unpaid losses and LAE related to claims prior to July 1, 1995	$ 1,500
Ceded premiums written	775
Amortization of deferred gain	1.9	$ 2
Net income	28.3	23.6
Deferred reinsurance gain—LPT Agreement	97.2		$ 99.2
Estimated remaining liabilities - LPT Agreement	287.1		291.7
Paid losses and LAE claims related to LPT	882.2		$ 877.6
Impact of the LPT Agreement	2.1	$ 2
LPT Contingent Commission Adjustment [Abstract]	0.2
Indemnification Agreement [Member]
Reinsurance Agreement [Line Items]
Coverage provided under LPT Agreement	$ 2,000

Notes Payable Letters of Credit

Notes Payable Letters of Credit (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Letters of Credit Facilities [Line Items]
Interest and financing expenses	$ 0	$ 2.3
Letters of credit, unused capacity, commitment fee percentage	15%
Federal Home Loan Bank [Member]
Letters of Credit Facilities [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 70		$ 70
Letters of credit collateral amount	$ 275.1		$ 286.4

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income [Abstract]
Net unrealized losses on investments, before taxes	$ (122.6)	$ (108.9)
Deferred tax benefit on net unrealized losses	25.7	22.9
Total accumulated other comprehensive loss	$ (96.9)	$ (86)

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended		12 Months Ended
		Mar. 01, 2024	Feb. 26, 2024	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-options exercised					23,500	23,500
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of outstanding options or share units				240,365
Restricted Stock Units (RSUs) [Member] | Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation award, shares issued	[1]	4,712	61,280
Fair value of awards awarded on grant date	[1]	$ 0.2	$ 2.8
Vesting rights for RSUs awarded				vest 25% on March 15, 2025 and each of the subsequent three anniversaries of that date
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[1]	$ 45	$ 46.36
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of outstanding options or share units				208,015
Performance Shares [Member] | Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation award, shares issued	[2]		77,360
Fair value of awards awarded on grant date	[2]		$ 3.6
Performance share awards performance period				three years
Performance share awards, minimum payout				0%
Performance share awards, maximum payout				250%
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	[2]		$ 46.36
[1] These RSUs were awarded to certain employees of the Company on two separate dates and all vest 25% on March 15, 2025 and each of the subsequent three anniversaries of that date. These PSUs were awarded to certain employees of the Company and have a performance period of three years. The PSU awards are subject to certain performance goals with payouts that range from 0% to 250% of the target awards. The value shown in the table represents the aggregate number of PSUs awarded at the target level.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net income available to stockholders - basic and diluted	$ 28.3	$ 23.6
Weighted average number of shares outstanding - basic	25,345,942	27,176,823
Effect of dilutive securities:
Dilutive securities	190,029	215,855
Weighted average number of shares outstanding - diluted	25,535,971	27,392,678
Performance Shares [Member]
Effect of dilutive securities:
Dilutive securities	115,021	141,246
Stock Option [Member]
Effect of dilutive securities:
Dilutive securities	0	8,286
Restricted Stock Units (RSUs) [Member]
Effect of dilutive securities:
Dilutive securities	75,008	66,323

Segment Reporting Segment Net I

Segment Reporting Segment Net Income Before Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Premiums Written, Gross	$ 210.9	$ 194.9
Premiums Written, Net	209.1	193.1
Net premiums earned	184.9	172.7
Net investment income	26.8	27.6
Net realized and unrealized (losses) gains on investments	11.4	6.4
Other income (loss)	0	(0.2)
Revenues	(223.1)	(206.5)
Losses and loss adjustment expenses	116.5	107.4
Commission expense	25.5	23.4
Underwriting and general and administrative expenses	45.8	44.4
Interest and financing expenses	0	2.3
Operating Expenses	187.8	177.5
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	35.3	29
Net income	28.3	23.6
Income tax expense	7	5.4
Insurance Operations
Segment Reporting Information [Line Items]
Premiums Written, Gross	210.9	194.9
Premiums Written, Net	209.1	193.1
Net premiums earned	184.9	172.7
Net investment income	26.8	27.6
Net realized and unrealized (losses) gains on investments	11.4	6.4
Other income (loss)		(0.2)
Revenues	(223.1)	(206.5)
Losses and loss adjustment expenses	116.5	107.4
Commission expense	25.5	23.4
Underwriting and general and administrative expenses	45.8	44.4
Interest and financing expenses		2.3
Operating Expenses	187.8	177.5
Net (loss) income before income taxes	35.3	29
Net income	28.3	23.6
Income tax expense	$ 7	$ 5.4

Segment Reporting Geographic In

Segment Reporting Geographic Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Revenue, Major Customer [Line Items]
Segment Reporting, Disclosure of Major Customers	10
CALIFORNIA
Revenue, Major Customer [Line Items]
Premiums In Force	$ 320.1	$ 311.5	$ 282.9	$ 279.7
Policies In force	43,832	43,353	42,908	42,876
FLORIDA
Revenue, Major Customer [Line Items]
Premiums In Force	$ 57.5	$ 56.6	$ 50.5	$ 49.4
Policies In force	10,277	10,008	9,560	9,417
NEW YORK
Revenue, Major Customer [Line Items]
Premiums In Force	$ 33.6	$ 31.9	$ 28.5	$ 27.3
Policies In force	7,679	7,603	7,478	7,497
AllOtherStates [Member]
Revenue, Major Customer [Line Items]
Premiums In Force	$ 301.6	$ 294.6	$ 269	$ 266.1
Policies In force	65,696	65,445	62,738	61,566
UNITED STATES
Revenue, Major Customer [Line Items]
Premiums In Force	$ 712.8	$ 694.6	$ 630.9	$ 622.5
Policies In force	127,484	126,409	122,684	121,356
Final audit policies in-force	0	0	0	0
Final audit premium	$ 44.7	$ 42.9	$ 36.7	$ 32.4
Total in-force policies, includingfinal audit	127,484	126,409	122,684	121,356
Total in-force, including final audit premium	$ 757.5	$ 737.5	$ 667.6	$ 654.9