Selective Insurance (SIGI) 10-K 10 Feb 23 2022 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2022	Jan. 31, 2023	Jun. 30, 2022
Document and Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Document Transition Report	false
Entity File Number	001-33067
Entity Registrant Name	SELECTIVE INSURANCE GROUP, INC.
Entity Incorporation, State or Country Code	NJ
Entity Tax Identification Number	22-2168890
Entity Address, Address Line One	40 Wantage Avenue
Entity Address, City or Town	Branchville
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07890
City Area Code	(973)
Local Phone Number	948-3000
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 5,158,579,316
Entity Common Stock, Shares Outstanding		60,338,831
Entity Central Index Key	0000230557
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false
Documents Incorporated by Reference	Portions of the registrant’s definitive Proxy Statement for the 2023 Annual Meeting of Stockholders to be held on May 3, 2023, are incorporated by reference into Part III of this report.
Document Information [Line Items]
Document Period End Date	Dec. 31, 2022
Document Fiscal Year Focus	2022
Depositary Shares [Member]
Document Information [Line Items]
Security Exchange Name	NASDAQ
Trading Symbol	SIGIP
Title of 12(b) Security	Depositary Shares, each representing a 1/1,000th interest in a share of 4.60% Non-Cumulative Preferred Stock, Series B, without par value
Common Stock [Member]
Document Information [Line Items]
Security Exchange Name	NASDAQ
Trading Symbol	SIGI
Title of 12(b) Security	Common Stock, par value $2 per share

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Auditor [Line Items]
Auditor Name	KPMG LLP
Auditor Firm ID	185
Auditor Location	New York, New York

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
ASSETS
Fixed income securities, held-to-maturity - at carrying value	$ 31,157	$ 28,850
Less: allowance for credit losses	0	(65)
Fixed income securities, held-to-maturity, net of allowance for credit losses	31,157	28,785
Fixed income securities, available-for-sale - at fair value	6,612,107	6,709,976
Commercial mortgage loans, at carrying value	149,305	95,795
Less: allowance for credit losses	(116)	0
Commercial mortgage loans, net of allowance for credit losses	149,189	95,795
Equity securities - at fair value	162,000	335,537
Short-term investments	440,456	447,863
Alternative investments	371,316	359,732
Other investments	71,244	49,300
Total investments (Notes 5 and 7)	7,837,469	8,026,988
Cash	26	455
Restricted cash	25,183	44,608
Accrued investment income	59,167	48,247
Premiums receivable	1,101,787	958,787
Less: allowance for credit losses (Note 8)	(16,100)	(13,600)
Premiums receivable, net of allowance for credit losses	1,085,687	945,187
Reinsurance recoverable	784,410	601,668
Less: allowance for credit losses (Note 9)	(1,600)	(1,600)
Reinsurance recoverable, net of allowance for credit losses	782,810	600,068
Prepaid reinsurance premiums (Note 9)	172,371	183,007
Current federal income tax (Note 14)	3,545	772
Deferred federal income tax (Note 14)	172,733	0
Property and equipment - at cost, net of accumulated depreciation and amortization	84,306	82,053
Deferred policy acquisition costs (Note 2)	368,624	326,915
Goodwill (Note 12)	7,849	7,849
Other assets	202,491	195,240
Total assets	10,802,261	10,461,389
LIABILITIES AND STOCKHOLDERS’ EQUITY
Reserve for loss and loss expense (Note 10)	5,144,821	4,580,903
Unearned premiums	1,992,781	1,803,207
Long-term debt (Note 11)	504,676	506,050
Deferred federal income tax (Note 14)	0	13,413
Accrued salaries and benefits	115,185	121,057
Other liabilities	517,234	453,874
Total liabilities	8,274,697	7,478,504
Stockholders’ Equity:
Preferred stock of $0 par value per share (Note 17): Authorized shares: 5,000,000; Issued shares: 8,000 with $25,000 liquidation preference per share - 2022 and 2021	200,000	200,000
Common stock of $2 par value per share: Authorized shares: 360,000,000 Issued: 104,847,111 - 2022; 104,450,916 - 2021	209,694	208,902
Additional paid-in capital	493,488	464,347
Retained earnings	2,749,703	2,603,472
Accumulated other comprehensive (loss) income (Note 6)	(498,042)	115,099
Treasury stock, at cost (shares: 44,508,211 - 2022; 44,266,534 - 2021)	(627,279)	(608,935)
Total stockholders’ equity	2,527,564	2,982,885
Commitments and contingencies (Notes 19 and 20)
Total liabilities and stockholders’ equity	$ 10,802,261	$ 10,461,389

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Fixed income securities, held-to-maturity, fair value	$ 29,837	$ 29,460
Fixed income securities, available-for-sale, allowance for credit loss	45,721	9,724
Fixed income securities, available-for-sale, amortized cost	7,185,754	6,490,753
Commercial mortgage loans, fair value	139,243	97,598
Equity securities, at cost	167,431	308,840
Accumulated depreciation and amortization, property and equipment	$ 251,209	$ 253,427
Preferred Stock, Shares Outstanding	8,000	8,000
Commercial mortgage loans, fair value	$ 139,243	$ 97,598
Preferred Stock [Member]
Preferred Stock, Par or Stated Value (in dollars per share)	$ 0	$ 0
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Issued	8,000	8,000
Preferred Stock, Shares Outstanding	8,000	8,000
Preferred Stock, Liquidation Preference (in dollars per share)	$ 25,000	$ 25,000
Common Stock [Member]
Common Stock, Par or Stated Value (in dollars per share)	$ 2	$ 2
Common Stock, Shares Authorized	360,000,000	360,000,000
Common Stock, Shares, Issued	104,847,111	104,450,916
Treasury stock [Member]
Treasury Stock, Shares	44,508,211	44,266,534

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Net premiums earned	$ 3,373,380	$ 3,017,253	$ 2,681,814
Net investment income earned	288,155	326,589	227,107
Net realized and unrealized investment (losses) gains	(114,808)	17,599	(4,217)
Other income	11,335	17,723	17,570
Total revenues	3,558,062	3,379,164	2,922,274
Expenses:
Loss and loss expense incurred	2,111,778	1,813,984	1,635,823
Amortization of deferred policy acquisition costs	705,822	626,469	560,271
Other insurance expenses	400,313	375,931	366,941
Interest expense	28,847	29,165	30,839
Corporate expenses	31,116	28,305	25,412
Total expenses	3,277,876	2,873,854	2,619,286
Income before federal income tax	280,186	505,310	302,988
Federal income tax expense:
Current	78,308	87,335	60,059
Deferred	(23,008)	14,138	(3,426)
Total federal income tax expense	55,300	101,473	56,633
Net income	224,886	403,837	246,355
Preferred stock dividends	9,200	9,353	0
Net Income available to common stockholders	$ 215,686	$ 394,484	$ 246,355
Earnings per common share:
Earnings per common share - net income available to common stockholders - Basic	$ 3.57	$ 6.55	$ 4.12
Earnings per common share - net income available to common stockholders - Diluted	$ 3.54	$ 6.50	$ 4.09

Consolidation Statements of Com

Consolidation Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net income	$ 224,886	$ 403,837	$ 246,355
Unrealized holding (losses) gains arising during year	527,805	119,598	133,104
Unrealized losses on securities with credit loss recognized in earnings	(148,495)	(7,159)	(6,459)
Amounts reclassified into net income: Held-to-maturity securities	3	(9)	(19)
Amounts reclassified into net income: Net realized losses (gains) on disposals and losses on intent-to-sell available-for-sale securities	47,438	(3,022)	4,247
Amounts reclassified into net income: Credit loss expense	30,944	5,418	3,984
Total unrealized (losses) gains on investment securities	(597,915)	(124,370)	(134,857)
Net actuarial (loss) gain	(16,543)	17,093	1,197
Amount reclassified into net income: Net actuarial loss, Net	1,317	2,190	2,382
Total defined benefit pension and post-retirement plans, net	(15,226)	19,283	3,579
Other comprehensive (loss) income	(613,141)	(105,087)	138,436
Comprehensive (loss) income	$ (388,255)	$ 298,750	$ 384,791

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional paid-in capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Accounting Standards Update 2016-13 [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Accumulated other comprehensive (loss) income [Member]	Treasury stock [Member]
Beginning of year at Dec. 31, 2019		$ 0	$ 206,968	$ 418,521	$ 2,080,529	$ 1,435	$ 2,081,964	$ 81,750	$ (592,832)
Issuance of preferred stock		200,000
Dividend reinvestment plan			58	1,645
Preferred stock issuance costs				(5,416)
Stock purchase and compensation plans			1,040	24,235
Net income	$ 246,355				246,355
Dividends to preferred stockholders					0
Dividends to common stockholders					(56,782)
Other comprehensive (loss) income	138,436							138,436
Acquisition of Treasury Stock - share repurchase authorization									0
Acquisition of treasury stock - shares acquired related to employee-share based compensation plans									(7,053)
End of year at Dec. 31, 2020	$ 2,738,889	$ 200,000	208,066	438,985	2,271,537	0	2,271,537	220,186	(599,885)
Dividends declared per share to preferred stockholders	$ 0
Dividends declared per share to common stockholders	$ 0.94
Preferred stock, shares outstanding, beginning of period at Dec. 31, 2019	0
Issuance of preferred stock, shares		8,000
Preferred stock, shares outstanding, end of period at Dec. 31, 2020	8,000
Common stock, shares outstanding, beginning of period at Dec. 31, 2019	59,461,153
Dividend reinvestment plan, shares	28,890
Stock purchase and compensation plan, shares	519,863
Acquisition of treasury stock, share repurchase authorization, shares	0
Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	(104,103)
Common stock, shares outstanding, end of period at Dec. 31, 2020	59,905,803
Issuance of preferred stock		$ 0
Dividend reinvestment plan			46	1,707
Preferred stock issuance costs				0
Stock purchase and compensation plans			790	23,655
Net income	$ 403,837				403,837
Dividends to preferred stockholders					(9,353)
Dividends to common stockholders					(62,549)
Other comprehensive (loss) income	(105,087)							(105,087)
Acquisition of Treasury Stock - share repurchase authorization									(3,404)
Acquisition of treasury stock - shares acquired related to employee-share based compensation plans									(5,646)
End of year at Dec. 31, 2021	$ 2,982,885	$ 200,000	208,902	464,347	2,603,472	$ 0	$ 2,603,472	115,099	(608,935)
Dividends declared per share to preferred stockholders	$ 1,169.17
Dividends declared per share to common stockholders	$ 1.03
Issuance of preferred stock, shares		0
Preferred stock, shares outstanding, end of period at Dec. 31, 2021	8,000
Dividend reinvestment plan, shares	22,986
Stock purchase and compensation plan, shares	395,018
Acquisition of treasury stock, share repurchase authorization, shares	(52,781)
Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	(86,644)
Common stock, shares outstanding, end of period at Dec. 31, 2021	60,184,382
Issuance of preferred stock		$ 0
Dividend reinvestment plan			44	1,784
Preferred stock issuance costs				0
Stock purchase and compensation plans			748	27,357
Net income	$ 224,886				224,886
Dividends to preferred stockholders					(9,200)
Dividends to common stockholders					(69,455)
Other comprehensive (loss) income	(613,141)							(613,141)
Acquisition of Treasury Stock - share repurchase authorization	(12,400)								(12,424)
Acquisition of treasury stock - shares acquired related to employee-share based compensation plans									(5,920)
End of year at Dec. 31, 2022	$ 2,527,564	$ 200,000	$ 209,694	$ 493,488	$ 2,749,703			$ (498,042)	$ (627,279)
Dividends declared per share to preferred stockholders	$ 1,150
Dividends declared per share to common stockholders	$ 1.14
Issuance of preferred stock, shares		0
Preferred stock, shares outstanding, end of period at Dec. 31, 2022	8,000
Dividend reinvestment plan, shares	22,093
Stock purchase and compensation plan, shares	374,102
Acquisition of treasury stock, share repurchase authorization, shares	(165,159)
Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	(76,518)
Common stock, shares outstanding, end of period at Dec. 31, 2022	60,338,900

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities
Net income	$ 224,886	$ 403,837	$ 246,355
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	42,336	55,109	59,350
Stock-based compensation expense	18,428	15,893	16,227
Undistributed gains of equity method investments	(12,946)	(69,873)	(12,408)
Distributions in excess of current year income of equity method investments	43,184	2,910	3,472
Net realized and unrealized losses (gains)	114,808	(17,599)	4,217
Loss on disposal of fixed assets	172	50	22
Changes in assets and liabilities:
Increase in reserve for loss and loss expense, net of reinsurance recoverable	381,176	307,972	181,839
Increase in unearned premiums, net of prepaid reinsurance	200,210	172,460	91,278
(Increase) decrease in net federal income taxes	(25,932)	(542)	7,708
Increase in premiums receivable	(140,500)	(109,173)	(13,171)
Increase in deferred policy acquisition costs	(41,709)	(38,337)	(17,392)
Increase in accrued investment income	(10,920)	(3,243)	(158)
(Decrease) increase in accrued salaries and benefits	(3,092)	7,216	(13,264)
Increase in other assets	(37,561)	(33,379)	(27,927)
Increase in other liabilities	49,869	78,121	27,897
Net cash provided by operating activities	802,409	771,422	554,045
Investing Activities
Purchases of fixed income securities, held-to-maturity	(6,691)	(16,250)	0
Purchases of fixed income securities, available-for-sale	(2,648,974)	(2,165,555)	(1,723,818)
Purchases of commercial mortgage loans	(64,008)	(50,204)	(46,506)
Purchases of equity securities	(26,675)	(88,640)	(230,813)
Purchases of alternative investments and other investments	(73,408)	(85,044)	(79,598)
Purchases of short-term investments	(4,506,500)	(4,345,140)	(5,762,725)
Sales of fixed income securities, available-for-sale	1,211,739	502,911	487,087
Proceeds from commercial mortgage loans	10,498	714	201
Sales of short-term investments	4,513,940	4,306,684	5,635,463
Redemption and maturities of fixed income securities, held-to-maturity	4,351	4,192	3,888
Redemption and maturities of fixed income securities, available-for-sale	669,211	1,217,555	1,019,132
Sales of equity securities	186,144	99,235	1,320
Sales of other investments	3,281	5,428	5,375
Distributions from alternative investments and other investments	18,664	17,497	24,884
Purchases of property and equipment	(26,019)	(22,163)	(22,064)
Net cash used in investing activities	(734,447)	(618,780)	(688,174)
Financing Activities
Dividends to preferred stockholders	(9,200)	(9,353)	0
Dividends to common stockholders	(66,920)	(60,136)	(54,486)
Acquisition of treasury stock	(18,344)	(9,050)	(7,053)
Net proceeds from stock purchase and compensation plans	9,086	7,976	8,411
Preferred stock issued, net of issuance costs	0	(479)	195,063
Proceeds from borrowings	60,000	0	587,000
Repayment of borrowings	(60,000)	(50,000)	(587,000)
Repayment of finance lease obligations	(2,438)	(1,768)	(550)
Net cash (used in) provided by financing activities	(87,816)	(122,810)	141,385
Net (decrease) increase in cash and restricted cash	(19,854)	29,832	7,256
Cash and restricted cash, beginning of year	45,063	15,231	7,975
Cash and restricted cash, end of year	$ 25,209	$ 45,063	$ 15,231

Organization

Organization	12 Months Ended
	Dec. 31, 2022
Organization [Abstract]
Organization	Organization Selective Insurance Group, Inc., through its subsidiaries, (collectively referred to as “we,” “us,” or “our”) offers standard commercial, standard personal, and excess and surplus ("E&S") lines property and casualty insurance products. Selective Insurance Group, Inc. (referred to as the “Parent”) was incorporated in New Jersey in 1977 and its corporate headquarters is located in Branchville, New Jersey. The Parent’s common and preferred stock are publicly traded on the Nasdaq Global Select Market under the symbols “SIGI” and "SIGIP," respectively. We have provided a glossary of terms as Exhibit 99.1 to this Form 10-K, which defines certain industry-specific and other terms that are used in this Form 10-K. We classify our business into four reportable segments, which are as follows: • Standard Commercial Lines – comprised of property and casualty insurance products and services provided in the standard marketplace to commercial enterprises, which are typically businesses, non-profit organizations, and local government agencies. • Standard Personal Lines – comprised of property and casualty insurance products and services, including flood insurance coverage, provided primarily to individuals acquiring coverage in the standard marketplace. • E&S Lines – comprised of property and casualty insurance products and services provided to customers who are unable to obtain coverage in the standard marketplace. • Investments – invests the premiums collected by our insurance operations, as well as amounts generated through our capital management strategies, which may include the issuance of debt and equity securities.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Signifcant Accounting Policies	Summary of Significant Accounting Policies (a) Principles of Consolidation The accompanying consolidated financial statements (“Financial Statements”) include the accounts of the Parent and its subsidiaries, and have been prepared in conformity with: (i) United States ("U.S.") generally accepted accounting principles ("GAAP"); and (ii) the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). All significant intercompany accounts and transactions are eliminated in consolidation. (b) Use of Estimates The preparation of our Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported financial statement balances, as well as the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. (c) Investments Portfolio Composition and Presentation in the Consolidated Balance Sheet Our investment portfolio is primarily comprised of fixed income investments. We also hold commercial mortgage loans ("CMLs"), equity securities, short-term investments, alternative investments, and other investments. A description of our portfolio holdings, and the related presentation in our Consolidated Balance Sheet, is provided below. Fixed Income Investments Our fixed income investments include our fixed income securities portfolio and our CML portfolio. Fixed Income Securities We hold the following types of securities in our fixed income securities portfolio: • U.S. government and government agency obligations; • Foreign government obligations; • Obligations of states and political subdivisions, including special revenue and general obligation bonds; • Corporate securities, which may include investment grade and below investment grade bonds, bank loan investments, redeemable preferred stock, and non-redeemable preferred stock with certain debt-like characteristics; • Collateralized loan obligations ("CLOs") and other asset-backed securities ("ABS"); • Residential mortgage-backed securities ("RMBS"); and • Commercial mortgage-backed securities ("CMBS"). We have designated substantially all of the holdings in our fixed income securities as available-for-sale ("AFS"). These securities are reported at fair value in our Consolidated Balance Sheet. The after-tax difference between fair value and cost or amortized cost is reflected in stockholders’ equity as a component of accumulated other comprehensive (loss) income ("AOCI"). The amortized cost of fixed income securities is adjusted for the amortization of premiums and the accretion of discounts over the expected life of the security using the effective yield method. Callable debt securities held at a premium are amortized to the earliest call date. Premiums and discounts arising from the purchase of RMBS, CMBS, CLO and other ABS are amortized over the expected life of the security based on future principal payments, giving additional consideration to prepayments. These prepayments are estimated based on historical and projected cash flows. Prepayment assumptions are reviewed quarterly and adjusted to reflect actual prepayments and changes in expectations. Future amortization of any premium and/or discount is adjusted to reflect the revised assumptions. Accrued interest on our fixed income securities is recorded as a component of “Accrued investment income” on our Consolidated Balance Sheet. If accrued interest is due but not paid within 90 days, we reverse the delinquent amount and record this reversal through earnings as a component of “Net investment income earned” on our Consolidated Statement of Income. CMLs CMLs are loans secured by commercial property, such as an office building, multi-family apartment complex, industrial warehouse, or shopping center. We may acquire investments in CMLs through (i) direct originations under a loan syndication arrangement or (ii) a marketplace purchase. We record our investment in CMLs on the settlement date of the loan. Our CMLs are reported at amortized cost, net of any allowance for credit losses ("ACL"), on our Consolidated Balance Sheet. Interest is recorded using the effective yield method and accrued interest on our CMLs is recorded as a component of “Accrued investment income” on our Consolidated Balance Sheet. Other Portfolio Holdings Equity securities may include common and non-redeemable preferred stocks. Equity securities with readily determinable fair values are reported at fair value. Equity securities without readily determinable fair values are reported at net asset value ("NAV") as a practical expedient. Short-term investments may include money market instruments, savings accounts, commercial paper, and fixed income securities purchased with a maturity of less than one year. We may also enter into reverse repurchase agreements that are included in short-term investments. These repurchase agreements are fully collateralized by high-quality, readily-marketable instruments that support the principal amount. At maturity, we receive principal and interest income on these agreements. Short-term investments are generally reported at fair value. Alternative investments are limited partnership investments in private equity, private credit, and real estate strategies. These alternative investments are accounted for using the equity method, with income typically recognized on a one-quarter lag. Because these alternative investments are recorded under the equity method of accounting, with the underlying holdings carried at fair value, the valuation and income recognized on these investments may be impacted by volatility in the financial markets. We categorize distributions from our equity method on our Consolidated Statement of Cash Flows using the cumulative earnings approach. Under this approach, distributions received are classified as cash flows from operating activities until such time that the cumulative distributions exceed cumulative earnings for the investment. When such an excess occurs, the excess portion of the current period distribution is considered a return of investment and is classified as a cash flow from investing activities. We evaluate our alternative investments to determine whether those investments are variable interest entities ("VIEs") and if so, whether consolidation is required. A VIE is an entity that either has equity investors that lack certain essential characteristics of a controlling financial interest or lack sufficient funds to finance its own activities without financial support provided by other entities. We consider several significant factors in determining if our investments are VIEs and if we are the primary beneficiary, including whether we have (i) the power to direct activities of the VIE, (ii) the ability to remove the decision maker of the VIE, (iii) the ability to participate in making decisions that are significant to the VIE, and (iv) the obligation to absorb losses and the right to receive benefits that could potentially be significant to the VIE. We have reviewed our alternative investments and have concluded that they are VIEs, but that we are not the primary beneficiary and therefore, consolidation is not required. Our other investment portfolio includes Federal Home Loan Bank stock (“FHLB Stock”) and tax credit investments. The FHLB Stock is reported at cost. Accounting for our tax credit investments is dependent on the type of credit we have purchased, as follows: • Federal low income housing tax credits are accounted for under the proportional amortization method; and • All other tax credits in our investment portfolio are accounted for using the equity method. For federal tax credits accounted for under the equity method, we use the deferral method for recognizing the benefit of the tax credit with the related deferred revenue being recognized in our Consolidated Income Statement as a component of "Federal income tax expense" proportionately over the life of the investment. Presentation in the Consolidated Statement of Income Net Investment Income Earned Net investment income earned on our Consolidated Statement of Income includes the following: • Interest income, as well as amortization and accretion, on fixed income securities; • Interest income on CMLs; • Dividend income on equity securities; • Interest income on our short-term investments; and • Income recognized on our alternative and other investments accounted for under the equity method of accounting, except for federal tax credits, as discussed below. Income related to federal tax credits (either low income housing tax credits or other federal credits) is recorded in our Consolidated Statement of Income as a component of “Federal income tax expense” proportionately over the life of the investment. Net Realized and Unrealized Investment (Losses) Gains Net realized and unrealized investment (losses) gains on our Consolidated Statement of Income include the following: • Realized gains and losses on the disposal of holdings in our investment portfolio, which are determined on the basis of the cost of the specific investments sold; • Changes in unrealized gains or losses on our equity securities; • Losses on investments for which we have the intent to sell, which are discussed further below; and • Net credit loss expense or benefit resulting from changes in the ACL related to our investment portfolio, which is also discussed further below. Losses on Investments for which we have the Intent to Sell For our AFS fixed income securities and short-term investments, we review our fixed income securities in an unrealized loss position to determine (i) if we have the intent to sell the security, or (ii) if it is more likely than not we will be required to sell the security before its anticipated recovery. If we determine that we have the intent or likely requirement to sell the security, we write down its amortized cost to its fair value. In writing down amortized cost, any amount previously recorded as an ACL is reversed and any incremental reduction in amortized cost is recorded directly to earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. For our alternative and other investments, if we determine that we intend to sell a holding and the expected proceeds are less than the recorded value of the investment, we will record a loss on those securities we intend to sell in earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. After reviewing our portfolio, if (i) we do not have the intent to sell, or (ii) it is more likely than not we will not be required to sell the security before its anticipated recovery, then our intent is to hold the investment securities to maturity and recover the decline in valuation as prices accrete to par. However, our intent may change prior to maturity due to certain types of events, which include, but are not limited to, changes in the financial markets, our analysis of an issuer’s credit metrics and prospects, changes in tax laws or the regulatory environment, or as a result of significant unforeseen changes in liquidity needs. As such, we may, from time to time, sell invested assets subsequent to the balance sheet date that we did not intend to sell at the balance sheet date. Conversely, we may not sell invested assets that we asserted we intended to sell at the balance sheet date. Such changes in intent are due to events occurring subsequent to the balance sheet date. ACL on AFS Fixed Income Securities and Short-Term Investments When fixed income securities are in an unrealized loss position and we do not record any losses on securities for which we intend to sell, we record an ACL for the portion of the unrealized loss due to an expected credit loss. We estimate expected credit losses on fixed income securities by performing a discounted cash flow (“DCF”). The ACL is equal to the excess of amortized cost over the greater of: (i) our estimate of the present value of expected future cash flows, or (ii) fair value. The ACL is recorded as a contra-asset reflected in the carrying value of the investment on the Consolidated Balance Sheet. The initial ACL and any subsequent changes are recorded to earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. Any remaining unrealized loss is the non-credit amount and is recorded in AOCI. The ACL cannot exceed the unrealized loss of an AFS security and therefore it may fluctuate with changes in the fair value of the security. The ACL is written off against the amortized cost basis in the period in which it is determined uncollectible. Our DCF analyses calculate the present value of expected future cash flows using various models specific to the major security types in our portfolio. These models use security-specific information, as well as reasonable and forecasted macroeconomic data, to determine possible expected credit loss scenarios based on projected changes in the economy. The forecasted economic data incorporated into the models is based on the Federal Reserve Board’s annual supervisory stress test review on certain large banks and financial institutions. We also have the ability to incorporate internally-developed forecast information into the models as we deem appropriate. The discount rate used in a DCF is one of the following: • The current yield in effect at the reporting date to accrete the beneficial interest for RMBS, CMBS, CLO and other ABS that were not of high credit quality at acquisition; • The effective interest rate in effect as of the reporting date for non-fixed rate securities; and • The effective interest rate implicit in the security at the date of acquisition for all other securities. DCFs may include, but are not necessarily limited to: (i) generating cash flows for each tranche considering tranche-specific data, market data, and other pertinent information, such as the historical performance of the underlying collateral, including net operating income generated by underlying properties, conditional default rate assumptions, loan loss severity assumptions, consensus projections, prepayment projections, and actual pool and collateral information; (ii) identifying applicable benchmark yields; and (iii) applying market-based tranche specific spreads to determine an appropriate yield by incorporating collateral performance, tranche-level attributes, trades, bids, and offers. We do not record a valuation allowance on the accrued interest balance associated with our fixed income securities as we reverse delinquent amounts on a timely basis. We consider a fixed income security to be past due at the time any principal or interest payments become 90 days delinquent. ACL on CMLs We evaluate our CMLs on a quarterly basis for expected credit losses. If we hold a CML with a specific credit concern, we record an individual ACL on that loan. For all other CMLs, we record an ACL on the pool of loans based on lifetime expected credit losses. The ACL is recorded as a contra-asset reflected in the carrying value of our CMLs on the Consolidated Balance Sheet. Our initial ACL and any subsequent changes are recorded to earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. We utilize a forecasting model to estimate lifetime expected credit losses at a loan level under multiple economic scenarios. The scenarios apply reasonable and forecasted macroeconomic data such as unemployment, inflation, and rent assumptions to project property-specific operating income and capitalization rates that are used to estimate the value of the future operating income stream. This information, coupled with historical data about mortgage loan performance, is used to project the probability of default, the amount of loss given a default, and the resulting lifetime expected loss. Credit Losses on Alternative Investments We review our alternative investment portfolio for potential credit losses through quarterly fund reports and conversations with the general partners of the alternative investments concerning the following: • The current investment strategy; • Changes made or future changes to be made to the investment strategy; • Emerging issues that may affect the success of the strategy; and • The appropriateness of the valuation methodology used regarding the underlying investments. Credit Losses on Other Investments Our evaluation for potential credit loss on tax credits and FHLB Stock include a qualitative assessment of credit indicators, which include, but are not limited to, the following: • An adverse development of the expected receipt of remaining tax credits and other tax benefits; and • A significant deterioration in the financial condition or liquidity of the Federal Home Loan Bank. If we do not intend to sell a security, and we expect a credit loss on a holding in our alternative or other investments portfolio, we record a charge to earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. (d) Fair Values of Financial Instruments Assets The fair values of our investments are generated using various valuation techniques and are placed into the fair value hierarchy considering the following: (i) the highest priority is given to quoted prices in active markets for identical assets (Level 1); (ii) the next highest priority is given to quoted prices in markets that are not active or inputs that are observable either directly or indirectly, including quoted prices for similar assets in markets that are not active and other inputs that can be derived principally from, or corroborated by, observable market data for substantially the full term of the assets (Level 2); and (iii) the lowest priority is given to unobservable inputs supported by little or no market activity and that reflect our assumptions about the exit price, including assumptions that market participants would use in pricing the asset (Level 3). An asset’s classification within the fair value hierarchy is based on the lowest level of significant input to its valuation. The techniques used to value our financial assets are as follows: Level 1 Pricing Security Type Methodology Equity Securities; U.S. Treasury Notes Equity and U.S. Treasury Note prices are received from an independent pricing service that are based on observable market transactions. We validate these prices against a second external pricing service, and if established market value comparison thresholds are breached, further analysis is performed to determine the price to be used. Short-Term Investments Short-term investments are recorded at fair value. Given the liquid nature of our short-term investments, we generally validate their fair value by way of active trades within approximately one week of the financial statement close. Level 2 Pricing We utilize a market approach for our Level 2 securities, using primarily matrix pricing models prepared by external pricing services. Matrix pricing models use mathematical techniques to value fixed income securities by relying on the securities' relationship to other benchmark quoted securities, and not relying exclusively on quoted prices for specific securities, as the specific securities are not always frequently traded. As a matter of policy, we consistently use one pricing service as our primary source and secondary pricing services if prices are not available from the primary pricing service. Fixed income security pricing is reviewed for reasonableness by (i) comparing our pricing to other third-party pricing services as well as benchmark indexed pricing, (ii) comparing fair value fluctuations between months for reasonableness, (iii) reviewing stale prices, and (iv) internally reviewing prices for reasonableness if a price from another third-party source is not available. If further analysis is needed, a challenge is sent to the pricing service for review and confirmation of the price. Further information on our Level 2 asset pricing is included in the following table: Security Type Methodology Corporate Securities, including preferred stocks classified as Fixed Income Securities, and U.S. Government and Government Agencies Evaluations include obtaining relevant trade data, benchmark quotes and spreads, and incorporating this information into either spread-based or price-based evaluations as determined by the observed market data. Spread-based evaluations include: (i) creating a range of spreads for relevant maturities of each issuer based on the new issue market, secondary trading, and dealer quotes; and (ii) incorporating option adjusted spreads for issues that have early redemption features. Based on the findings in (i) and (ii) above, final spreads are derived and added to benchmark curves. Price-based evaluations include matching each issue to its best-known market maker and contacting firms that transact in these securities. Obligations of States and Political Subdivisions Evaluations are based on yield curves that are developed based on factors such as: (i) benchmarks to issues with interest rates near prevailing market rates; (ii) established trading spreads over widely-accepted market benchmarks; (iii) yields on new issues; and (iv) market information from third-party sources such as reportable trades, broker-dealers, or issuers. RMBS, CMBS, CLO and other ABS Evaluations are based on a DCF, including: (i) generating cash flows for each tranche considering tranche-specific data, market data, and other pertinent information, such as historical performance of the underlying collateral, including net operating income generated by the underlying properties, conditional default rate assumptions, loan loss severity assumptions, consensus projections, prepayment projections, and actual pool and loan level collateral information; (ii) identifying applicable benchmark yields; and (iii) applying market-based tranche-specific spreads to determine an appropriate yield by incorporating collateral performance, tranche-level attributes, trades, bids, and offers. Foreign Government Evaluations are performed using a DCF model and by incorporating observed market yields of benchmarks as inputs, adjusting for varied maturities. Level 3 Pricing Security Type Methodology CMLs Evaluations are performed by a third-party and are based on matrix pricing. For fixed rate loans, the matrix process uses a yield build up approach to create a pricing yield, with components for base yield, credit quality spread, property type spread, and a weighted average life spread. Floating rate loans are priced with a target quality spread over the swap curve. In addition to our CML portfolio, certain securities in our AFS fixed income portfolio are priced using unobservable inputs. These valuations are primarily based on broker quotes, or they are received from other third-party sources, for which there is a lack of transparency as to the inputs used to generate the valuation. The quantitative detail of these unobservable inputs is neither provided to us, nor reasonably available to us. Liabilities The techniques used to value our notes payable are as follows: Level 2 Pricing Security Type Methodology 7.25% Senior Notes; 6.70% Senior Notes; Based on matrix pricing models prepared by external pricing services. Borrowings from Federal Home Loan Banks Evaluations are performed using a DCF model based on current borrowing rates provided by the Federal Home Loan Banks that are consistent with the remaining term of the borrowing. (e) Allowance for Credit Losses on Premiums Receivable We estimate an ACL on our outstanding premiums receivable balance at each reporting date. In determining this allowance, we use a method that considers the aging of the receivable, based on the effective year of the related policy, along with our historical receivable loss experience. We also contemplate expected macroeconomic conditions over the expected collection period, which are short-term in nature because the majority of the balances are collected within two years of policy issuance. Changes in our ACL are charged to earnings as credit loss expense or benefit, which is a component of "Other insurance expenses" on our Consolidated Statements of Income, with an offsetting ACL recorded as a contra-asset reflected in the carrying value of the receivable. We charge write-offs against the allowance when we determine the account to be uncollectible after considering information obtained from our collection efforts. (f) Share-Based Compensation Share-based compensation consists of all share-based payment transactions in which an entity acquires goods or services by issuing (or offering to issue) its shares, share units, share options, or other equity instruments. The cost resulting from all share-based payment transactions are recognized in the Financial Statements based on the fair value of both equity and liability awards. The fair value is measured at grant date for equity awards, whereas the fair value for liability awards are remeasured at each reporting period. The fair value of both equity and liability awards is recognized over the requisite service period. The requisite service period is typically the lesser of the vesting period or the period of time from the grant date to the date of retirement eligibility. The expense recognized for share-based awards, which, in some cases, contain performance criteria, is based on the number of shares or units expected to be issued at the end of the performance period. We repurchase the Parent’s stock from our employees in connection with tax withholding obligations, as permitted under our stock-based compensation plans. This activity is disclosed in our Consolidated Statement of Stockholders' Equity. (g) Reinsurance The “Reinsurance recoverable” balance on our Consolidated Balance Sheet represents our estimate of amounts that will be recovered from reinsurers under our various treaties. Generally, amounts recoverable from reinsurers are recognized as assets at the same time and in a manner consistent with the paid and unpaid losses associated with the reinsured policies. We would consider a recoverable balance from a reinsurer to be past due if payment is not received by the first day following the invoice due date. We require collateral to secure reinsurance recoverable balances primarily from our reinsurance carriers that are not authorized, otherwise approved, or certified to do business in one or more of our ten insurance subsidiaries' domiciliary states. Our ten insurance subsidiaries are collectively referred to as the "Insurance Subsidiaries." The collateral received is typically in the form of a letter of credit, trust funds, or funds withheld against reinsurance recoverables. We estimate an ACL on our outstanding reinsurance recoverable balance at each reporting date. Credit risk is mitigated to the extent we have obtained collateral. As part of our estimation of the ACL, we reduce the recoverable balance by the amount of the collateral. We then pool the uncollateralized balances by similar risk characteristics, including the financial strength rating of the reinsurer, and use a probability-of-default methodology to calculate the allowance. Historical default rates are sourced from AM Best Company ("AM Best") and are coupled with severity assumptions in developing a baseline scenario. We then stress this scenario by incorporating forecasts of industry catastrophe losses and economic factors sourced through third-party data providers. In developing our best estimate of the allowance for credit losses, we consider our outlook as to the probability of each of these scenarios occurring. Changes in our ACL are charged to earnings as credit loss expense, which is a component of “Loss and loss expense incurred” on our Consolidated Statement of Income, with an offsetting ACL recorded as a contra-asset reflected in the carrying value of the recoverable balance. We charge write-offs against the ACL when we determine the recoverable balance to be uncollectible after considering information obtained from our efforts to collect amounts due or through a review of the financial condition of the reinsurer. (h) Property and Equipment Property and equipment used in operations, including certain costs incurred to develop or obtain computer software for internal use, are capitalized and recorded at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. The following estimated useful lives can be considered as general guidelines: Asset Category Years Computer hardware 3 Computer software 3 to 5 Software licenses 3 to 5 Internally developed software 5 Furniture and fixtures 10 Buildings and improvements 5 to 40 We recorded depreciation expense of $24.6 million, $24.3 million, and $21.5 million for 2022, 2021, and 2020, respectively. (i) Deferred Policy Acquisition Costs Deferred policy acquisition costs are limited to costs directly related to the successful acquisition of insurance contracts. Costs meeting this definition typically include, among other things, sales commissions paid to our distribution partners, premium taxes, and the portion of employee salaries and benefits directly related to time spent on acquired contracts. These costs are deferred and amortized over the life of the contracts. Accounting guidance requires a premium deficiency analysis to be performed at the level an entity acquires, services, and measures the profitability of its insurance contracts. We currently perform three premium deficiency analyses for our insurance operations, consistent with our reportable segments of Standard Commercial Lines, Standard Personal Lines, and E&S Lines. A combined ratio of over 100% does not necessarily indicate a premium deficiency, as any year's combined ratio includes a portion of underwriting expenses that are expensed at policy inception and therefore are not covered by the remaining unearned premium. In addition, investment income is not contemplated in the combined ratio calculation. There were no premium deficiencies for any of the reported years, as the sum of the anticipated loss and loss expense, unamortized acquisition costs, policyholder dividends, and other expenses for each segment did not exceed that segment’s related unearned premium and anticipated investment income. The investment yields assumed in the premium deficiency assessment for each reporting period, which were based on our actual average investment yield before tax as of the September 30 calculation date, were 3.5% for 2022, 4.3% for 2021, and 3.0% for 2020. (j) Goodwill Goodwill results from business acquisitions where the cost of assets and liabilities acquired exceeds the fair value of those assets and liabilities. A quantitative goodwill impairment analysis is performed if our quarterly qualitative analysis indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. Goodwill is allocated to the reporting units for purposes of these analyses. Based on our analysis at December 31, 2022, goodwill was not impaired. (k) Reserve for Loss and Loss Expense Reserves for loss and loss expense includes case reserves on reported claims and reserves known as incurred but not reported ("IBNR") reserves. Case reserves are estimated on each individual claim, and based on claim-specific facts and circumstances known at the time. The case reserves may be adjusted upward or downward as the specific facts and circumstances change. IBNR reserves are established at more aggregated levels and include provisions for (i) claims not yet reported, (ii) future development on reported claims, (iii) previously closed claims that could be reopened in the future, and (iv) anticipated salvage and subrogation recoveries. We evaluate our reserves quarterly, through our comprehensive reserve review process and adjustments to recorded reserves are made accordingly. The primary input in evaluating reserve levels is the quarterly reserve review prepared by our internal actuaries, which provides comprehensive loss and loss expense projections. Our reviews are based primarily on our own loss experience, organized by line of business. Where sufficient statistical credibility exists, we may further segment the experience by coverage within line, or by geographic area. Generally accepted actuarial methodologies are applied to these reserve groups to produce ultimate loss and loss expense projections. Ty

Adoption of Accounting Pronounc

Adoption of Accounting Pronouncements	12 Months Ended
	Dec. 31, 2022
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Adoption of Accounting Pronouncements There was no adoption of accounting pronouncements in 2022. Pronouncements to be effective in the future In March 2020, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”). ASU 2020-04 provides optional expedients and exceptions to the GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition away from the London Interbank Offered Rate ("LIBOR") and other interbank offered rates to alternative reference rates. Companies can elect to adopt ASU 2020-04 as of the beginning of the interim period that includes March 2020, or any date thereafter through December 31, 2024, as permitted by the newly issued ASU 2022-06, Reference Rate Reform (Topic 848) - Deferral of the Sunset Date of Topic 848 . We are currently evaluating the impact of this guidance, but we do not anticipate its adoption to have a material impact on our financial condition and results of operations. In June 2022, the FASB issued ASU 2022-03 , Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions (“ASU 2022-03”). ASU 2022-03 clarifies that a contractual sales restriction on an equity security is not considered when determining the security's fair value. This ASU was issued to eliminate diversity in practice by clarifying that contractual arrangements restricting an entity's ability to sell the security for a certain period of time is a characteristic of the reporting entity and should not be contemplated when determining the security's fair value. ASU 2022-03 requires new disclosures that provide investors with information about the restriction, including the nature and remaining duration of the restriction. The ASU is effective for annual periods beginning after December 15, 2023, including interim periods within those annual periods. Early adoption is permitted. We are currently evaluating the impact of this guidance.

Statements of Cash Flow

Statements of Cash Flow	12 Months Ended
	Dec. 31, 2022
Supplemental Cash Flow Information [Abstract]
Statements of Cash Flow	Statements of Cash Flows Supplemental cash flow information for the years ended December 31, 2022, 2021, and 2020 was as follows: ($ in thousands) 2022 2021 2020 Cash paid during the period for: Interest $ 26,639 28,930 30,464 Federal income tax 75,000 100,000 47,000 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases 8,148 7,935 9,498 Operating cash flows from financing leases 46 35 15 Financing cash flows from finance leases 2,438 1,768 550 Non-cash items: Corporate actions related to fixed income securities, AFS 1 38,106 56,365 55,446 Corporate actions related to fixed income securities, held-to-maturity ("HTM") 1 — — 2,589 Corporate actions related to equity securities 1 — 30,666 10,890 Conversion of AFS fixed income securities to equity securities 1,463 15,139 — Assets acquired under finance lease arrangements 707 6,709 324 Assets acquired under operating lease arrangements 16,649 3,272 22,390 Non-cash purchase of property and equipment 70 472 590 1 Examples of corporate actions include like-kind exchanges, non-cash acquisitions, and stock-splits. The following table provides a reconciliation of cash and restricted cash reported within the Consolidated Balance Sheets that equate to the amount reported in the Consolidated Statements of Cash Flows: ($ in thousands) December 31, 2022 December 31, 2021 Cash $ 26 455 Restricted cash 25,183 44,608 Total cash and restricted cash shown in the Statements of Cash Flows $ 25,209 45,063 Amounts in restricted cash represent cash received from the National Flood Insurance Program ("NFIP") that can only be used to pay flood claims under the Write Your Own program. Restricted cash was elevated at December 31, 2021, primarily to pay Hurricane Ida flood claims.

Investments

Investments	12 Months Ended
	Dec. 31, 2022
Investments [Abstract]
Investments	Investments (a) Net unrealized losses and gains on investments included in "Other comprehensive (loss) income" ("OCI") by asset class were as follows for the years ended December 31, 2022, 2021, and 2020: ($ in thousands) 2022 2021 2020 AFS securities: Fixed income securities $ (527,926) 228,947 386,380 Total AFS securities (527,926) 228,947 386,380 HTM securities: Fixed income securities — (4) 7 Total HTM securities — (4) 7 Short-term securities 35 20 6 Total net unrealized (losses) gains (527,891) 228,963 386,393 Deferred income tax 110,857 (48,082) (81,142) Net unrealized (losses) gains, net of deferred income tax (417,034) 180,881 305,251 (Decrease) increase in net unrealized (losses) gains in OCI, net of deferred income tax $ (597,915) (124,370) 134,857 (b) Information regarding our AFS securities as of December 31, 2022 and December 31, 2021 were as follows: December 31, 2022 Cost/ Amortized Allowance for Unrealized Unrealized Fair ($ in thousands) Cost Credit Losses Gains Losses Value AFS fixed income securities: U.S. government and government agencies $ 209,528 — 37 (20,326) 189,239 Foreign government 11,199 (284) — (1,307) 9,608 Obligations of states and political subdivisions 965,231 (1,024) 1,812 (48,001) 918,018 Corporate securities 2,558,655 (30,330) 3,509 (196,809) 2,335,025 CLO and other ABS 1,607,660 (2,375) 2,408 (121,720) 1,485,973 RMBS 1,169,546 (11,597) 1,148 (99,265) 1,059,832 CMBS 663,935 (111) 348 (49,760) 614,412 Total AFS fixed income securities $ 7,185,754 (45,721) 9,262 (537,188) 6,612,107 December 31, 2021 Cost/ Amortized Allowance for Unrealized Unrealized Fair ($ in thousands) Cost Credit Losses Gains Losses Value AFS fixed income securities: U.S. government and government agencies $ 127,974 — 3,629 (1,145) 130,458 Foreign government 15,420 (46) 609 (123) 15,860 Obligations of states and political subdivisions 1,121,422 (137) 68,258 (235) 1,189,308 Corporate securities 2,478,348 (6,682) 106,890 (4,953) 2,573,603 CLO and other ABS 1,343,687 (939) 14,350 (6,284) 1,350,814 RMBS 756,280 (1,909) 24,813 (2,932) 776,252 CMBS 647,622 (11) 27,752 (1,682) 673,681 Total AFS fixed income securities $ 6,490,753 $ (9,724) 246,301 (17,354) 6,709,976 The following tables provide a roll forward of the allowance for credit losses on our AFS fixed income securities for the years indicated: 2022 Beginning Balance Current Provision for Securities without Prior Allowance Initial Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirements) to Sell Securities Reductions for Securities Sold Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period Ending Balance ($ in thousands) Foreign government $ 46 291 — 4 (57) — 284 Obligations of states and political subdivisons 137 1,087 — (6) (194) — 1,024 Corporate securities 6,682 30,670 — 3,714 (6,902) (3,834) 30,330 CLO and other ABS 939 2,158 — (652) (50) (20) 2,375 RMBS 1,909 245 8,318 1,558 (433) — 11,597 CMBS 11 110 — (10) — — 111 Total AFS fixed income securities $ 9,724 34,561 8,318 4,608 (7,636) (3,854) 45,721 2021 Beginning Balance Current Provisions for Securities without Prior Allowance Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirements) to Sell Securities Reductions for Securities Sold Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period Ending Balance ($ in thousands) Foreign government $ 1 46 (1) — — 46 Obligations of states and political subdivisons 4 122 11 — — 137 Corporate securities 2,782 5,785 (992) (723) (170) 6,682 CLO and other ABS 592 579 (211) (21) — 939 RMBS 561 1,593 (63) (182) — 1,909 CMBS 29 10 (28) — — 11 Total AFS fixed income securities $ 3,969 8,135 (1,284) (926) (170) 9,724 During 2022 or 2021, we had no write-offs or recoveries of our AFS fixed income securities. As disclosed in Note 2. "Summary of Significant Accounting Policies," we do not evaluate accrued interest on our AFS securities for expected credit loss as we write-off these balances in a timely manner. Accrued interest on AFS securities was $56.4 million as of December 31, 2022, and $46.3 million as of December 31, 2021. We did not record any material write-offs of accrued interest during 2022 or 2021. (c) Quantitative information about unrealized losses on our AFS portfolio follows: December 31, 2022 Less than 12 months 12 months or longer Total ($ in thousands) Fair Unrealized Fair Unrealized Fair Unrealized AFS fixed income securities: U.S. government and government agencies $ 166,975 (13,658) 16,011 (6,668) 182,986 (20,326) Foreign government 5,573 (608) 2,456 (699) 8,029 (1,307) Obligations of states and political subdivisions 681,795 (43,767) 16,618 (4,234) 698,413 (48,001) Corporate securities 1,889,492 (164,197) 133,223 (32,612) 2,022,715 (196,809) CLO and other ABS 916,423 (69,155) 411,283 (52,565) 1,327,706 (121,720) RMBS 887,229 (76,432) 108,041 (22,833) 995,270 (99,265) CMBS 512,953 (37,815) 77,181 (11,945) 590,134 (49,760) Total AFS fixed income securities $ 5,060,440 (405,632) 764,813 (131,556) 5,825,253 (537,188) December 31, 2021 Less than 12 months 12 months or longer Total ($ in thousands) Fair Unrealized Fair Unrealized Fair Unrealized AFS fixed income securities: U.S. government and government agencies $ 34,857 (746) 7,827 (399) 42,684 (1,145) Foreign government 2,000 (84) 1,061 (39) 3,061 (123) Obligations of states and political subdivisions 25,837 (235) — — 25,837 (235) Corporate securities 300,549 (4,903) 2,520 (50) 303,069 (4,953) CLO and other ABS 663,976 (4,934) 53,368 (1,350) 717,344 (6,284) RMBS 236,010 (2,931) 20 (1) 236,030 (2,932) CMBS 112,899 (1,016) 20,326 (666) 133,225 (1,682) Total AFS fixed income securities $ 1,376,128 (14,849) 85,122 (2,505) 1,461,250 (17,354) We currently do not intend to sell any of the securities summarized in the tables above, nor will we be required to sell any of them. The increase in gross unrealized losses as December 31, 2022, compared to December 31, 2021, was driven by an increase in benchmark U.S. Treasury rates and a widening of credit spreads, with the increase in interest rates having the most significant impact. The severity of impairment on these securities is less than 10% at both periods. Considering these factors and our review of these securities under our credit loss policy as described in Note 2. “Summary of Significant Accounting Policies” of this Form 10-K, we have concluded that no allowance for credit loss is required on these balances beyond the allowance for credit loss recorded as of December 31, 2022. This conclusion reflects our current judgment about the financial position and future prospects of the entities that issued the investment security and underlying collateral. (d) AFS and HTM fixed income securities at December 31, 2022, by contractual maturity are shown below. The maturities of mortgage-backed securities were calculated using each security's estimated average life. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. AFS HTM ($ in thousands) Fair Value Carrying Value Fair Value Due in one year or less $ 324,394 6,093 6,090 Due after one year through five years 2,928,594 3,779 3,798 Due after five years through 10 years 2,600,001 21,285 19,949 Due after 10 years 759,118 — — Total fixed income securities $ 6,612,107 31,157 29,837 (e) The following table summarizes our alternative investment portfolio by strategy: December 31, 2022 December 31, 2021 ($ in thousands) Carrying Remaining Maximum Carrying Remaining Maximum Alternative investments Private equity $ 280,980 134,676 415,656 273,070 99,734 372,804 Private credit 54,866 89,481 144,347 63,138 92,674 155,812 Real assets 35,470 21,945 57,415 23,524 22,579 46,103 Total alternative investments 371,316 246,102 617,418 359,732 214,987 574,719 We are contractually committed to make additional investments up to the remaining commitments stated above. We did not provide any non-contractual financial support during 2022 or 2021. The following is a description of our alternative investment strategies: Our private equity strategy includes the following: • Primary Private Equity : This strategy makes private equity investments, primarily in established large and middle market companies across diverse industries globally, with an emphasis on North America. • Secondary Private Equity: This strategy purchases seasoned private equity funds from investors desiring liquidity prior to normal fund termination. Investments are made across all sectors of the private equity market, including leveraged buyouts ("LBO"), venture capital, distressed securities, mezzanine financing, real estate, and infrastructure. • Venture Capital : In general, these investments are made principally by investing in equity securities of startup companies and small-to-medium sized privately-held corporations with strong long-term growth potential. This strategy makes private equity investments in seed stage, early stage, late stage, and growth equity partnerships. Our private credit strategy includes the following: • Direct Lending : This strategy provides privately negotiated loans to U.S. middle market companies. Typically, these are floating rate, senior secured loans diversified across industries. Loans are made to companies that may or may not have private equity sponsors to finance LBOs, recapitalizations, and acquisitions. • Mezzanine Financing: This strategy provides privately-negotiated fixed income securities, generally with an equity component, to LBO firms and private and publicly-traded large, mid, and small-cap companies to finance LBOs, recapitalizations, and acquisitions . • Opportunistic and Distressed Debt : This strategy makes investments in debt and equity securities of companies that are experiencing financial distress, operational issues, or dislocated pricing of publicly-traded securities. Investments include buying indebtedness of bankrupt or financially-troubled companies, small balance loan portfolios, special situations and capital structure arbitrage trades, commercial real estate mortgages, and similar non-U.S. securities and debt obligations. Our real assets strategy includes the following: • I nfrastructure: This strategy invests in the equity or debt of cash flow generating assets, diversified across a variety of industries, including transportation, energy infrastructure, renewable power, such as wind and solar, social infrastructure, power generation, water, telecom, and other regulated entities principally located in North America and Western Europe. • Real Estate : This strategy invests in real estate in North America, Europe, and Asia via direct property ownership, joint ventures, mortgages, and investments in equity and debt instruments. Our alternative investment strategies may employ leverage and may use hedging to reduce foreign exchange or interest rate volatility. At this time, our alternative investment strategies do not include hedge funds. We typically cannot redeem our investments with the general partners of these investments; however, occasionally these partnership positions can be sold on the secondary market. Once liquidation is triggered by clauses within the limited partnership agreements or at the funds’ stated end date, we receive our final allocation of capital and any earned appreciation of the underlying investments, assuming we have not divested ourselves of our partnership interests prior to that time. We currently receive distributions from these alternative investments through the realization of the underlying investments of, or income generated by, the limited partnerships. The following tables show gross summarized financial information for our alternative investments portfolio, including the portion we do not own. As the majority of these investments report results to us on a one quarter lag, the summarized financial statement information is as of, and for the 12-month period ended, September 30: Balance Sheet Information December 31, ($ in millions) 2022 2021 Investments $ 114,038 107,347 Total assets 128,158 112,232 Total liabilities 15,464 12,371 Total partners’ capital 112,694 99,861 Income Statement Information 12 months ended September 30, ($ in millions) 2022 2021 2020 Net investment income (loss) $ 765 653 (26) Realized gains 12,590 6,121 1,452 Net change in unrealized appreciation (5,215) 26,877 4,898 Net income $ 8,140 33,651 6,324 Alternative investment income included in "Net investment income earned" on our Consolidated Statements of Income 23.0 117.7 26.5 (f) We did not have exposure to any credit concentration risk of a single issuer greater than 10% of our stockholders' equity, other than to certain U.S. government agencies, as of December 31, 2022 or December 31, 2021. (g) We have pledged certain AFS fixed income securities as collateral related to our borrowing relationships with the Federal Home Loan Bank of Indianapolis ("FHLBI") and the Federal Home Loan Bank of New York ("FHLBNY"). In addition, we had certain securities on deposit with various state and regulatory agencies at December 31, 2022 to comply with insurance laws. We retain all rights regarding all securities pledged as collateral. The following table summarizes the market value of these securities at December 31, 2022: ($ in millions) FHLBI Collateral FHLBNY Collateral Regulatory Deposits Total U.S. government and government agencies $ — — 19.3 19.3 Obligations of states and political subdivisions — — 3.6 3.6 RMBS 61.4 28.8 — 90.2 CMBS 4.6 9.6 — 14.2 Total pledged as collateral $ 66.0 38.4 22.9 127.3 (h) The components of pre-tax net investment income earned were as follows: ($ in thousands) 2022 2021 2020 Fixed income securities $ 259,918 209,709 203,926 CMLs 5,555 2,743 844 Equity securities 13,554 15,920 9,286 Short-term investments 3,997 260 1,821 Alternative investments 23,003 117,701 26,504 Other investments 258 359 418 Investment expenses (18,130) (20,103) (15,692) Net investment income earned $ 288,155 326,589 227,107 (i) The following table summarizes net realized and unrealized investment gains and losses for the periods indicated: ($ in thousands) 2022 2021 2020 Gross gains on sales $ 28,419 15,284 18,893 Gross losses on sales (60,055) (8,140) (9,745) Net realized (losses) gains on disposals (31,636) 7,144 9,148 Net unrealized (losses) gains on equity securities (32,127) 17,881 7,939 Net credit loss (expense) on fixed income securities, AFS (39,169) (6,858) (5,042) Net credit loss (expense) benefit on fixed income securities, HTM 63 (49) 4 Net credit loss (expense) on CMLs (116) — — Losses on securities for which we have the intent to sell (11,823) (519) (16,266) Net realized and unrealized investment (losses) gains $ (114,808) 17,599 (4,217) Net realized and unrealized investment losses in 2022 were primarily driven by (i) a decrease in valuations reflecting the current public equities market, (ii) active trading of our fixed income securities in an effort to opportunistically increase yield given the rising interest rate environment, and (iii) higher credit loss expense on our AFS fixed income securities portfolio. Net unrealized losses and gains recognized in income on equity securities, as reflected in the table above, included the following: ($ in thousands) 2022 2021 2020 Unrealized (losses) gains recognized in income on equity securities: On securities remaining in our portfolio at end of period $ (10,454) 16,473 7,936 On securities sold in period (21,673) 1,408 3 Total unrealized (losses) gains recognized in income on equity securities $ (32,127) 17,881 7,939 Proceeds from the sales of AFS fixed income securities were $1,211.7 million, $502.9 million, and $487.1 million in 2022, 2021, and 2020, respectively. Proceeds from the sales of equity securities were $186.1 million, $99.2 million, and $1.3 million in 2022, 2021, and 2020, respectively.

Comprehensive Income

Comprehensive Income	12 Months Ended
	Dec. 31, 2022
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Comprehensive Income	Comprehensive Income (a) The components of comprehensive income, both gross and net of tax, for 2022, 2021, and 2020 are as follows: 2022 ($ in thousands) Gross Tax Net Net income $ 280,186 55,300 224,886 Components of OCI: Unrealized (losses) gains on investment securities : Unrealized holding losses during the year (668,107) (140,302) (527,805) Unrealized losses on securities with credit loss recognized in earnings (187,968) (39,473) (148,495) Amounts reclassified into net income: HTM securities 4 1 3 Net realized losses on disposals and intent-to-sell AFS securities 60,048 12,610 47,438 Credit loss expense 39,169 8,225 30,944 Total unrealized losses on investment securities (756,854) (158,939) (597,915) Defined benefit pension and post-retirement plans: Net actuarial loss (20,941) (4,398) (16,543) Amounts reclassified into net income: Net actuarial loss 1,668 351 1,317 Total defined benefit pension and post-retirement plans (19,273) (4,047) (15,226) Other comprehensive loss (776,127) (162,986) (613,141) Comprehensive loss $ (495,941) (107,686) (388,255) 2021 ($ in thousands) Gross Tax Net Net income $ 505,310 101,473 403,837 Components of OCI: Unrealized (losses) gains on investment securities : Unrealized holding losses during the year (151,391) (31,793) (119,598) Unrealized losses on securities with credit loss recognized in earnings (9,061) (1,902) (7,159) Amounts reclassified into net income: HTM securities (11) (2) (9) Net realized gains on disposals and losses on intent-to-sell AFS securities (3,825) (803) (3,022) Credit loss expense 6,858 1,440 5,418 Total unrealized losses on investment securities (157,430) (33,060) (124,370) Defined benefit pension and post-retirement plans: Net actuarial gain 21,636 4,543 17,093 Amounts reclassified into net income: Net actuarial loss 2,772 582 2,190 Total defined benefit pension and post-retirement plans 24,408 5,125 19,283 Other comprehensive loss (133,022) (27,935) (105,087) Comprehensive income $ 372,288 73,538 298,750 2020 ($ in thousands) Gross Tax Net Net income $ 302,988 56,633 246,355 Components of OCI: Unrealized gains (losses) on investment securities : Unrealized holding gains during the year 168,487 35,383 133,104 Unrealized losses on securities with credit loss recognized in earnings (8,176) (1,717) (6,459) Amounts reclassified into net income: HTM securities (24) (5) (19) Net realized losses on disposals and intent-to-sell AFS securities 5,376 1,129 4,247 Credit loss expense 5,042 1,058 3,984 Total unrealized gains on investment securities 170,705 35,848 134,857 Defined benefit pension and post-retirement plans: Net actuarial gain 1,515 318 1,197 Amounts reclassified into net income: Net actuarial loss 3,015 633 2,382 Total defined benefit pension and post-retirement plans 4,530 951 3,579 Other comprehensive income 175,235 36,799 138,436 Comprehensive income $ 478,223 93,432 384,791 (b) The balances of, and changes in, each component of AOCI (net of taxes) as of December 31, 2022 and 2021 were as follows: Net Unrealized (Losses) Gains on Investment Securities Defined Benefit Pension and Post-retirement Plans ($ in thousands) Credit Loss Related 1 HTM Related All Other Investments Subtotal Total AOCI Balance, December 31, 2020 $ (2,546) 6 307,790 305,250 (85,064) 220,186 OCI before reclassifications (7,159) — (119,598) (126,757) 17,093 (109,664) Amounts reclassified from AOCI 5,418 (9) (3,022) 2,387 2,190 4,577 Net current period OCI (1,741) (9) (122,620) (124,370) 19,283 (105,087) Balance, December 31, 2021 (4,287) (3) 185,170 180,880 (65,781) 115,099 OCI before reclassifications (148,495) — (527,805) (676,300) (16,543) (692,843) Amounts reclassified from AOCI 30,944 3 47,438 78,385 1,317 79,702 Net current period OCI (117,551) 3 (480,367) (597,915) (15,226) (613,141) Balance, December 31, 2022 $ (121,838) — (295,197) (417,035) (81,007) (498,042) 1 Represents change in unrealized loss on securities with credit loss recognized in earnings. The reclassifications out of AOCI are as follows: ($ in thousands) Year ended December 31, 2022 Year ended December 31, 2021 Affected Line Item in the Consolidated Statements of Income HTM related Unrealized gains on HTM disposals $ (7) (14) Net realized and unrealized investment (losses) gains Amortization of net unrealized losses on HTM securities 11 3 Net investment income earned 4 (11) Income before federal income tax (1) 2 Total federal income tax expense 3 (9) Net income Net realized losses (gains) on disposals and losses on intent-to-sell AFS securities Net realized losses (gains) on disposals and losses on intent-to-sell AFS securities 60,048 (3,825) Net realized and unrealized investment (losses) gains 60,048 (3,825) Income before federal income tax (12,610) 803 Total federal income tax expense 47,438 (3,022) Net income Credit loss related Credit loss expense 39,169 6,858 Net realized and unrealized investment (losses) gains 39,169 6,858 Income before federal income tax (8,225) (1,440) Total federal income tax expense 30,944 5,418 Net income Defined benefit pension and post-retirement life plans Net actuarial loss 359 638 Loss and loss expense incurred 1,309 2,134 Other insurance expenses Total defined benefit pension and post-retirement life 1,668 2,772 Income before federal income tax (351) (582) Total federal income tax expense 1,317 2,190 Net income Total reclassifications for the period $ 79,702 4,577 Net income

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The financial assets in our investment portfolio are primarily measured at fair value as disclosed on the Consolidated Balance Sheets. The following table presents the carrying amounts and estimated fair values of our financial liabilities as of December 31, 2022 and 2021: December 31, 2022 December 31, 2021 ($ in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Financial Liabilities Long-term debt: 7.25% Senior Notes $ 49,921 51,705 49,917 63,719 6.70% Senior Notes 99,542 99,264 99,520 127,574 5.375% Senior Notes 294,424 258,459 294,330 395,652 3.03% Borrowings from FHLBI 60,000 57,175 60,000 64,126 Subtotal long-term debt 503,887 466,603 503,767 651,071 Unamortized debt issuance costs (2,929) (3,167) Finance lease obligations 3,718 5,450 Total long-term debt $ 504,676 $ 506,050 For discussion regarding the fair value techniques of our financial instruments, refer to Note 2. "Summary of Significant Accounting Policies" of this Form 10-K. The following tables provide quantitative disclosures of our financial assets that were measured and recorded at fair value at December 31, 2022 and 2021: December 31, 2022 Fair Value Measurements Using ($ in thousands) Assets Measured at Fair Value Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 189,239 109,240 79,999 — Foreign government 9,608 — 9,608 — Obligations of states and political subdivisions 918,018 — 911,357 6,661 Corporate securities 2,335,025 — 2,147,045 187,980 CLO and other ABS 1,485,973 — 1,332,631 153,342 RMBS 1,059,832 — 1,059,832 — CMBS 614,412 — 614,037 375 Total AFS fixed income securities 6,612,107 109,240 6,154,509 348,358 Equity securities: Common stock 1 160,355 55,846 — 897 Preferred stock 1,645 1,645 — — Total equity securities 162,000 57,491 — 897 Short-term investments 440,456 418,199 22,257 — Total assets measured at fair value $ 7,214,563 584,930 6,176,766 349,255 December 31, 2021 Fair Value Measurements Using ($ in thousands) Assets Measured at Fair Value Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 130,458 60,615 69,843 — Foreign government 15,860 — 15,860 — Obligations of states and political subdivisions 1,189,308 — 1,181,563 7,745 Corporate securities 2,573,603 — 2,459,476 114,127 CLO and other ABS 1,350,814 — 1,225,905 124,909 RMBS 776,252 — 776,007 245 CMBS 673,681 — 669,425 4,256 Total AFS fixed income securities 6,709,976 60,615 6,398,079 251,282 Equity securities: Common stock 1 333,449 249,846 — — Preferred stock 2,088 2,088 — — Total equity securities 335,537 251,934 — — Short-term investments 447,863 442,723 5,140 — Total assets measured at fair value $ 7,493,376 755,272 6,403,219 251,282 1 Investments amounting to $103.6 million and $83.6 million at December 31, 2022 and December 31, 2021, respectively, were measured at fair value using the net asset value per share (or its practical expedient) and have not been classified in the fair value hierarchy. These investments are not redeemable and the timing of liquidations of the underlying assets is unknown at each reporting period. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total assets measured at fair value. The following tables provide a summary of Level 3 changes for the years indicated: 2022 ($ in thousands) Obligations of states and political subdivisions Corporate Securities CLO and Other ABS RMBS CMBS Common Stock Total Fair value, December 31, 2021 $ 7,745 114,127 124,909 245 4,256 — 251,282 Total net (losses) gains for the period included in: OCI (985) (23,624) (11,287) (17) (481) — (36,394) Net realized and unrealized investment (losses) gains (99) (2,414) (876) — — — (3,389) Net investment income earned — 68 229 — 45 — 342 Purchases — 99,868 100,406 — — — 200,274 Sales — — — — — — — Issuances — — — — — — — Settlements — (10,148) (12,361) (11) (15) — (22,535) Transfers into Level 3 — 19,214 502 — — 897 20,613 Transfers out of Level 3 — (9,111) (48,180) (217) (3,430) — (60,938) Fair value, December 31, 2022 $ 6,661 187,980 153,342 — 375 897 349,255 Change in unrealized losses for the period included in earnings for assets held at period end (99) (2,399) (876) — — — (3,374) Change in unrealized losses for the period included in OCI for assets held at period end (985) (23,630) (11,246) (17) (481) — (36,359) 2021 ($ in thousands) Obligations of states and political subdivisions Corporate Securities CLO and Other ABS RMBS CMBS Total Fair value, December 31, 2020 $ 2,894 70,700 56,375 — — 129,969 Total net (losses) gains for the period included in: OCI (239) 1,636 (520) — (196) 681 Net realized and unrealized investment (losses) gains (11) (50) (214) — 5 (270) Net investment income earned — 27 16 — 19 62 Purchases — 64,813 76,731 249 98 141,891 Sales — — — — — — Issuances — — — — — — Settlements — (544) (5,161) (4) (52) (5,761) Transfers into Level 3 5,101 981 11,344 — 4,382 21,808 Transfers out of Level 3 — (23,436) (13,662) — — (37,098) Fair value, December 31, 2021 $ 7,745 114,127 124,909 245 4,256 251,282 Change in unrealized (losses) gains for the period included in earnings for assets held at period end (11) (50) (214) — 5 (270) Change in unrealized (losses) gains for the period included in OCI for assets held at period end (239) 1,636 (520) — (196) 681 The following tables present quantitative information about the significant unobservable inputs used in the fair value measurements of Level 3 assets at December 31, 2022 and 2021: December 31, 2022 ($ in thousands) Assets Measured at Fair Value Valuation Techniques Unobservable Inputs Range Weighted Average Internal valuations: Corporate securities $ 81,867 Discounted Cash Flow Illiquidity Spread (4.4)% - 5.3% 1.3% CLO and other ABS 59,452 Discounted Cash Flow Illiquidity Spread 0.01% - 19.6% 2.5% Total internal valuations 141,319 Other 1 207,936 Total Level 3 securities $ 349,255 December 31, 2021 ($ in thousands) Assets Measured at Fair Value Valuation Techniques Unobservable Inputs Range Weighted Average Internal valuations: Corporate securities $ 54,135 Discounted Cash Flow Illiquidity Spread 0.3% - 3.0% (1.2)% CLO and other ABS 34,903 Discounted Cash Flow Illiquidity Spread 0.7% - 8.0% (2.1)% Total internal valuations 89,038 Other 1 162,244 Total Level 3 securities $ 251,282 1 Other is comprised of broker quotes or other third-party pricing for which there is a lack of transparency into the inputs used to develop the valuations. The quantitative details of these unobservable inputs is neither provided to us, nor reasonably available to us, and therefore are not included in the tables above. For the securities in the tables above valued using a discounted cash flow analysis, we apply an illiquidity spread in our determination of fair value. An increase in this assumption would result in a lower fair value measurement. The following tables provide quantitative information regarding our financial assets and liabilities that were not measured at fair value, but were disclosed as such at December 31, 2022 and 2021: December 31, 2022 Fair Value Measurements Using ($ in thousands) Assets/Liabilities Disclosed at Quoted Prices in Active Markets for Identical Assets/Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Financial Assets HTM: Obligations of states and political subdivisions $ 3,405 — 3,405 — Corporate securities 26,432 — 26,432 — Total HTM fixed income securities $ 29,837 — 29,837 — CMLs $ 139,243 — — 139,243 Financial Liabilities Long-term debt: 7.25% Senior Notes $ 51,705 — 51,705 — 6.70% Senior Notes 99,264 — 99,264 — 5.375% Senior Notes 258,459 — 258,459 — 3.03% Borrowings from FHLBI 57,175 — 57,175 — Total long-term debt $ 466,603 — 466,603 — December 31, 2021 Fair Value Measurements Using ($ in thousands) Assets/Liabilities Disclosed at Quoted Prices in Active Markets for Identical Assets/Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Financial Assets HTM: Obligations of states and political subdivisions $ 3,576 — 3,576 — Corporate securities 25,884 — 25,884 — Total HTM fixed income securities $ 29,460 — 29,460 — CMLs $ 97,598 — — 97,598 Financial Liabilities Long-term debt: 7.25% Senior Notes $ 63,719 — 63,719 — 6.70% Senior Notes 127,574 — 127,574 — 5.375% Senior Notes 395,652 — 395,652 — 3.03% Borrowings from FHLBI 64,126 — 64,126 — Total long-term debt $ 651,071 — 651,071 —

Allowance for Credit Losses on

Allowance for Credit Losses on Premiums Receivable	12 Months Ended
	Dec. 31, 2022
Premiums Receivable [Abstract]
Allowance for Credit Losses on Premiums Receivable Note [Text Block]	Allowance for Credit Losses on Premiums Receivable The following table provides a roll forward of the ACL on our premiums receivable balance for 2022 and 2021: ($ in thousands) December 31, 2022 December 31, 2021 Balance at beginning of year $ 13,600 21,000 Current period change for expected credit losses 6,065 1,291 Write-offs charged against the allowance for credit losses (4,978) (9,343) Recoveries 1,413 652 ACL, end of year $ 16,100 13,600 In 2022, we recognized an additional allowance for credit losses on premiums receivable of $7.5 million, excluding the impact of write-offs. The additional allowance consisted of a reserve of $9.3 million on 2022 premiums based on our historical write-off percentages and assumptions, partially offset by a $1.8 million allowance reduction on 2021 and older policies, primarily impacted by the COVID-19 pandemic, for which the credit loss did not fully materialize. In 2021, we recognized an additional allowance for credit losses on premiums receivable of $1.9 million, excluding the impact of write-offs. The additional allowance consisted of a reserve of $8.3 million on 2021 premiums based on our historical write-off percentages and assumptions, partially offset by a $6.4 million allowance reduction on older policies, primarily impacted by the COVID-19 pandemic, for which the credit loss did not fully materialize, as mentioned above. For a discussion of the methodology used to evaluate our estimate of expected credit losses on premiums receivable, refer to Note 2. "Summary of Significant Accounting Policies."

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2022
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance Our Financial Statements reflect the effects of assumed and ceded reinsurance transactions. Assumed reinsurance refers to the acceptance of certain insurance risks that other insurance entities have underwritten. Ceded reinsurance involves transferring certain insurance risks (along with the related written and earned premiums) that we have underwritten to other insurance companies that agree to share these risks. The primary purpose of ceded reinsurance is to protect the Insurance Subsidiaries from potential losses in excess of the amount that we are prepared to accept. Our major treaties covering property, property catastrophe, and casualty business are excess of loss contracts. In addition, we have an intercompany quota share (proportional) pooling arrangement and other minor reinsurance treaties. As a Standard Commercial Lines and E&S Lines writer, we are subject to the Terrorism Risk Insurance Program Reauthorization Act ("TRIPRA"), which was extended by Congress to December 31, 2027. TRIPRA requires private insurers and the U. S. government to share the risk of loss on future acts of terrorism certified by the U.S. Secretary of the Treasury. Under TRIPRA, each participating insurer is responsible for paying a deductible of specified losses before federal assistance is available. This deductible is based on a percentage of the prior year’s applicable Standard Commercial Lines and E&S Lines premiums. In 2023, our deductible, before tax, is approximately $480 million. For losses above the deductible, the federal government will pay 80% of losses to an industry limit of $100 billion, and the insurer retains 20%. The Insurance Subsidiaries remain liable to policyholders to the extent that any reinsurer becomes unable to meet their contractual obligations. In addition to this direct counterparty credit risk, we have indirect counterparty credit risk as our reinsurers often enter into their own reinsurance programs, or retrocessions, as part of managing their exposure to large losses and improving their financial strength ratings. The credit quality of our reinsurers is also impacted by other factors, such as their reserve adequacy, investment portfolio, regulatory capital position, catastrophe aggregations, and risk management expertise. We evaluate and monitor the financial condition of our reinsurers under voluntary reinsurance arrangements to minimize our exposure to significant losses from reinsurer insolvencies. The following tables provide (i) a disaggregation of our reinsurance recoverable balance by financial strength rating, and (ii) an aging analysis of our past due reinsurance recoverable balances as of December 31, 2022 and 2021: December 31, 2022 ($ in thousands) Current Past Due Total Reinsurance Recoverables Financial strength rating of rated reinsurers A++ $ 46,282 $ 1 $ 46,283 A+ 425,395 3,191 428,586 A 106,102 1,315 107,417 A- 7,148 89 7,237 Total rated reinsurers $ 584,927 $ 4,596 $ 589,523 Non-rated reinsurers Federal and state pools $ 180,794 $ — $ 180,794 Other than federal and state pools 13,678 415 14,093 Total non-rated reinsurers $ 194,472 $ 415 $ 194,887 Total reinsurance recoverable, gross $ 779,399 $ 5,011 $ 784,410 Less: ACL (1,600) Total reinsurance recoverable, net $ 782,810 December 31, 2021 ($ in thousands) Current Past Due Total Reinsurance Recoverables Financial strength rating of rated reinsurers A++ $ 38,601 $ 9 $ 38,610 A+ 339,857 1,520 341,377 A 95,675 1,227 96,902 A- 3,209 145 3,354 Total rated reinsurers $ 477,342 $ 2,901 $ 480,243 Non-rated reinsurers Federal and state pools $ 116,378 $ — $ 116,378 Other than federal and state pools 4,597 450 5,047 Total non-rated reinsurers $ 120,975 $ 450 $ 121,425 Total reinsurance recoverable, gross $ 598,317 $ 3,351 $ 601,668 Less: ACL (1,600) Total reinsurance recoverable, net $ 600,068 The $109.3 million increase in "Total rated reinsurers" as of December 31, 2022, compared to December 31, 2021, was primarily due to reserves recorded for Winter Storm Elliott, which impacted 37 states, 26 of which are in our Standard Commercial Lines footprint. Additionally, the $64.4 million increase in "Federal and state pools" as of December 31, 2022, compared to December 31, 2021, was primarily due to NFIP reserves recorded for flood losses in Florida and surrounding states as a result of Hurricane Ian, which are 100% ceded to the NFIP. The following table provides a roll forward of the allowance for credit losses on our reinsurance recoverable balance for 2022 and 2021: ($ in thousands) December 31, 2022 December 31, 2021 Balance at beginning of year $ 1,600 $ 1,777 Current period change for expected credit losses — (177) Write-offs charged against the allowance for credit losses — — Recoveries — — ACL, end of year $ 1,600 $ 1,600 For a discussion of the methodology used to evaluate our estimate of expected credit losses on our reinsurance recoverable balance, refer to Note 2. "Summary of Significant Accounting Policies." The following table represents our total reinsurance balances segregated by reinsurer to illustrate our concentration of risk throughout our reinsurance portfolio: As of December 31, 2022 As of December 31, 2021 ($ in thousands) Reinsurance Balances % of Reinsurance Balance Reinsurance Balances % of Reinsurance Balance Total reinsurance recoverables, net of allowance for credit losses $ 782,810 $ 600,068 Total prepaid reinsurance premiums 172,371 183,007 Total reinsurance balance 955,181 783,075 Federal and state pools 1 : NFIP 276,541 29 % 223,845 29 % New Jersey Unsatisfied Claim Judgment Fund 45,496 5 49,738 6 Other 3,488 — 2,385 — Total federal and state pools 325,525 34 275,968 35 Remaining reinsurance balance $ 629,656 66 $ 507,107 65 Munich Re Group (AM Best rated "A+") $ 127,106 13 $ 108,381 14 Hannover Ruckversicherungs AG (AM Best rated "A+") 124,706 13 107,110 14 AXIS Reinsurance Company (AM Best rated "A") 70,957 8 70,814 9 Swiss Re Group (AM Best rated "A+") 36,525 4 29,186 4 Transatlantic Reinsurance Company (AM Best rated “A+”) 32,730 3 26,490 3 All other reinsurers 239,232 25 166,726 21 Total reinsurers 631,256 66 % 508,707 65 % Less: ACL (1,600) (1,600) Reinsurers, net of ACL 629,656 507,107 Less: collateral 2 (126,167) (128,699) Reinsurers, net of collateral $ 503,489 $ 378,408 1 Considered to have minimal risk of default. 2 Includes letters of credit, trust funds, and funds held against reinsurance recoverables. Under our reinsurance arrangements, which are prospective in nature, reinsurance premiums ceded are recorded as prepaid reinsurance and amortized over the remaining contract period in proportion to the reinsurance protection provided, or recorded periodically, as per the terms of the contract, in a direct relationship to the gross premium recording. Reinsurance recoveries are recognized as gross losses are incurred. The following table lists direct, assumed, and ceded reinsurance amounts for premiums written, premiums earned, and loss and loss expense incurred for the indicated periods: ($ in thousands) 2022 2021 2020 Premiums written: Direct $ 4,068,518 3,656,537 3,204,512 Assumed 32,320 22,664 24,288 Ceded (527,248) (489,488) (455,708) Net $ 3,573,590 3,189,713 2,773,092 Premiums earned: Direct $ 3,880,522 3,472,715 3,108,687 Assumed 30,742 21,550 25,010 Ceded (537,884) (477,012) (451,883) Net $ 3,373,380 3,017,253 2,681,814 Loss and loss expense incurred: Direct $ 2,537,638 2,096,512 1,822,034 Assumed 23,160 13,813 17,201 Ceded (449,020) (296,341) (203,412) Net $ 2,111,778 1,813,984 1,635,823 Ceded premiums written, ceded premiums earned, and ceded loss and loss expense incurred related to our participation in the NFIP, to which we cede 100% of our NFIP flood premiums, losses, and loss expenses, were as follows: Ceded to NFIP ($ in thousands) 2022 2021 2020 Ceded premiums written $ (259,246) (284,311) (274,042) Ceded premiums earned (274,100) (274,384) (271,598) Ceded loss and loss expense incurred (200,467) (215,224) (78,993)

Reserve for Loss and Loss Expen

Reserve for Loss and Loss Expense	12 Months Ended
	Dec. 31, 2022
Insurance Loss Reserves [Abstract]
Reserve for Loss and Loss Expense	Reserve for Loss and Loss Expense (a) The table below provides a roll forward of reserves for loss and loss expense for beginning and ending reserve balances: ($ in thousands) 2022 2021 2020 Gross reserves for loss and loss expense, at beginning of year $ 4,580,903 4,260,355 4,067,163 Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year 1 578,641 554,269 547,066 Net reserves for loss and loss expense, at beginning of year 4,002,262 3,706,086 3,520,097 Incurred loss and loss expense for claims occurring in the: Current year 2,190,668 1,896,837 1,708,755 Prior years (78,890) (82,853) (72,932) Total incurred loss and loss expense 2,111,778 1,813,984 1,635,823 Paid loss and loss expense for claims occurring in the: Current year 768,583 676,331 642,586 Prior years 958,149 841,477 807,248 Total paid loss and loss expense 1,726,732 1,517,808 1,449,834 Net reserves for loss and loss expense, at end of year 4,387,308 4,002,262 3,706,086 Add: Reinsurance recoverable on unpaid loss and loss expense, at end of year 757,513 578,641 554,269 Gross reserves for loss and loss expense at end of year $ 5,144,821 4,580,903 4,260,355 1 2020 includes an adjustment of $2.9 million related to our adoption of ASU 2016-13, Financial Instruments - Credit Losses. Our net loss and loss expense reserves increased by $385.0 million in 2022, $296.2 million in 2021, and $183.1 million in 2020. The loss and loss expense reserves are net of anticipated recoveries for salvage and subrogation claims, which amounted to $91.3 million for 2022, $87.0 million for 2021, and $80.9 million for 2020. The increase in net loss and loss expense reserves in 2022 was primarily driven by increases in exposure due to premium growth. This increase in our net loss and loss expense reserves was partially offset by favorable prior year loss reserve development. In 2022, we experienced overall net favorable prior year loss reserve development of $78.9 million, compared to $82.9 million in 2021 and $72.9 million in 2020. The following table summarizes the prior year reserve development by line of business: (Favorable)/Unfavorable Prior Year Development ($ in millions) 2022 2021 2020 General Liability $ (5.0) (29.0) (35.0) Commercial Automobile 22.5 13.3 7.1 Workers Compensation (70.0) (58.0) (60.0) Businessowners' Policies (7.3) (0.4) 3.9 Commercial Property (1.6) (2.6) 9.2 Bonds (10.0) — — Homeowners (0.6) 1.8 7.7 Personal Automobile 0.5 (0.2) (1.8) E&S Casualty Lines (5.0) (7.0) — E&S Property Lines (2.5) (0.8) (4.0) Other 0.1 — — Total $ (78.9) (82.9) (72.9) The Insurance Subsidiaries had $78.9 million of favorable prior year reserve development during 2022, which included $86.0 million of net favorable casualty reserve development and $7.1 million of unfavorable property reserve development. The net favorable casualty reserve development was largely driven by the workers compensation line of business, which was impacted by continued favorable medical trends in accident years 2020 and prior, and favorable inception-to-date claim frequencies in accident year 2020. Partially offsetting this net favorable reserve development was $15.0 million of unfavorable casualty reserve development in the commercial auto line of business ($22.5 million net of property reserve development), primarily driven by increased loss severities in accident year 2021. The Insurance Subsidiaries had $82.9 million of favorable prior year reserve development during 2021, which included $81.0 million of net favorable casualty reserve development and $1.9 million of favorable property reserve development. The net favorable casualty reserve development was largely driven by the workers compensation and general liability lines of business. Workers compensation was impacted by continued favorable medical trends in accident years 2019 and prior, and general liability development was attributable to lower loss severities in accident years 2018 and prior. In addition, our E&S casualty lines experienced favorable reserve development of $7.0 million in 2021. Partially offsetting this net favorable reserve development was $15.0 million of unfavorable casualty reserve development in the commercial auto line of business ($13.3 million net of property reserve development), driven by unfavorable reserve development on loss severities in accident years 2016 through 2019. The Insurance Subsidiaries had $72.9 million of favorable prior year reserve development during 2020, which included $85.0 million of net favorable casualty reserve development and $12.1 million of unfavorable property reserve development. The net favorable casualty reserve development was largely driven by the workers compensation and general liability lines of business. Workers compensation was impacted by continued favorable medical trends in accident years 2018 and prior, and general liability development was attributable to lower loss severities in accident years 2017 and prior. Partially offsetting this net favorable reserve development was $10.0 million of unfavorable casualty reserve development in the commercial auto line of business ($7.1 million net of property reserve development), driven by unfavorable reserve development on loss severities in accident years 2016 through 2019, and higher than expected frequencies in accident year 2019. (b) We have exposure to abuse or molestation claims within our general liability line of business, primarily through insurance policies that we issue to schools, religious institutions, day-care facilities, and other social services. We also have exposure to abuse or molestation claims from recently enacted state laws that extend the statute of limitations or permit windows to be opened for abuse or molestation claims and lawsuits that were previously barred by statutes of limitations. The emergence of these claims is highly unpredictable and may be reported over an extended period of time. In addition to legislative changes that increase our exposure, there are significant uncertainties in estimating our exposure to abuse or molestation claims (for both case and IBNR reserves) resulting from (i) lack of relevant historical data, (ii) the delayed and inconsistent reporting patterns associated with these claims, (iii) the obligation of an insurer to defend a claim, (iv) the extent to which a party can prove the existence of coverage, and (v) uncertainty as to the number and identity of claimants. It is possible, as a result, that we may receive claims decades after the allegations occurred from coverages provided by us or our predecessor companies, that will require complex claims coverage determinations, potential litigation, and the need to collect from reinsurers under older reinsurance agreements. (c) Reserves established for liability insurance include exposure to asbestos and environmental claims. These claims have arisen primarily from insured exposures in municipal government, small non-manufacturing commercial risk, and homeowners policies. The emergence of these claims is highly unpredictable and may be reported over an extended period of time. There are significant uncertainties in estimating our exposure to asbestos and environmental claims (for both case and IBNR reserves) resulting from (i) lack of relevant historical data, (ii) the delayed and inconsistent reporting patterns associated with these claims, and (iii) uncertainty as to the number and identity of claimants and complex legal and coverage issues. Legal issues that arise in asbestos and environmental cases include federal or state venue, choice of law, causation, admissibility of evidence, allocation of damages and contribution among joint defendants, successor and predecessor liability, and whether direct action against insurers can be maintained. Coverage issues that arise in asbestos and environmental cases include the interpretation and application of policy exclusions, the determination and calculation of policy limits, the determination of the ultimate amount of a loss, the extent to which a loss is covered by a policy, if at all, the obligation of an insurer to defend a claim, and the extent to which a party can prove the existence of coverage. Courts have reached different and sometimes inconsistent conclusions on these legal and coverage issues. Traditional accident year loss development methods cannot be applied because past loss history is not necessarily indicative of future behavior. Instead, we review the experience by calendar year and rely on alternative metrics, such as paid and incurred survival ratios. As a result, reserves for asbestos and environmental require a high degree of judgment. The following table details our loss and loss expense reserves for various asbestos and environmental claims showing gross and net of reinsurance: 2022 ($ in millions) Gross Net Asbestos $ 5.9 4.7 Landfill sites 11.8 7.5 Underground storage tanks 10.1 8.1 Total $ 27.8 20.3 Historically, our asbestos and environmental claims have been significantly lower in volume than many other Standard Commercial Lines carriers since, prior to the introduction of the absolute pollution exclusion endorsement in the mid-1980’s, we primarily wrote Standard Personal Lines, and therefore, our exposure to asbestos and environmental claims has been limited. The following table provides a roll forward of asbestos and environmental incurred loss and loss expense and related reserves thereon showing gross and net of reinsurance: 2022 2021 2020 ($ in thousands) Gross Net Gross Net Gross Net Asbestos Reserves for loss and loss expense at beginning of year $ 6,115 4,884 6,254 5,023 6,288 5,057 Incurred loss and loss expense 8 8 51 51 320 320 Less: loss and loss expense paid (232) (232) (190) (190) (354) (354) Reserves for loss and loss expense at the end of year $ 5,891 4,660 6,115 4,884 6,254 5,023 Environmental Reserves for loss and loss expense at beginning of year $ 21,658 16,191 22,276 16,398 22,413 16,532 Incurred loss and loss expense 696 (213) (613) (14) (447) (474) Less: loss and loss expense paid (477) (309) (5) (193) 310 340 Reserves for loss and loss expense at the end of year $ 21,877 15,669 21,658 16,191 22,276 16,398 Total Asbestos and Environmental Claims Reserves for loss and loss expense at beginning of year $ 27,773 21,075 28,530 21,421 28,701 21,589 Incurred loss and loss expense 704 (205) (562) 37 (127) (154) Less: loss and loss expense paid (709) (541) (195) (383) (44) (14) Reserves for loss and loss expense at the end of year $ 27,768 20,329 27,773 21,075 28,530 21,421 (d) The following is information about incurred and paid claims development as of December 31, 2022, net of reinsurance, as well as the associated IBNR liabilities. During the experience period we implemented a series of underwriting and claims-related initiatives, including claims management changes. These initiatives focused on general underwriting and claims improvements occurring naturally through our portfolio and may impact some relationships in the tables below. As a result, several historical patterns have changed and may no longer be appropriate to use as the sole basis for projections. The tables below also include information regarding reported claims. Claims are counted at the occurrence, line of business, and policy level. For example, if a single occurrence (e.g. an automobile accident) leads to a claim under an automobile and an associated umbrella policy, they are each counted separately. Conversely, multiple claimants under the same occurrence/line/policy would contribute only a single count. A claim is considered reported when a reserve is established or a payment is made. Therefore, claims closed without payment are included in the count as long as there was an associated case reserve at some point in its life cycle. The cumulative number of reported claims for each accident year in the tables below are updated with information available as of December 31, 2022. Therefore, the claim counts presented for the more recent accident years may not be representative of the ultimate claim counts, as they are for the more mature accident years presented. All Lines (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 1,044,142 1,062,045 1,047,230 1,021,007 1,002,316 987,763 984,858 973,739 957,958 951,813 33,631 91,959 2014 1,107,513 1,133,798 1,146,990 1,124,014 1,104,218 1,100,208 1,089,529 1,094,367 1,090,345 42,087 95,835 2015 1,114,081 1,130,513 1,144,830 1,138,313 1,119,441 1,108,860 1,103,592 1,103,543 45,698 95,173 2016 1,188,608 1,203,634 1,227,142 1,199,734 1,180,829 1,171,273 1,167,539 67,934 95,944 2017 1,270,110 1,313,372 1,313,585 1,288,526 1,268,941 1,273,039 84,415 99,877 2018 1,413,800 1,461,603 1,457,415 1,441,303 1,425,540 153,214 107,095 2019 1,483,945 1,523,041 1,526,566 1,529,859 272,639 104,096 2020 1,591,972 1,587,607 1,550,195 395,519 94,752 2021 1,784,661 1,781,054 636,984 97,914 2022 2,073,343 1,089,571 94,382 Total 13,946,270 All Lines (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 335,956 518,872 644,475 748,758 833,823 872,331 891,841 904,825 911,657 916,769 2014 405,898 614,075 736,154 855,959 936,425 981,868 1,002,157 1,020,961 1,032,400 2015 376,641 581,203 725,385 845,868 929,222 967,857 1,000,509 1,018,023 2016 387,272 617,958 764,331 892,390 983,852 1,025,264 1,061,952 2017 433,440 678,453 829,134 954,792 1,050,258 1,116,336 2018 511,271 779,466 942,893 1,083,556 1,187,744 2019 510,091 781,462 949,996 1,109,628 2020 572,302 831,976 988,463 2021 609,889 934,965 2022 699,789 Total 10,066,069 All outstanding liabilities before 2013, net of reinsurance 379,073 Liabilities for loss and loss expenses, net of reinsurance 4,259,274 General Liability (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 250,609 251,421 239,776 225,709 210,785 203,831 202,697 195,697 192,782 189,594 12,561 10,462 2014 244,312 249,946 257,132 239,333 234,082 237,125 229,679 230,247 228,933 18,901 10,704 2015 254,720 245,710 246,990 233,249 219,204 214,176 211,768 210,137 19,932 10,565 2016 277,214 272,048 277,986 263,245 252,733 246,643 243,669 30,556 10,825 2017 293,747 293,128 301,384 289,883 278,607 283,379 46,761 11,324 2018 317,934 336,326 345,224 332,013 324,567 92,627 11,802 2019 347,150 356,363 358,301 366,184 154,311 11,575 2020 361,554 360,302 352,834 201,089 9,645 2021 422,748 414,279 287,278 10,136 2022 482,590 409,505 8,988 Total 3,096,166 General Liability (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 12,789 35,113 72,127 104,587 139,114 153,628 163,764 169,847 172,983 174,987 2014 14,901 46,825 79,972 121,969 154,957 179,192 187,352 198,772 204,212 2015 14,665 39,978 78,668 116,804 144,216 157,071 173,697 179,117 2016 15,684 46,549 89,431 133,757 164,136 181,770 199,032 2017 17,366 49,470 92,355 131,980 167,002 201,948 2018 19,531 60,784 108,421 155,538 197,286 2019 18,097 58,284 100,206 160,680 2020 21,858 58,699 100,356 2021 28,069 71,664 2022 31,502 Total 1,520,784 All outstanding liabilities before 2013, net of reinsurance 113,263 Liabilities for loss and loss expenses, net of reinsurance 1,688,645 Workers Compensation (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 199,794 194,318 187,658 173,160 166,662 162,787 159,767 157,645 153,436 149,975 16,818 11,385 2014 199,346 187,065 182,579 172,515 164,420 160,646 159,604 161,021 158,479 17,598 10,498 2015 193,729 194,639 183,604 179,642 176,242 172,572 170,577 169,008 18,790 10,554 2016 196,774 184,946 176,248 166,009 156,540 155,210 151,961 21,205 10,586 2017 195,202 184,306 175,853 162,672 154,159 151,221 19,961 10,813 2018 193,894 193,818 181,151 173,428 167,974 25,963 11,133 2019 188,625 188,596 174,912 164,940 32,088 10,324 2020 168,643 168,594 159,229 44,323 7,534 2021 185,198 185,151 74,474 8,547 2022 207,206 116,968 8,517 Total 1,665,144 Workers Compensation (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 36,829 74,568 96,376 109,739 118,669 124,130 126,822 129,224 130,467 131,390 2014 35,924 78,944 100,876 113,626 119,392 124,077 127,858 130,726 132,809 2015 33,857 77,320 98,195 112,601 120,097 124,046 129,019 132,235 2016 34,525 78,531 98,037 109,166 115,159 119,800 122,186 2017 40,375 82,216 100,645 110,645 116,426 120,468 2018 41,122 84,780 105,903 119,904 126,206 2019 37,826 77,878 100,812 112,649 2020 29,559 68,277 87,211 2021 32,918 76,015 2022 45,814 Total 1,086,983 All outstanding liabilities before 2013, net of reinsurance 230,858 Liabilities for loss and loss expenses, net of reinsurance 809,019 Commercial Automobile (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 188,289 205,282 209,197 207,994 210,410 207,975 209,602 208,040 207,554 207,564 535 26,221 2014 200,534 212,725 216,824 219,925 218,172 217,334 216,461 214,992 214,816 516 28,263 2015 220,994 240,958 253,074 259,495 260,565 261,386 262,054 262,766 1,627 30,085 2016 255,187 274,367 285,302 285,304 290,359 291,674 294,297 2,635 32,041 2017 301,274 329,389 324,291 322,197 326,461 325,654 4,664 33,345 2018 347,908 352,487 345,547 350,310 348,202 11,375 36,002 2019 385,212 398,346 404,854 407,051 32,019 36,375 2020 381,654 381,163 375,636 70,872 30,343 2021 483,831 512,673 155,984 36,843 2022 572,421 278,004 36,909 Total 3,521,080 Commercial Automobile (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 76,469 109,893 140,015 169,850 189,626 200,750 202,622 205,064 206,162 206,641 2014 80,810 117,169 148,884 180,701 202,821 209,655 212,481 213,689 213,847 2015 91,347 132,260 175,866 211,515 238,142 249,905 255,600 257,668 2016 106,022 155,720 200,701 233,939 264,858 277,242 284,870 2017 117,287 178,823 220,422 262,349 296,600 309,810 2018 134,867 193,788 243,713 291,725 319,819 2019 149,538 221,590 283,410 331,152 2020 139,016 198,034 254,365 2021 187,200 283,411 2022 216,180 Total 2,677,763 All outstanding liabilities before 2013, net of reinsurance 4,650 Liabilities for loss and loss expenses, net of reinsurance 847,967 Businessowners' Policies (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 49,617 42,618 41,005 40,624 41,369 39,709 39,699 39,358 38,930 38,984 169 3,484 2014 55,962 60,949 62,548 59,806 58,517 58,093 57,302 57,483 57,355 96 4,067 2015 52,871 53,768 57,245 55,925 54,454 52,325 52,200 52,514 608 3,968 2016 52,335 53,792 54,993 53,835 53,367 53,147 53,201 828 3,854 2017 46,624 48,698 51,524 48,067 43,606 42,374 879 3,895 2018 55,024 57,202 62,427 60,393 56,625 3,125 4,262 2019 53,531 59,466 64,667 65,762 8,181 3,639 2020 71,836 73,680 73,077 7,630 5,421 2021 66,312 63,648 10,539 3,454 2022 86,194 33,995 3,074 Total 589,734 Businessowners' Policies (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 17,412 26,592 30,845 34,760 37,993 38,464 39,085 39,212 39,440 39,445 2014 28,914 40,584 44,911 49,460 52,940 55,458 55,708 55,729 56,861 2015 24,189 36,014 42,710 46,571 49,073 49,839 50,005 51,120 2016 24,655 36,848 39,973 45,308 48,786 50,536 52,070 2017 21,865 31,337 36,950 40,359 39,940 40,845 2018 29,995 39,791 44,316 48,144 51,239 2019 27,718 41,587 46,113 52,887 2020 43,376 57,210 60,596 2021 34,412 47,436 2022 36,421 Total 488,920 All outstanding liabilities before 2013, net of reinsurance 9,657 Liabilities for loss and loss expenses, net of reinsurance 110,471 Commercial Property (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 88,101 90,639 90,103 90,005 90,436 90,278 90,218 90,486 90,461 90,799 4 5,716 2014 141,192 136,249 136,820 138,751 138,155 136,212 136,237 136,151 136,112 5 6,517 2015 110,270 109,513 111,750 111,566 112,496 112,582 112,937 112,915 9 6,407 2016 121,927 126,185 125,937 124,487 123,567 123,005 123,126 14 6,743 2017 138,773 149,106 149,044 153,664 154,119 154,942 20 6,906 2018 183,177 190,834 192,558 194,016 196,413 47 8,293 2019 173,826 177,075 179,574 180,605 230 7,315 2020 232,060 225,278 226,107 2,023 10,147 2021 246,319 239,822 4,672 7,942 2022 297,318 56,716 7,224 Total 1,758,159 Commercial Property (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 60,244 87,874 90,446 90,350 90,840 90,696 90,646 90,917 90,891 91,206 2014 101,131 132,909 136,634 137,883 137,418 136,008 135,928 136,141 136,107 2015 79,048 106,182 109,829 110,994 110,969 112,117 112,410 112,391 2016 83,966 118,789 122,930 123,828 123,601 122,909 123,265 2017 99,047 142,338 148,589 152,018 153,750 154,689 2018 135,416 184,813 192,698 193,487 196,376 2019 130,891 172,768 177,825 179,538 2020 164,613 215,107 220,953 2021 161,757 227,259 2022 186,677 Total 1,628,461 All outstanding liabilities before 2013, net of reinsurance 579 Liabilities for loss and loss expenses, net of reinsurance 130,277 Personal Automobile (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 108,417 109,620 106,225 106,703 107,759 107,680 107,916 107,803 107,754 107,758 57 22,376 2014 102,250 109,325 106,757 107,452 106,821 107,104 107,106 107,566 107,543 47 22,509 2015 96,387 99,698 100,214 99,570 98,718 98,588 98,596 98,669 117 20,865 2016 92,727 98,032 100,202 101,140 99,544 99,858 100,395 409 19,827 2017 101,880 105,139 103,653 103,260 103,557 105,079 710 20,748 2018 111,594 113,569 112,030 112,418 113,647 2,098 22,684 2019 114,043 115,688 115,993 118,669 4,163 22,860 2020 95,625 94,532 90,179 6,584 17,533 2021 108,244 102,777 10,411 19,672 2022 121,030 26,632 20,345 Total 1,065,746 Personal Automobile (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 61,384 80,861 92,637 100,528 105,131 106,679 106,876 107,419 107,423 107,417 2014 62,519 83,739 92,589 99,173 104,055 105,709 106,478 107,108 107,325 2015 58,725 76,470 87,163 92,102 95,997 97,275 97,761 97,920 2016 57,961 76,823 86,752 94,372 98,080 98,977 99,656 2017 62,854 82,730 91,479 97,628 100,521 103,556 2018 69,721 89,628 99,982 107,026 109,644 2019 69,699 92,162 102,930 109,844 2020 53,407 68,691 76,710 2021 65,325 84,743 2022 75,994 Total 972,809 All outstanding liabilities before 2013, net of reinsurance 7,045 Liabilities for loss and loss expenses, net of reinsurance 99,982 Homeowners (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 73,670 72,528 71,494 72,145 71,714 72,148 72,318 71,948 71,955 71,960 67 7,753 2014 80,111 82,461 83,637 83,844 83,539 83,824 83,525 83,830 83,819 60 8,776 2015 76,637 76,400 76,559 74,723 74,978 74,673 74,682 74,237 20 7,753 2016 60,105 60,931 62,391 61,723 61,735 60,855 60,841 438 6,896 2017 59,167 67,978 70,365 70,064 68,938 68,902 504 7,389 2018 62,961 68,526 69,832 68,931 68,416 608 7,608 2019 64,306 72,772 73,816 73,070 1,412 7,010 2020 109,033 112,523 113,804 3,611 9,824 2021 82,425 83,295 3,657 6,884 2022 93,826 17,362 5,819 Total 792,170 Homeowners (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 50,664 65,528 67,838 69,775 71,776 72,197 72,433 72,446 72,447 72,415 2014 61,561 76,007 79,751 81,664 82,583 82,836 82,831 83,321 83,782 2015 52,589 70,078 72,202 72,927 74,079 74,052 74,096 74,108 2016 42,252 57,333 59,546 60,082 61,187 60,449 60,474 2017 45,466 63,290 67,193 67,767 68,078 68,282 2018 49,430 64,137 65,348 66,634 67,739 2019 49,680 67,631 69,911 70,880 2020 83,838 105,690 109,145 2021 59,054 77,018 2022 68,832 Total 752,675 All outstanding liabilities before 2013, net of reinsurance 6,102 Liabilities for loss and loss expenses, net of reinsurance 45,597 E&S Casualty Lines (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 55,468 $ 60,309 67,099 69,112 67,647 68,972 68,451 68,029 60,349 60,511 3,504 2,311 2014 55,316 63,505 69,929 71,719 71,206 71,153 70,846 74,270 74,538 4,918 2,141 2015 75,498 76,432 82,404 90,488 90,355 90,126 87,662 90,263 4,646 2,887 2016 94,451 96,416 104,655 105,120 104,730 102,476 101,873 12,138 2,998 2017 91,438 95,783 99,866 99,395 99,960 102,045 11,390 2,848 2018 98,324 103,004 103,184 104,983 105,756 17,093 2,816 2019 117,087 118,298 117,736 117,113 39,429 2,683 2020 103,872 103,137 95,832 49,633 1,788 2021 128,099 125,436 89,909 1,751 2022 146,999 132,276 1,285 Total 1,020,366 E&S Casualty Lines (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 2,715 $ 9,470 21,980 35,200 46,108 51,142 54,974 55,988 57,152 58,584 2014 2,353 12,234 25,571 43,877 53,780 60,092 64,698 66,661 68,648 2015 3,036 13,057 29,389 50,712 64,529 71,421 75,844 81,396 2016 3,720 16,195 33,950 56,581 69,448 75,004 81,932 2017 5,057 14,672 34,179 53,238 68,266 77,090 2018 5,509 21,337 39,174 57,962 73,605 2019 4,422 17,812 35,844 57,701 2020 3,695 13,064 27,861 2021 4,326 15,835 2022 4,198 Total 546,850 All outstanding liabilities before 2013, net of reinsurance 5,991 Liabilities for loss and loss expenses, net of reinsurance 479,507 (e) The reconciliation of the net incurred and paid claims development tables to the liability for loss and loss expenses in the consolidated statement of financial position is as follows: (in thousands) December 31, 2022 Net outstanding liabilities: Standard Commercial Lines General liability $ 1,688,645 Workers compensation 809,019 Commercial automobile 847,967 Businessowners' policies 110,471 Commercial property 130,277 Other Standard Commercial Lines 17,995 Total Standard Commercial Lines net outstanding liabilities 3,604,374 Standard Personal Lines Personal automobile 99,982 Homeowners 45,597 Other Standard Personal Lines 11,739 Total Standard Personal Lines net outstanding liabilities 157,318 E&S Lines Casualty lines 479,507 Property lines 18,075 Total E&S Lines net outstanding liabilities 497,582 Total liabilities for unpaid loss and loss expenses, net of reinsurance 4,259,274 Reinsurance recoverable on unpaid claims: Standard Commercial Lines General liability 246,736 Workers compensation 199,057 Commercial automobile 14,271 Businessowners' policies 19,277 Commercial property 81,970 Other Standard Commercial Lines 4,443 Total Standard Commercial Lines reinsurance recoverable on unpaid loss 565,754 Standard Personal Lines Personal automobile 36,529 Homeowners 7,124 Other Standard Personal Lines 132,525 Total Standard Personal Lines reinsurance recoverable on unpaid loss 176,178 E&S Lines Casualty lines 11,397 Property lines 4,184 Total E&S Lines reinsurance recoverable on unpaid loss 15,581 Total reinsurance recoverable on unpaid loss 757,513 Unallocated loss expenses 128,034 Total gross liability for unpaid loss and loss expenses $ 5,144,821 (f) The table below reflects the historical average annual percentage payout of incurred claims by age. For example, the general liability line of business averages payout of 6.3% of its ultimate losses in the first year, 11.8% in the second year, and so forth. The following is supplementary information about average historical claims duration as of December 31, 2022: Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 General liability 6.3% 11.8 15.5 17.4 15.1 9.9 7.2 4.1 3.0 2.1 Workers compensation 22.3 25.9 13.9 8.9 4.7 3.0 1.9 1.8 3.1 2.2 Commercial automobile 36.8 16.9 14.6 13.3 9.9 4.2 1.9 1.1 0.7 0.1 Businessowners’ policies 49.0 21.8 8.3 8.1 6.1 3.1 1.3 0.6 0.3 0.2 Commercial property 68.7 26.4 3.2 1.0 0.4 — — — — — Personal automobile 59.8 18.1 8.8 6.5 3.7 1.7 0.5 0.4 0.2 0.1 Homeowners 70.8 21.8 3.5 1.6 1.7 0.2 0.2 0.1 0.1 — E&S Lines - casualty 3.9 11.5 18.0 21.7 15.8 7.9 6.8 5.2 2.6 3.5

Indebtedness

Indebtedness	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Indebtedness	Indebtedness The table below provides a summary of our outstanding debt at December 31, 2022 and 2021: Outstanding Debt 2022 Carry Value Issuance Date Maturity Date Interest Rate Original Amount Unamortized Issuance Costs Debt Discount December 31, 2022 December 31, 2021 ($ in thousands) Description Long term (1) Senior Notes 3/1/2019 3/1/2049 5.375 % 300,000 $ 2,543 5,576 291,881 291,597 (2) FHLBI 12/16/2016 12/16/2026 3.03 % 60,000 — — 60,000 60,000 (3) Senior Notes 11/3/2005 11/1/2035 6.70 % 100,000 256 458 99,286 99,233 (4) Senior Notes 11/16/2004 11/15/2034 7.25 % 50,000 130 79 49,791 49,770 Finance lease obligations 3,718 5,450 Total long-term debt $ 2,929 6,113 504,676 506,050 On November 7, 2022, the Parent entered into a Credit Agreement (the “Line of Credit”) among the Parent, the lenders named therein (the “Lenders”), and Wells Fargo Bank, National Association, as Administrative Agent. Under the Line of Credit, the Lenders have agreed to provide the Parent with a $50 million revolving credit facility, which can be increased to $125 million with the consent of the Lenders. The Line of Credit will mature on November 7, 2025, and has a variable interest rate based on the Parent’s debt ratings. The Parent, as borrower, was a party to a Credit Agreement dated December 20, 2019, for a $50 million revolving credit facility, which could be increased to $125 million with the consent of the lenders, with the lenders named therein, and Bank of Montreal, Chicago Branch, as Administrative Agent (“Bank of Montreal”), which was scheduled to mature on December 20, 2022 (the “Prior Credit Agreement”). In anticipation of entering into the Line of Credit, the Parent exercised termination rights under the Prior Credit Agreement by sending a termination letter to Bank of Montreal on November 3, 2022. The effective date of the termination of the Prior Credit Agreement was November 7, 2022. Our Line of Credit contains representations, warranties, and covenants that are customary for credit facilities of this type, including, without limitation, financial covenants under which we are obligated to maintain a minimum consolidated net worth, a maximum ratio of consolidated debt to total capitalization, and covenants limiting our ability to: (i) merge or liquidate; (ii) incur debt or liens; (iii) dispose of assets; (iv) make investments and acquisitions; and (v) engage in transactions with affiliates. The table below outlines information regarding certain covenants in the Line of Credit: Required as of Actual as of December 31, 2022 December 31, 2022 Consolidated net worth 1 Not less than $1.9 billion $3 billion Debt to total capitalization ratio 1 Not to exceed 35% 14.3% 1 Calculated in accordance with the Line of Credit. In addition to the above requirements, the Line of Credit contains a cross-default provision that provides that the Line of Credit will be in default if we fail to comply with any condition, covenant, or agreement (including payment of principal and interest when due on any debt with an aggregate principal amount of at least $30 million), which causes or permits the acceleration of principal. Additionally, the Line of Credit limits borrowings from the FHLBI and the FHLBNY to 10% of the respective member company's admitted assets for the previous year. Short-term Debt Activity (1) On April 1, 2022, SICA borrowed short-term funds of $35 million from the FHLBNY at an interest rate of 0.7%. This borrowing was refinanced and extended through June 27, 2022, at an interest rate of 1.10%. This borrowing was repaid on June 27, 2022. (2) On October 3, 2022, SICA borrowed short-term funds of $25 million from the FHLBNY at an interest rate of 3.21%. This borrowing was repaid on November 3, 2022. Long-term Debt Activity (1) In the first quarter of 2019, we issued $300 million of 5.375% Senior Notes due 2049 at a discount of $5.9 million which, when coupled with debt issuance costs of approximately $3.3 million, resulted in net proceeds from the offering of $290.8 million. The 5.375% Senior Notes pay interest on March 1 and September 1 of each year. The first payment was made on September 1, 2019. A portion of the proceeds from this debt issuance was used to fully redeem the $185 million aggregate principal amount of our 5.875% Senior Notes due 2043, with the remaining $106 million being used for general corporate purposes. The 5.875% Senior Notes had pre-tax debt retirement costs of $4.2 million, or $3.3 million after tax, which was recorded in Interest expense on the Consolidated Statements of Income in the first quarter of 2019. There are no financial debt covenants to which we are required to comply in regards to the 5.375% Senior Notes. (2) In the first quarter of 2009, Selective Insurance Company of South Carolina ("SICSC") and Selective Insurance Company of the Southeast ("SICSE"), which are collectively referred to as the "Indiana Subsidiaries" as they are domiciled in Indiana, joined, and invested in, the FHLBI, which provides them with access to additional liquidity. The Indiana Subsidiaries’ aggregate investment in the FHLBI was $5.2 million at December 31, 2022 and $5.7 million at December 31, 2021. Our investment provides us the ability to borrow approximately 20 times the total amount of the FHLBI common stock purchased with additional collateral, at comparatively low borrowing rates. The proceeds from the FHLBI borrowing on December 16, 2016 of $60 million were used to repay a $45 million borrowing from the FHLBI that was outstanding at the time, with the remaining $15 million used for general corporate purposes. All borrowings from the FHLBI require security. There are no financial debt covenants to which we are required to comply with in regards to these borrowings. For information on investments that are pledged as collateral for these borrowings, see Note 5. "Investments" above. (3) In November 2005, we issued $100 million of 6.70% Senior Notes due 2035. These notes were issued at a discount of $0.7 million resulting in an effective yield of 6.754%. Net proceeds of approximately $50 million were used to fund an irrevocable trust that subsequently funded certain payment obligations in respect of our outstanding debt. The remainder of the proceeds was used for general corporate purposes. The agreements covering these notes contain a standard default cross-acceleration provision that provides the 6.70% Senior Notes will enter a state of default upon the failure to pay principal when due or upon any event or condition that results in an acceleration of principal of any other debt instrument in excess of $10 million that we have outstanding concurrently with the 6.70% Senior Notes. There are no financial debt covenants to which we are required to comply in regards to these notes. (4) In November 2004, we issued $50 million of 7.25% Senior Notes due 2034. These notes were issued at a discount of $0.1 million, resulting in an effective yield of 7.27%. We contributed $25 million of the bond proceeds to the Insurance Subsidiaries as capital. The remainder of the proceeds was used for general corporate purposes. The agreements covering these notes contain a standard default cross-acceleration provision that provides the 7.25% Senior Notes will enter a state of default upon the failure to pay principal when due or upon any event or condition that results in an acceleration of principal of any other debt instrument in excess of $10 million that we have outstanding concurrently with the 7.25% Senior Notes. There are no financial debt covenants to which we are required to comply in regards to these notes.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2022
Segment Reporting [Abstract]
Segment Information	Segment Information We evaluate the results of our four reportable segments as follows: • Our Standard Commercial Lines, Standard Personal Lines, and E&S Lines are evaluated on before and after-tax underwriting results (net premiums earned, incurred loss and loss expense, policyholders dividends, policy acquisition costs, and other underwriting expenses), return on equity ("ROE") contribution, and combined ratios. • Our Investments segment is primarily evaluated on after-tax net investment income and its ROE contribution. After-tax net realized and unrealized gains and losses are also included in our Investment segment results. In computing each segment's results, we do not make adjustments for interest expense or corporate expenses. No segment has a separate investment portfolio or allocated assets. Our combined insurance operations are subject to certain geographic concentrations, particularly in the Eastern region of the country. In 2022, approximately 17% of NPW were related to insurance policies written in New Jersey. We also had a goodwill balance of $7.8 million at both December 31, 2022 and 2021 on our Consolidated Balance Sheet that relates to our Standard Commercial Lines reporting unit. The following summaries present revenues (net investment income and net realized and unrealized gains and losses on investments in the case of the Investments segment) and pre-tax income for the individual segments: Revenue by Segment Years ended December 31, ($ in thousands) 2022 2021 2020 Standard Commercial Lines: Net premiums earned: General liability $ 902,428 807,158 694,019 Commercial automobile 812,306 724,398 615,181 Commercial property 495,647 436,412 388,120 Workers compensation 335,955 306,428 278,062 Businessowners’ policies 124,474 110,622 110,210 Bonds 43,354 35,762 36,742 Other 25,655 23,105 20,850 Miscellaneous income 9,519 16,056 15,512 Total Standard Commercial Lines revenue 2,749,338 2,459,941 2,158,696 Standard Personal Lines: Net premiums earned: Personal automobile 162,899 163,007 165,020 Homeowners 128,222 122,526 125,405 Other 8,284 8,026 8,715 Miscellaneous income 1,816 1,667 2,058 Total Standard Personal Lines revenue 301,221 295,226 301,198 E&S Lines: Net premiums earned: Casualty lines 233,086 197,779 174,408 Property lines 101,070 82,030 65,082 Total E&S Lines revenue 334,156 279,809 239,490 Investments: Net investment income 288,155 326,589 227,107 Net realized and unrealized investment (losses) gains (114,808) 17,599 (4,217) Total Investments revenues 173,347 344,188 222,890 Total revenues $ 3,558,062 3,379,164 2,922,274 Income Before and After Federal Income Tax Years ended December 31, ($ in thousands) 2022 2021 2020 Standard Commercial Lines: Underwriting income, before federal income tax $ 143,696 198,596 151,731 Underwriting income, after federal income tax 113,520 156,891 119,867 Combined ratio 94.8 % 91.9 % 92.9 % ROE contribution 4.6 % 5.9 5.1 Standard Personal Lines: Underwriting income (loss), before federal income tax (7,193) 3,966 (15,508) Underwriting income (loss), after federal income tax (5,682) 3,133 (12,251) Combined ratio 102.4 % 98.6 % 105.2 % ROE contribution (0.2) % 0.1 (0.5) E&S Lines: Underwriting income, before federal income tax 30,299 16,030 126 Underwriting income, after federal income tax 23,936 12,664 100 Combined ratio 90.9 % 94.3 % 99.9 % ROE contribution 1.0 % 0.5 — Investments: Net investment income earned $ 288,155 326,589 227,107 Net realized and unrealized investment (losses) gains (114,808) 17,599 (4,217) Total investment segment income, before federal income tax 173,347 344,188 222,890 Tax on investment segment income 31,846 67,284 41,609 Total investment segment income, after federal income tax $ 141,501 276,904 181,281 ROE contribution of after-tax net investment income earned 9.4 % 9.9 7.8 Reconciliation of Segment Results to Income Before Federal Income Tax Years ended December 31, ($ in thousands) 2022 2021 2020 Underwriting income (loss) Standard Commercial Lines $ 143,696 198,596 151,731 Standard Personal Lines (7,193) 3,966 (15,508) E&S Lines 30,299 16,030 126 Investment income 173,347 344,188 222,890 Total all segments 340,149 562,780 359,239 Interest expense (28,847) (29,165) (30,839) Corporate expenses (31,116) (28,305) (25,412) Income, before federal income tax $ 280,186 505,310 302,988 Preferred stock dividends (9,200) (9,353) — Income available to common stockholders, before federal income tax $ 270,986 $ 495,957 $ 302,988

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Earnings Per Share	Earnings per Share The following table presents the calculations of earnings per common share ("EPS") on a basic and diluted basis: ($ in thousands, except per share amounts) 2022 2021 2020 Net income available to common stockholders: $ 215,686 394,484 246,355 Weighted average common shares outstanding: Weighted average common shares outstanding - basic 60,407 60,183 59,862 Effect of dilutive securities - stock compensation plans 468 484 431 Weighted average common shares outstanding - diluted 60,875 60,667 60,293 EPS: Basic $ 3.57 6.55 4.12 Diluted 3.54 6.50 4.09

Federal Income Taxes

Federal Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal Income Taxes	Federal Income Taxes (a) A reconciliation of federal income tax on income at the corporate rate (21.0%) to the effective tax rate is as follows: ($ in thousands) 2022 2021 2020 Tax at statutory rate $ 58,839 106,115 63,627 Tax-advantaged interest (4,087) (4,514) (4,730) Dividends received deduction (469) (558) (514) Executive compensation 1,848 2,469 2,246 Stock-based compensation (893) (693) (1,846) Other 62 (1,346) (2,150) Federal income tax expense 55,300 101,473 56,633 Income before federal income tax, less preferred stock dividends 270,986 495,957 302,988 Effective tax rate 20.4 % 20.5 % 18.7 % (b) The tax effects of the significant temporary differences that gave rise to deferred tax assets and liabilities were as follows: ($ in thousands) 2022 2021 Deferred tax assets: Net loss reserve discounting $ 65,907 60,227 Net unearned premiums 76,513 68,086 Employee benefits 7,064 2,787 Long-term incentive compensation 6,384 5,904 Unrealized losses on fixed income securities 110,857 — Temporary investment write-downs 12,480 4,314 Other 9,824 2,245 Total deferred tax assets 289,029 143,563 Deferred tax liabilities: Deferred policy acquisition costs 77,411 68,652 Unrealized gains on investment securities — 48,082 Other investment-related items, net 26,713 27,044 Accelerated depreciation and amortization 12,172 13,198 Total deferred tax liabilities 116,296 156,976 Net deferred federal income tax assets (liabilities) $ 172,733 (13,413) The increase in net deferred federal income tax assets was primarily due to an increase in unrealized losses on our investment portfolio resulting from an increase in benchmark U.S. Treasury rates, and to a lesser extent the widening of credit spreads. After considering all evidence, both positive and negative, with respect to our federal tax loss carryback availability, expected levels of pre-tax financial statement income, and federal taxable income, we believe it is more likely than not that the existing deductible temporary differences will reverse during periods in which we generate net federal taxable income or have adequate federal carryback availability. As a result, we had no valuation allowance recognized for federal deferred tax assets at December 31, 2022 or 2021. We did not have unrecognized tax expense or benefit as of December 31, 2022.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Retirement Plans	Retirement Plans (a) Selective Insurance Retirement Savings Plan (“Retirement Savings Plan”) and the Selective Insurance Company of America Deferred Compensation Plan ("Deferred Compensation Plan") SICA offers a voluntary defined contribution 401(k) plan that is available to most of our employees and is a tax-qualified retirement plan subject to ERISA. In addition, SICA offers a Deferred Compensation Plan to a group of management or highly compensated employees as a method of recognizing and retaining such employees. Expenses recorded for these plans were $19.8 million in 2022, $19.2 million in 2021, and $18.6 million in 2020. (b) Retirement Income Plan SICA maintains a defined benefit pension plan, the Retirement Income Plan for Selective Insurance Company of America (the "Pension Plan"). This qualified, noncontributory plan is closed to new entrants, and existing participants ceased accruing benefits after March 31, 2016. The following tables provide details on the Pension Plan for 2022 and 2021: December 31, Pension Plan ($ in thousands) 2022 2021 Change in Benefit Obligation: Benefit obligation, beginning of year $ 407,758 425,161 Interest cost 9,944 8,593 Actuarial gains (91,653) (12,844) Benefits paid (14,104) (13,152) Benefit obligation, end of year $ 311,945 407,758 Change in Fair Value of Assets: Fair value of assets, beginning of year $ 450,305 432,716 Actual return on plan assets, net of expenses (93,227) 30,741 Benefits paid (14,104) (13,152) Fair value of assets, end of year $ 342,974 450,305 Funded status $ 31,029 42,547 Amounts Recognized in the Consolidated Balance Sheet: Net pension assets, end of year $ 31,029 42,547 Amounts Recognized in AOCI: Net actuarial loss $ 100,561 78,304 Other Information as of December 31: Accumulated benefit obligation $ 311,945 407,758 Weighted-Average Liability Assumptions as of December 31: Discount rate 5.21 % 2.98 When determining the most appropriate discount rate to be used in the valuation at December 31, 2022, we consider, among other factors, our expected payout patterns of the Pension Plan's obligations as well as our investment strategy. We ultimately select the rate that we believe best represents our estimate of the inherent interest rate at which our pension benefits can be effectively settled. The approach we utilize discounts the individual expected cash flows using the applicable spot rates derived from the yield curve over the projected cash flow period. Our discount rate increased 223 basis points, to 5.21% as of December 31, 2022, from 2.98% as of December 31, 2021, which drove the decrease in the benefit obligation for the period. Pension Plan ($ in thousands) 2022 2021 2020 Components of Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Income: Net Periodic Benefit Cost (Benefit): Interest cost $ 9,944 8,593 11,312 Expected return on plan assets (22,147) (22,976) (21,907) Amortization of unrecognized actuarial loss 1,465 2,501 2,817 Total net periodic pension cost (benefit) 1 $ (10,738) (11,882) (7,778) Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income: Net actuarial loss (gain) $ 23,722 (20,609) (2,894) Reversal of amortization of net actuarial loss (1,465) (2,501) (2,817) Total recognized in other comprehensive income $ 22,257 (23,110) (5,711) Total recognized in net periodic benefit cost and other comprehensive income $ 11,519 (34,992) (13,489) 1 The components of net periodic pension cost (benefit) are included within "Loss and loss expense incurred" and "Other insurance expenses" on the Consolidated Statements of Income. Pension Plan 2022 2021 2020 Weighted-Average Expense Assumptions for the years ended December 31: Discount rate 2.98 % 2.68 % 3.33 % Interest rate 2.48 % 2.06 % 2.95 % Expected return on plan assets 5.00 5.40 5.80 Pension Plan Assets Assets of the Pension Plan are invested to adequately support the liability associated with the Pension Plan's defined benefit obligation. Our return objective is to exceed the returns of the plan's policy benchmark, which is the return the plan would have earned if the assets were invested according to the target asset class weightings and earned index returns shown below. In 2023, we will continue to phase in adjustments to the asset allocation to steadily close the gap between the duration of the assets and the duration of the liabilities, provided certain improved funding targets are achieved. Over time, the target and actual asset allocations may change based on the funded status of the Pension Plan and market return expectations. The Pension Plan’s target ranges, as well as the actual weighted average asset allocation by strategy, at December 31 were as follows: 2022 2021 Target Percentage Actual Percentage Actual Percentage Minimum Maximum Return seeking assets 1 50 % 80 % 71 % 66 % Liability hedging assets 20 % 50 % 27 % 33 % Short-term investments - - 2 % 1 % Total 100 % 100 % 1 Includes limited partnerships. The use of derivative instruments is permitted under certain circumstances for the Pension Plan portfolio, but may not be used for unrelated speculative purposes or to create exposures that are not permitted in the Pension Plan's investment guidelines. We currently invest in a U.S. Treasury overlay derivative strategy, within the funds in our liability hedging assets, to manage the interest rate duration mismatch between the assets and liabilities of the Pension Plan to help insulate the funded status of the plan. Considering the impact of this derivative overlay, the liability hedging assets provide for an approximate 77% hedge against the projected benefit obligation. The Pension Plan had no investments in the Parent’s common stock as of December 31, 2022 or 2021. For information regarding investments in funds of our related parties, refer to Note 18. "Related Party Transactions" below. The techniques used to determine the fair value of the Pension Plan's invested assets that appear on the following page are as follows: • The investments in the equities and liability hedging funds include collective investment funds and fund of funds that utilize a market approach wherein the published prices in the active market for identical assets are used. These investments are traded at their net asset value per share. These investments are classified as Level 1 in the fair value hierarchy. • The investments in private limited partnerships are valued utilizing net asset value as a practical expedient for fair value. These investments are not classified in the fair value hierarchy. • Short-term investments are recorded at fair value. Given that these investments are listed on active exchanges, coupled with their liquid nature, these investments are classified as Level 1 in the fair value hierarchy. • The deposit administration contract is recorded at cost, which approximates fair value. Given the liquid nature of the underlying investments in overnight cash deposits and other short-term duration products, we have determined that a correlation exists between the deposit administration contract and other short-term investments, such as money market funds. As such, this investment is classified as Level 2 in the fair value hierarchy. For discussion regarding the levels within the fair value hierarchy, see Note 2. "Summary of Significant Accounting Policies." In addition, refer to Note 5. "Investments" for discussion regarding the primary private equity, venture capital, and real asset limited partnership investment strategies as these investments are part of the Pension Plan's investment portfolio. The following tables provide quantitative disclosures of the Pension Plan’s invested assets that are measured at fair value on a recurring basis: December 31, 2022 Fair Value Measurements at 12/31/22 Using ($ in thousands) Assets Measured at Fair Value At 12/31/22 Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Description Return seeking assets: Equities: Global equity $ 63,852 63,852 — — Diversified credit 58,761 58,761 — — Real assets 95,396 95,396 — — Liquid diversifiers 1 23,978 23,978 — — Total equities 241,987 241,987 — — Limited partnerships (at net asset value) 2 : Real assets 27 — — — Private equity 331 — — — Total limited partnerships 358 — — — Total return seeking assets 242,345 241,987 — — Liability hedging assets: Fixed income 35,378 35,378 — — U.S. Treasury overlay 56,255 56,255 — — Total liability hedging assets 91,633 91,633 — — Cash and short-term investments: Short-term investments 5,108 5,108 — — Deposit administration contracts 2,740 — 2,740 — Total cash and short-term investments 7,848 5,108 2,740 — Total invested assets $ 341,826 338,728 2,740 — December 31, 2021 Fair Value Measurements at 12/31/21 Using ($ in thousands) Assets Measured at Fair Value At 12/31/21 Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Description Return seeking assets: Equities: Global equity $ 144,634 144,634 — — Diversified credit 66,165 66,165 — — Real assets 89,590 89,590 — — Total equities 300,389 300,389 — — Limited partnerships (at net asset value) 2 : Real assets 47 — — — Private equity 413 — — — Total limited partnerships 460 — — — Total return seeking assets 300,849 300,389 — — Liability hedging assets: Fixed income 86,183 86,183 — — U.S. Treasury overlay 65,304 65,304 — — Total liability hedging assets 151,487 151,487 — — Cash and short-term investments: Short-term investments 1,744 1,744 — — Deposit administration contracts 2,422 — 2,422 — Total cash and short-term investments 4,166 1,744 2,422 — Total invested assets $ 456,502 453,620 2,422 — 1 Liquid diversifiers are investments that unbundle return drivers from hedge funds, providing investors access to liquid, diversifying returns. 2 In accordance with the FASB issued ASU 2015-07, Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) , certain investments that are measured at fair value using the net asset value per share (or its practical expedient) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total Pension Plan invested assets. Contributions We presently do not anticipate contributing to the Pension Plan in 2023, as we have no minimum required contribution amounts. Benefit Payments ($ in thousands) Pension Plan Benefits Expected to be Paid in Future Fiscal Years: 2023 $ 16,925 2024 17,265 2025 18,317 2026 19,391 2027 20,328 2028-2032 111,842

Share-Based Payments

Share-Based Payments	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Share-based Payment Arrangement [Text Block]	Share-Based Payments Active Plans As of December 31, 2022, the following four plans were available for the issuance of share-based payment awards: • The 2014 Omnibus Stock Plan, As Amended and Restated Effective as of May 2, 2018 (the "Stock Plan"); • The Cash Incentive Plan, As Amended and Restated as of May 1, 2014 (the "Cash Plan"); • The Employee Stock Purchase Plan, As Amended and Restated as of July 1, 2021 ("ESPP"); and • The Amended and Restated Stock Purchase Plan for Independent Insurance Agencies (2010), Amended and Restated as of November 1, 2020 (the "Agent Plan"). The following table provides information regarding the approval of these plans: Plan Approvals Stock Plan Approved effective as of May 1, 2014 by stockholders on April 23, 2014. Cash Plan Approved effective April 1, 2005 by stockholders on April 27, 2005. ESPP Approved effective July 1, 2009 by stockholders on April 29, 2009. Agent Plan Approved by stockholders on April 26, 2006. The types of awards that can be issued under each of these plans are as follows: Plan Types of Share-Based Payments Issued Stock Plan Qualified and nonqualified stock options, stock appreciation rights ("SARs"), restricted stock, restricted stock units ("RSUs"), stock grants, and other awards valued in whole or in part by reference to the Parent's common stock. The maximum exercise period for an option grant under this plan is 10 years from the date of the grant. Dividend equivalent units ("DEUs") are earned during the vesting period on RSU grants. The DEUs are reinvested in the Parent's common stock at fair value on each dividend payment date. The requisite service period for grants to employees under this plan is the lesser of: (i) the stated vested date, which is typically three years from issuance; or (ii) the date the employee becomes eligible to retire. Cash Plan Cash incentive units (“CIUs”). The initial dollar value of each CIU will be adjusted to reflect the percentage increase or decrease in the total shareholder return on the Parent's common stock over a specified performance period. In addition, for certain grants, the number of CIUs granted will be increased or decreased to reflect our performance on specified performance indicators compared to targeted peer companies. The requisite service period for grants under this plan is the lesser of: (i) the stated vested date, which is typically three years from issuance; or (ii) the date the employee becomes eligible to retire. ESPP Enables employees to purchase shares of the Parent’s common stock. The purchase price is the lower of: (i) 85% of the closing market price at the time the option is granted; or (ii) 85% of the closing price at the time the option is exercised. Shares are generally issued on June 30 and December 31 of each year. Agent Plan Quarterly offerings to purchase the Parent's common stock at a 10% discount with a one-year restricted period during which the shares purchased cannot be sold or transferred. Only our independent retail insurance agencies and wholesale general agencies, and certain eligible persons associated with the agencies, are eligible to participate in this plan. Shares authorized and available for issuance as of December 31, 2022 were as follows: Authorized Available for Issuance Awards Outstanding Stock Plan 4,750,000 2,474,585 657,311 ESPP 5,500,000 1,116,863 — Agent Plan 3,000,000 1,551,498 — Retired Plans The following plans are closed for the issuance of new awards as of December 31, 2022, although awards outstanding continue in effect according to the terms of the applicable award agreements: Plan Types of Share-Based Payments Issued Reserve Shares Awards Outstanding 1 2005 Omnibus Stock Plan ("2005 Stock Plan") Qualified and nonqualified stock options, SARs, restricted stock, RSUs, phantom stock, stock bonuses, and other awards in such amounts and with such terms and conditions as it determined, subject to the provisions of the 2005 Stock Plan. The maximum exercise period for an option grant under this plan is 10 years from the date of the grant. DEUs are earned during the vesting period on RSU grants. The DEUs are reinvested in the Parent's common stock at fair value on each dividend payment date. 1,954,922 29,522 Parent's Stock Compensation Plan for Non-employee Directors Directors could elect to receive a portion of their annual compensation in shares of the Parent's common stock. 40,940 40,940 1 Awards outstanding under the 2005 Stock Plan represent shares deferred by our non-employee directors. RSU Transactions A summary of the RSU transactions under our share-based payment plans is as follows: Number Weighted Average Unvested RSU awards at December 31, 2021 641,636 $ 63.73 Granted 2022 248,619 76.09 Vested 2022 (232,742) 63.79 Forfeited 2022 (20,451) 66.77 Unvested RSU awards at December 31, 2022 637,062 $ 68.84 As of December 31, 2022, total unrecognized compensation expense related to unvested RSU awards granted under our Stock Plan was $11.3 million. That expense is expected to be recognized over a weighted-average period of 1.7 years. The total intrinsic value of RSUs vested was $18.1 million for 2022, $17.2 million for 2021, and $20.6 million for 2020. In connection with vested RSUs, the total value of the DEUs that vested was $0.7 million in 2022, $0.6 million in 2021, and $0.7 million in 2020. CIU Transactions The liability recorded in connection with our Cash Plan was $11.1 million as of December 31, 2022, and $11.0 million as of December 31, 2021. The remaining cost associated with the CIUs is expected to be recognized over a weighted average period of 1.1 years. The CIU payments made in connection with the CIU vestings were $2.9 million in 2022, $2.2 million in 2021, and $2.3 million in 2020. ESPP and Agent Plan Transactions A summary of ESPP and Agent Plan share issuances is as follows: 2022 2021 2020 ESPP Issuances 67,986 72,239 99,141 Agent Plan Issuances 56,736 50,999 69,238 Fair Value Measurements The grant date fair value of RSUs is based on the market price of our common stock on the grant date, adjusted for the present value of our expected dividend payments. The expense recognized for share-based awards is based on the number of shares or units expected to be issued at the end of the performance period and the grant date fair value. The grant date fair value of each option award is estimated using the Black Scholes option valuation model ("Black Scholes"). The following are the significant assumptions used in applying Black Scholes: (i) the risk-free interest rate, which is the implied yield currently available on U.S. Treasury zero-coupon issues with an equal remaining term; (ii) the expected term, which is based on historical experience of similar awards; (iii) the dividend yield, which is determined by dividing the expected per share dividend during the coming year by the grant date stock price; and (iv) the expected volatility, which is based on the volatility of the Parent's stock price over a historical period comparable to the expected term. In applying Black Scholes, we use the weighted average assumptions illustrated in the following table: ESPP 2022 2021 2020 Risk-free interest rate 1.42 % 0.07 0.76 Expected term 6 months 6 months 6 months Dividend yield 1.3 % 1.4 1.6 Expected volatility 21 % 28 37 The weighted-average fair value per share of options and stock, including RSUs granted under the Parent's stock plans, during 2022, 2021, and 2020 was as follows: 2022 2021 2020 RSUs $ 76.09 64.03 62.91 ESPP: Six month option 4.43 4.69 4.82 Discount of grant date market value 12.61 10.98 8.61 Total ESPP 17.04 15.67 13.43 Agent Plan: Discount of grant date market value 8.28 7.57 5.73 The fair value of the CIU liability is remeasured at each reporting period through the settlement date of the awards, which is three years from the date of grant, based on an amount expected to be paid. A Monte Carlo simulation is performed to approximate the projected fair value of the CIUs that, in accordance with the CIU agreements established under the Cash Plan, is adjusted to reflect our performance on specified indicators compared to targeted peer companies. Expense Recognition The following table provides share-based compensation expense in 2022, 2021, and 2020: ($ in millions) 2022 2021 2020 Share-based compensation expense, pre-tax $ 23.6 22.3 19.8 Income tax benefit, including the benefit related to stock grants that vested during the year (5.6) (5.1) (5.7) Share-based compensation expense, after-tax $ 18.0 17.2 14.1

Equity

Equity	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Equity Text Block	Preferred Stock We have 5,000,000 shares of preferred stock authorized, with no par value, of which (i) 300,000 shares are designated Series A junior preferred stock, which have not been issued, and (ii) 8,000 shares were issued as Series B in 2020 as discussed below. On December 2, 2020, we issued 8.0 million depository shares, each representing a 1/1,000th interest in a share of our perpetual 4.60% Non-Cumulative Preferred Stock, Series B, without par value, with a liquidation preference of $25,000 per share (equivalent to $25.00 per depository share) (“Preferred Stock”), for net proceeds of $194.6 million. Dividends are recorded when declared and, if declared, are payable quarterly in arrears on the 15th day of March, June, September, and December. If a dividend is not declared and paid or made payable on all outstanding shares of the Preferred Stock for the latest completed dividend period, no dividends may be declared or paid on our common stock and we may not purchase, redeem, or otherwise acquire our outstanding common stock. The Preferred Stock is redeemable at our option in whole or in part, from time to time, on or after December 15, 2025 at a redemption price equal to $25,000 per share of Preferred Stock (equivalent to $25.00 per depository share), plus unpaid dividends attributable to the then current dividend period. Prior to December 15, 2025, the Preferred Stock is redeemable at the Company’s option, in whole but not in part, within 90 days of the occurrence of (a) a rating agency event at a redemption price equal to $25,500 per share of Preferred Stock (equivalent to $25.50 per depository share), plus unpaid dividends attributable to the current dividend period in circumstances where a rating agency changes its criteria used to assign equity credit to securities like the Preferred Stock; or (b) a regulatory capital event at a redemption price equal to $25,000 per share of Preferred Stock (equivalent to $25.00 per depository share), plus unpaid dividends attributable to the current dividend period in circumstances where a capital regulator such as a state insurance regulator changes or proposes to change capital adequacy rules. Share Repurchase Program On December 2, 2020, we announced that our Board authorized a $100 million share repurchase program, with no set expiration or termination date. Our repurchase program does not obligate us to acquire any particular amount of our common stock. Management will determine the timing and amount of any share repurchases under the authorization at its discretion based on market conditions and other considerations. For the year ended December 31, 2022, 165,159 shares were repurchased under the share repurchase program at a total cost of $12.4 million, including commissions. We had $84.2 million of remaining capacity under our share repurchase program as of December 31, 2022.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions William M. Rue, a Director of the Parent, is Chairman of, and owns more than 10% of the equity of Rue Holding Company, which owns 100% of Chas. E. Rue & Son, Inc., t/a Rue Insurance, a general independent retail insurance agency ("Rue Insurance"). Rue Insurance is an appointed distribution partner of the Insurance Subsidiaries on terms and conditions similar to those of our other distribution partners, which includes the right to participate in the Agent Plan. Mr. Rue’s son is President, and an employee, of Rue Insurance, and owns more than 10% of the equity of Rue Holding Company. Mr. Rue’s daughter is an employee of Rue Insurance and owns less than 10% of the equity of Rue Holding Company. Our relationship with Rue Insurance has existed since 1928. Rue Insurance placed insurance policies with the Insurance Subsidiaries for its customers and itself. Direct premiums written associated with these policies were $14.3 million in 2022, $12.8 million in 2021, and $11.0 million in 2020. In return, the Insurance Subsidiaries paid standard market commissions, including supplemental commissions, to Rue Insurance of $2.7 million in 2022, $2.0 million in 2021, and $1.8 million in 2020. Amounts due to Rue Insurance at December 31, 2022 and December 31, 2021 were $0.7 million and $0.7 million, respectively. All contracts and transactions with Rue Insurance were consummated in the ordinary course of business on an arm's-length basis. In 2005, we established a private foundation, now named The Selective Insurance Group Foundation (the "Foundation"), under Section 501(c)(3) of the Internal Revenue Code. The Board of the Foundation is comprised of some of the Parent's officers. We made $0.3 million of contributions to the Foundation in 2022, $1.3 million in 2021 and $0.5 million in 2020. BlackRock, Inc., a leading publicly-traded investment management firm (“BlackRock”), has purchased our common shares in the ordinary course of its investment business and has previously filed Schedules 13G/A with the SEC. On January 23, 2023, BlackRock filed a Schedule 13G/A reporting beneficial ownership as of December 31, 2022, of 11.8% of our common stock. In connection with purchasing our common shares, BlackRock filed the necessary filings with insurance regulatory authorities. On the basis of those filings, BlackRock is deemed not to be a controlling person for the purposes of applicable insurance law. We are required to disclose related party information for our transactions with BlackRock. BlackRock is highly regulated, serves its clients as a fiduciary, and has a diverse platform of active (alpha) and index (beta) investment strategies across asset classes that enables it to tailor investment outcomes and asset allocation solutions for clients. BlackRock also offers the BlackRock Solutions ® investment and risk management technology platform, Aladdin ® , risk analytics, advisory, and technology services and solutions to a broad base of institutional and wealth management investors. We incurred expenses related to BlackRock for services rendered of $1.8 million in 2022, $1.8 million in 2021, and $2.0 million in 2020. Amounts payable for such services were $0.8 million at December 31, 2022, $0.5 million at December 31, 2021, and $1.3 million at December 31, 2020. As part of our overall investment diversification, we invest in various BlackRock funds from time to time. These funds accounted for less than 1% of our invested assets at December 31, 2022 and December 31, 2021, and are predominately reflected in "Fixed income securities" on our Consolidated Balance Sheet. During 2022, with regard to BlackRock funds, we (i) purchased $18.5 million in securities, (ii) sold $32.3 million, (iii) recognized net realized and unrealized losses of $6.9 million, and (iv) recorded $1.8 million in income. During 2021, we (i) purchased $16.5 million in securities, (ii) sold $32.5 million, (iii) recognized net realized and unrealized losses of $0.6 million, and (iv) recorded $0.9 million in income. During 2020, we (i) purchased $62.2 million in securities, (ii) recognized net unrealized losses of $0.2 million, and (iii) recorded $0.4 million in income. We did not make any sales of BlackRock funds in 2020. There were no amounts payable on the settlement of these investment transactions at December 31, 2022 and December 31, 2021. Our Pension Plan's investment portfolio contained investments in BlackRock funds of $120.1 million at December 31, 2022 and $209.9 million at December 31, 2021. During 2022, with regard to BlackRock funds, the Pension Plan (i) purchased $56.4 million in securities, (ii) sold $65.7 million, and (iii) recorded net investment losses of $80.5 million. During 2021, with regard to BlackRock funds, the Pension Plan (i) purchased $18.0 million in securities, (ii) sold $18.1 million, and (iii) recorded net investment income of $18.2 million. During 2020, with regard to BlackRock funds, the Pension Plan (i) purchased $56.7 million in securities, (ii) sold $44.9 million, and (iii) recorded net investment income of $35.8 million. In addition, our Deferred Compensation Plan and Retirement Savings Plan may offer our employees the option to invest in various BlackRock funds. All contracts and transactions with BlackRock were consummated in the ordinary course of business on an arm's-length basis. Vanguard, one of the world’s largest investment management companies, has purchased our common shares in the ordinary course of its investment business and has previously filed Schedules 13G/A with the SEC. Vanguard offers low-cost mutual funds and exchange-traded funds, as well as other investment related services. On February 10, 2023, Vanguard filed a Schedule 13G/A reporting beneficial ownership of 10.03% of our common stock as of January 31, 2023. In connection with purchasing our common shares, Vanguard filed the necessary filings with insurance regulatory authorities. On the basis of those filings, we do not expect Vanguard to be deemed a controlling person for the purposes of applicable insurance law. As part of our overall investment diversification, we may invest in various Vanguard funds from time to time. These funds accounted for less than 1% of our invested assets at December 31, 2022, and less than 3% of our invested assets at December 31, 2021, and are predominately reflected in "Equity securities" on our Consolidated Balance Sheet. During 2022, with regard to Vanguard funds, we (i) purchased $3.5 million in securities, (ii) sold $125.2 million, (iii) recognized net realized and unrealized losses of $10.4 million, and (iv) recorded $4.7 million in income. During 2021, we (i) purchased $19.3 million in securities, (ii) sold $23.6 million, (iii) recognized net realized and unrealized gains of $17.7 million, and (iv) recorded $7.5 million in income. During 2020, we (i) purchased $150.9 million in securities, (ii) recognized net realized and unrealized gains of $10.2 million, and (iii) recorded $2.4 million in income. We did not make any sales of Vanguard funds in 2020. There were no amounts payable on the settlement of these investment transactions at December 31, 2022 and December 31, 2021. Our deferred compensation plan offers our employees investment options based on the notional value of various Vanguard funds. Our defined contribution plan offers our employees the option to invest in a Vanguard fund. All transactions with Vanguard are consummated in the ordinary course of business on an arm’s-length basis.

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Lessee Disclosure [Text Block]	Leases We have various operating leases for office space, equipment, and fleet vehicles. In addition, we have various finance leases for computer hardware. Such lease agreements, which expire at various dates through 2032, are generally renewed or replaced by similar leases. The components of lease expense for the year ended December 31, 2022 and 2021 were as follows: ($ in thousands) 2022 2021 Operating lease cost, included in Other insurance expenses on the Consolidated Statements of Income $ 8,148 7,935 Finance lease cost: Amortization of assets, included in Other insurance expenses on the Consolidated Statements of Income 2,440 1,765 Interest on lease liabilities, included in Interest expense on the Consolidated Statements of Income 46 35 Total finance lease cost 2,486 1,800 Variable lease cost, included in Other insurance expenses on the Consolidated Statements of Income 1,384 291 Short-term lease cost, included in Other insurance expenses on the Consolidated Statements of Income $ 166 832 The following table provides supplemental information regarding our operating and finance leases. December 31, 2022 December 31, 2021 Weighted-average remaining lease term Operating leases 8 7 years Finance leases 2 2 Weighted-average discount rate Operating leases 2.6 2.1 % Finance leases 1.2 0.8 Operating and finance lease asset and liability balances are included within the following line items on the Consolidated Balance Sheets: ($ in thousands) December 31, 2022 December 31, 2021 Operating leases Other assets $ 42,403 35,644 Other liabilities 44,505 37,296 Finance leases Property and equipment - at cost, net of accumulated depreciation and amortization 3,713 5,446 Long-term debt $ 3,718 5,450 The maturities of our lease liabilities at December 31, 2022 were as follows: ($ in thousands) Finance Leases Operating Leases Total Year ended December 31, 2023 $ 2,490 7,290 9,780 2024 1,029 6,943 7,972 2025 190 6,649 6,839 2026 54 6,156 6,210 2027 2 6,053 6,055 Thereafter — 18,832 18,832 Total lease payments 3,765 51,923 55,688 Less: imputed interest 47 4,496 4,543 Less: leases that have not yet commenced — 2,922 2,922 Total lease liabilities $ 3,718 44,505 48,223 Refer to Note 4. "Statements of Cash Flows" in Item 8. "Financial Statements and Supplementary Data." of Form 10-K for supplemental cash and non-cash transactions included in the measurement of operating and finance lease liabilities.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies (a) We purchase annuities from life insurance companies to fulfill obligations under claim settlements that provide for periodic future payments to claimants. As of December 31, 2022, we had purchased such annuities with a present value of $31.0 million for settlement of claims on a structured basis for which we are contingently liable. To our knowledge, there are no material defaults from any of the issuers of such annuities. (b) As of December 31, 2022, we have made commitments that may require us to invest additional amounts into our investment portfolio, which are as follows: ($ in millions) Amount of Obligation Alternative investments $ 246.1 Non-publicly traded collateralized loan obligations in our fixed income securities portfolio 106.6 Non-publicly traded common stock within our equity portfolio 35.0 CMLs 4.9 Privately-placed corporate securities 20.1 Total $ 412.7 There is no certainty that any such additional investment will be required. We expect to have the capacity to repay or refinance these obligations as they come due.

Litigation

Litigation	12 Months Ended
	Dec. 31, 2022
Loss Contingency, Information about Litigation Matters [Abstract]
Litigation	Litigation As of December 31, 2022, we do not believe we are involved in any legal action that could have a material adverse effect on our consolidated financial condition, results of operations, or cash flows. In the ordinary course of conducting business, we are parties in various legal actions. Most are claims litigation involving our Insurance Subsidiaries as (i) liability insurers defending or providing indemnity for third-party claims brought against our customers, (ii) insurers defending first-party coverage claims brought against them, or (iii) liability insurers seeking declaratory judgment on our insurance coverage obligations. We account for such activity by establishing unpaid loss and loss expense reserves. Considering potential losses and defense costs reserves, we expect that any potential ultimate liability for ordinary course claims litigation will not be material to our consolidated financial condition, results of operations, or cash flows. All our commercial property and businessowners' policies require direct physical loss of or damage to property by a covered cause of loss. All our standard lines commercial property and businessowners' policies also include or attach an exclusion that states all loss or property damage caused by or resulting from any virus, bacterium, or other microorganism that induces or is capable of inducing physical distress, illness, or disease is not a covered cause of loss ("Virus Exclusion"). Whether COVID-19-related contamination, the existence of the COVID-19 pandemic, and the resulting COVID-19-related government shutdown orders cause physical loss of or damage to property is the subject of much public debate and first-party coverage litigation against some insurers, including us. The Virus Exclusion also is the subject of first-party coverage litigation against some insurers, including us. To date, insurers (including us) have prevailed in the majority of these suits, with most decisions holding that COVID-19 does not cause physical loss of or damage to property and the Virus Exclusion is valid. Nonetheless, these two matters continue to be litigated in trial courts, are subject to review by state and federal appellate courts, and their ultimate outcome cannot be assured. From time to time, our Insurance Subsidiaries also are named as defendants in other legal actions, some asserting claims for substantial amounts. Plaintiffs may style these actions as class actions and seek judicial certification of a state or national class for allegations involving our business practices, such as improper medical provider reimbursement under workers compensation and personal and commercial automobile insurance policies or improper reimbursement for automobile parts. Similarly, our Insurance Subsidiaries can be named defendants in individual actions seeking extra-contractual damages, punitive damages, or penalties, often alleging bad faith in the handling of insurance claims. We believe that we have valid defenses to these allegations and we account for such activity by establishing unpaid loss and loss expense reserves. Considering estimated losses and defense costs reserves, we expect that any potential ultimate liability for these other legal actions will not be material to our consolidated financial condition. As litigation outcomes are inherently unpredictable and the amounts sought in certain actions are large or indeterminate, adverse outcomes could potentially have a material adverse effect on our consolidated results of operations or cash flows in particular quarterly or annual periods.

Statutory Financial Information

Statutory Financial Information, Capital Requirements, and Restrictions on Dividends and Transfers of Funds	12 Months Ended
	Dec. 31, 2022
Insurance [Abstract]
Statutory Financial Information, Capital Requirments, and Retrictions on Dividends and Transfers of Funds	Statutory Financial Information, Capital Requirements, and Restrictions on Dividends and Transfers of Funds (a) Statutory Financial Information The Insurance Subsidiaries prepare their statutory financial statements in accordance with accounting principles prescribed or permitted by the various state insurance departments of domicile. Prescribed statutory accounting principles include state laws, regulations, and general administrative rules, as well as a variety of publications of the National Association of Insurance Commissioners (“NAIC"). Permitted statutory accounting principles encompass all accounting principles that are not prescribed; such principles differ from state to state, may differ from company to company within a state and may change in the future. The Insurance Subsidiaries do not utilize any permitted statutory accounting principles that affect the determination of statutory surplus, statutory net income, or risk-based capital (“RBC”). As of December 31, 2022, the various state insurance departments of domicile have adopted the March 2022 version of the NAIC Accounting Practices and Procedures manual in its entirety, as a component of prescribed or permitted practices. The following table provides statutory data for each of our Insurance Subsidiaries: State of Domicile Unassigned Surplus Statutory Surplus Statutory Net Income ($ in millions) 2022 2021 2022 2021 2022 2021 2020 SICA New Jersey $ 686.6 673.1 851.8 838.3 103.1 134.7 81.8 Selective Way Insurance Company ("SWIC") New Jersey 461.9 436.4 517.8 492.4 69.6 74.5 54.0 SICSC Indiana 164.1 166.3 198.4 200.6 17.0 24.2 20.8 SICSE Indiana 135.9 132.7 163.5 160.3 14.2 19.4 16.8 SICNY New York 137.4 127.0 165.1 154.7 13.2 18.6 15.3 Selective Insurance Company of New England ("SICNE") New Jersey 38.2 34.5 69.3 65.6 5.1 7.5 6.8 Selective Auto Insurance Company of New Jersey ("SAICNJ") New Jersey 102.2 90.4 147.1 135.2 12.7 16.7 12.9 Mesa Underwriters Specialty Insurance Company ("MUSIC") New Jersey 52.8 47.4 122.3 116.9 9.7 13.9 11.4 Selective Casualty Insurance Company ("SCIC") New Jersey 91.4 83.4 167.9 159.9 14.0 20.6 16.2 Selective Fire and Casualty Insurance Company ("SFCIC") New Jersey 37.6 34.2 70.5 67.1 5.8 8.2 6.4 Total $ 1,908.1 1,825.4 2,473.7 2,391.0 264.4 338.3 242.4 (b) Capital Requirements The Insurance Subsidiaries are required to maintain certain minimum amounts of statutory surplus to satisfy the requirements of their various state insurance departments of domicile. RBC requirements for property and casualty insurance companies are designed to assess capital adequacy and to raise the level of protection that statutory surplus provides for policyholders. The Insurance Subsidiaries' combined total adjusted capital exceeded the required level of capital as defined by the NAIC based on their 2022 statutory financial statements. In the fourth quarter of 2020, the NAIC adopted the basic structure of Group Capital Calculation ("GCC"), along with a model law to enable the GCC after state legislative enactment. The GCC expands the existing RBC calculation to include (i) capital requirements for other regulated entities in the group, and (ii) defined capital calculation for other group entities that are unregulated. Our New Jersey state insurance regulators adopted the GCC model law in 2022. Based on our 2022 statutory financial statements, our GCC ratio exceeds the regulatory action minimum threshold. In addition to statutory capital requirements, we are impacted by various rating agency requirements related to certain rating levels. These required capital levels may be higher than statutory requirements. (c) Restrictions on Dividends and Transfers of Funds Our ability to declare and pay dividends on the Parent's common stock is dependent on liquidity at the Parent coupled with the ability of the Insurance Subsidiaries to declare and pay dividends, if necessary, and/or the availability of other sources of liquidity to the Parent. In addition to regulatory restrictions on the availability of dividends that our Insurance Subsidiaries can pay to the Parent, the maximum amount of dividends the Parent can pay our shareholders is limited by certain New Jersey corporate law provisions that limit dividends if either: (i) the Parent would be unable to pay its debts as they became due in the usual course of business; or (ii) the Parent’s total assets would be less than its total liabilities. The Parent’s ability to pay dividends to shareholders also are impacted by (i) covenants in its Line of Credit that obligate it, among other things, to maintain a minimum consolidated net worth and a maximum ratio of consolidated debt to total capitalization, and (ii) the terms of our preferred stock that prohibit dividends to be declared or paid on our common stock if dividends are not declared and paid, or made payable, on all outstanding preferred stock for the latest completed dividend period. As of December 31, 2022, the Parent had an aggregate of $484.3 million in investments and cash available to fund future dividends and interest payments. These amounts are not subject to any regulatory restrictions other than the standard state insolvency restrictions noted above, whereas our consolidated retained earnings of $2.7 billion are predominately restricted due to regulations applicable to our Insurance Subsidiaries. In 2023, the Insurance Subsidiaries have the ability to provide for $283.1 million in annual dividends to the Parent; however, as regulated entities, these dividends are subject to certain restrictions, which are further discussed below. The Parent also has other potential sources of liquidity, such as: (i) borrowings from our Indiana Subsidiaries; (ii) debt issuances; (iii) common and preferred stock issuances; and (iv) borrowings under our Line of Credit. Borrowings from our Indiana Subsidiaries are governed by approved intercompany lending agreements with the Parent that provide for additional capacity of $121.5 million as of December 31, 2022, based on restrictions in these agreements that limit borrowings to 10% of the admitted assets of the Indiana Subsidiaries. For additional restrictions on the Parent's debt, see Note 11. "Indebtedness" in this Form 10-K. Insurance Subsidiaries Dividend Restrictions As noted above, the restriction on our net assets and retained earnings is predominantly driven by our Insurance Subsidiaries' ability to pay dividends to the Parent under applicable laws and regulations. Under the insurance laws of the domiciliary states of the Insurance Subsidiaries, New Jersey, Indiana, and New York, an insurer can potentially make an ordinary dividend payment if its statutory surplus following such dividend is reasonable in relation to its outstanding liabilities, is adequate to its financial needs, and the dividend does not exceed the insurer's unassigned surplus. In general, New Jersey defines an ordinary dividend as a dividend whose fair market value, together with other dividends made within the preceding 12 months, is less than the greater of 10% of the insurer's statutory surplus as of the preceding December 31, or the insurer's net income (excluding capital gains) for the 12-month period ending on the preceding December 31. Indiana's ordinary dividend calculation is consistent with New Jersey's, except that it does not exclude capital gains from net income. In general, New York defines an ordinary dividend as a dividend whose fair market value, together with other dividends made within the preceding 12 months, is less than the lesser of 10% of the insurer's statutory surplus, or 100% of adjusted net investment income. New Jersey and Indiana require notice of the declaration of any ordinary dividend distribution. During the notice period, the relevant state regulatory authority may disallow all or part of the proposed dividend if it determines that the dividend is not appropriate given the above considerations. New York does not require notice of ordinary dividends. Dividend payments exceeding ordinary dividends are referred to as extraordinary dividends and require review and approval by the applicable domiciliary insurance regulatory authority prior to payment. The table below provides the following information: (i) quantitative data regarding all Insurance Subsidiaries' dividends paid to the Parent in 2022, which was used for debt service, shareholder dividends, and general operating purposes; and (ii) the maximum ordinary dividends that can be paid to the Parent by the Insurance Subsidiaries in 2023, based on the 2022 statutory financial statements. Dividends Twelve Months ended December 31, 2022 2023 ($ in millions) State of Domicile Ordinary Dividends Paid Maximum Ordinary Dividends SICA New Jersey $ 62.3 $ 103.1 SWIC New Jersey 24.3 69.6 SICSC Indiana 5.6 19.8 SICSE Indiana 6.6 16.4 SICNY New York 3.0 16.5 SICNE New Jersey 1.5 6.9 SAICNJ New Jersey 1.3 14.7 MUSIC New Jersey 5.3 12.2 SCIC New Jersey 7.8 16.8 SFCIC New Jersey 2.3 7.1 Total $ 120.0 $ 283.1

Schedule I - Summary of Investm

Schedule I - Summary of Investments - Other Than Investments in Related Parties	12 Months Ended
	Dec. 31, 2022
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Abstract]
Schedule I - Summary of Investments- Other than Investments in Related Parties	SCHEDULE I SELECTIVE INSURANCE GROUP, INC. AND CONSOLIDATED SUBSIDIARIES SUMMARY OF INVESTMENTS - OTHER THAN INVESTMENTS IN RELATED PARTIES December 31, 2022 Types of investment ($ in thousands) Amortized Cost or Cost Fair Value Carrying Amount Fixed income securities: Held-to-maturity: Obligations of states and political subdivisions $ 3,405 3,405 3,405 Public utilities — — — All other corporate securities 27,752 26,432 27,752 Total fixed income securities, held-to-maturity 31,157 29,837 31,157 Available-for-sale: U.S. government and government agencies 209,528 189,239 189,239 Foreign government 11,199 9,608 9,608 Obligations of states and political subdivisions 965,231 918,018 918,018 Public utilities 110,544 97,717 97,717 All other corporate securities 2,448,111 2,237,308 2,237,308 Collateralized loan obligation securities and other asset-backed securities 1,607,660 1,485,973 1,485,973 Residential mortgage-backed securities 1,169,546 1,059,832 1,059,832 Commercial mortgage-backed securities 663,935 614,412 614,412 Total fixed income securities, available-for-sale 7,185,754 6,612,107 6,612,107 Equity securities: Common stock: Banks, trusts and insurance companies 22,579 20,201 20,201 Industrial, miscellaneous and all other 142,892 140,154 140,154 Nonredeemable preferred stock 1,960 1,645 1,645 Total equity securities 167,431 162,000 162,000 Commercial mortgage loans 149,305 149,189 Short-term investments 440,439 440,456 Alternative investments 371,316 371,316 Other investments 71,244 71,244 Total investments $ 8,045,330 7,837,469 See accompanying Report of Independent Registered Public Accounting Firm in Item 8. "Financial Statements and Supplementary Data." of this Form 10-K

Schedule II - Parent Corporatio

Schedule II - Parent Corporation Finanical Statements	12 Months Ended
	Dec. 31, 2022
Condensed Financial Information Disclosure [Abstract]
Schedule II- Parent Corporation Financial Statements	SCHEDULE II SELECTIVE INSURANCE GROUP, INC. (Parent Corporation) Balance Sheets December 31, ($ in thousands, except share amounts) 2022 2021 Assets: Fixed income securities, available-for-sale – at fair value (allowance for credit losses: $1,194 – 2022; $542 – 2021; amortized cost: $418,588 – 2022; $317,703 – 2021 $ 387,535 325,014 Equity securities 48,095 136,362 Short-term investments 33,008 56,042 Alternative investments 15,631 9,241 Cash 26 455 Investment in subsidiaries 2,524,448 2,954,725 Current federal income tax 8,894 7,208 Deferred federal income tax 14,733 4,487 Other assets 11,104 9,178 Total assets $ 3,043,474 3,502,712 Liabilities: Long-term debt $ 440,958 440,600 Intercompany notes payable 56,266 57,980 Accrued long-term stock compensation 11,101 10,965 Other liabilities 7,585 10,282 Total liabilities $ 515,910 519,827 Stockholders’ Equity: Preferred stock of $0 par value per share: Authorized shares: 5,000,000; Issued shares: 8,000 with $25,000 liquidation preference per share – 2022 and 2021 $ 200,000 200,000 Common stock of $2 par value per share: Authorized shares: 360,000,000 Issued: 104,847,111 – 2022; 104,450,916 – 2021 209,694 208,902 Additional paid-in capital 493,488 464,347 Retained earnings 2,749,703 2,603,472 Accumulated other comprehensive (loss) income (498,042) 115,099 Treasury stock – at cost (shares: 44,508,211 – 2022; 44,266,534 – 2021) (627,279) (608,935) Total stockholders’ equity 2,527,564 2,982,885 Total liabilities and stockholders’ equity $ 3,043,474 3,502,712 See accompanying Report of Independent Registered Public Accounting Firm. Information should be read in conjunction with the Notes to Consolidated Financial Statements of Selective Insurance Group, Inc. and its subsidiaries. Both items are in Item 8. “Financial Statements and Supplementary Data.” of this Form 10-K. SCHEDULE II (continued) SELECTIVE INSURANCE GROUP, INC. (Parent Corporation) Statements of Income Year ended December 31, ($ in thousands) 2022 2021 2020 Revenues: Dividends from subsidiaries $ 120,007 140,018 104,992 Net investment income earned 18,622 15,454 7,579 Net realized and unrealized investment (losses) gains (17,855) 1,898 1,756 Total revenues 120,774 157,370 114,327 Expenses: Interest expense 28,897 28,988 29,220 Other expenses 31,116 28,305 25,412 Total expenses 60,013 57,293 54,632 Income before federal income tax 60,761 100,077 59,695 Federal income tax (benefit) expense: Current (9,381) (6,552) (10,987) Deferred (2,189) 12 473 Total federal income tax benefit (11,570) (6,540) (10,514) Net income before equity in undistributed income of subsidiaries 72,331 106,617 70,209 Equity in undistributed income of subsidiaries, net of tax 152,555 297,220 176,146 Net income $ 224,886 403,837 246,355 Preferred stock dividends 9,200 9,353 — Net income available to common stockholders $ 215,686 394,484 246,355 See accompanying Report of Independent Registered Public Accounting Firm. Information should be read in conjunction with the Notes to Consolidated Financial Statements of Selective Insurance Group, Inc. and its subsidiaries. Both items are in Item 8. “Financial Statements and Supplementary Data.” of this Form 10-K. SCHEDULE II (continued) SELECTIVE INSURANCE GROUP, INC. (Parent Corporation) Statements of Cash Flows Year ended December 31, ($ in thousands) 2022 2021 2020 Operating Activities: Net income $ 224,886 403,837 246,355 Adjustments to reconcile net income to net cash provided by (used in) operating activities: Equity in undistributed income of subsidiaries, net of tax (152,555) (297,220) (176,146) Stock-based compensation expense 18,428 15,893 16,227 Net realized and unrealized investment losses (gains) 17,855 (1,898) (1,756) Undistributed (income) losses of equity method investments (2,240) (1,859) 672 Amortization – other (154) 1,076 1,080 Changes in assets and liabilities: Increase (decrease) in accrued long-term stock compensation 136 2,727 (366) (Increase) decrease in net federal income taxes (3,875) 3,843 5,549 Increase in other assets (1,961) (7,251) (317) Decrease in other liabilities (2,813) (1,742) (390) Net cash provided by operating activities 97,707 117,406 90,908 Investing Activities: Purchases of fixed income securities, available-for-sale (208,512) (113,829) (89,726) Purchases of equity securities (1,647) (5,676) (157,411) Purchases of short-term investments (362,213) (330,843) (523,961) Purchases of alternative investments (4,149) (4,949) (4,065) Redemption and maturities of fixed income securities, available-for-sale 35,527 51,524 26,877 Sales of fixed income securities, available-for-sale 66,725 15,713 23,276 Sales of equity securities 77,971 31,204 — Sales of short-term investments 385,254 311,225 523,813 Proceeds from alternative investments — 959 — Capital contribution to subsidiaries — — (30,000) Net cash used in investing activities (11,044) (44,672) (231,197) Financing Activities: Dividends to preferred stockholders (9,200) (9,353) — Dividends to common stockholders (66,920) (60,136) (54,486) Acquisition of treasury stock (18,344) (9,050) (7,053) Proceeds from borrowings — — 50,000 Repayment of borrowings — — (50,000) Net proceeds from stock purchase and compensation plans 9,086 7,976 8,411 Preferred stock issued, net of issuance costs — (479) 195,063 Principal payment on borrowings from subsidiaries (1,714) (1,631) (1,552) Net cash (used in) provided by financing activities (87,092) (72,673) 140,383 Net (decrease) increase in cash (429) 61 94 Cash, beginning of year 455 394 300 Cash, end of year $ 26 455 394 See accompanying Report of Independent Registered Public Accounting Firm. Information should be read in conjunction with the Notes to Consolidated Financial Statements of Selective Insurance Group, Inc. and its subsidiaries. Both items are in Item 8. “Financial Statements and Supplementary Data.” of this Form 10-K.

Schedule III - Supplementary In

Schedule III - Supplementary Insurance Information	12 Months Ended
	Dec. 31, 2022
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Abstract]
Schedule III- Supplementary Insurance Information	SCHEDULE III SELECTIVE INSURANCE GROUP, INC. AND CONSOLIDATED SUBSIDIARIES SUPPLEMENTARY INSURANCE INFORMATION Year ended December 31, 2022 ($ in thousands) Deferred Reserve Unearned premiums Net Net investment income 1 Loss Amortization Other operating expenses 2 Net Standard Commercial Lines Segment $ 311,535 4,275,002 1,511,447 2,739,819 — 1,683,988 605,845 306,290 2,901,984 Standard Personal Lines Segment 17,817 340,302 322,668 299,405 — 231,113 27,129 48,356 319,059 E&S Lines Segment 39,272 529,517 158,666 334,156 — 196,677 72,848 34,332 352,547 Investments Segment — — — — 173,347 — — — — Total $ 368,624 5,144,821 1,992,781 3,373,380 173,347 2,111,778 705,822 388,978 3,573,590 1 Includes “Net investment income earned” and “Net realized and unrealized investment (losses) gains” on the Consolidated Statements of Income. 2 “Other operating expenses” of $388,978 reconciles to the Consolidated Statements of Income as follows: Other insurance expenses $ 400,313 Other income (11,335) Total $ 388,978 See accompanying Report of Independent Registered Public Accounting Firm in Item 8. "Financial Statements and Supplementary Data." of this Form 10-K. Year ended December 31, 2021 ($ in thousands) Deferred Reserve Unearned premiums Net Net investment income 1 Loss Amortization Other operating expenses 2 Net Standard Commercial Lines Segment $ 279,850 3,832,151 1,346,809 2,443,885 — 1,426,768 539,606 278,915 2,593,018 Standard Personal Lines Segment 12,911 270,066 317,276 293,559 — 212,116 25,918 51,559 292,265 E&S Lines Segment 34,154 478,686 139,122 279,809 — 175,100 60,945 27,734 304,430 Investments Segment — — — — 344,188 — — — — Total $ 326,915 4,580,903 1,803,207 3,017,253 344,188 1,813,984 626,469 358,208 3,189,713 1 Includes “Net investment income earned” and “Net realized and unrealized investment (losses) gains” on the Consolidated Statements of Income. 2 “Other operating expenses” of $358,208 reconciles to the Consolidated Statements of Income as follows: Other insurance expenses $ 375,931 Other income (17,723) Total $ 358,208 See accompanying Report of Independent Registered Public Accounting Firm in Item 8. "Financial Statements and Supplementary Data." of this Form 10-K. Year ended December 31, 2020 ($ in thousands) Deferred Reserve Unearned premiums Net Net investment income 1 Loss Amortization Other operating expenses 2 Net Standard Commercial Lines Segment $ 246,494 3,596,340 1,196,243 2,143,184 — 1,245,627 474,322 271,504 2,230,636 Standard Personal Lines Segment 13,803 228,348 308,183 299,140 — 233,260 30,694 50,694 295,166 E&S Lines Segment 28,281 435,667 113,845 239,490 — 156,936 55,255 27,173 247,290 Investments Segment — — — — 222,890 — — — — Total $ 288,578 4,260,355 1,618,271 2,681,814 222,890 1,635,823 560,271 349,371 2,773,092 1 Includes “Net investment income earned” and “Net realized and unrealized investment (losses) gains” on the Consolidated Statements of Income. 2 “Other operating expenses” of $349,371 reconciles to the Consolidated Statements of Income as follows: Other insurance expenses $ 366,941 Other income (17,570) Total $ 349,371 See accompanying Report of Independent Registered Public Accounting Firm in Item 8. "Financial Statements and Supplementary Data." of this Form 10-K.

Schedule IV - Reinsurance

Schedule IV - Reinsurance	12 Months Ended
	Dec. 31, 2022
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Schedule IV - Reinsurance	SCHEDULE IV SELECTIVE INSURANCE GROUP, INC. AND CONSOLIDATED SUBSIDIARIES REINSURANCE Years ended December 31, 2022, 2021, and 2020 ($ thousands) Direct Amount Assumed from Other Companies Ceded to Other Companies Net Amount % of Amount Assumed to Net 2022 Premiums earned: Accident and health insurance $ — — — — — Property and liability insurance 3,880,522 30,742 537,884 3,373,380 1 % Total premiums earned 3,880,522 30,742 537,884 3,373,380 1 % 2021 Premiums earned: Accident and health insurance $ 2 — 2 — — Property and liability insurance 3,472,713 21,550 477,010 3,017,253 1 % Total premiums earned 3,472,715 21,550 477,012 3,017,253 1 % 2020 Premiums earned: Accident and health insurance $ 13 — 13 — — Property and liability insurance 3,108,674 25,010 451,870 2,681,814 1 % Total premiums earned 3,108,687 25,010 451,883 2,681,814 1 % See accompanying Report of Independent Registered Public Accounting Firm in Item 8. "Financial Statements and Supplementary Data." of this Form 10-K.

Schedule V - Allowance for Cred

Schedule V - Allowance for Credit Losses on Premiums and Other Receivables	12 Months Ended
	Dec. 31, 2022
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule V - Allowance for Credit Losses on Premiums and Other Receivables	SCHEDULE V SELECTIVE INSURANCE GROUP, INC. AND CONSOLIDATED SUBSIDIARIES ALLOWANCE FOR CREDIT LOSSES ON PREMIUMS AND OTHER RECEIVABLES Years ended December 31, 2022, 2021, and 2020 ($ in thousands) 2022 2021 2020 Balance, January $ 15,200 22,777 10,800 Cumulative effect adjustment — — (1,845) Balance at the beginning of the period, as adjusted 15,200 22,777 8,955 Additions 7,478 1,766 17,576 Deductions (4,978) (9,343) (3,754) Balance, December 31 $ 17,700 15,200 22,777 See accompanying Report of Independent Registered Public Accounting Firm in Item 8. "Financial Statements and Supplementary Data." of this Form 10-K.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Principles of Consolidation	Principles of ConsolidationThe accompanying consolidated financial statements (“Financial Statements”) include the accounts of the Parent and its subsidiaries, and have been prepared in conformity with: (i) United States ("U.S.") generally accepted accounting principles ("GAAP"); and (ii) the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). All significant intercompany accounts and transactions are eliminated in consolidation.
Use of Estimates	Use of EstimatesThe preparation of our Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported financial statement balances, as well as the disclosure of contingent assets and liabilities. Actual results could differ from those estimates.
Investments	Investments Portfolio Composition and Presentation in the Consolidated Balance Sheet Our investment portfolio is primarily comprised of fixed income investments. We also hold commercial mortgage loans ("CMLs"), equity securities, short-term investments, alternative investments, and other investments. A description of our portfolio holdings, and the related presentation in our Consolidated Balance Sheet, is provided below. Fixed Income Investments Our fixed income investments include our fixed income securities portfolio and our CML portfolio. Fixed Income Securities We hold the following types of securities in our fixed income securities portfolio: • U.S. government and government agency obligations; • Foreign government obligations; • Obligations of states and political subdivisions, including special revenue and general obligation bonds; • Corporate securities, which may include investment grade and below investment grade bonds, bank loan investments, redeemable preferred stock, and non-redeemable preferred stock with certain debt-like characteristics; • Collateralized loan obligations ("CLOs") and other asset-backed securities ("ABS"); • Residential mortgage-backed securities ("RMBS"); and • Commercial mortgage-backed securities ("CMBS"). We have designated substantially all of the holdings in our fixed income securities as available-for-sale ("AFS"). These securities are reported at fair value in our Consolidated Balance Sheet. The after-tax difference between fair value and cost or amortized cost is reflected in stockholders’ equity as a component of accumulated other comprehensive (loss) income ("AOCI"). The amortized cost of fixed income securities is adjusted for the amortization of premiums and the accretion of discounts over the expected life of the security using the effective yield method. Callable debt securities held at a premium are amortized to the earliest call date. Premiums and discounts arising from the purchase of RMBS, CMBS, CLO and other ABS are amortized over the expected life of the security based on future principal payments, giving additional consideration to prepayments. These prepayments are estimated based on historical and projected cash flows. Prepayment assumptions are reviewed quarterly and adjusted to reflect actual prepayments and changes in expectations. Future amortization of any premium and/or discount is adjusted to reflect the revised assumptions. Accrued interest on our fixed income securities is recorded as a component of “Accrued investment income” on our Consolidated Balance Sheet. If accrued interest is due but not paid within 90 days, we reverse the delinquent amount and record this reversal through earnings as a component of “Net investment income earned” on our Consolidated Statement of Income. CMLs CMLs are loans secured by commercial property, such as an office building, multi-family apartment complex, industrial warehouse, or shopping center. We may acquire investments in CMLs through (i) direct originations under a loan syndication arrangement or (ii) a marketplace purchase. We record our investment in CMLs on the settlement date of the loan. Our CMLs are reported at amortized cost, net of any allowance for credit losses ("ACL"), on our Consolidated Balance Sheet. Interest is recorded using the effective yield method and accrued interest on our CMLs is recorded as a component of “Accrued investment income” on our Consolidated Balance Sheet. Other Portfolio Holdings Equity securities may include common and non-redeemable preferred stocks. Equity securities with readily determinable fair values are reported at fair value. Equity securities without readily determinable fair values are reported at net asset value ("NAV") as a practical expedient. Short-term investments may include money market instruments, savings accounts, commercial paper, and fixed income securities purchased with a maturity of less than one year. We may also enter into reverse repurchase agreements that are included in short-term investments. These repurchase agreements are fully collateralized by high-quality, readily-marketable instruments that support the principal amount. At maturity, we receive principal and interest income on these agreements. Short-term investments are generally reported at fair value. Alternative investments are limited partnership investments in private equity, private credit, and real estate strategies. These alternative investments are accounted for using the equity method, with income typically recognized on a one-quarter lag. Because these alternative investments are recorded under the equity method of accounting, with the underlying holdings carried at fair value, the valuation and income recognized on these investments may be impacted by volatility in the financial markets. We categorize distributions from our equity method on our Consolidated Statement of Cash Flows using the cumulative earnings approach. Under this approach, distributions received are classified as cash flows from operating activities until such time that the cumulative distributions exceed cumulative earnings for the investment. When such an excess occurs, the excess portion of the current period distribution is considered a return of investment and is classified as a cash flow from investing activities. We evaluate our alternative investments to determine whether those investments are variable interest entities ("VIEs") and if so, whether consolidation is required. A VIE is an entity that either has equity investors that lack certain essential characteristics of a controlling financial interest or lack sufficient funds to finance its own activities without financial support provided by other entities. We consider several significant factors in determining if our investments are VIEs and if we are the primary beneficiary, including whether we have (i) the power to direct activities of the VIE, (ii) the ability to remove the decision maker of the VIE, (iii) the ability to participate in making decisions that are significant to the VIE, and (iv) the obligation to absorb losses and the right to receive benefits that could potentially be significant to the VIE. We have reviewed our alternative investments and have concluded that they are VIEs, but that we are not the primary beneficiary and therefore, consolidation is not required. Our other investment portfolio includes Federal Home Loan Bank stock (“FHLB Stock”) and tax credit investments. The FHLB Stock is reported at cost. Accounting for our tax credit investments is dependent on the type of credit we have purchased, as follows: • Federal low income housing tax credits are accounted for under the proportional amortization method; and • All other tax credits in our investment portfolio are accounted for using the equity method. For federal tax credits accounted for under the equity method, we use the deferral method for recognizing the benefit of the tax credit with the related deferred revenue being recognized in our Consolidated Income Statement as a component of "Federal income tax expense" proportionately over the life of the investment. Presentation in the Consolidated Statement of Income Net Investment Income Earned Net investment income earned on our Consolidated Statement of Income includes the following: • Interest income, as well as amortization and accretion, on fixed income securities; • Interest income on CMLs; • Dividend income on equity securities; • Interest income on our short-term investments; and • Income recognized on our alternative and other investments accounted for under the equity method of accounting, except for federal tax credits, as discussed below. Income related to federal tax credits (either low income housing tax credits or other federal credits) is recorded in our Consolidated Statement of Income as a component of “Federal income tax expense” proportionately over the life of the investment. Net Realized and Unrealized Investment (Losses) Gains Net realized and unrealized investment (losses) gains on our Consolidated Statement of Income include the following: • Realized gains and losses on the disposal of holdings in our investment portfolio, which are determined on the basis of the cost of the specific investments sold; • Changes in unrealized gains or losses on our equity securities; • Losses on investments for which we have the intent to sell, which are discussed further below; and • Net credit loss expense or benefit resulting from changes in the ACL related to our investment portfolio, which is also discussed further below. Losses on Investments for which we have the Intent to Sell For our AFS fixed income securities and short-term investments, we review our fixed income securities in an unrealized loss position to determine (i) if we have the intent to sell the security, or (ii) if it is more likely than not we will be required to sell the security before its anticipated recovery. If we determine that we have the intent or likely requirement to sell the security, we write down its amortized cost to its fair value. In writing down amortized cost, any amount previously recorded as an ACL is reversed and any incremental reduction in amortized cost is recorded directly to earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. For our alternative and other investments, if we determine that we intend to sell a holding and the expected proceeds are less than the recorded value of the investment, we will record a loss on those securities we intend to sell in earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. After reviewing our portfolio, if (i) we do not have the intent to sell, or (ii) it is more likely than not we will not be required to sell the security before its anticipated recovery, then our intent is to hold the investment securities to maturity and recover the decline in valuation as prices accrete to par. However, our intent may change prior to maturity due to certain types of events, which include, but are not limited to, changes in the financial markets, our analysis of an issuer’s credit metrics and prospects, changes in tax laws or the regulatory environment, or as a result of significant unforeseen changes in liquidity needs. As such, we may, from time to time, sell invested assets subsequent to the balance sheet date that we did not intend to sell at the balance sheet date. Conversely, we may not sell invested assets that we asserted we intended to sell at the balance sheet date. Such changes in intent are due to events occurring subsequent to the balance sheet date. ACL on AFS Fixed Income Securities and Short-Term Investments When fixed income securities are in an unrealized loss position and we do not record any losses on securities for which we intend to sell, we record an ACL for the portion of the unrealized loss due to an expected credit loss. We estimate expected credit losses on fixed income securities by performing a discounted cash flow (“DCF”). The ACL is equal to the excess of amortized cost over the greater of: (i) our estimate of the present value of expected future cash flows, or (ii) fair value. The ACL is recorded as a contra-asset reflected in the carrying value of the investment on the Consolidated Balance Sheet. The initial ACL and any subsequent changes are recorded to earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. Any remaining unrealized loss is the non-credit amount and is recorded in AOCI. The ACL cannot exceed the unrealized loss of an AFS security and therefore it may fluctuate with changes in the fair value of the security. The ACL is written off against the amortized cost basis in the period in which it is determined uncollectible. Our DCF analyses calculate the present value of expected future cash flows using various models specific to the major security types in our portfolio. These models use security-specific information, as well as reasonable and forecasted macroeconomic data, to determine possible expected credit loss scenarios based on projected changes in the economy. The forecasted economic data incorporated into the models is based on the Federal Reserve Board’s annual supervisory stress test review on certain large banks and financial institutions. We also have the ability to incorporate internally-developed forecast information into the models as we deem appropriate. The discount rate used in a DCF is one of the following: • The current yield in effect at the reporting date to accrete the beneficial interest for RMBS, CMBS, CLO and other ABS that were not of high credit quality at acquisition; • The effective interest rate in effect as of the reporting date for non-fixed rate securities; and • The effective interest rate implicit in the security at the date of acquisition for all other securities. DCFs may include, but are not necessarily limited to: (i) generating cash flows for each tranche considering tranche-specific data, market data, and other pertinent information, such as the historical performance of the underlying collateral, including net operating income generated by underlying properties, conditional default rate assumptions, loan loss severity assumptions, consensus projections, prepayment projections, and actual pool and collateral information; (ii) identifying applicable benchmark yields; and (iii) applying market-based tranche specific spreads to determine an appropriate yield by incorporating collateral performance, tranche-level attributes, trades, bids, and offers. We do not record a valuation allowance on the accrued interest balance associated with our fixed income securities as we reverse delinquent amounts on a timely basis. We consider a fixed income security to be past due at the time any principal or interest payments become 90 days delinquent. ACL on CMLs We evaluate our CMLs on a quarterly basis for expected credit losses. If we hold a CML with a specific credit concern, we record an individual ACL on that loan. For all other CMLs, we record an ACL on the pool of loans based on lifetime expected credit losses. The ACL is recorded as a contra-asset reflected in the carrying value of our CMLs on the Consolidated Balance Sheet. Our initial ACL and any subsequent changes are recorded to earnings as a component of “Net realized and unrealized investment (losses) gains” on our Consolidated Statement of Income. We utilize a forecasting model to estimate lifetime expected credit losses at a loan level under multiple economic scenarios. The scenarios apply reasonable and forecasted macroeconomic data such as unemployment, inflation, and rent assumptions to project property-specific operating income and capitalization rates that are used to estimate the value of the future operating income stream. This information, coupled with historical data about mortgage loan performance, is used to project the probability of default, the amount of loss given a default, and the resulting lifetime expected loss. Credit Losses on Alternative Investments We review our alternative investment portfolio for potential credit losses through quarterly fund reports and conversations with the general partners of the alternative investments concerning the following: • The current investment strategy; • Changes made or future changes to be made to the investment strategy; • Emerging issues that may affect the success of the strategy; and • The appropriateness of the valuation methodology used regarding the underlying investments. Credit Losses on Other Investments Our evaluation for potential credit loss on tax credits and FHLB Stock include a qualitative assessment of credit indicators, which include, but are not limited to, the following: • An adverse development of the expected receipt of remaining tax credits and other tax benefits; and • A significant deterioration in the financial condition or liquidity of the Federal Home Loan Bank.
Fair Value of Financial Instruments	Fair Values of Financial Instruments Assets The fair values of our investments are generated using various valuation techniques and are placed into the fair value hierarchy considering the following: (i) the highest priority is given to quoted prices in active markets for identical assets (Level 1); (ii) the next highest priority is given to quoted prices in markets that are not active or inputs that are observable either directly or indirectly, including quoted prices for similar assets in markets that are not active and other inputs that can be derived principally from, or corroborated by, observable market data for substantially the full term of the assets (Level 2); and (iii) the lowest priority is given to unobservable inputs supported by little or no market activity and that reflect our assumptions about the exit price, including assumptions that market participants would use in pricing the asset (Level 3). An asset’s classification within the fair value hierarchy is based on the lowest level of significant input to its valuation. The techniques used to value our financial assets are as follows: Level 1 Pricing Security Type Methodology Equity Securities; U.S. Treasury Notes Equity and U.S. Treasury Note prices are received from an independent pricing service that are based on observable market transactions. We validate these prices against a second external pricing service, and if established market value comparison thresholds are breached, further analysis is performed to determine the price to be used. Short-Term Investments Short-term investments are recorded at fair value. Given the liquid nature of our short-term investments, we generally validate their fair value by way of active trades within approximately one week of the financial statement close. Level 2 Pricing We utilize a market approach for our Level 2 securities, using primarily matrix pricing models prepared by external pricing services. Matrix pricing models use mathematical techniques to value fixed income securities by relying on the securities' relationship to other benchmark quoted securities, and not relying exclusively on quoted prices for specific securities, as the specific securities are not always frequently traded. As a matter of policy, we consistently use one pricing service as our primary source and secondary pricing services if prices are not available from the primary pricing service. Fixed income security pricing is reviewed for reasonableness by (i) comparing our pricing to other third-party pricing services as well as benchmark indexed pricing, (ii) comparing fair value fluctuations between months for reasonableness, (iii) reviewing stale prices, and (iv) internally reviewing prices for reasonableness if a price from another third-party source is not available. If further analysis is needed, a challenge is sent to the pricing service for review and confirmation of the price. Further information on our Level 2 asset pricing is included in the following table: Security Type Methodology Corporate Securities, including preferred stocks classified as Fixed Income Securities, and U.S. Government and Government Agencies Evaluations include obtaining relevant trade data, benchmark quotes and spreads, and incorporating this information into either spread-based or price-based evaluations as determined by the observed market data. Spread-based evaluations include: (i) creating a range of spreads for relevant maturities of each issuer based on the new issue market, secondary trading, and dealer quotes; and (ii) incorporating option adjusted spreads for issues that have early redemption features. Based on the findings in (i) and (ii) above, final spreads are derived and added to benchmark curves. Price-based evaluations include matching each issue to its best-known market maker and contacting firms that transact in these securities. Obligations of States and Political Subdivisions Evaluations are based on yield curves that are developed based on factors such as: (i) benchmarks to issues with interest rates near prevailing market rates; (ii) established trading spreads over widely-accepted market benchmarks; (iii) yields on new issues; and (iv) market information from third-party sources such as reportable trades, broker-dealers, or issuers. RMBS, CMBS, CLO and other ABS Evaluations are based on a DCF, including: (i) generating cash flows for each tranche considering tranche-specific data, market data, and other pertinent information, such as historical performance of the underlying collateral, including net operating income generated by the underlying properties, conditional default rate assumptions, loan loss severity assumptions, consensus projections, prepayment projections, and actual pool and loan level collateral information; (ii) identifying applicable benchmark yields; and (iii) applying market-based tranche-specific spreads to determine an appropriate yield by incorporating collateral performance, tranche-level attributes, trades, bids, and offers. Foreign Government Evaluations are performed using a DCF model and by incorporating observed market yields of benchmarks as inputs, adjusting for varied maturities. Level 3 Pricing Security Type Methodology CMLs Evaluations are performed by a third-party and are based on matrix pricing. For fixed rate loans, the matrix process uses a yield build up approach to create a pricing yield, with components for base yield, credit quality spread, property type spread, and a weighted average life spread. Floating rate loans are priced with a target quality spread over the swap curve. In addition to our CML portfolio, certain securities in our AFS fixed income portfolio are priced using unobservable inputs. These valuations are primarily based on broker quotes, or they are received from other third-party sources, for which there is a lack of transparency as to the inputs used to generate the valuation. The quantitative detail of these unobservable inputs is neither provided to us, nor reasonably available to us. Liabilities The techniques used to value our notes payable are as follows: Level 2 Pricing Security Type Methodology 7.25% Senior Notes; 6.70% Senior Notes; Based on matrix pricing models prepared by external pricing services. Borrowings from Federal Home Loan Banks Evaluations are performed using a DCF model based on current borrowing rates provided by the Federal Home Loan Banks that are consistent with the remaining term of the borrowing.
Allowance for Uncollectible Accounts	Allowance for Credit Losses on Premiums Receivable We estimate an ACL on our outstanding premiums receivable balance at each reporting date. In determining this allowance, we use a method that considers the aging of the receivable, based on the effective year of the related policy, along with our historical receivable loss experience. We also contemplate expected macroeconomic conditions over the expected collection period, which are short-term in nature because the majority of the balances are collected within two years of policy issuance. Changes in our ACL are charged to earnings as credit loss expense or benefit, which is a component of "Other insurance expenses" on our Consolidated Statements of Income, with an offsetting ACL recorded as a contra-asset reflected in the
Share-Based Compensation	Share-Based CompensationShare-based compensation consists of all share-based payment transactions in which an entity acquires goods or services by issuing (or offering to issue) its shares, share units, share options, or other equity instruments. The cost resulting from all share-based payment transactions are recognized in the Financial Statements based on the fair value of both equity and liability awards. The fair value is measured at grant date for equity awards, whereas the fair value for liability awards are remeasured at each reporting period. The fair value of both equity and liability awards is recognized over the requisite service period. The requisite service period is typically the lesser of the vesting period or the period of time from the grant date to the date of retirement eligibility. The expense recognized for share-based awards, which, in some cases, contain performance criteria, is based on the number of shares or units expected to be issued at the end of the performance period. We repurchase the Parent’s stock from our employees in connection with tax withholding obligations, as permitted under our stock-based compensation plans. This activity is disclosed in our Consolidated Statement of Stockholders' Equity.
Reinsurance	Reinsurance The “Reinsurance recoverable” balance on our Consolidated Balance Sheet represents our estimate of amounts that will be recovered from reinsurers under our various treaties. Generally, amounts recoverable from reinsurers are recognized as assets at the same time and in a manner consistent with the paid and unpaid losses associated with the reinsured policies. We would consider a recoverable balance from a reinsurer to be past due if payment is not received by the first day following the invoice due date. We require collateral to secure reinsurance recoverable balances primarily from our reinsurance carriers that are not authorized, otherwise approved, or certified to do business in one or more of our ten insurance subsidiaries' domiciliary states. Our ten insurance subsidiaries are collectively referred to as the "Insurance Subsidiaries." The collateral received is typically in the form of a letter of credit, trust funds, or funds withheld against reinsurance recoverables. We estimate an ACL on our outstanding reinsurance recoverable balance at each reporting date. Credit risk is mitigated to the extent we have obtained collateral. As part of our estimation of the ACL, we reduce the recoverable balance by the amount of the collateral. We then pool the uncollateralized balances by similar risk characteristics, including the financial strength rating of the reinsurer, and use a probability-of-default methodology to calculate the allowance. Historical default rates are sourced from AM Best Company ("AM Best") and are coupled with severity assumptions in developing a baseline scenario. We then stress this scenario by incorporating forecasts of industry catastrophe losses and economic factors sourced through third-party data providers. In developing our best estimate of the allowance for credit losses, we consider our outlook as to the probability of each of these scenarios occurring.
Property and Equipment	Property and Equipment Property and equipment used in operations, including certain costs incurred to develop or obtain computer software for internal use, are capitalized and recorded at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. The following estimated useful lives can be considered as general guidelines: Asset Category Years Computer hardware 3 Computer software 3 to 5 Software licenses 3 to 5 Internally developed software 5 Furniture and fixtures 10 Buildings and improvements 5 to 40
Deferred Policy Acquisition Costs	Deferred Policy Acquisition CostsDeferred policy acquisition costs are limited to costs directly related to the successful acquisition of insurance contracts. Costs meeting this definition typically include, among other things, sales commissions paid to our distribution partners, premium taxes, and the portion of employee salaries and benefits directly related to time spent on acquired contracts. These costs are deferred and amortized over the life of the contracts. Accounting guidance requires a premium deficiency analysis to be performed at the level an entity acquires, services, and measures the profitability of its insurance contracts. We currently perform three premium deficiency analyses for our insurance operations, consistent with our reportable segments of Standard Commercial Lines, Standard Personal Lines, and E&S Lines. A combined ratio of over 100% does not necessarily indicate a premium deficiency, as any year's combined ratio includes a portion of underwriting expenses that are expensed at policy inception and therefore are not covered by the remaining unearned premium. In addition, investment income is not contemplated in the combined ratio calculation.
Goodwill	GoodwillGoodwill results from business acquisitions where the cost of assets and liabilities acquired exceeds the fair value of those assets and liabilities. A quantitative goodwill impairment analysis is performed if our quarterly qualitative analysis indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. Goodwill is allocated to the reporting units for purposes of these analyses. Based on our analysis at December 31, 2022, goodwill was not impaired.
Reserve for Loss and Loss Expense	Reserve for Loss and Loss Expense Reserves for loss and loss expense includes case reserves on reported claims and reserves known as incurred but not reported ("IBNR") reserves. Case reserves are estimated on each individual claim, and based on claim-specific facts and circumstances known at the time. The case reserves may be adjusted upward or downward as the specific facts and circumstances change. IBNR reserves are established at more aggregated levels and include provisions for (i) claims not yet reported, (ii) future development on reported claims, (iii) previously closed claims that could be reopened in the future, and (iv) anticipated salvage and subrogation recoveries. We evaluate our reserves quarterly, through our comprehensive reserve review process and adjustments to recorded reserves are made accordingly. The primary input in evaluating reserve levels is the quarterly reserve review prepared by our internal actuaries, which provides comprehensive loss and loss expense projections. Our reviews are based primarily on our own loss experience, organized by line of business. Where sufficient statistical credibility exists, we may further segment the experience by coverage within line, or by geographic area. Generally accepted actuarial methodologies are applied to these reserve groups to produce ultimate loss and loss expense projections. Typically, we organize our experience by accident year and age, which lends itself to the application of various loss development methods. These methods rely on historical claims reporting and payment patterns to project ultimate loss or expense for open accident years. Consideration is also given to the prior loss estimate, particularly for longer-tailed lines of business, and the current accident year. For the current accident year, this expectation comes from our detailed actuarial planning process. The initial estimate is adjusted over time as actual experience emerges. These methods require numerous assumptions, such as the selection of loss and loss expense development factors and the weight applied to each individual projection method, among others. Therefore, no single method can be interpreted as definitive. Instead, ultimate loss and loss expenses are selected based on the various methods, considering the strengths and weaknesses of each as it applies to the specific line of business and accident year. Certain liabilities, by their nature, do not lend themselves to loss development methods. Examples include property catastrophes (low frequency/high severity, unique events), latent claims (where losses are incurred over an extended period of time), and unallocated loss expenses (loss expenses that cannot be attributed to a specific claim). Alternate estimation techniques are used for these liabilities, some of which are primarily exposure-based methods. These methods include individual claims reviews, calendar year counts and averages, aggregate benchmark measures, such as paid and incurred “survival ratios,” and others. These approaches often require additional assumptions and a greater amount of professional judgment. The result of the reserve review is a set of ultimate loss and loss expense estimates by line of business, including the current and prior accident years. The selected ultimate losses are separated into their components of claim frequency and severity, along with their associated trends, to provide additional insight. While these ultimate loss and loss expense estimates serve as the primary basis for determining the recorded IBNR reserves, other internal and external factors are considered in our overall reserve review. Internal factors include (i) changes to our underwriting and claims practices, (ii) supplemental data on claims reporting and settlement trends, (iii) exposure estimates for reported claims, (iv) potential large or complex claims, and (v) additional trends observed by claims personnel or defense counsel. External factors considered include (i) legislative and regulatory enactments, (ii) judicial trends and decisions, (iii) social trends, including the impacts of social inflation, and (iv) trends in general economic conditions, including the effects of inflation on medical costs, raw materials, and labor. The combination of IBNR estimates and case reserve estimates on individual claims results in our total reserves for loss and loss expense. These reserves are expected to be sufficient for settling loss and loss expense obligations under our policies on unpaid claims, including changes in the (i) volume of business written, (ii) claims frequency and severity, (iii) mix of business, (iv) claims processing, and (v) other items that management expects to affect our ultimate settlement of loss and loss expense. However, our loss and loss expense reserves are estimates of future events, the outcomes of which are not yet known. As with all estimates, they carry inherent uncertainty, which may be driven by internal factors, such as changes to our claims or underwriting operations, or external factors, such as changes in legislative, judicial, economic, or social trends. Actual outcomes are further impacted by inherent randomness, such as the actual number of accidents/incidents, or the occurrence or non-occurrence of a single large event. Because of these uncertainties, it is possible that actual outcomes will differ materially from the reserves established. While this risk cannot be eliminated, we review our reserves quarterly based on the information available at that time, and make adjustments to our ultimate loss and loss expense estimates accordingly. These changes in our ultimate loss and loss expense estimates are reflected in the Consolidated Statements of Income for the period in which such estimates are changed. Changes in the liability estimate could be material to the results of operations in future periods. Loss reserves are estimates, and as such, we also consider a range of possible loss and loss expense reserve estimates. This range is determined at the beginning of each year, using prior year-end data, and reflects the fact that there is no single precise method for estimating the required reserves, due to the many factors that may influence the amounts ultimately paid. We do not discount to present value that portion of our loss and loss expense reserves expected to be paid in future periods. Our loss and loss expense reserves implicitly include anticipated recoveries for salvage and subrogation claims. Claims are counted at the occurrence, line of business, and policy level. For example, if a single occurrence (e.g. an automobile accident) leads to a claim under an automobile and an associated umbrella policy, they are each counted separately. Conversely, multiple claimants under the same occurrence/line/policy would contribute only a single count. The claim counts provided are on a reported basis. A claim is considered reported when a reserve is established or a payment is made. Therefore, claims closed without payment are included in the count as long as there was an associated case reserve at some point in its life cycle.
Revenue Recognition	Revenue RecognitionPremiums written are recognized as revenue over the period that coverage is provided using the semi-monthly pro-rata method. Unearned premiums and prepaid reinsurance premiums represent that portion of premiums written that are applicable to the unexpired terms of policies in force.The Insurance Subsidiaries' net premiums written (“NPW”) include direct insurance policy writings, plus reinsurance assumed, less reinsurance ceded. The estimated premium on the workers compensation and general liability lines is referred to as audit premium. We estimate this premium, as it is anticipated to be either billed or returned on policies subsequent to expiration based on exposure levels (i.e. payroll or sales) when it is reasonably possible to do so based on historical trends adjusted for the uncertainty of future economic conditions. If we determine it is not reasonably possible to estimate this premium, we do not do so.
Dividends to Policyholders	Dividends to PolicyholdersWe establish reserves for dividends to policyholders on certain policies, most significantly workers compensation policies. These dividends are based on the policyholders' loss experience. Dividend reserves are established based on past experience, adjusted for the effects of current developments and anticipated trends. The expense for these dividends is recognized over a period that begins at policy inception and ends with the payment of the dividend. We report these dividends within "Other insurance expenses" on the Consolidated Statement of Income. We do not issue policies that entitle the policyholder to participate in the statutory earnings or surplus of our Insurance Subsidiaries.
Federal Income Tax	Federal Income TaxWe use the asset and liability method of accounting for income taxes. Current federal income taxes are recognized for the estimated taxes payable or refundable on tax returns for the current year. Deferred federal income taxes arise from the recognition of temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities. We consider all evidence, both positive and negative, with respect to our federal net operating and capital loss carryback availability, expected levels of pre-tax financial statement income, and federal taxable income, when evaluating whether the temporary differences will be realized. In projecting future taxable income, we begin with budgeted pre-tax income adjusted for estimated taxable and non-taxable items. The assumptions about future taxable income require significant judgment and are consistent with the plans and estimates we use to manage our businesses. A valuation allowance is established when it is more likely than not that some portion of the deferred tax asset will not be realized. The evaluation of a valuation allowance considers the character of the taxable income, ordinary income versus capital income. A liability for uncertain tax positions is recorded when it is more likely than not that a tax position will not be sustained upon examination by taxing authorities. The effect of a change in tax rates is recognized in the period of enactment. If we were to be levied interest and penalties by the Internal Revenue Service, these amounts would be recognized as a component of “Total federal income tax expense” on the Consolidated Statement of Income.
Leases	LeasesWe have various operating leases for office space, equipment, and fleet vehicles. In addition, we have various finance leases for computer hardware. We determine if an arrangement is a lease on the commencement date of the contract. Lease assets represent our right to use an underlying asset for the lease term, and lease liabilities represent our obligation to make lease payments arising from the lease. The lease asset and liability are measured by the present value of the future minimum lease payments over the lease term. Our fleet vehicle leases include a residual value guarantee; however, the residual value guarantee is not probable of being owed. Therefore, there is no impact to the lease liability or lease asset. To measure the present value, we use the discount rate in the contract. If the discount rate is not readily determinable, our incremental borrowing rate is used. The lease asset is then adjusted to exclude lease incentives. We recognize variable lease payments in the periods in which the obligations for those payments are incurred. In calculating a lease liability, we include options to extend or terminate the lease if it is reasonably certain that we will exercise such option. Lease expense is calculated using the straight-line method. In addition, we have adopted accounting policy elections to: (i) aggregate lease and non-lease components into a single lease component; and (ii) expense short-term leases on a straight-line basis over the lease term.
Pension	Pension Our pension obligations and related costs are calculated using actuarial methods, within the framework of GAAP. Our pension benefit obligation is determined as the actuarial present value of the vested benefits to which employees are currently entitled, based on the average life expectancy of the employees. Our funding policy provides that payments to our pension trust shall be equal to the minimum funding requirements of the Employee Retirement Income Security Act of 1974 ("ERISA"), plus additional amounts that the Board of Directors (the "Board") of Selective Insurance Company of America (“SICA”) may approve from time to time. Two key assumptions, the benefit obligation discount rate and the expected return on plan assets, are important elements of expense and/or liability measurement. We evaluate these key assumptions annually unless facts indicate that a more frequent review is required. The discount rate enables us to state expected future cash flows at their present value on the measurement date. The purpose of the discount rate is to determine the interest rates inherent in the price at which pension benefits could be effectively settled. Our discount rate selection is based on high-quality, long-term corporate bonds. To determine the expected long-term rate of return on the plan assets, we consider the current and expected asset allocation, as well as historical and expected returns on each plan asset class. Other assumptions involve demographic factors such as retirement age and mortality. A portion of our plan assets is allocated to a liability hedging strategy through which we have an expectation that our plan assets will move in tandem with a portion of the plan liabilities, helping to mitigate funding ratio volatility.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Estimated Useful Life for Property and Equipment	Asset Category Years Computer hardware 3 Computer software 3 to 5 Software licenses 3 to 5 Internally developed software 5 Furniture and fixtures 10 Buildings and improvements 5 to 40

Statements of Cash Flow (Tables

Statements of Cash Flow (Tables)	12 Months Ended
	Dec. 31, 2022
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	($ in thousands) 2022 2021 2020 Cash paid during the period for: Interest $ 26,639 28,930 30,464 Federal income tax 75,000 100,000 47,000 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases 8,148 7,935 9,498 Operating cash flows from financing leases 46 35 15 Financing cash flows from finance leases 2,438 1,768 550 Non-cash items: Corporate actions related to fixed income securities, AFS 1 38,106 56,365 55,446 Corporate actions related to fixed income securities, held-to-maturity ("HTM") 1 — — 2,589 Corporate actions related to equity securities 1 — 30,666 10,890 Conversion of AFS fixed income securities to equity securities 1,463 15,139 — Assets acquired under finance lease arrangements 707 6,709 324 Assets acquired under operating lease arrangements 16,649 3,272 22,390 Non-cash purchase of property and equipment 70 472 590 1 Examples of corporate actions include like-kind exchanges, non-cash acquisitions, and stock-splits.
Schedule of Cash and Cash Equivalents	($ in thousands) December 31, 2022 December 31, 2021 Cash $ 26 455 Restricted cash 25,183 44,608 Total cash and restricted cash shown in the Statements of Cash Flows $ 25,209 45,063

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2022
Investment [Line Items]
Schedule of Unrealized Gains (Losses) On Investments	($ in thousands) 2022 2021 2020 AFS securities: Fixed income securities $ (527,926) 228,947 386,380 Total AFS securities (527,926) 228,947 386,380 HTM securities: Fixed income securities — (4) 7 Total HTM securities — (4) 7 Short-term securities 35 20 6 Total net unrealized (losses) gains (527,891) 228,963 386,393 Deferred income tax 110,857 (48,082) (81,142) Net unrealized (losses) gains, net of deferred income tax (417,034) 180,881 305,251 (Decrease) increase in net unrealized (losses) gains in OCI, net of deferred income tax $ (597,915) (124,370) 134,857
Schedule of Available For Sale Securities	December 31, 2022 Cost/ Amortized Allowance for Unrealized Unrealized Fair ($ in thousands) Cost Credit Losses Gains Losses Value AFS fixed income securities: U.S. government and government agencies $ 209,528 — 37 (20,326) 189,239 Foreign government 11,199 (284) — (1,307) 9,608 Obligations of states and political subdivisions 965,231 (1,024) 1,812 (48,001) 918,018 Corporate securities 2,558,655 (30,330) 3,509 (196,809) 2,335,025 CLO and other ABS 1,607,660 (2,375) 2,408 (121,720) 1,485,973 RMBS 1,169,546 (11,597) 1,148 (99,265) 1,059,832 CMBS 663,935 (111) 348 (49,760) 614,412 Total AFS fixed income securities $ 7,185,754 (45,721) 9,262 (537,188) 6,612,107 December 31, 2021 Cost/ Amortized Allowance for Unrealized Unrealized Fair ($ in thousands) Cost Credit Losses Gains Losses Value AFS fixed income securities: U.S. government and government agencies $ 127,974 — 3,629 (1,145) 130,458 Foreign government 15,420 (46) 609 (123) 15,860 Obligations of states and political subdivisions 1,121,422 (137) 68,258 (235) 1,189,308 Corporate securities 2,478,348 (6,682) 106,890 (4,953) 2,573,603 CLO and other ABS 1,343,687 (939) 14,350 (6,284) 1,350,814 RMBS 756,280 (1,909) 24,813 (2,932) 776,252 CMBS 647,622 (11) 27,752 (1,682) 673,681 Total AFS fixed income securities $ 6,490,753 $ (9,724) 246,301 (17,354) 6,709,976
Schedule of debt securities, available-for-sale, allowance for credit losses	2022 Beginning Balance Current Provision for Securities without Prior Allowance Initial Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirements) to Sell Securities Reductions for Securities Sold Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period Ending Balance ($ in thousands) Foreign government $ 46 291 — 4 (57) — 284 Obligations of states and political subdivisons 137 1,087 — (6) (194) — 1,024 Corporate securities 6,682 30,670 — 3,714 (6,902) (3,834) 30,330 CLO and other ABS 939 2,158 — (652) (50) (20) 2,375 RMBS 1,909 245 8,318 1,558 (433) — 11,597 CMBS 11 110 — (10) — — 111 Total AFS fixed income securities $ 9,724 34,561 8,318 4,608 (7,636) (3,854) 45,721 2021 Beginning Balance Current Provisions for Securities without Prior Allowance Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirements) to Sell Securities Reductions for Securities Sold Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period Ending Balance ($ in thousands) Foreign government $ 1 46 (1) — — 46 Obligations of states and political subdivisons 4 122 11 — — 137 Corporate securities 2,782 5,785 (992) (723) (170) 6,682 CLO and other ABS 592 579 (211) (21) — 939 RMBS 561 1,593 (63) (182) — 1,909 CMBS 29 10 (28) — — 11 Total AFS fixed income securities $ 3,969 8,135 (1,284) (926) (170) 9,724
Schedule of Fair Value and Gross Pre-Tax Net Unrealized/Unrecognized Loss of Securities by Length of Time	December 31, 2022 Less than 12 months 12 months or longer Total ($ in thousands) Fair Unrealized Fair Unrealized Fair Unrealized AFS fixed income securities: U.S. government and government agencies $ 166,975 (13,658) 16,011 (6,668) 182,986 (20,326) Foreign government 5,573 (608) 2,456 (699) 8,029 (1,307) Obligations of states and political subdivisions 681,795 (43,767) 16,618 (4,234) 698,413 (48,001) Corporate securities 1,889,492 (164,197) 133,223 (32,612) 2,022,715 (196,809) CLO and other ABS 916,423 (69,155) 411,283 (52,565) 1,327,706 (121,720) RMBS 887,229 (76,432) 108,041 (22,833) 995,270 (99,265) CMBS 512,953 (37,815) 77,181 (11,945) 590,134 (49,760) Total AFS fixed income securities $ 5,060,440 (405,632) 764,813 (131,556) 5,825,253 (537,188) December 31, 2021 Less than 12 months 12 months or longer Total ($ in thousands) Fair Unrealized Fair Unrealized Fair Unrealized AFS fixed income securities: U.S. government and government agencies $ 34,857 (746) 7,827 (399) 42,684 (1,145) Foreign government 2,000 (84) 1,061 (39) 3,061 (123) Obligations of states and political subdivisions 25,837 (235) — — 25,837 (235) Corporate securities 300,549 (4,903) 2,520 (50) 303,069 (4,953) CLO and other ABS 663,976 (4,934) 53,368 (1,350) 717,344 (6,284) RMBS 236,010 (2,931) 20 (1) 236,030 (2,932) CMBS 112,899 (1,016) 20,326 (666) 133,225 (1,682) Total AFS fixed income securities $ 1,376,128 (14,849) 85,122 (2,505) 1,461,250 (17,354)
Schedule of Investments Classified by Contractual Maturity Date	AFS HTM ($ in thousands) Fair Value Carrying Value Fair Value Due in one year or less $ 324,394 6,093 6,090 Due after one year through five years 2,928,594 3,779 3,798 Due after five years through 10 years 2,600,001 21,285 19,949 Due after 10 years 759,118 — — Total fixed income securities $ 6,612,107 31,157 29,837
Schedule of Other Investment Portfolio by Strategy and the Remaining Commitment Amount Associated With Each Strategy	December 31, 2022 December 31, 2021 ($ in thousands) Carrying Remaining Maximum Carrying Remaining Maximum Alternative investments Private equity $ 280,980 134,676 415,656 273,070 99,734 372,804 Private credit 54,866 89,481 144,347 63,138 92,674 155,812 Real assets 35,470 21,945 57,415 23,524 22,579 46,103 Total alternative investments 371,316 246,102 617,418 359,732 214,987 574,719
Schedule of Aggregated Summarized Balance Sheet Financial Information For Partnerships In Our Alternative Investment Portfolio	Balance Sheet Information December 31, ($ in millions) 2022 2021 Investments $ 114,038 107,347 Total assets 128,158 112,232 Total liabilities 15,464 12,371 Total partners’ capital 112,694 99,861
Schedule of Aggregated Summarized Income Statement Financial Information For Partnerships In Our Alternative Investment Portfolio	Income Statement Information 12 months ended September 30, ($ in millions) 2022 2021 2020 Net investment income (loss) $ 765 653 (26) Realized gains 12,590 6,121 1,452 Net change in unrealized appreciation (5,215) 26,877 4,898 Net income $ 8,140 33,651 6,324 Alternative investment income included in "Net investment income earned" on our Consolidated Statements of Income 23.0 117.7 26.5
Schedule Of Securities Pledged As Collateral	($ in millions) FHLBI Collateral FHLBNY Collateral Regulatory Deposits Total U.S. government and government agencies $ — — 19.3 19.3 Obligations of states and political subdivisions — — 3.6 3.6 RMBS 61.4 28.8 — 90.2 CMBS 4.6 9.6 — 14.2 Total pledged as collateral $ 66.0 38.4 22.9 127.3
Schedule of Components of Pre-Tax Net Investment Income Earned	($ in thousands) 2022 2021 2020 Fixed income securities $ 259,918 209,709 203,926 CMLs 5,555 2,743 844 Equity securities 13,554 15,920 9,286 Short-term investments 3,997 260 1,821 Alternative investments 23,003 117,701 26,504 Other investments 258 359 418 Investment expenses (18,130) (20,103) (15,692) Net investment income earned $ 288,155 326,589 227,107
Schedule of realized and unrealized gains (losses) on securities	($ in thousands) 2022 2021 2020 Gross gains on sales $ 28,419 15,284 18,893 Gross losses on sales (60,055) (8,140) (9,745) Net realized (losses) gains on disposals (31,636) 7,144 9,148 Net unrealized (losses) gains on equity securities (32,127) 17,881 7,939 Net credit loss (expense) on fixed income securities, AFS (39,169) (6,858) (5,042) Net credit loss (expense) benefit on fixed income securities, HTM 63 (49) 4 Net credit loss (expense) on CMLs (116) — — Losses on securities for which we have the intent to sell (11,823) (519) (16,266) Net realized and unrealized investment (losses) gains $ (114,808) 17,599 (4,217)
Unrealized Gain (Loss) on Equity Securities	($ in thousands) 2022 2021 2020 Unrealized (losses) gains recognized in income on equity securities: On securities remaining in our portfolio at end of period $ (10,454) 16,473 7,936 On securities sold in period (21,673) 1,408 3 Total unrealized (losses) gains recognized in income on equity securities $ (32,127) 17,881 7,939

Comprehensive Income (Tables)

Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2022
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Schedule of Components of Comprehensive Income-Gross and Net of Tax	2022 ($ in thousands) Gross Tax Net Net income $ 280,186 55,300 224,886 Components of OCI: Unrealized (losses) gains on investment securities : Unrealized holding losses during the year (668,107) (140,302) (527,805) Unrealized losses on securities with credit loss recognized in earnings (187,968) (39,473) (148,495) Amounts reclassified into net income: HTM securities 4 1 3 Net realized losses on disposals and intent-to-sell AFS securities 60,048 12,610 47,438 Credit loss expense 39,169 8,225 30,944 Total unrealized losses on investment securities (756,854) (158,939) (597,915) Defined benefit pension and post-retirement plans: Net actuarial loss (20,941) (4,398) (16,543) Amounts reclassified into net income: Net actuarial loss 1,668 351 1,317 Total defined benefit pension and post-retirement plans (19,273) (4,047) (15,226) Other comprehensive loss (776,127) (162,986) (613,141) Comprehensive loss $ (495,941) (107,686) (388,255) 2021 ($ in thousands) Gross Tax Net Net income $ 505,310 101,473 403,837 Components of OCI: Unrealized (losses) gains on investment securities : Unrealized holding losses during the year (151,391) (31,793) (119,598) Unrealized losses on securities with credit loss recognized in earnings (9,061) (1,902) (7,159) Amounts reclassified into net income: HTM securities (11) (2) (9) Net realized gains on disposals and losses on intent-to-sell AFS securities (3,825) (803) (3,022) Credit loss expense 6,858 1,440 5,418 Total unrealized losses on investment securities (157,430) (33,060) (124,370) Defined benefit pension and post-retirement plans: Net actuarial gain 21,636 4,543 17,093 Amounts reclassified into net income: Net actuarial loss 2,772 582 2,190 Total defined benefit pension and post-retirement plans 24,408 5,125 19,283 Other comprehensive loss (133,022) (27,935) (105,087) Comprehensive income $ 372,288 73,538 298,750 2020 ($ in thousands) Gross Tax Net Net income $ 302,988 56,633 246,355 Components of OCI: Unrealized gains (losses) on investment securities : Unrealized holding gains during the year 168,487 35,383 133,104 Unrealized losses on securities with credit loss recognized in earnings (8,176) (1,717) (6,459) Amounts reclassified into net income: HTM securities (24) (5) (19) Net realized losses on disposals and intent-to-sell AFS securities 5,376 1,129 4,247 Credit loss expense 5,042 1,058 3,984 Total unrealized gains on investment securities 170,705 35,848 134,857 Defined benefit pension and post-retirement plans: Net actuarial gain 1,515 318 1,197 Amounts reclassified into net income: Net actuarial loss 3,015 633 2,382 Total defined benefit pension and post-retirement plans 4,530 951 3,579 Other comprehensive income 175,235 36,799 138,436 Comprehensive income $ 478,223 93,432 384,791
Schedule of Components of Accumulated Other Comprehensive Income	Net Unrealized (Losses) Gains on Investment Securities Defined Benefit Pension and Post-retirement Plans ($ in thousands) Credit Loss Related 1 HTM Related All Other Investments Subtotal Total AOCI Balance, December 31, 2020 $ (2,546) 6 307,790 305,250 (85,064) 220,186 OCI before reclassifications (7,159) — (119,598) (126,757) 17,093 (109,664) Amounts reclassified from AOCI 5,418 (9) (3,022) 2,387 2,190 4,577 Net current period OCI (1,741) (9) (122,620) (124,370) 19,283 (105,087) Balance, December 31, 2021 (4,287) (3) 185,170 180,880 (65,781) 115,099 OCI before reclassifications (148,495) — (527,805) (676,300) (16,543) (692,843) Amounts reclassified from AOCI 30,944 3 47,438 78,385 1,317 79,702 Net current period OCI (117,551) 3 (480,367) (597,915) (15,226) (613,141) Balance, December 31, 2022 $ (121,838) — (295,197) (417,035) (81,007) (498,042)
Schedule of Reclassification out of Accumulated Other Comprehensive Income	($ in thousands) Year ended December 31, 2022 Year ended December 31, 2021 Affected Line Item in the Consolidated Statements of Income HTM related Unrealized gains on HTM disposals $ (7) (14) Net realized and unrealized investment (losses) gains Amortization of net unrealized losses on HTM securities 11 3 Net investment income earned 4 (11) Income before federal income tax (1) 2 Total federal income tax expense 3 (9) Net income Net realized losses (gains) on disposals and losses on intent-to-sell AFS securities Net realized losses (gains) on disposals and losses on intent-to-sell AFS securities 60,048 (3,825) Net realized and unrealized investment (losses) gains 60,048 (3,825) Income before federal income tax (12,610) 803 Total federal income tax expense 47,438 (3,022) Net income Credit loss related Credit loss expense 39,169 6,858 Net realized and unrealized investment (losses) gains 39,169 6,858 Income before federal income tax (8,225) (1,440) Total federal income tax expense 30,944 5,418 Net income Defined benefit pension and post-retirement life plans Net actuarial loss 359 638 Loss and loss expense incurred 1,309 2,134 Other insurance expenses Total defined benefit pension and post-retirement life 1,668 2,772 Income before federal income tax (351) (582) Total federal income tax expense 1,317 2,190 Net income Total reclassifications for the period $ 79,702 4,577 Net income

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Carrying Amounts and Estimated Fair Values of Financial Instruments	December 31, 2022 December 31, 2021 ($ in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Financial Liabilities Long-term debt: 7.25% Senior Notes $ 49,921 51,705 49,917 63,719 6.70% Senior Notes 99,542 99,264 99,520 127,574 5.375% Senior Notes 294,424 258,459 294,330 395,652 3.03% Borrowings from FHLBI 60,000 57,175 60,000 64,126 Subtotal long-term debt 503,887 466,603 503,767 651,071 Unamortized debt issuance costs (2,929) (3,167) Finance lease obligations 3,718 5,450 Total long-term debt $ 504,676 $ 506,050
Schedule of Quantitative Disclosures of our Financial Assets that were Measured at Fair Value	December 31, 2022 Fair Value Measurements Using ($ in thousands) Assets Measured at Fair Value Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 189,239 109,240 79,999 — Foreign government 9,608 — 9,608 — Obligations of states and political subdivisions 918,018 — 911,357 6,661 Corporate securities 2,335,025 — 2,147,045 187,980 CLO and other ABS 1,485,973 — 1,332,631 153,342 RMBS 1,059,832 — 1,059,832 — CMBS 614,412 — 614,037 375 Total AFS fixed income securities 6,612,107 109,240 6,154,509 348,358 Equity securities: Common stock 1 160,355 55,846 — 897 Preferred stock 1,645 1,645 — — Total equity securities 162,000 57,491 — 897 Short-term investments 440,456 418,199 22,257 — Total assets measured at fair value $ 7,214,563 584,930 6,176,766 349,255 December 31, 2021 Fair Value Measurements Using ($ in thousands) Assets Measured at Fair Value Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 130,458 60,615 69,843 — Foreign government 15,860 — 15,860 — Obligations of states and political subdivisions 1,189,308 — 1,181,563 7,745 Corporate securities 2,573,603 — 2,459,476 114,127 CLO and other ABS 1,350,814 — 1,225,905 124,909 RMBS 776,252 — 776,007 245 CMBS 673,681 — 669,425 4,256 Total AFS fixed income securities 6,709,976 60,615 6,398,079 251,282 Equity securities: Common stock 1 333,449 249,846 — — Preferred stock 2,088 2,088 — — Total equity securities 335,537 251,934 — — Short-term investments 447,863 442,723 5,140 — Total assets measured at fair value $ 7,493,376 755,272 6,403,219 251,282 1 Investments amounting to $103.6 million and $83.6 million at December 31, 2022 and December 31, 2021, respectively, were measured at fair value using the net asset value per share (or its practical expedient) and have not been classified in the fair value hierarchy. These investments are not redeemable and the timing of liquidations of the underlying assets is unknown at each reporting period. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total assets measured at fair value.
Schedule of Summary of the Changes in Fair Value of Securities Using Level 3 Inputs	2022 ($ in thousands) Obligations of states and political subdivisions Corporate Securities CLO and Other ABS RMBS CMBS Common Stock Total Fair value, December 31, 2021 $ 7,745 114,127 124,909 245 4,256 — 251,282 Total net (losses) gains for the period included in: OCI (985) (23,624) (11,287) (17) (481) — (36,394) Net realized and unrealized investment (losses) gains (99) (2,414) (876) — — — (3,389) Net investment income earned — 68 229 — 45 — 342 Purchases — 99,868 100,406 — — — 200,274 Sales — — — — — — — Issuances — — — — — — — Settlements — (10,148) (12,361) (11) (15) — (22,535) Transfers into Level 3 — 19,214 502 — — 897 20,613 Transfers out of Level 3 — (9,111) (48,180) (217) (3,430) — (60,938) Fair value, December 31, 2022 $ 6,661 187,980 153,342 — 375 897 349,255 Change in unrealized losses for the period included in earnings for assets held at period end (99) (2,399) (876) — — — (3,374) Change in unrealized losses for the period included in OCI for assets held at period end (985) (23,630) (11,246) (17) (481) — (36,359) 2021 ($ in thousands) Obligations of states and political subdivisions Corporate Securities CLO and Other ABS RMBS CMBS Total Fair value, December 31, 2020 $ 2,894 70,700 56,375 — — 129,969 Total net (losses) gains for the period included in: OCI (239) 1,636 (520) — (196) 681 Net realized and unrealized investment (losses) gains (11) (50) (214) — 5 (270) Net investment income earned — 27 16 — 19 62 Purchases — 64,813 76,731 249 98 141,891 Sales — — — — — — Issuances — — — — — — Settlements — (544) (5,161) (4) (52) (5,761) Transfers into Level 3 5,101 981 11,344 — 4,382 21,808 Transfers out of Level 3 — (23,436) (13,662) — — (37,098) Fair value, December 31, 2021 $ 7,745 114,127 124,909 245 4,256 251,282 Change in unrealized (losses) gains for the period included in earnings for assets held at period end (11) (50) (214) — 5 (270) Change in unrealized (losses) gains for the period included in OCI for assets held at period end (239) 1,636 (520) — (196) 681
Fair Value Measurement Inputs and Valuation Techniques	December 31, 2022 ($ in thousands) Assets Measured at Fair Value Valuation Techniques Unobservable Inputs Range Weighted Average Internal valuations: Corporate securities $ 81,867 Discounted Cash Flow Illiquidity Spread (4.4)% - 5.3% 1.3% CLO and other ABS 59,452 Discounted Cash Flow Illiquidity Spread 0.01% - 19.6% 2.5% Total internal valuations 141,319 Other 1 207,936 Total Level 3 securities $ 349,255 December 31, 2021 ($ in thousands) Assets Measured at Fair Value Valuation Techniques Unobservable Inputs Range Weighted Average Internal valuations: Corporate securities $ 54,135 Discounted Cash Flow Illiquidity Spread 0.3% - 3.0% (1.2)% CLO and other ABS 34,903 Discounted Cash Flow Illiquidity Spread 0.7% - 8.0% (2.1)% Total internal valuations 89,038 Other 1 162,244 Total Level 3 securities $ 251,282 1 Other is comprised of broker quotes or other third-party pricing for which there is a lack of transparency into the inputs used to develop the valuations. The quantitative details of these unobservable inputs is neither provided to us, nor reasonably available to us, and therefore are not included in the tables above.
Schedule of Quantitative Information of our Financial Assets and Liabilities that were Disclosed at Fair Value	December 31, 2022 Fair Value Measurements Using ($ in thousands) Assets/Liabilities Disclosed at Quoted Prices in Active Markets for Identical Assets/Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Financial Assets HTM: Obligations of states and political subdivisions $ 3,405 — 3,405 — Corporate securities 26,432 — 26,432 — Total HTM fixed income securities $ 29,837 — 29,837 — CMLs $ 139,243 — — 139,243 Financial Liabilities Long-term debt: 7.25% Senior Notes $ 51,705 — 51,705 — 6.70% Senior Notes 99,264 — 99,264 — 5.375% Senior Notes 258,459 — 258,459 — 3.03% Borrowings from FHLBI 57,175 — 57,175 — Total long-term debt $ 466,603 — 466,603 — December 31, 2021 Fair Value Measurements Using ($ in thousands) Assets/Liabilities Disclosed at Quoted Prices in Active Markets for Identical Assets/Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Financial Assets HTM: Obligations of states and political subdivisions $ 3,576 — 3,576 — Corporate securities 25,884 — 25,884 — Total HTM fixed income securities $ 29,460 — 29,460 — CMLs $ 97,598 — — 97,598 Financial Liabilities Long-term debt: 7.25% Senior Notes $ 63,719 — 63,719 — 6.70% Senior Notes 127,574 — 127,574 — 5.375% Senior Notes 395,652 — 395,652 — 3.03% Borrowings from FHLBI 64,126 — 64,126 — Total long-term debt $ 651,071 — 651,071 —

Allowance for Credit Losses o_2

Allowance for Credit Losses on Premiums Receivable (Tables)	12 Months Ended
	Dec. 31, 2022
Premiums Receivable [Abstract]
Allowance for Credit Losses on Premiums Receivable [Table Text Block]	($ in thousands) December 31, 2022 December 31, 2021 Balance at beginning of year $ 13,600 21,000 Current period change for expected credit losses 6,065 1,291 Write-offs charged against the allowance for credit losses (4,978) (9,343) Recoveries 1,413 652 ACL, end of year $ 16,100 13,600

Reinsurance (Tables)

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2022
Reinsurance Disclosures [Abstract]
Reinsurance Recoverable, Credit Quality Indicator	December 31, 2022 ($ in thousands) Current Past Due Total Reinsurance Recoverables Financial strength rating of rated reinsurers A++ $ 46,282 $ 1 $ 46,283 A+ 425,395 3,191 428,586 A 106,102 1,315 107,417 A- 7,148 89 7,237 Total rated reinsurers $ 584,927 $ 4,596 $ 589,523 Non-rated reinsurers Federal and state pools $ 180,794 $ — $ 180,794 Other than federal and state pools 13,678 415 14,093 Total non-rated reinsurers $ 194,472 $ 415 $ 194,887 Total reinsurance recoverable, gross $ 779,399 $ 5,011 $ 784,410 Less: ACL (1,600) Total reinsurance recoverable, net $ 782,810 December 31, 2021 ($ in thousands) Current Past Due Total Reinsurance Recoverables Financial strength rating of rated reinsurers A++ $ 38,601 $ 9 $ 38,610 A+ 339,857 1,520 341,377 A 95,675 1,227 96,902 A- 3,209 145 3,354 Total rated reinsurers $ 477,342 $ 2,901 $ 480,243 Non-rated reinsurers Federal and state pools $ 116,378 $ — $ 116,378 Other than federal and state pools 4,597 450 5,047 Total non-rated reinsurers $ 120,975 $ 450 $ 121,425 Total reinsurance recoverable, gross $ 598,317 $ 3,351 $ 601,668 Less: ACL (1,600) Total reinsurance recoverable, net $ 600,068
Reinsurance Recoverable, Allowance for Credit Loss	($ in thousands) December 31, 2022 December 31, 2021 Balance at beginning of year $ 1,600 $ 1,777 Current period change for expected credit losses — (177) Write-offs charged against the allowance for credit losses — — Recoveries — — ACL, end of year $ 1,600 $ 1,600 For a discussion of the methodology used to evaluate our estimate of expected credit losses on our reinsurance recoverable balance, refer to Note 2. "Summary of Significant Accounting Policies."
Schedule of Total Reinsurance Balances Segregated By Reinsurer	As of December 31, 2022 As of December 31, 2021 ($ in thousands) Reinsurance Balances % of Reinsurance Balance Reinsurance Balances % of Reinsurance Balance Total reinsurance recoverables, net of allowance for credit losses $ 782,810 $ 600,068 Total prepaid reinsurance premiums 172,371 183,007 Total reinsurance balance 955,181 783,075 Federal and state pools 1 : NFIP 276,541 29 % 223,845 29 % New Jersey Unsatisfied Claim Judgment Fund 45,496 5 49,738 6 Other 3,488 — 2,385 — Total federal and state pools 325,525 34 275,968 35 Remaining reinsurance balance $ 629,656 66 $ 507,107 65 Munich Re Group (AM Best rated "A+") $ 127,106 13 $ 108,381 14 Hannover Ruckversicherungs AG (AM Best rated "A+") 124,706 13 107,110 14 AXIS Reinsurance Company (AM Best rated "A") 70,957 8 70,814 9 Swiss Re Group (AM Best rated "A+") 36,525 4 29,186 4 Transatlantic Reinsurance Company (AM Best rated “A+”) 32,730 3 26,490 3 All other reinsurers 239,232 25 166,726 21 Total reinsurers 631,256 66 % 508,707 65 % Less: ACL (1,600) (1,600) Reinsurers, net of ACL 629,656 507,107 Less: collateral 2 (126,167) (128,699) Reinsurers, net of collateral $ 503,489 $ 378,408 1 Considered to have minimal risk of default. 2 Includes letters of credit, trust funds, and funds held against reinsurance recoverables.
Schedule of List Of Direct, Assumed, And Ceded Reinsurance Amounts	($ in thousands) 2022 2021 2020 Premiums written: Direct $ 4,068,518 3,656,537 3,204,512 Assumed 32,320 22,664 24,288 Ceded (527,248) (489,488) (455,708) Net $ 3,573,590 3,189,713 2,773,092 Premiums earned: Direct $ 3,880,522 3,472,715 3,108,687 Assumed 30,742 21,550 25,010 Ceded (537,884) (477,012) (451,883) Net $ 3,373,380 3,017,253 2,681,814 Loss and loss expense incurred: Direct $ 2,537,638 2,096,512 1,822,034 Assumed 23,160 13,813 17,201 Ceded (449,020) (296,341) (203,412) Net $ 2,111,778 1,813,984 1,635,823
Schedule of Ceded Premiums and Losses Related to Flood Operations	Ceded to NFIP ($ in thousands) 2022 2021 2020 Ceded premiums written $ (259,246) (284,311) (274,042) Ceded premiums earned (274,100) (274,384) (271,598) Ceded loss and loss expense incurred (200,467) (215,224) (78,993)

Reserve for Loss and Loss Exp_2

Reserve for Loss and Loss Expense (Tables)	12 Months Ended
	Dec. 31, 2022
Insurance Loss Reserves [Abstract]
Schedule of Roll Forward of Reserve for Loss and Loss Expense	($ in thousands) 2022 2021 2020 Gross reserves for loss and loss expense, at beginning of year $ 4,580,903 4,260,355 4,067,163 Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year 1 578,641 554,269 547,066 Net reserves for loss and loss expense, at beginning of year 4,002,262 3,706,086 3,520,097 Incurred loss and loss expense for claims occurring in the: Current year 2,190,668 1,896,837 1,708,755 Prior years (78,890) (82,853) (72,932) Total incurred loss and loss expense 2,111,778 1,813,984 1,635,823 Paid loss and loss expense for claims occurring in the: Current year 768,583 676,331 642,586 Prior years 958,149 841,477 807,248 Total paid loss and loss expense 1,726,732 1,517,808 1,449,834 Net reserves for loss and loss expense, at end of year 4,387,308 4,002,262 3,706,086 Add: Reinsurance recoverable on unpaid loss and loss expense, at end of year 757,513 578,641 554,269 Gross reserves for loss and loss expense at end of year $ 5,144,821 4,580,903 4,260,355
Schedule of (Favorable)/ Unfavorable Prior Year Development	(Favorable)/Unfavorable Prior Year Development ($ in millions) 2022 2021 2020 General Liability $ (5.0) (29.0) (35.0) Commercial Automobile 22.5 13.3 7.1 Workers Compensation (70.0) (58.0) (60.0) Businessowners' Policies (7.3) (0.4) 3.9 Commercial Property (1.6) (2.6) 9.2 Bonds (10.0) — — Homeowners (0.6) 1.8 7.7 Personal Automobile 0.5 (0.2) (1.8) E&S Casualty Lines (5.0) (7.0) — E&S Property Lines (2.5) (0.8) (4.0) Other 0.1 — — Total $ (78.9) (82.9) (72.9)
Schedule of Exposure to Various Asbestos and Environmental Claims	2022 ($ in millions) Gross Net Asbestos $ 5.9 4.7 Landfill sites 11.8 7.5 Underground storage tanks 10.1 8.1 Total $ 27.8 20.3
Schedule of Roll Forward of Gross and Net Asbestos and Environmental Incurred Losses and Loss Expenses and Related Reserves	2022 2021 2020 ($ in thousands) Gross Net Gross Net Gross Net Asbestos Reserves for loss and loss expense at beginning of year $ 6,115 4,884 6,254 5,023 6,288 5,057 Incurred loss and loss expense 8 8 51 51 320 320 Less: loss and loss expense paid (232) (232) (190) (190) (354) (354) Reserves for loss and loss expense at the end of year $ 5,891 4,660 6,115 4,884 6,254 5,023 Environmental Reserves for loss and loss expense at beginning of year $ 21,658 16,191 22,276 16,398 22,413 16,532 Incurred loss and loss expense 696 (213) (613) (14) (447) (474) Less: loss and loss expense paid (477) (309) (5) (193) 310 340 Reserves for loss and loss expense at the end of year $ 21,877 15,669 21,658 16,191 22,276 16,398 Total Asbestos and Environmental Claims Reserves for loss and loss expense at beginning of year $ 27,773 21,075 28,530 21,421 28,701 21,589 Incurred loss and loss expense 704 (205) (562) 37 (127) (154) Less: loss and loss expense paid (709) (541) (195) (383) (44) (14) Reserves for loss and loss expense at the end of year $ 27,768 20,329 27,773 21,075 28,530 21,421
Schedule of Short-duration Insurance Contracts, Claims Development	All Lines (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 1,044,142 1,062,045 1,047,230 1,021,007 1,002,316 987,763 984,858 973,739 957,958 951,813 33,631 91,959 2014 1,107,513 1,133,798 1,146,990 1,124,014 1,104,218 1,100,208 1,089,529 1,094,367 1,090,345 42,087 95,835 2015 1,114,081 1,130,513 1,144,830 1,138,313 1,119,441 1,108,860 1,103,592 1,103,543 45,698 95,173 2016 1,188,608 1,203,634 1,227,142 1,199,734 1,180,829 1,171,273 1,167,539 67,934 95,944 2017 1,270,110 1,313,372 1,313,585 1,288,526 1,268,941 1,273,039 84,415 99,877 2018 1,413,800 1,461,603 1,457,415 1,441,303 1,425,540 153,214 107,095 2019 1,483,945 1,523,041 1,526,566 1,529,859 272,639 104,096 2020 1,591,972 1,587,607 1,550,195 395,519 94,752 2021 1,784,661 1,781,054 636,984 97,914 2022 2,073,343 1,089,571 94,382 Total 13,946,270 All Lines (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 335,956 518,872 644,475 748,758 833,823 872,331 891,841 904,825 911,657 916,769 2014 405,898 614,075 736,154 855,959 936,425 981,868 1,002,157 1,020,961 1,032,400 2015 376,641 581,203 725,385 845,868 929,222 967,857 1,000,509 1,018,023 2016 387,272 617,958 764,331 892,390 983,852 1,025,264 1,061,952 2017 433,440 678,453 829,134 954,792 1,050,258 1,116,336 2018 511,271 779,466 942,893 1,083,556 1,187,744 2019 510,091 781,462 949,996 1,109,628 2020 572,302 831,976 988,463 2021 609,889 934,965 2022 699,789 Total 10,066,069 All outstanding liabilities before 2013, net of reinsurance 379,073 Liabilities for loss and loss expenses, net of reinsurance 4,259,274 General Liability (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 250,609 251,421 239,776 225,709 210,785 203,831 202,697 195,697 192,782 189,594 12,561 10,462 2014 244,312 249,946 257,132 239,333 234,082 237,125 229,679 230,247 228,933 18,901 10,704 2015 254,720 245,710 246,990 233,249 219,204 214,176 211,768 210,137 19,932 10,565 2016 277,214 272,048 277,986 263,245 252,733 246,643 243,669 30,556 10,825 2017 293,747 293,128 301,384 289,883 278,607 283,379 46,761 11,324 2018 317,934 336,326 345,224 332,013 324,567 92,627 11,802 2019 347,150 356,363 358,301 366,184 154,311 11,575 2020 361,554 360,302 352,834 201,089 9,645 2021 422,748 414,279 287,278 10,136 2022 482,590 409,505 8,988 Total 3,096,166 General Liability (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 12,789 35,113 72,127 104,587 139,114 153,628 163,764 169,847 172,983 174,987 2014 14,901 46,825 79,972 121,969 154,957 179,192 187,352 198,772 204,212 2015 14,665 39,978 78,668 116,804 144,216 157,071 173,697 179,117 2016 15,684 46,549 89,431 133,757 164,136 181,770 199,032 2017 17,366 49,470 92,355 131,980 167,002 201,948 2018 19,531 60,784 108,421 155,538 197,286 2019 18,097 58,284 100,206 160,680 2020 21,858 58,699 100,356 2021 28,069 71,664 2022 31,502 Total 1,520,784 All outstanding liabilities before 2013, net of reinsurance 113,263 Liabilities for loss and loss expenses, net of reinsurance 1,688,645 Workers Compensation (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 199,794 194,318 187,658 173,160 166,662 162,787 159,767 157,645 153,436 149,975 16,818 11,385 2014 199,346 187,065 182,579 172,515 164,420 160,646 159,604 161,021 158,479 17,598 10,498 2015 193,729 194,639 183,604 179,642 176,242 172,572 170,577 169,008 18,790 10,554 2016 196,774 184,946 176,248 166,009 156,540 155,210 151,961 21,205 10,586 2017 195,202 184,306 175,853 162,672 154,159 151,221 19,961 10,813 2018 193,894 193,818 181,151 173,428 167,974 25,963 11,133 2019 188,625 188,596 174,912 164,940 32,088 10,324 2020 168,643 168,594 159,229 44,323 7,534 2021 185,198 185,151 74,474 8,547 2022 207,206 116,968 8,517 Total 1,665,144 Workers Compensation (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 36,829 74,568 96,376 109,739 118,669 124,130 126,822 129,224 130,467 131,390 2014 35,924 78,944 100,876 113,626 119,392 124,077 127,858 130,726 132,809 2015 33,857 77,320 98,195 112,601 120,097 124,046 129,019 132,235 2016 34,525 78,531 98,037 109,166 115,159 119,800 122,186 2017 40,375 82,216 100,645 110,645 116,426 120,468 2018 41,122 84,780 105,903 119,904 126,206 2019 37,826 77,878 100,812 112,649 2020 29,559 68,277 87,211 2021 32,918 76,015 2022 45,814 Total 1,086,983 All outstanding liabilities before 2013, net of reinsurance 230,858 Liabilities for loss and loss expenses, net of reinsurance 809,019 Commercial Automobile (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 188,289 205,282 209,197 207,994 210,410 207,975 209,602 208,040 207,554 207,564 535 26,221 2014 200,534 212,725 216,824 219,925 218,172 217,334 216,461 214,992 214,816 516 28,263 2015 220,994 240,958 253,074 259,495 260,565 261,386 262,054 262,766 1,627 30,085 2016 255,187 274,367 285,302 285,304 290,359 291,674 294,297 2,635 32,041 2017 301,274 329,389 324,291 322,197 326,461 325,654 4,664 33,345 2018 347,908 352,487 345,547 350,310 348,202 11,375 36,002 2019 385,212 398,346 404,854 407,051 32,019 36,375 2020 381,654 381,163 375,636 70,872 30,343 2021 483,831 512,673 155,984 36,843 2022 572,421 278,004 36,909 Total 3,521,080 Commercial Automobile (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 76,469 109,893 140,015 169,850 189,626 200,750 202,622 205,064 206,162 206,641 2014 80,810 117,169 148,884 180,701 202,821 209,655 212,481 213,689 213,847 2015 91,347 132,260 175,866 211,515 238,142 249,905 255,600 257,668 2016 106,022 155,720 200,701 233,939 264,858 277,242 284,870 2017 117,287 178,823 220,422 262,349 296,600 309,810 2018 134,867 193,788 243,713 291,725 319,819 2019 149,538 221,590 283,410 331,152 2020 139,016 198,034 254,365 2021 187,200 283,411 2022 216,180 Total 2,677,763 All outstanding liabilities before 2013, net of reinsurance 4,650 Liabilities for loss and loss expenses, net of reinsurance 847,967 Businessowners' Policies (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 49,617 42,618 41,005 40,624 41,369 39,709 39,699 39,358 38,930 38,984 169 3,484 2014 55,962 60,949 62,548 59,806 58,517 58,093 57,302 57,483 57,355 96 4,067 2015 52,871 53,768 57,245 55,925 54,454 52,325 52,200 52,514 608 3,968 2016 52,335 53,792 54,993 53,835 53,367 53,147 53,201 828 3,854 2017 46,624 48,698 51,524 48,067 43,606 42,374 879 3,895 2018 55,024 57,202 62,427 60,393 56,625 3,125 4,262 2019 53,531 59,466 64,667 65,762 8,181 3,639 2020 71,836 73,680 73,077 7,630 5,421 2021 66,312 63,648 10,539 3,454 2022 86,194 33,995 3,074 Total 589,734 Businessowners' Policies (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 17,412 26,592 30,845 34,760 37,993 38,464 39,085 39,212 39,440 39,445 2014 28,914 40,584 44,911 49,460 52,940 55,458 55,708 55,729 56,861 2015 24,189 36,014 42,710 46,571 49,073 49,839 50,005 51,120 2016 24,655 36,848 39,973 45,308 48,786 50,536 52,070 2017 21,865 31,337 36,950 40,359 39,940 40,845 2018 29,995 39,791 44,316 48,144 51,239 2019 27,718 41,587 46,113 52,887 2020 43,376 57,210 60,596 2021 34,412 47,436 2022 36,421 Total 488,920 All outstanding liabilities before 2013, net of reinsurance 9,657 Liabilities for loss and loss expenses, net of reinsurance 110,471 Commercial Property (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 88,101 90,639 90,103 90,005 90,436 90,278 90,218 90,486 90,461 90,799 4 5,716 2014 141,192 136,249 136,820 138,751 138,155 136,212 136,237 136,151 136,112 5 6,517 2015 110,270 109,513 111,750 111,566 112,496 112,582 112,937 112,915 9 6,407 2016 121,927 126,185 125,937 124,487 123,567 123,005 123,126 14 6,743 2017 138,773 149,106 149,044 153,664 154,119 154,942 20 6,906 2018 183,177 190,834 192,558 194,016 196,413 47 8,293 2019 173,826 177,075 179,574 180,605 230 7,315 2020 232,060 225,278 226,107 2,023 10,147 2021 246,319 239,822 4,672 7,942 2022 297,318 56,716 7,224 Total 1,758,159 Commercial Property (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 60,244 87,874 90,446 90,350 90,840 90,696 90,646 90,917 90,891 91,206 2014 101,131 132,909 136,634 137,883 137,418 136,008 135,928 136,141 136,107 2015 79,048 106,182 109,829 110,994 110,969 112,117 112,410 112,391 2016 83,966 118,789 122,930 123,828 123,601 122,909 123,265 2017 99,047 142,338 148,589 152,018 153,750 154,689 2018 135,416 184,813 192,698 193,487 196,376 2019 130,891 172,768 177,825 179,538 2020 164,613 215,107 220,953 2021 161,757 227,259 2022 186,677 Total 1,628,461 All outstanding liabilities before 2013, net of reinsurance 579 Liabilities for loss and loss expenses, net of reinsurance 130,277 Personal Automobile (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 108,417 109,620 106,225 106,703 107,759 107,680 107,916 107,803 107,754 107,758 57 22,376 2014 102,250 109,325 106,757 107,452 106,821 107,104 107,106 107,566 107,543 47 22,509 2015 96,387 99,698 100,214 99,570 98,718 98,588 98,596 98,669 117 20,865 2016 92,727 98,032 100,202 101,140 99,544 99,858 100,395 409 19,827 2017 101,880 105,139 103,653 103,260 103,557 105,079 710 20,748 2018 111,594 113,569 112,030 112,418 113,647 2,098 22,684 2019 114,043 115,688 115,993 118,669 4,163 22,860 2020 95,625 94,532 90,179 6,584 17,533 2021 108,244 102,777 10,411 19,672 2022 121,030 26,632 20,345 Total 1,065,746 Personal Automobile (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 61,384 80,861 92,637 100,528 105,131 106,679 106,876 107,419 107,423 107,417 2014 62,519 83,739 92,589 99,173 104,055 105,709 106,478 107,108 107,325 2015 58,725 76,470 87,163 92,102 95,997 97,275 97,761 97,920 2016 57,961 76,823 86,752 94,372 98,080 98,977 99,656 2017 62,854 82,730 91,479 97,628 100,521 103,556 2018 69,721 89,628 99,982 107,026 109,644 2019 69,699 92,162 102,930 109,844 2020 53,407 68,691 76,710 2021 65,325 84,743 2022 75,994 Total 972,809 All outstanding liabilities before 2013, net of reinsurance 7,045 Liabilities for loss and loss expenses, net of reinsurance 99,982 Homeowners (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 73,670 72,528 71,494 72,145 71,714 72,148 72,318 71,948 71,955 71,960 67 7,753 2014 80,111 82,461 83,637 83,844 83,539 83,824 83,525 83,830 83,819 60 8,776 2015 76,637 76,400 76,559 74,723 74,978 74,673 74,682 74,237 20 7,753 2016 60,105 60,931 62,391 61,723 61,735 60,855 60,841 438 6,896 2017 59,167 67,978 70,365 70,064 68,938 68,902 504 7,389 2018 62,961 68,526 69,832 68,931 68,416 608 7,608 2019 64,306 72,772 73,816 73,070 1,412 7,010 2020 109,033 112,523 113,804 3,611 9,824 2021 82,425 83,295 3,657 6,884 2022 93,826 17,362 5,819 Total 792,170 Homeowners (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Year Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 50,664 65,528 67,838 69,775 71,776 72,197 72,433 72,446 72,447 72,415 2014 61,561 76,007 79,751 81,664 82,583 82,836 82,831 83,321 83,782 2015 52,589 70,078 72,202 72,927 74,079 74,052 74,096 74,108 2016 42,252 57,333 59,546 60,082 61,187 60,449 60,474 2017 45,466 63,290 67,193 67,767 68,078 68,282 2018 49,430 64,137 65,348 66,634 67,739 2019 49,680 67,631 69,911 70,880 2020 83,838 105,690 109,145 2021 59,054 77,018 2022 68,832 Total 752,675 All outstanding liabilities before 2013, net of reinsurance 6,102 Liabilities for loss and loss expenses, net of reinsurance 45,597 E&S Casualty Lines (in thousands, except for claim counts) Incurred Loss and Allocated Loss Expenses, Net of Reinsurance As of December 31, 2022 Accident Year Unaudited IBNR Cumulative Number of Reported Claims 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 55,468 $ 60,309 67,099 69,112 67,647 68,972 68,451 68,029 60,349 60,511 3,504 2,311 2014 55,316 63,505 69,929 71,719 71,206 71,153 70,846 74,270 74,538 4,918 2,141 2015 75,498 76,432 82,404 90,488 90,355 90,126 87,662 90,263 4,646 2,887 2016 94,451 96,416 104,655 105,120 104,730 102,476 101,873 12,138 2,998 2017 91,438 95,783 99,866 99,395 99,960 102,045 11,390 2,848 2018 98,324 103,004 103,184 104,983 105,756 17,093 2,816 2019 117,087 118,298 117,736 117,113 39,429 2,683 2020 103,872 103,137 95,832 49,633 1,788 2021 128,099 125,436 89,909 1,751 2022 146,999 132,276 1,285 Total 1,020,366 E&S Casualty Lines (in thousands) Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance Accident Unaudited 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2013 $ 2,715 $ 9,470 21,980 35,200 46,108 51,142 54,974 55,988 57,152 58,584 2014 2,353 12,234 25,571 43,877 53,780 60,092 64,698 66,661 68,648 2015 3,036 13,057 29,389 50,712 64,529 71,421 75,844 81,396 2016 3,720 16,195 33,950 56,581 69,448 75,004 81,932 2017 5,057 14,672 34,179 53,238 68,266 77,090 2018 5,509 21,337 39,174 57,962 73,605 2019 4,422 17,812 35,844 57,701 2020 3,695 13,064 27,861 2021 4,326 15,835 2022 4,198 Total 546,850 All outstanding liabilities before 2013, net of reinsurance 5,991 Liabilities for loss and loss expenses, net of reinsurance 479,507
Schedule of Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability	(in thousands) December 31, 2022 Net outstanding liabilities: Standard Commercial Lines General liability $ 1,688,645 Workers compensation 809,019 Commercial automobile 847,967 Businessowners' policies 110,471 Commercial property 130,277 Other Standard Commercial Lines 17,995 Total Standard Commercial Lines net outstanding liabilities 3,604,374 Standard Personal Lines Personal automobile 99,982 Homeowners 45,597 Other Standard Personal Lines 11,739 Total Standard Personal Lines net outstanding liabilities 157,318 E&S Lines Casualty lines 479,507 Property lines 18,075 Total E&S Lines net outstanding liabilities 497,582 Total liabilities for unpaid loss and loss expenses, net of reinsurance 4,259,274 Reinsurance recoverable on unpaid claims: Standard Commercial Lines General liability 246,736 Workers compensation 199,057 Commercial automobile 14,271 Businessowners' policies 19,277 Commercial property 81,970 Other Standard Commercial Lines 4,443 Total Standard Commercial Lines reinsurance recoverable on unpaid loss 565,754 Standard Personal Lines Personal automobile 36,529 Homeowners 7,124 Other Standard Personal Lines 132,525 Total Standard Personal Lines reinsurance recoverable on unpaid loss 176,178 E&S Lines Casualty lines 11,397 Property lines 4,184 Total E&S Lines reinsurance recoverable on unpaid loss 15,581 Total reinsurance recoverable on unpaid loss 757,513 Unallocated loss expenses 128,034 Total gross liability for unpaid loss and loss expenses $ 5,144,821
Schedule of Short-duration Insurance Contracts, Schedule of Historical Claims Duration	Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance Years 1 2 3 4 5 6 7 8 9 10 General liability 6.3% 11.8 15.5 17.4 15.1 9.9 7.2 4.1 3.0 2.1 Workers compensation 22.3 25.9 13.9 8.9 4.7 3.0 1.9 1.8 3.1 2.2 Commercial automobile 36.8 16.9 14.6 13.3 9.9 4.2 1.9 1.1 0.7 0.1 Businessowners’ policies 49.0 21.8 8.3 8.1 6.1 3.1 1.3 0.6 0.3 0.2 Commercial property 68.7 26.4 3.2 1.0 0.4 — — — — — Personal automobile 59.8 18.1 8.8 6.5 3.7 1.7 0.5 0.4 0.2 0.1 Homeowners 70.8 21.8 3.5 1.6 1.7 0.2 0.2 0.1 0.1 — E&S Lines - casualty 3.9 11.5 18.0 21.7 15.8 7.9 6.8 5.2 2.6 3.5

Indebtedness (Tables)

Indebtedness (Tables)	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Outstanding Debt 2022 Carry Value Issuance Date Maturity Date Interest Rate Original Amount Unamortized Issuance Costs Debt Discount December 31, 2022 December 31, 2021 ($ in thousands) Description Long term (1) Senior Notes 3/1/2019 3/1/2049 5.375 % 300,000 $ 2,543 5,576 291,881 291,597 (2) FHLBI 12/16/2016 12/16/2026 3.03 % 60,000 — — 60,000 60,000 (3) Senior Notes 11/3/2005 11/1/2035 6.70 % 100,000 256 458 99,286 99,233 (4) Senior Notes 11/16/2004 11/15/2034 7.25 % 50,000 130 79 49,791 49,770 Finance lease obligations 3,718 5,450 Total long-term debt $ 2,929 6,113 504,676 506,050
Line of Credit Covenant Requirements	Required as of Actual as of December 31, 2022 December 31, 2022 Consolidated net worth 1 Not less than $1.9 billion $3 billion Debt to total capitalization ratio 1 Not to exceed 35% 14.3%

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2022
Segment Reporting [Abstract]
Schedule of Revenue from Continuing Operations By Segment	Revenue by Segment Years ended December 31, ($ in thousands) 2022 2021 2020 Standard Commercial Lines: Net premiums earned: General liability $ 902,428 807,158 694,019 Commercial automobile 812,306 724,398 615,181 Commercial property 495,647 436,412 388,120 Workers compensation 335,955 306,428 278,062 Businessowners’ policies 124,474 110,622 110,210 Bonds 43,354 35,762 36,742 Other 25,655 23,105 20,850 Miscellaneous income 9,519 16,056 15,512 Total Standard Commercial Lines revenue 2,749,338 2,459,941 2,158,696 Standard Personal Lines: Net premiums earned: Personal automobile 162,899 163,007 165,020 Homeowners 128,222 122,526 125,405 Other 8,284 8,026 8,715 Miscellaneous income 1,816 1,667 2,058 Total Standard Personal Lines revenue 301,221 295,226 301,198 E&S Lines: Net premiums earned: Casualty lines 233,086 197,779 174,408 Property lines 101,070 82,030 65,082 Total E&S Lines revenue 334,156 279,809 239,490 Investments: Net investment income 288,155 326,589 227,107 Net realized and unrealized investment (losses) gains (114,808) 17,599 (4,217) Total Investments revenues 173,347 344,188 222,890 Total revenues $ 3,558,062 3,379,164 2,922,274
Schedule of Income from Continuing Operations before and after Federal Income Tax	Income Before and After Federal Income Tax Years ended December 31, ($ in thousands) 2022 2021 2020 Standard Commercial Lines: Underwriting income, before federal income tax $ 143,696 198,596 151,731 Underwriting income, after federal income tax 113,520 156,891 119,867 Combined ratio 94.8 % 91.9 % 92.9 % ROE contribution 4.6 % 5.9 5.1 Standard Personal Lines: Underwriting income (loss), before federal income tax (7,193) 3,966 (15,508) Underwriting income (loss), after federal income tax (5,682) 3,133 (12,251) Combined ratio 102.4 % 98.6 % 105.2 % ROE contribution (0.2) % 0.1 (0.5) E&S Lines: Underwriting income, before federal income tax 30,299 16,030 126 Underwriting income, after federal income tax 23,936 12,664 100 Combined ratio 90.9 % 94.3 % 99.9 % ROE contribution 1.0 % 0.5 — Investments: Net investment income earned $ 288,155 326,589 227,107 Net realized and unrealized investment (losses) gains (114,808) 17,599 (4,217) Total investment segment income, before federal income tax 173,347 344,188 222,890 Tax on investment segment income 31,846 67,284 41,609 Total investment segment income, after federal income tax $ 141,501 276,904 181,281 ROE contribution of after-tax net investment income earned 9.4 % 9.9 7.8
Schedule of Reconciliation of Segment Results to Income From Continuing Operations, Before Federal Income Tax	Reconciliation of Segment Results to Income Before Federal Income Tax Years ended December 31, ($ in thousands) 2022 2021 2020 Underwriting income (loss) Standard Commercial Lines $ 143,696 198,596 151,731 Standard Personal Lines (7,193) 3,966 (15,508) E&S Lines 30,299 16,030 126 Investment income 173,347 344,188 222,890 Total all segments 340,149 562,780 359,239 Interest expense (28,847) (29,165) (30,839) Corporate expenses (31,116) (28,305) (25,412) Income, before federal income tax $ 280,186 505,310 302,988 Preferred stock dividends (9,200) (9,353) — Income available to common stockholders, before federal income tax $ 270,986 $ 495,957 $ 302,988

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of Reconciliation of Earnings Per Share	($ in thousands, except per share amounts) 2022 2021 2020 Net income available to common stockholders: $ 215,686 394,484 246,355 Weighted average common shares outstanding: Weighted average common shares outstanding - basic 60,407 60,183 59,862 Effect of dilutive securities - stock compensation plans 468 484 431 Weighted average common shares outstanding - diluted 60,875 60,667 60,293 EPS: Basic $ 3.57 6.55 4.12 Diluted 3.54 6.50 4.09

Federal Income Taxes (Tables)

Federal Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of Federal Income Tax on Income at the Corporate Rate to the Effective Tax Rate	($ in thousands) 2022 2021 2020 Tax at statutory rate $ 58,839 106,115 63,627 Tax-advantaged interest (4,087) (4,514) (4,730) Dividends received deduction (469) (558) (514) Executive compensation 1,848 2,469 2,246 Stock-based compensation (893) (693) (1,846) Other 62 (1,346) (2,150) Federal income tax expense 55,300 101,473 56,633 Income before federal income tax, less preferred stock dividends 270,986 495,957 302,988 Effective tax rate 20.4 % 20.5 % 18.7 %
Schedule of Deferred Tax Assets and Liabilities	($ in thousands) 2022 2021 Deferred tax assets: Net loss reserve discounting $ 65,907 60,227 Net unearned premiums 76,513 68,086 Employee benefits 7,064 2,787 Long-term incentive compensation 6,384 5,904 Unrealized losses on fixed income securities 110,857 — Temporary investment write-downs 12,480 4,314 Other 9,824 2,245 Total deferred tax assets 289,029 143,563 Deferred tax liabilities: Deferred policy acquisition costs 77,411 68,652 Unrealized gains on investment securities — 48,082 Other investment-related items, net 26,713 27,044 Accelerated depreciation and amortization 12,172 13,198 Total deferred tax liabilities 116,296 156,976 Net deferred federal income tax assets (liabilities) $ 172,733 (13,413)

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Schedule of Funded Status Of Retirement Income Plan And Retirement Life Plan	December 31, Pension Plan ($ in thousands) 2022 2021 Change in Benefit Obligation: Benefit obligation, beginning of year $ 407,758 425,161 Interest cost 9,944 8,593 Actuarial gains (91,653) (12,844) Benefits paid (14,104) (13,152) Benefit obligation, end of year $ 311,945 407,758 Change in Fair Value of Assets: Fair value of assets, beginning of year $ 450,305 432,716 Actual return on plan assets, net of expenses (93,227) 30,741 Benefits paid (14,104) (13,152) Fair value of assets, end of year $ 342,974 450,305 Funded status $ 31,029 42,547
Schedule of Amounts Recognized in Consolidated Balance Sheet	Amounts Recognized in the Consolidated Balance Sheet: Net pension assets, end of year $ 31,029 42,547
Schedule of Amounts recognized in Accumulated Other than Comprehensive Income	Amounts Recognized in AOCI: Net actuarial loss $ 100,561 78,304
Schedule of Other Information as of December 31	Other Information as of December 31: Accumulated benefit obligation $ 311,945 407,758
Schedule of Components Of Net Periodic Benefit Cost And Other Amounts Recognized In Other Comprehensive Income	Pension Plan ($ in thousands) 2022 2021 2020 Components of Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Income: Net Periodic Benefit Cost (Benefit): Interest cost $ 9,944 8,593 11,312 Expected return on plan assets (22,147) (22,976) (21,907) Amortization of unrecognized actuarial loss 1,465 2,501 2,817 Total net periodic pension cost (benefit) 1 $ (10,738) (11,882) (7,778) Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income: Net actuarial loss (gain) $ 23,722 (20,609) (2,894) Reversal of amortization of net actuarial loss (1,465) (2,501) (2,817) Total recognized in other comprehensive income $ 22,257 (23,110) (5,711) Total recognized in net periodic benefit cost and other comprehensive income $ 11,519 (34,992) (13,489)
Schedule Of Weighted- Average Expense and Liability Assumptions	Weighted-Average Liability Assumptions as of December 31: Discount rate 5.21 % 2.98 Pension Plan 2022 2021 2020 Weighted-Average Expense Assumptions for the years ended December 31: Discount rate 2.98 % 2.68 % 3.33 % Interest rate 2.48 % 2.06 % 2.95 % Expected return on plan assets 5.00 5.40 5.80
Schedule of Allocation of Plan Assets	2022 2021 Target Percentage Actual Percentage Actual Percentage Minimum Maximum Return seeking assets 1 50 % 80 % 71 % 66 % Liability hedging assets 20 % 50 % 27 % 33 % Short-term investments - - 2 % 1 % Total 100 % 100 %
Schedule of Quantitative Disclosures of our Financial Assets that were Measured at Fair Value	December 31, 2022 Fair Value Measurements Using ($ in thousands) Assets Measured at Fair Value Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 189,239 109,240 79,999 — Foreign government 9,608 — 9,608 — Obligations of states and political subdivisions 918,018 — 911,357 6,661 Corporate securities 2,335,025 — 2,147,045 187,980 CLO and other ABS 1,485,973 — 1,332,631 153,342 RMBS 1,059,832 — 1,059,832 — CMBS 614,412 — 614,037 375 Total AFS fixed income securities 6,612,107 109,240 6,154,509 348,358 Equity securities: Common stock 1 160,355 55,846 — 897 Preferred stock 1,645 1,645 — — Total equity securities 162,000 57,491 — 897 Short-term investments 440,456 418,199 22,257 — Total assets measured at fair value $ 7,214,563 584,930 6,176,766 349,255 December 31, 2021 Fair Value Measurements Using ($ in thousands) Assets Measured at Fair Value Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 130,458 60,615 69,843 — Foreign government 15,860 — 15,860 — Obligations of states and political subdivisions 1,189,308 — 1,181,563 7,745 Corporate securities 2,573,603 — 2,459,476 114,127 CLO and other ABS 1,350,814 — 1,225,905 124,909 RMBS 776,252 — 776,007 245 CMBS 673,681 — 669,425 4,256 Total AFS fixed income securities 6,709,976 60,615 6,398,079 251,282 Equity securities: Common stock 1 333,449 249,846 — — Preferred stock 2,088 2,088 — — Total equity securities 335,537 251,934 — — Short-term investments 447,863 442,723 5,140 — Total assets measured at fair value $ 7,493,376 755,272 6,403,219 251,282 1 Investments amounting to $103.6 million and $83.6 million at December 31, 2022 and December 31, 2021, respectively, were measured at fair value using the net asset value per share (or its practical expedient) and have not been classified in the fair value hierarchy. These investments are not redeemable and the timing of liquidations of the underlying assets is unknown at each reporting period. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total assets measured at fair value.
Schedule of Expected Benefit Payments	Payments ($ in thousands) Pension Plan Benefits Expected to be Paid in Future Fiscal Years: 2023 $ 16,925 2024 17,265 2025 18,317 2026 19,391 2027 20,328 2028-2032 111,842
Retirement Income Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Schedule of Quantitative Disclosures of our Financial Assets that were Measured at Fair Value	December 31, 2022 Fair Value Measurements at 12/31/22 Using ($ in thousands) Assets Measured at Fair Value At 12/31/22 Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Description Return seeking assets: Equities: Global equity $ 63,852 63,852 — — Diversified credit 58,761 58,761 — — Real assets 95,396 95,396 — — Liquid diversifiers 1 23,978 23,978 — — Total equities 241,987 241,987 — — Limited partnerships (at net asset value) 2 : Real assets 27 — — — Private equity 331 — — — Total limited partnerships 358 — — — Total return seeking assets 242,345 241,987 — — Liability hedging assets: Fixed income 35,378 35,378 — — U.S. Treasury overlay 56,255 56,255 — — Total liability hedging assets 91,633 91,633 — — Cash and short-term investments: Short-term investments 5,108 5,108 — — Deposit administration contracts 2,740 — 2,740 — Total cash and short-term investments 7,848 5,108 2,740 — Total invested assets $ 341,826 338,728 2,740 — December 31, 2021 Fair Value Measurements at 12/31/21 Using ($ in thousands) Assets Measured at Fair Value At 12/31/21 Quoted Prices in Active Markets for Identical Assets/ Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Description Return seeking assets: Equities: Global equity $ 144,634 144,634 — — Diversified credit 66,165 66,165 — — Real assets 89,590 89,590 — — Total equities 300,389 300,389 — — Limited partnerships (at net asset value) 2 : Real assets 47 — — — Private equity 413 — — — Total limited partnerships 460 — — — Total return seeking assets 300,849 300,389 — — Liability hedging assets: Fixed income 86,183 86,183 — — U.S. Treasury overlay 65,304 65,304 — — Total liability hedging assets 151,487 151,487 — — Cash and short-term investments: Short-term investments 1,744 1,744 — — Deposit administration contracts 2,422 — 2,422 — Total cash and short-term investments 4,166 1,744 2,422 — Total invested assets $ 456,502 453,620 2,422 — 1 Liquid diversifiers are investments that unbundle return drivers from hedge funds, providing investors access to liquid, diversifying returns. 2 In accordance with the FASB issued ASU 2015-07, Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) , certain investments that are measured at fair value using the net asset value per share (or its practical expedient) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total Pension Plan invested assets.

Share-Based Payments (Tables)

Share-Based Payments (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Schedule Of Share-Based Compensation Plan Approval	Plan Approvals Stock Plan Approved effective as of May 1, 2014 by stockholders on April 23, 2014. Cash Plan Approved effective April 1, 2005 by stockholders on April 27, 2005. ESPP Approved effective July 1, 2009 by stockholders on April 29, 2009. Agent Plan Approved by stockholders on April 26, 2006.
Schedule of Types of Share-Based Payments Issued	Plan Types of Share-Based Payments Issued Stock Plan Qualified and nonqualified stock options, stock appreciation rights ("SARs"), restricted stock, restricted stock units ("RSUs"), stock grants, and other awards valued in whole or in part by reference to the Parent's common stock. The maximum exercise period for an option grant under this plan is 10 years from the date of the grant. Dividend equivalent units ("DEUs") are earned during the vesting period on RSU grants. The DEUs are reinvested in the Parent's common stock at fair value on each dividend payment date. The requisite service period for grants to employees under this plan is the lesser of: (i) the stated vested date, which is typically three years from issuance; or (ii) the date the employee becomes eligible to retire. Cash Plan Cash incentive units (“CIUs”). The initial dollar value of each CIU will be adjusted to reflect the percentage increase or decrease in the total shareholder return on the Parent's common stock over a specified performance period. In addition, for certain grants, the number of CIUs granted will be increased or decreased to reflect our performance on specified performance indicators compared to targeted peer companies. The requisite service period for grants under this plan is the lesser of: (i) the stated vested date, which is typically three years from issuance; or (ii) the date the employee becomes eligible to retire. ESPP Enables employees to purchase shares of the Parent’s common stock. The purchase price is the lower of: (i) 85% of the closing market price at the time the option is granted; or (ii) 85% of the closing price at the time the option is exercised. Shares are generally issued on June 30 and December 31 of each year. Agent Plan Quarterly offerings to purchase the Parent's common stock at a 10% discount with a one-year restricted period during which the shares purchased cannot be sold or transferred. Only our independent retail insurance agencies and wholesale general agencies, and certain eligible persons associated with the agencies, are eligible to participate in this plan.
Schedule of Share-Based Compensation Shares Authorized and Available for Issuance	Authorized Available for Issuance Awards Outstanding Stock Plan 4,750,000 2,474,585 657,311 ESPP 5,500,000 1,116,863 — Agent Plan 3,000,000 1,551,498 —
Schedule of Share-Based Compensation Retired Plans	Plan Types of Share-Based Payments Issued Reserve Shares Awards Outstanding 1 2005 Omnibus Stock Plan ("2005 Stock Plan") Qualified and nonqualified stock options, SARs, restricted stock, RSUs, phantom stock, stock bonuses, and other awards in such amounts and with such terms and conditions as it determined, subject to the provisions of the 2005 Stock Plan. The maximum exercise period for an option grant under this plan is 10 years from the date of the grant. DEUs are earned during the vesting period on RSU grants. The DEUs are reinvested in the Parent's common stock at fair value on each dividend payment date. 1,954,922 29,522 Parent's Stock Compensation Plan for Non-employee Directors Directors could elect to receive a portion of their annual compensation in shares of the Parent's common stock. 40,940 40,940 1 Awards outstanding under the 2005 Stock Plan represent shares deferred by our non-employee directors.
Schedule of Summary of Restricted Stock Units Transactions under Share-Based Payment Plans	Number Weighted Average Unvested RSU awards at December 31, 2021 641,636 $ 63.73 Granted 2022 248,619 76.09 Vested 2022 (232,742) 63.79 Forfeited 2022 (20,451) 66.77 Unvested RSU awards at December 31, 2022 637,062 $ 68.84
Schedule of Share-Based Compensation ESPP and ASPP Shares Granted	2022 2021 2020 ESPP Issuances 67,986 72,239 99,141 Agent Plan Issuances 56,736 50,999 69,238
Schedule of Weighted Average Assumptions for Employee Stock Purchase Plan	ESPP 2022 2021 2020 Risk-free interest rate 1.42 % 0.07 0.76 Expected term 6 months 6 months 6 months Dividend yield 1.3 % 1.4 1.6 Expected volatility 21 % 28 37
Schedule of Weighted-Average Fair Value of Options and Stock Per Share	2022 2021 2020 RSUs $ 76.09 64.03 62.91 ESPP: Six month option 4.43 4.69 4.82 Discount of grant date market value 12.61 10.98 8.61 Total ESPP 17.04 15.67 13.43 Agent Plan: Discount of grant date market value 8.28 7.57 5.73
Schedule of Compensation Cost for Share-based Payment Arrangements	($ in millions) 2022 2021 2020 Share-based compensation expense, pre-tax $ 23.6 22.3 19.8 Income tax benefit, including the benefit related to stock grants that vested during the year (5.6) (5.1) (5.7) Share-based compensation expense, after-tax $ 18.0 17.2 14.1

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Components of Lease Expense	($ in thousands) 2022 2021 Operating lease cost, included in Other insurance expenses on the Consolidated Statements of Income $ 8,148 7,935 Finance lease cost: Amortization of assets, included in Other insurance expenses on the Consolidated Statements of Income 2,440 1,765 Interest on lease liabilities, included in Interest expense on the Consolidated Statements of Income 46 35 Total finance lease cost 2,486 1,800 Variable lease cost, included in Other insurance expenses on the Consolidated Statements of Income 1,384 291 Short-term lease cost, included in Other insurance expenses on the Consolidated Statements of Income $ 166 832
Supplemental Lease Information	December 31, 2022 December 31, 2021 Weighted-average remaining lease term Operating leases 8 7 years Finance leases 2 2 Weighted-average discount rate Operating leases 2.6 2.1 % Finance leases 1.2 0.8
Lease Assets and Liabilities	($ in thousands) December 31, 2022 December 31, 2021 Operating leases Other assets $ 42,403 35,644 Other liabilities 44,505 37,296 Finance leases Property and equipment - at cost, net of accumulated depreciation and amortization 3,713 5,446 Long-term debt $ 3,718 5,450
Maturities of Lease Liabilities	($ in thousands) Finance Leases Operating Leases Total Year ended December 31, 2023 $ 2,490 7,290 9,780 2024 1,029 6,943 7,972 2025 190 6,649 6,839 2026 54 6,156 6,210 2027 2 6,053 6,055 Thereafter — 18,832 18,832 Total lease payments 3,765 51,923 55,688 Less: imputed interest 47 4,496 4,543 Less: leases that have not yet commenced — 2,922 2,922 Total lease liabilities $ 3,718 44,505 48,223

Commitments and Contingencies I

Commitments and Contingencies Investments Contractual Obligations (Tables)	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Investments Classified by Contractual Maturity Date [Table Text Block]	($ in millions) Amount of Obligation Alternative investments $ 246.1 Non-publicly traded collateralized loan obligations in our fixed income securities portfolio 106.6 Non-publicly traded common stock within our equity portfolio 35.0 CMLs 4.9 Privately-placed corporate securities 20.1 Total $ 412.7

Statutory Financial Informati_2

Statutory Financial Information, Capital Requirements, and Restrictions on Dividends and Transfers of Funds (Tables)	12 Months Ended
	Dec. 31, 2022
Insurance [Abstract]
Schedule of Insurance Subsidiaries Statutory Surplus Data	State of Domicile Unassigned Surplus Statutory Surplus Statutory Net Income ($ in millions) 2022 2021 2022 2021 2022 2021 2020 SICA New Jersey $ 686.6 673.1 851.8 838.3 103.1 134.7 81.8 Selective Way Insurance Company ("SWIC") New Jersey 461.9 436.4 517.8 492.4 69.6 74.5 54.0 SICSC Indiana 164.1 166.3 198.4 200.6 17.0 24.2 20.8 SICSE Indiana 135.9 132.7 163.5 160.3 14.2 19.4 16.8 SICNY New York 137.4 127.0 165.1 154.7 13.2 18.6 15.3 Selective Insurance Company of New England ("SICNE") New Jersey 38.2 34.5 69.3 65.6 5.1 7.5 6.8 Selective Auto Insurance Company of New Jersey ("SAICNJ") New Jersey 102.2 90.4 147.1 135.2 12.7 16.7 12.9 Mesa Underwriters Specialty Insurance Company ("MUSIC") New Jersey 52.8 47.4 122.3 116.9 9.7 13.9 11.4 Selective Casualty Insurance Company ("SCIC") New Jersey 91.4 83.4 167.9 159.9 14.0 20.6 16.2 Selective Fire and Casualty Insurance Company ("SFCIC") New Jersey 37.6 34.2 70.5 67.1 5.8 8.2 6.4 Total $ 1,908.1 1,825.4 2,473.7 2,391.0 264.4 338.3 242.4
Schedule of Insurance Subsidiaries Dividend Paid To Parent	Dividends Twelve Months ended December 31, 2022 2023 ($ in millions) State of Domicile Ordinary Dividends Paid Maximum Ordinary Dividends SICA New Jersey $ 62.3 $ 103.1 SWIC New Jersey 24.3 69.6 SICSC Indiana 5.6 19.8 SICSE Indiana 6.6 16.4 SICNY New York 3.0 16.5 SICNE New Jersey 1.5 6.9 SAICNJ New Jersey 1.3 14.7 MUSIC New Jersey 5.3 12.2 SCIC New Jersey 7.8 16.8 SFCIC New Jersey 2.3 7.1 Total $ 120.0 $ 283.1

Organization (Narrative) (Detai

Organization (Narrative) (Details)	12 Months Ended
	Dec. 31, 2022
Segment Reporting [Abstract]
Number of Operating Segments	4

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended			12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Depreciation expense				$ 24.6	$ 24.3	$ 21.5
Investment yields before tax assumed in premium deficiency assessment	3.50%	4.30%	3%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Property and Equipment) (Details)	12 Months Ended
	Dec. 31, 2022
Computer hardware [Member]
Property and equipment, estimated useful lives	3
Internally developed software [Member]
Property and equipment, estimated useful lives	5
Furniture and fixtures [Member]
Property and equipment, estimated useful lives	10
Maximum [Member] | Computer software [Member]
Property and equipment, estimated useful lives	5
Maximum [Member] | Software licenses [Member]
Property and equipment, estimated useful lives	5
Maximum [Member] | Building and improvements [Member]
Property and equipment, estimated useful lives	40
Minimum [Member] | Computer software [Member]
Property and equipment, estimated useful lives	3
Minimum [Member] | Software licenses [Member]
Property and equipment, estimated useful lives	3
Minimum [Member] | Building and improvements [Member]
Property and equipment, estimated useful lives	5

Statements of Cash Flow (Cash F

Statements of Cash Flow (Cash Flow Supplemental Disclosures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest	$ 26,639	$ 28,930	$ 30,464
Federal income tax	75,000	100,000	47,000
Operating cash flows from operating leases	8,148	7,935	9,498
Operating cash flows from financing leases	46	35	15
Financing cash flows from financing leases	2,438	1,768	550
Assets acquired under finance lease arrangements	707	6,709	324
Assets acquired under operating lease arrangements	16,649	3,272	22,390
Non-cash purchase of property and equipment	70	472	590
Available-for-sale Securities [Member]
Corporate actions related to securities	38,106	56,365	55,446
Held-to-maturity Securities [Member]
Corporate actions related to securities	0	0	2,589
Equity Securities [Member]
Corporate actions related to securities	0	30,666	10,890
Conversion of AFS fixed income securities to equity securities	$ 1,463	$ 15,139	$ 0

Statements of Cash Flow Stateme

Statements of Cash Flow Statements of Cash Flow (Cash and Restricted Cash) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Supplemental Cash Flow Information [Abstract]
Cash	$ 26	$ 455
Restricted cash	25,183	44,608
Total cash and restricted cash shown in the Statements of Cash Flows	$ 25,209	$ 45,063	$ 15,231	$ 7,975

Investments (Unrealized Gains o

Investments (Unrealized Gains on Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net unrealized (losses) gains	$ (527,891)	$ 228,963	$ 386,393
Deferred income tax	110,857	(48,082)	(81,142)
Net unrealized (losses) gains, net of deferred income tax	(417,034)	180,881	305,251
(Decrease) Increase in net unrealized gains in OCI, net of deferred income tax	(597,915)	(124,370)	(134,857)
Available-for-sale Securities [Member]
Net unrealized (losses) gains	(527,926)	228,947	386,380
Total HTM Securities [Member]
Net unrealized (losses) gains	0	(4)	7
Short-term Investments [Member]
Net unrealized (losses) gains	$ 35	$ 20	$ 6

Investments (Available-For-Sale

Investments (Available-For-Sale Securities Disclosure) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Fixed income securities, available-for-sale, amortized cost	$ 7,185,754	$ 6,490,753
Fixed income securities, available-for-sale, allowance for credit loss	45,721	9,724	$ 3,969
Unrealized gains	9,262	246,301
Unrealized losses	537,188	17,354
Debt Securities, Available-for-sale, Fair Value	6,612,107	6,709,976
U.S. Government and Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Fixed income securities, available-for-sale, amortized cost	209,528	127,974
Fixed income securities, available-for-sale, allowance for credit loss	0	0
Unrealized gains	37	3,629
Unrealized losses	20,326	1,145
Debt Securities, Available-for-sale, Fair Value	189,239	130,458
Foreign Government [Member]
Debt Securities, Available-for-sale [Line Items]
Fixed income securities, available-for-sale, amortized cost	11,199	15,420
Fixed income securities, available-for-sale, allowance for credit loss	284	46	1
Unrealized gains	0	609
Unrealized losses	1,307	123
Debt Securities, Available-for-sale, Fair Value	9,608	15,860
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Fixed income securities, available-for-sale, amortized cost	965,231	1,121,422
Fixed income securities, available-for-sale, allowance for credit loss	1,024	137	4
Unrealized gains	1,812	68,258
Unrealized losses	48,001	235
Debt Securities, Available-for-sale, Fair Value	918,018	1,189,308
Corporate Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fixed income securities, available-for-sale, amortized cost	2,558,655	2,478,348
Fixed income securities, available-for-sale, allowance for credit loss	30,330	6,682	2,782
Unrealized gains	3,509	106,890
Unrealized losses	196,809	4,953
Debt Securities, Available-for-sale, Fair Value	2,335,025	2,573,603
Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fixed income securities, available-for-sale, amortized cost	1,607,660	1,343,687
Fixed income securities, available-for-sale, allowance for credit loss	2,375	939	592
Unrealized gains	2,408	14,350
Unrealized losses	121,720	6,284
Debt Securities, Available-for-sale, Fair Value	1,485,973	1,350,814
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fixed income securities, available-for-sale, amortized cost	1,169,546	756,280
Fixed income securities, available-for-sale, allowance for credit loss	11,597	1,909	561
Unrealized gains	1,148	24,813
Unrealized losses	99,265	2,932
Debt Securities, Available-for-sale, Fair Value	1,059,832	776,252
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fixed income securities, available-for-sale, amortized cost	663,935	647,622
Fixed income securities, available-for-sale, allowance for credit loss	111	11	$ 29
Unrealized gains	348	27,752
Unrealized losses	49,760	1,682
Debt Securities, Available-for-sale, Fair Value	$ 614,412	$ 673,681

Investments (Available-for-sa_2

Investments (Available-for-sale allowance for credit losses roll forward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Allowance for credit losses, beginning balance	$ 9,724	$ 3,969
Current provision for securities without prior allowance	34,561	8,135
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	8,318
Increase or (Decrease) on securities with prior allowance, excluding intent (or Requirements) to sell securities	4,608	(1,284)
Reduction for securities sold	(7,636)	(926)
Reduction for securities identified as intent (or requirement) to sell during the period	(3,854)	(170)
Allowance for credit losses, ending balance	45,721	9,724
Foreign Government [Member]
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Allowance for credit losses, beginning balance	46	1
Current provision for securities without prior allowance	291	46
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	0
Increase or (Decrease) on securities with prior allowance, excluding intent (or Requirements) to sell securities	4	(1)
Reduction for securities sold	(57)	0
Reduction for securities identified as intent (or requirement) to sell during the period	0	0
Allowance for credit losses, ending balance	284	46
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Allowance for credit losses, beginning balance	137	4
Current provision for securities without prior allowance	1,087	122
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	0
Increase or (Decrease) on securities with prior allowance, excluding intent (or Requirements) to sell securities	(6)	11
Reduction for securities sold	(194)	0
Reduction for securities identified as intent (or requirement) to sell during the period	0	0
Allowance for credit losses, ending balance	1,024	137
Corporate Securities [Member]
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Allowance for credit losses, beginning balance	6,682	2,782
Current provision for securities without prior allowance	30,670	5,785
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	0
Increase or (Decrease) on securities with prior allowance, excluding intent (or Requirements) to sell securities	3,714	(992)
Reduction for securities sold	(6,902)	(723)
Reduction for securities identified as intent (or requirement) to sell during the period	(3,834)	(170)
Allowance for credit losses, ending balance	30,330	6,682
Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Allowance for credit losses, beginning balance	939	592
Current provision for securities without prior allowance	2,158	579
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	0
Increase or (Decrease) on securities with prior allowance, excluding intent (or Requirements) to sell securities	(652)	(211)
Reduction for securities sold	(50)	(21)
Reduction for securities identified as intent (or requirement) to sell during the period	(20)	0
Allowance for credit losses, ending balance	2,375	939
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Allowance for credit losses, beginning balance	1,909	561
Current provision for securities without prior allowance	245	1,593
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	8,318
Increase or (Decrease) on securities with prior allowance, excluding intent (or Requirements) to sell securities	1,558	(63)
Reduction for securities sold	(433)	(182)
Reduction for securities identified as intent (or requirement) to sell during the period	0	0
Allowance for credit losses, ending balance	11,597	1,909
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items]
Allowance for credit losses, beginning balance	11	29
Current provision for securities without prior allowance	110	10
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	0
Increase or (Decrease) on securities with prior allowance, excluding intent (or Requirements) to sell securities	(10)	(28)
Reduction for securities sold	0	0
Reduction for securities identified as intent (or requirement) to sell during the period	0	0
Allowance for credit losses, ending balance	$ 111	$ 11

Investments (Accrued Investment

Investments (Accrued Investment Income) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accrued Interest on Investments [Line Items]
Accrued investment income	$ 59,167	$ 48,247
Available-for-sale Securities [Member]
Accrued Interest on Investments [Line Items]
Accrued investment income	$ 56,400	$ 46,300

Investments (Fair Value and Gro

Investments (Fair Value and Gross Pre-Tax Net Unrealized Loss of Securities By Length of Time) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Percentage Decline in Fair Value Percentage	10%	10%
Available-for-sale Securities [Member]
AFS Fair Value, Less than 12 Months	$ 5,060,440	$ 1,376,128
AFS Unrealized Losses, Less than 12 months	405,632	14,849
AFS Fair Value, 12 months or longer	764,813	85,122
AFS Unrealized Losses, 12 months or longer	131,556	2,505
AFS Fair Value	5,825,253	1,461,250
AFS Unrealized Losses	537,188	17,354
Available-for-sale Securities [Member] | U.S. Government and Government Agencies [Member]
AFS Fair Value, Less than 12 Months	166,975	34,857
AFS Unrealized Losses, Less than 12 months	13,658	746
AFS Fair Value, 12 months or longer	16,011	7,827
AFS Unrealized Losses, 12 months or longer	6,668	399
AFS Fair Value	182,986	42,684
AFS Unrealized Losses	20,326	1,145
Available-for-sale Securities [Member] | Foreign Government [Member]
AFS Fair Value, Less than 12 Months	5,573	2,000
AFS Unrealized Losses, Less than 12 months	608	84
AFS Fair Value, 12 months or longer	2,456	1,061
AFS Unrealized Losses, 12 months or longer	699	39
AFS Fair Value	8,029	3,061
AFS Unrealized Losses	1,307	123
Available-for-sale Securities [Member] | Obligations of States and Political Subdivisions [Member]
AFS Fair Value, Less than 12 Months	681,795	25,837
AFS Unrealized Losses, Less than 12 months	43,767	235
AFS Fair Value, 12 months or longer	16,618	0
AFS Unrealized Losses, 12 months or longer	4,234	0
AFS Fair Value	698,413	25,837
AFS Unrealized Losses	48,001	235
Available-for-sale Securities [Member] | Corporate Securities [Member]
AFS Fair Value, Less than 12 Months	1,889,492	300,549
AFS Unrealized Losses, Less than 12 months	164,197	4,903
AFS Fair Value, 12 months or longer	133,223	2,520
AFS Unrealized Losses, 12 months or longer	32,612	50
AFS Fair Value	2,022,715	303,069
AFS Unrealized Losses	196,809	4,953
Available-for-sale Securities [Member] | Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
AFS Fair Value, Less than 12 Months	916,423	663,976
AFS Unrealized Losses, Less than 12 months	69,155	4,934
AFS Fair Value, 12 months or longer	411,283	53,368
AFS Unrealized Losses, 12 months or longer	52,565	1,350
AFS Fair Value	1,327,706	717,344
AFS Unrealized Losses	121,720	6,284
Available-for-sale Securities [Member] | Residential Mortgage Backed Securities [Member]
AFS Fair Value, Less than 12 Months	887,229	236,010
AFS Unrealized Losses, Less than 12 months	76,432	2,931
AFS Fair Value, 12 months or longer	108,041	20
AFS Unrealized Losses, 12 months or longer	22,833	1
AFS Fair Value	995,270	236,030
AFS Unrealized Losses	99,265	2,932
Available-for-sale Securities [Member] | Commercial Mortgage Backed Securities [Member]
AFS Fair Value, Less than 12 Months	512,953	112,899
AFS Unrealized Losses, Less than 12 months	37,815	1,016
AFS Fair Value, 12 months or longer	77,181	20,326
AFS Unrealized Losses, 12 months or longer	11,945	666
AFS Fair Value	590,134	133,225
AFS Unrealized Losses	$ 49,760	$ 1,682

Investments (Fixed Maturity Sec

Investments (Fixed Maturity Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
AFS due in one year or less fair value	$ 324,394
AFS due after one year through five years fair value	2,928,594
AFS due after five years through 10 years fair value	2,600,001
AFS due after 10 years fair value	759,118
Total AFS Fixed income securities, Fair Value	6,612,107	$ 6,709,976
HTM due in one year or less carrying value	6,093
HTM due after one year through five years carrying value	3,779
HTM due after five years through 10 years carrying value	21,285
HTM due after 10 years carrying value	0
Fixed income securities, held-to-maturity, net of allowance for credit losses	31,157	28,785
HTM due in one year or less fair value	6,090
HTM due after one year through five years fair value	3,798
HTM due after five years through 10 years fair value	19,949
HTM due after 10 years fair value	0
Total HTM fixed income securities fair value	$ 29,837	$ 29,460

Investments (Other Investment P

Investments (Other Investment Portfolio by Strategy and the Remaining Commitment Amount Associated With Each Strategy) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Carrying Value	$ 71,244	$ 49,300
Private Equity [Member]
Carrying Value	280,980	273,070
Remaining Commitment	134,676	99,734
Maximum Exposure to Loss	415,656	372,804
Private Credit Funds [Member]
Carrying Value	54,866	63,138
Remaining Commitment	89,481	92,674
Maximum Exposure to Loss	144,347	155,812
Real Assets [Member]
Carrying Value	35,470	23,524
Remaining Commitment	21,945	22,579
Maximum Exposure to Loss	57,415	46,103
Alternative Investments [Member]
Carrying Value	371,316	359,732
Remaining Commitment	246,102	214,987
Maximum Exposure to Loss	$ 617,418	$ 574,719

Investments (Aggregated Balance

Investments (Aggregated Balance Sheet Summarized Financial Information for Partnerships in our Alternative Investment Portfolio) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Assets	$ 128,158	$ 112,232
Equity Method Investment, Nonconsolidated Investee, Other
Partner's capital	112,694	99,861
Investments Accounted For Under The Equity Method [Member]
Investments	114,038	107,347
Liabilities	$ 15,464	$ 12,371

Investments (Aggregated Income

Investments (Aggregated Income Statement Summarized Financial Information for Partnerships in our Alternative Investment Portfolio) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Schedule of Equity Method Investments [Line Items]
Net investment income earned	$ 288,155		$ 326,589		$ 227,107
Investments Accounted For Under The Equity Method [Member]
Schedule of Equity Method Investments [Line Items]
Net investment (loss) income		$ 765,000		$ 653,000		$ (26,000)
Realized gains		12,590,000		6,121,000		1,452,000
Net change in unrealized appreciation		(5,215,000)		26,877,000		4,898,000
Net Income before tax		8,140,000		33,651,000		6,324,000
Alternative Investments [Member]
Schedule of Equity Method Investments [Line Items]
Net investment income earned	$ 23,003	$ 23,000	$ 117,701	$ 117,700	$ 26,504	$ 26,500

Investments (Credit Concentrati

Investments (Credit Concentration Risk) (Details)	Dec. 31, 2022	Dec. 31, 2021
Investments [Abstract]
Maximum exposure to credit concentration risk of the Company's stockholder's equity other than certain U.S. government agencies	10%	10%

Investments (Investments Pledge

Investments (Investments Pledged as Collateral) (Details) $ in Millions	Dec. 31, 2022 USD ($)
U.S. Government and Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	$ 19.3
Securities owned and pledged as collateral, fair value	19.3
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	3.6
Securities owned and pledged as collateral, fair value	3.6
Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	0
Securities owned and pledged as collateral, fair value	90.2
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	0
Securities owned and pledged as collateral, fair value	14.2
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral on deposit with various state and regulatory agencies	22.9
Securities owned and pledged as collateral, fair value	127.3
Federal Home Loan Bank of New York [Member] | U.S. Government and Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	0
Federal Home Loan Bank of New York [Member] | Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	0
Federal Home Loan Bank of New York [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	28.8
Federal Home Loan Bank of New York [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	9.6
Federal Home Loan Bank of New York [Member] | Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	38.4
Federal Home Loan Bank of Indianapolis [Member] | U.S. Government and Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	0
Federal Home Loan Bank of Indianapolis [Member] | Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	0
Federal Home Loan Bank of Indianapolis [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	61.4
Federal Home Loan Bank of Indianapolis [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	4.6
Federal Home Loan Bank of Indianapolis [Member] | Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Securities pledged as collateral with FHLB	$ 66

Investments (Pre-tax Net Invest

Investments (Pre-tax Net Investment Income Earned) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Statement [Line Items]
Net investment income earned	$ 288,155		$ 326,589		$ 227,107
Fixed Income Securities [Member]
Statement [Line Items]
Net investment income earned	259,918		209,709		203,926
Commercial Mortgage Loans [Member]
Statement [Line Items]
Net investment income earned	5,555		2,743		844
Equity Securities [Member]
Statement [Line Items]
Net investment income earned	13,554		15,920		9,286
Short-term Investments [Member]
Statement [Line Items]
Net investment income earned	3,997		260		1,821
Alternative Investments [Member]
Statement [Line Items]
Net investment income earned	23,003	$ 23,000	117,701	$ 117,700	26,504	$ 26,500
Other Investment [Member]
Statement [Line Items]
Net investment income earned	258		359		418
Investment Expenses [Member]
Statement [Line Items]
Net investment income earned	$ (18,130)		$ (20,103)		$ (15,692)

Investments Realized and Unreal

Investments Realized and Unrealized Gains (Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Gain (Loss) on Securities [Line Items]
Gross gains on sales	$ 28,419	$ 15,284	$ 18,893
Gross losses on sales	(60,055)	(8,140)	(9,745)
Net realized investment gains (losses) on disposals	(31,636)	7,144	9,148
Net unrealized (losses) gains on equity securities	(32,127)	17,881	7,939
Losses on securities for which we have the intent to sell	(11,823)	(519)	(16,266)
Net realized and unrealized investment (losses) gains	(114,808)	17,599	(4,217)
Available-for-sale Securities [Member]
Gain (Loss) on Securities [Line Items]
Net credit loss (expense) benefit	(39,169)	(6,858)	(5,042)
Held-to-maturity Securities [Member]
Gain (Loss) on Securities [Line Items]
Net credit loss (expense) benefit	63	(49)	4
Commercial Mortgage Loans [Member]
Gain (Loss) on Securities [Line Items]
Net credit loss (expense) benefit	$ (116)	$ 0	$ 0

Investments (Components of Net

Investments (Components of Net Realized and Unrealized Gains (Losses Recognized in Income on Equity Securities)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Gain (Loss) on Securities [Line Items]
Unrealized (losses) gains recognized in income on equity securities remaining in our portfolio at end of period	$ (10,454)	$ 16,473	$ 7,936
Unrealized (losses) gains recognized in income on equity securities sold in period	(21,673)	1,408	3
Total unrealized (losses) gains recognized in income on equity securities	$ (32,127)	$ 17,881	$ 7,939

Investments, Proceeds from sale

Investments, Proceeds from sales of AFS and Equity securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Proceeds from the sale of AFS Fixed Income and Equity Securities [Line Items]
Sales of fixed income securities, available-for-sale	$ 1,211,739	$ 502,911	$ 487,087
Sales of equity securities	$ 186,144	$ 99,235	$ 1,320

Comprehensive Income (Component

Comprehensive Income (Components of Comprehensive Income-Gross and Net of Tax) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net income, Gross	$ 280,186	$ 505,310	$ 302,988
Unrealized holding (losses) gains during the period, Gross	(668,107)	(151,391)	168,487
Unrealized losses on securities with credit loss recognized in earnings, gross	(187,968)	9,061	(8,176)
Amounts reclassified into net income: HTM securities, gross	4	(11)	(24)
Amounts reclassified into net income: net realized losses (gains) on disposals and intent-to-sell AFS securities, gross	60,048	(3,825)	5,376
Amounts reclassified into net income: Credit loss expense, gross	39,169	6,858	5,042
Total unrealized losses (gains) on investment securities, gross	756,854	157,430	(170,705)
Defined benefit pension and post-retirement plans: Net actuarial loss (gain), gross	(20,941)	21,636	1,515
Amounts reclassified into net income: net actuarial loss, gross	1,668	2,772	3,015
Total defined benefit pension and post-retirement benefit plans, gross	(19,273)	24,408	4,530
Other comprehensive income (loss), gross	(776,127)	(133,022)	175,235
Comprehensive income (loss), gross	(495,941)	372,288	478,223
Net income, tax	55,300	101,473	56,633
Unrealized holding (losses) gains during the period, tax	(140,302)	(31,793)	35,383
Unrealized losses on securities with credit loss recognized in earnings, tax	(39,473)	(1,902)	(1,717)
Amounts reclassified into net income: HTM securities, tax	1	(2)	(5)
Amounts reclassified into net income: net realized losses (gains) on disposals and intent-to-sell AFS securities, tax	12,610	(803)	1,129
Amounts reclassified into net income: Credit loss expense, tax	8,225	1,440	1,058
Total unrealized (losses) gains on investment securities, tax	(158,939)	(33,060)	35,848
Defined benefit pension and post-retirement plans: Net actuarial (loss) gain, tax	(4,398)	4,543	318
Amount reclassified into net income: Net actuarial loss, tax	351	582	633
Total defined benefit pension and post-retirement benefit plans, tax	(4,047)	5,125	951
Other comprehensive (loss) income, tax	(162,986)	(27,935)	36,799
Comprehensive (loss) income, tax	(107,686)	73,538	93,432
Net income	224,886	403,837	246,355
Unrealized holding (losses) gains during period, net	527,805	119,598	133,104
Unrealized losses on securities with credit loss recognized in earnings	(148,495)	(7,159)	(6,459)
Amount reclassified into net income: HTM securities, net	3	(9)	(19)
Amounts reclassified into net income: Net realized losses (gains) on disposals and losses on intent-to-sell available-for-sale securities	47,438	(3,022)	4,247
Amounts reclassified into net income: Credit loss expense, net	30,944	5,418	3,984
Total unrealized (losses) gains on investment securities	(597,915)	(124,370)	(134,857)
Defined benefit pension and post-retirement plans: Net actuarial (loss) gain, net	(16,543)	17,093	1,197
Amount reclassified into net income: Net actuarial loss, net	1,317	2,190	2,382
Total defined benefit pension and post-retirement plans, net	(15,226)	19,283	3,579
Other comprehensive (loss) income	(613,141)	(105,087)	138,436
Comprehensive (loss) income	$ (388,255)	$ 298,750	$ 384,791

Comprehensive Income (Compone_2

Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ 115,099
Net current period OCI	(613,141)	$ (105,087)	$ 138,436
Balance, end of period	(498,042)	115,099
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(4,287)	(2,546)
OCI before reclassifications	(148,495)	(7,159)
Amounts reclassified from AOCI	30,944	5,418
Net current period OCI	(117,551)	(1,741)
Balance, end of period	(121,838)	(4,287)	(2,546)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(65,781)	(85,064)
OCI before reclassifications	(16,543)	17,093
Amounts reclassified from AOCI	(1,317)	(2,190)
Net current period OCI	15,226	(19,283)
Balance, end of period	(81,007)	(65,781)	(85,064)
Accumulated other comprehensive (loss) income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	115,099	220,186
OCI before reclassifications	(692,843)	(109,664)
Amounts reclassified from AOCI	(79,702)	(4,577)
Net current period OCI	(613,141)	(105,087)	138,436
Balance, end of period	(498,042)	115,099	220,186
Held-to-maturity Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(3)	6
OCI before reclassifications	0	0
Amounts reclassified from AOCI	3	(9)
Net current period OCI	3	(9)
Balance, end of period	0	(3)	6
Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	185,170	307,790
OCI before reclassifications	(527,805)	(119,598)
Amounts reclassified from AOCI	(47,438)	3,022
Net current period OCI	(480,367)	(122,620)
Balance, end of period	(295,197)	185,170	307,790
Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	180,880	305,250
OCI before reclassifications	(676,300)	(126,757)
Amounts reclassified from AOCI	(78,385)	(2,387)
Net current period OCI	(597,915)	(124,370)
Balance, end of period	$ (417,035)	$ 180,880	$ 305,250

Comprehensive Income (Reclassif

Comprehensive Income (Reclassification out of AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net realized and unrealized investment gains (losses)	$ (114,808)	$ 17,599	$ (4,217)
Net investment income earned	288,155	326,589	227,107
Income before federal income tax	280,186	505,310	302,988
Total federal income tax expense	(55,300)	(101,473)	(56,633)
Net income	224,886	403,837	246,355
Loss and loss expense incurred	2,111,778	1,813,984	1,635,823
Other insurance expenses	400,313	375,931	$ 366,941
Reclassification out of Accumulated Other Comprehensive Income [Member]
Net income	79,702	4,577
Reclassification out of Accumulated Other Comprehensive Income [Member] | Retirement Income Plan [Member]
Income before federal income tax	1,668	2,772
Total federal income tax expense	351	582
Net income	1,317	2,190
Loss and loss expense incurred	359	638
Other insurance expenses	1,309	2,134
Held-to-maturity Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Net realized and unrealized investment gains (losses)	(7)	(14)
Net investment income earned	11	3
Income before federal income tax	4	(11)
Total federal income tax expense	1	2
Net income	3	(9)
Available for sale securities, excluding credit losses [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Net realized and unrealized investment gains (losses)	60,048	(3,825)
Income before federal income tax	60,048	(3,825)
Total federal income tax expense	12,610	803
Net income	47,438	(3,022)
Available for sale securities, including credit losses | Reclassification out of Accumulated Other Comprehensive Income [Member]
Net realized and unrealized investment gains (losses)	39,169	6,858
Income before federal income tax	39,169	6,858
Total federal income tax expense	8,225	(1,440)
Net income	$ 30,944	$ 5,418

Fair Value Measurements (Carryi

Fair Value Measurements (Carrying Value and Estimated Fair Value of Financial Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 504,676	$ 506,050
Long-term debt, fair value	466,603	651,071
Unamortized Debt Issuance Costs	(2,929)
Finance lease obligations	3,718	5,450
Seven Point Twenty Five Percent Senior Notes [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	49,921	49,917
Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	51,705	63,719
Unamortized Debt Issuance Costs	(130)
Six Point Seventy Percent Senior Notes [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	99,542	99,520
Six Point Seventy Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	99,264	127,574
Unamortized Debt Issuance Costs	(256)
Five Point Three Hundred Seventy Five Percent Senior Notes [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	294,424	294,330
Five Point Three Hundred Seventy Five Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	258,459	395,652
Unamortized Debt Issuance Costs	(2,543)
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	60,000	60,000
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	57,175	64,126
Unamortized Debt Issuance Costs	0
Long Term Debt Excluding Issuance Costs [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	503,887	503,767
Unamortized Debt Issuance Costs [Member] | Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized Debt Issuance Costs	$ (2,929)	$ (3,167)

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative Disclosures of Financial Assets Measured and Recorded at Fair Value) (Details) - USD ($) $ in Thousands		Dec. 31, 2022	Dec. 31, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		$ 6,612,107	$ 6,709,976
Equity securities		162,000	335,537
Short-term investments		440,456	447,863
Investments measured at fair value using the net asset value per share		103,600	83,600
Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		6,612,107	6,709,976
Equity securities		162,000	335,537
Short-term investments		440,456	447,863
Total assets measured at fair value		7,214,563	7,493,376
U.S. Government and Government Agencies [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		189,239	130,458
U.S. Government and Government Agencies [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		189,239	130,458
Foreign Government [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		9,608	15,860
Foreign Government [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		9,608	15,860
Obligations of States and Political Subdivisions [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		918,018	1,189,308
Obligations of States and Political Subdivisions [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		918,018	1,189,308
Corporate Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		2,335,025	2,573,603
Corporate Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		2,335,025	2,573,603
Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		1,485,973	1,350,814
Collateralized Loan Obligations and Other Asset-Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		1,485,973	1,350,814
Residential Mortgage Backed Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		1,059,832	776,252
Residential Mortgage Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		1,059,832	776,252
Commercial Mortgage-backed Securities (CMBS) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		614,412	673,681
Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		614,412	673,681
Common Stock [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities	[1]	160,355	333,449
Preferred Stock [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities		1,645	2,088
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		109,240	60,615
Equity securities		57,491	251,934
Short-term investments		418,199	442,723
Total assets measured at fair value		584,930	755,272
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | U.S. Government and Government Agencies [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		109,240	60,615
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Foreign Government [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Corporate Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Collateralized Loan Obligations and Other Asset-Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Common Stock [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities	[1]	55,846	249,846
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Preferred Stock [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities		1,645	2,088
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		6,154,509	6,398,079
Equity securities		0	0
Short-term investments		22,257	5,140
Total assets measured at fair value		6,176,766	6,403,219
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government and Government Agencies [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		79,999	69,843
Significant Other Observable Inputs (Level 2) [Member] | Foreign Government [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		9,608	15,860
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		911,357	1,181,563
Significant Other Observable Inputs (Level 2) [Member] | Corporate Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		2,147,045	2,459,476
Significant Other Observable Inputs (Level 2) [Member] | Collateralized Loan Obligations and Other Asset-Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		1,332,631	1,225,905
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		1,059,832	776,007
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		614,037	669,425
Significant Other Observable Inputs (Level 2) [Member] | Common Stock [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities	[1]	0	0
Significant Other Observable Inputs (Level 2) [Member] | Preferred Stock [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		348,358	251,282
Equity securities		897	0
Short-term investments		0	0
Total assets measured at fair value		349,255	251,282
Significant Unobservable Inputs (Level 3) [Member] | U.S. Government and Government Agencies [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Foreign Government [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		6,661	7,745
Significant Unobservable Inputs (Level 3) [Member] | Corporate Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		187,980	114,127
Significant Unobservable Inputs (Level 3) [Member] | Collateralized Loan Obligations and Other Asset-Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		153,342	124,909
Significant Unobservable Inputs (Level 3) [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		0	245
Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
AFS fixed income securities		375	4,256
Significant Unobservable Inputs (Level 3) [Member] | Common Stock [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities	[1]	897	0
Significant Unobservable Inputs (Level 3) [Member] | Preferred Stock [Member] | Fair Value, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities		$ 0	$ 0
[1]Investments amounting to $103.6 million and $83.6 million at December 31, 2022 and December 31, 2021, respectively, were measured at fair value using the net asset value per share (or its practical expedient) and have not been classified in the fair value hierarchy. These investments are not redeemable and the timing of liquidations of the underlying assets is unknown at each reporting period. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total assets measured at fair value.

Fair Value Measurements (Change

Fair Value Measurements (Changes in Fair Value of Securities Using Level 3 Inputs) (Details) - Equity Securities [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Beginning of Year	$ 7,745	$ 2,894
Total net (losses) gains for the period included in OCI	(985)	(239)
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	5,101
Transfers out of Level 3	0	0
Fair Value, End of Year	6,661	7,745
Change in unrealized (losses) gains for the period included in earnings for assets held at period end	(99)	(11)
Change in unrealized losses (gains) for the period included in OCI for assets held at period end	(985)	(239)
Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Beginning of Year	114,127	70,700
Total net (losses) gains for the period included in OCI	(23,624)	1,636
Purchases	99,868	64,813
Sales	0	0
Issuances	0	0
Settlements	(10,148)	(544)
Transfers into Level 3	19,214	981
Transfers out of Level 3	(9,111)	(23,436)
Fair Value, End of Year	187,980	114,127
Change in unrealized (losses) gains for the period included in earnings for assets held at period end	(2,399)	(50)
Change in unrealized losses (gains) for the period included in OCI for assets held at period end	(23,630)	(1,636)
Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Beginning of Year	124,909	56,375
Total net (losses) gains for the period included in OCI	(11,287)	(520)
Purchases	100,406	76,731
Sales	0	0
Issuances	0	0
Settlements	(12,361)	(5,161)
Transfers into Level 3	502	11,344
Transfers out of Level 3	(48,180)	(13,662)
Fair Value, End of Year	153,342	124,909
Change in unrealized (losses) gains for the period included in earnings for assets held at period end	(876)	(214)
Change in unrealized losses (gains) for the period included in OCI for assets held at period end	(11,246)	(520)
Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Beginning of Year	245	0
Total net (losses) gains for the period included in OCI	(17)	0
Purchases	0	249
Sales	0	0
Issuances	0	0
Settlements	(11)	(4)
Transfers into Level 3	0	0
Transfers out of Level 3	(217)	0
Fair Value, End of Year	0	245
Change in unrealized (losses) gains for the period included in earnings for assets held at period end	0	0
Change in unrealized losses (gains) for the period included in OCI for assets held at period end	(17)	0
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Beginning of Year	4,256	0
Total net (losses) gains for the period included in OCI	(481)	(196)
Purchases	0	98
Sales	0	0
Issuances	0	0
Settlements	(15)	(52)
Transfers into Level 3	0	4,382
Transfers out of Level 3	(3,430)	0
Fair Value, End of Year	375	4,256
Change in unrealized (losses) gains for the period included in earnings for assets held at period end	0	(5)
Change in unrealized losses (gains) for the period included in OCI for assets held at period end	(481)	(196)
Common Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Beginning of Year	0
Total net (losses) gains for the period included in OCI	0
Purchases	0
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	897
Transfers out of Level 3	0
Fair Value, End of Year	897	0
Change in unrealized (losses) gains for the period included in earnings for assets held at period end	0
Change in unrealized losses (gains) for the period included in OCI for assets held at period end	0
Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Beginning of Year	251,282	129,969
Total net (losses) gains for the period included in OCI	(36,394)	681
Purchases	200,274	141,891
Sales	0	0
Issuances	0	0
Settlements	(22,535)	(5,761)
Transfers into Level 3	20,613	21,808
Transfers out of Level 3	(60,938)	(37,098)
Fair Value, End of Year	349,255	251,282
Change in unrealized (losses) gains for the period included in earnings for assets held at period end	(3,374)	(270)
Change in unrealized losses (gains) for the period included in OCI for assets held at period end	(36,359)	(681)
Net Investment Income Earned [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	0	0
Net Investment Income Earned [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	68	27
Net Investment Income Earned [Member] | Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	229	16
Net Investment Income Earned [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	0	0
Net Investment Income Earned [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	45	19
Net Investment Income Earned [Member] | Common Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	0
Net Investment Income Earned [Member] | Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	342	62
Gain (Loss) on Investments [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	(99)	(11)
Gain (Loss) on Investments [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	(2,414)	(50)
Gain (Loss) on Investments [Member] | Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	(876)	(214)
Gain (Loss) on Investments [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	0	0
Gain (Loss) on Investments [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	0	5
Gain (Loss) on Investments [Member] | Common Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	0
Gain (Loss) on Investments [Member] | Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total net (losses) gains for the period included in net income	$ (3,389)	$ (270)

Fair Value (Quantitative Inform

Fair Value (Quantitative Information about Significant Unobservable Inputs in the Fair Value Measurement of Level 3 Assets) (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Fair Value	$ 6,612,107	$ 6,709,976
Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Fair Value	2,335,025	2,573,603
Corporate Securities [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Level 3 Securities	187,980	114,127	$ 70,700
Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Fair Value	1,485,973	1,350,814
Collateralized Loan Obligations and Other Asset-Backed Securities [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Level 3 Securities	153,342	124,909	56,375
Valuation Technique, Discounted Cash Flow | Corporate Securities [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	81,867	54,135
Valuation Technique, Discounted Cash Flow | Collateralized Loan Obligations and Other Asset-Backed Securities [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 59,452	$ 34,903
Valuation Technique, Discounted Cash Flow | Measurement Input, Credit Spread | Minimum [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input	(0.044)	0.003
Valuation Technique, Discounted Cash Flow | Measurement Input, Credit Spread | Minimum [Member] | Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.0001	0.007
Valuation Technique, Discounted Cash Flow | Measurement Input, Credit Spread | Maximum [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.053	0.030
Valuation Technique, Discounted Cash Flow | Measurement Input, Credit Spread | Maximum [Member] | Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.196	0.080
Valuation Technique, Discounted Cash Flow | Measurement Input, Credit Spread | Weighted Average | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.013	(0.012)
Valuation Technique, Discounted Cash Flow | Measurement Input, Credit Spread | Weighted Average | Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.025	(0.021)
Investments [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investment assets measured at fair value	$ 207,936	$ 162,244
Total Level 3 Securities	349,255	251,282	$ 129,969
Investments [Member] | Valuation Technique, Discounted Cash Flow | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 141,319	$ 89,038

Fair Value Measurements (Quan_2

Fair Value Measurements (Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	$ 29,837	$ 29,460
Commercial mortgage loans, fair value	139,243	97,598
Long-term debt, fair value	466,603	651,071
Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	3,405	3,576
Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	26,432	25,884
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Commercial mortgage loans, fair value	0	0
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	29,837	29,460
Commercial mortgage loans, fair value	0	0
Long-term debt, fair value	466,603	651,071
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	3,405	3,576
Significant Other Observable Inputs (Level 2) [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	26,432	25,884
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Commercial mortgage loans, fair value	139,243	97,598
Long-term debt, fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed income securities, held-to-maturity - fair value	0	0
Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	51,705	63,719
Seven Point Twenty Five Percent Senior Notes [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	0	0
Seven Point Twenty Five Percent Senior Notes [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	51,705	63,719
Seven Point Twenty Five Percent Senior Notes [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	0	0
Six Point Seventy Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	99,264	127,574
Six Point Seventy Percent Senior Notes [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	0	0
Six Point Seventy Percent Senior Notes [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	99,264	127,574
Six Point Seventy Percent Senior Notes [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	0	0
Five Point Three Hundred Seventy Five Percent Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	258,459	395,652
Five Point Three Hundred Seventy Five Percent Senior Notes [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	0	0
Five Point Three Hundred Seventy Five Percent Senior Notes [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	258,459	395,652
Five Point Three Hundred Seventy Five Percent Senior Notes [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	0	0
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	57,175	64,126
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	0	0
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	57,175	64,126
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	0	0
Long-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	$ 466,603	$ 651,071

Allowance for Credit Losses o_3

Allowance for Credit Losses on Premiums Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Premiums Receivable, Allowance for Credit Loss [Line Items]
Premium Receivable, Allowance for Credit Loss	$ 16,100	$ 13,600
Change in allowance for credit losses on premiums receivable	7,500	1,900
Reductions in allowance for credit losses on premiums receivable
Premiums Receivable, Allowance for Credit Loss [Line Items]
Change in allowance for credit losses on premiums receivable	1,800	6,400
Premiums Receivable, Allowance for Credit Losses
Premiums Receivable, Allowance for Credit Loss [Line Items]
Change in allowance for credit losses on premiums receivable	9,300	8,300
Premiums Receivable [Member]
Premiums Receivable, Allowance for Credit Loss [Line Items]
Premium Receivable, Allowance for Credit Loss		13,600	$ 21,000
Current period provision for expected credit losses	6,065	1,291
Write-offs charged against the allowance for credit losses	(4,978)	(9,343)
Recoveries	$ 1,413	$ 652

Reinsurance Recoverable, Credit

Reinsurance Recoverable, Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables on Unpaid Losses, Gross	$ 784,410	$ 601,668
Reinsurance Recoverable, Allowance for Credit Loss	(1,600)	(1,600)	$ (1,777)
Reinsurance Recoverables, net of allowance for credit losses	782,810	600,068
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments, Gross [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	779,399	598,317
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments, Gross [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	5,011	3,351
Total federal and state pools [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	180,794	116,378
Change in Reinsurance Recoverable, Gross	64,400
Total federal and state pools [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	180,794	116,378
Total federal and state pools [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	0	0
Other Federal And State Pools [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	14,093	5,047
Other Federal And State Pools [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	13,678	4,597
Other Federal And State Pools [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	415	450
Total Non Rated Reinsurer [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	194,887	121,425
Total Non Rated Reinsurer [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	194,472	120,975
Total Non Rated Reinsurer [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	415	450
AM Best, A++ Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	46,283	38,610
AM Best, A++ Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	46,282	38,601
AM Best, A++ Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	1	9
AM Best, A+ Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	428,586	341,377
AM Best, A+ Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	425,395	339,857
AM Best, A+ Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	3,191	1,520
AM Best, A Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	107,417	96,902
AM Best, A Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	106,102	95,675
AM Best, A Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	1,315	1,227
AM Best, A- Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	7,237	3,354
AM Best, A- Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	7,148	3,209
AM Best, A- Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	89	145
AM Best Rated Reinsurer [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	589,523	480,243
Change in Reinsurance Recoverable, Gross	109,300
AM Best Rated Reinsurer [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	584,927	477,342
AM Best Rated Reinsurer [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	$ 4,596	$ 2,901

Reinsurance Allowance for Credi

Reinsurance Allowance for Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit loss, beginning balance	$ 1,600	$ 1,777
Current period change for expected credit losses	0	(177)
Write-offs charged against the allowance for credit losses	0	0
Recoveries	0	0
Allowance for credit loss, ending balance	$ 1,600	$ 1,600

Reinsurance (Total Reinsurance

Reinsurance (Total Reinsurance Balances Segregated By Reinsurer) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Terrorism Risk Insurance Program Companys Estimated Deductible		$ 480,000
Terrorism Risk Insurance Program Reimbursed Percentage Maximum		80%
Terrorism Risk Insurance Program Annual Cap		$ 100,000,000
Terrorism Risk Insurance Program Insurer Retainer		20%
Reinsurance recoverable, net of allowance for credit losses		$ 782,810	$ 600,068
Total prepaid reinsurance premiums		172,371	183,007
Total reinsurance balance		955,181	783,075
Less: collateral	[1]	(126,167)	(128,699)
Reinsurance Recoverable, Allowance for Credit Loss		(1,600)	(1,600)	$ (1,777)
National Flood Insurance Program [Member]
Total reinsurance balance	[2]	$ 276,541	$ 223,845
% of Net Reinsurance Balance	[2]	29%	29%
NJ Unsatisfied Claim Judgment Fund [Member]
Total reinsurance balance	[2]	$ 45,496	$ 49,738
% of Net Reinsurance Balance	[2]	5%	6%
Other Federal And State Pools [Member]
Total reinsurance balance	[2]	$ 3,488	$ 2,385
% of Net Reinsurance Balance	[2]	0%	0%
Total Federal And State Pools [Member]
Total reinsurance balance	[2]	$ 325,525	$ 275,968
% of Net Reinsurance Balance	[2]	34%	35%
Remaining Unsecured Reinsurance [Member]
Total reinsurance balance		$ 631,256	$ 508,707
% of Net Reinsurance Balance		66%	65%
Remaining Reinsurance, after Allowance for Credit Loss		$ 629,656	$ 507,107
Munich Re Group [Member]
Total reinsurance balance		$ 127,106	$ 108,381
% of Net Reinsurance Balance		13%	14%
Hanover Ruckversicherungs AG [Member]
Total reinsurance balance		$ 124,706	$ 107,110
% of Net Reinsurance Balance		13%	14%
AXIS Reinsurance Company [Member]
Total reinsurance balance		$ 70,957	$ 70,814
% of Net Reinsurance Balance		8%	9%
Swiss Re Group [Member]
Total reinsurance balance		$ 36,525	$ 29,186
% of Net Reinsurance Balance		4%	4%
Transatlantic Reinsurance Company [Member]
Total reinsurance balance		$ 32,730	$ 26,490
% of Net Reinsurance Balance		3%	3%
All Other Reinsurers [Member]
Total reinsurance balance		$ 239,232	$ 166,726
% of Net Reinsurance Balance		25%	21%
Remaining Unsecured Reinsurance, Net of Collateral [Member]
Total reinsurance balance		$ 503,489	$ 378,408
[1]Includes letters of credit, trust funds, and funds held against reinsurance recoverables[2]Considered to have minimal risk of default.

Reinsurance (List of direct, as

Reinsurance (List of direct, assumed and ceded Reinsurance Amounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Premiums Written:
Direct premiums written	$ 4,068,518	$ 3,656,537	$ 3,204,512
Assumed	32,320	22,664	24,288
Ceded premiums written	(527,248)	(489,488)	(455,708)
Net	3,573,590	3,189,713	2,773,092
Direct premiums written	4,068,518	3,656,537	3,204,512
Premiums Earned:
Direct	3,880,522	3,472,715	3,108,687
Assumed	30,742	21,550	25,010
Ceded premiums earned	(537,884)	(477,012)	(451,883)
Total net premiums earned	3,373,380	3,017,253	2,681,814
Loss and loss expense incurred:
Direct	2,537,638	2,096,512	1,822,034
Assumed	23,160	13,813	17,201
Ceded loss and loss expense	(449,020)	(296,341)	(203,412)
Net	$ 2,111,778	$ 1,813,984	$ 1,635,823

Reinsurance (Ceded Premiums and

Reinsurance (Ceded Premiums and Losses Related to Flood Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Percentage of NFIP claims ceded to the federal government	100%
Ceded premiums written	$ (527,248)	$ (489,488)	$ (455,708)
Ceded premiums earned	(537,884)	(477,012)	(451,883)
Ceded loss and loss expense	(449,020)	(296,341)	(203,412)
National Flood Insurance Program [Member]
Ceded premiums written	(259,246)	(284,311)	(274,042)
Ceded premiums earned	(274,100)	(274,384)	(271,598)
Ceded loss and loss expense	$ (200,467)	$ (215,224)	$ (78,993)

Reserve for Loss and Loss Exp_3

Reserve for Loss and Loss Expense (Rollforward of Reserve for Loss and Loss Expense) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Gross reserve for loss and loss expense, at beginning of year		$ 4,580,903	$ 4,260,355	$ 4,067,163
Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year		578,641	554,269
Net reserves for loss and loss expense, at beginning of year		4,002,262	3,706,086	3,520,097
Incurred loss and loss expense for claims occurring in the current year		2,190,668	1,896,837	1,708,755
Prior Year Claims and Claims Adjustment Expense		(78,890)	(82,853)	(72,932)
Total incurred loss and loss expense		2,111,778	1,813,984	1,635,823
Paid loss and loss expense for claims occurring in current year		768,583	676,331	642,586
Paid loss and loss expense for claims occurring in prior years		958,149	841,477	807,248
Total paid loss and loss expense		1,726,732	1,517,808	1,449,834
Net reserves for loss and loss expense, at end of year		4,387,308	4,002,262	3,706,086
Add: reinsurance recoverable on unpaid loss and loss expense, at end of year		757,513	578,641	554,269
Gross reserve for loss and loss expense, at end of year		5,144,821	4,580,903	4,260,355
Increase of net loss and loss expense reserves		385,000	296,200	183,100
Anticipated recoveries for salvage and subrogation claims		$ 91,300	87,000	80,900
Accounting Standards Update 2016-13 [Member]
Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year	[1]			547,066
Net reserves for loss and loss expense, at beginning of year			3,706,086
Net reserves for loss and loss expense, at end of year				3,706,086
Equity Impact on Cumulative Effect Adjustment			$ 0	0	$ (1,845)
Accounting Standards Update 2016-13 [Member] | Retained Earnings [Member]
Equity Impact on Cumulative Effect Adjustment				$ 2,900
[1] 1 2020 includes an adjustment of $2.9 million related to our adoption of ASU 2016-13, Financial Instruments - Credit Losses.

Reserve for Loss and Loss Exp_4

Reserve for Loss and Loss Expense (Reserve Loss Development) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Favorable or adverse loss development	$ (78,890)	$ (82,853)	$ (72,932)
Favorable or unfavorable loss development [Member]
Favorable or adverse loss development	(78,900)	(82,900)	(72,900)
Favorable or unfavorable loss development [Member] | Commercial Automobile [Member]
Favorable or adverse loss development	22,500	13,300	7,100
Favorable or unfavorable loss development [Member] | General Liability [Member]
Favorable or adverse loss development	(5,000)	(29,000)	(35,000)
Favorable or unfavorable loss development [Member] | Commercial Automobile [Member]
Favorable or adverse loss development	22,500	13,300	7,100
Favorable or unfavorable loss development [Member] | Workers Compensation [Member]
Favorable or adverse loss development	(70,000)	(58,000)	(60,000)
Favorable or unfavorable loss development [Member] | Business Owners' Policies [Member]
Favorable or adverse loss development	(7,300)	(400)	3,900
Favorable or unfavorable loss development [Member] | Commercial Property [Member]
Favorable or adverse loss development	(1,600)	(2,600)	9,200
Favorable or unfavorable loss development [Member] | Bonds [Member]
Favorable or adverse loss development	(10,000)	0	0
Favorable or unfavorable loss development [Member] | Homeowners [Member]
Favorable or adverse loss development	(600)	1,800	7,700
Favorable or unfavorable loss development [Member] | Personal Automobile [Member]
Favorable or adverse loss development	500	(200)	(1,800)
Favorable or unfavorable loss development [Member] | E&S Casualty Lines [Member]
Favorable or adverse loss development	(5,000)	(7,000)	0
Favorable or unfavorable loss development [Member] | E&S Property Lines [Member]
Favorable or adverse loss development	(2,500)	(800)	(4,000)
Favorable or unfavorable loss development [Member] | Insurance, Other [Member]
Favorable or adverse loss development	(100)	0	0
Favorable or unfavorable loss development [Member] | Property Insurance [Member]
Favorable or adverse loss development	7,100	(1,900)	12,100
Favorable or unfavorable loss development [Member] | Casualty Insurance Product Line [Member]
Favorable or adverse loss development	(86,000)	(81,000)	(85,000)
Favorable or unfavorable loss development [Member] | Casualty Insurance Product Line [Member] | Commercial Automobile [Member]
Favorable or adverse loss development	$ 15,000	$ 15,000	$ 10,000

Reserve for Loss and Loss Exp_5

Reserve for Loss and Loss Expense (Exposure to Environmental Claims) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Loss and Loss expense reserves, Gross	$ 27,768	$ 27,773	$ 28,530	$ 28,701
Liability for Asbestos and Environmental Claims, Net	20,329	$ 21,075	$ 21,421	$ 21,589
Asbestos Claim [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Loss and Loss expense reserves, Gross	5,900
Liability for Asbestos and Environmental Claims, Net	4,700
Landfill Sites Related Claims [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Loss and Loss expense reserves, Gross	11,800
Liability for Asbestos and Environmental Claims, Net	7,500
Underground Storage Tanks Claims [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Loss and Loss expense reserves, Gross	10,100
Liability for Asbestos and Environmental Claims, Net	$ 8,100

Reserve for Loss and Loss Exp_6

Reserve for Loss and Loss Expense (Roll Forward of Gross and Net Asbestos and Net Environmental Incurred Losses and Loss Expenses and Related Reserves) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for loss and loss expense at beginning of year, gross	$ 27,773	$ 28,530	$ 28,701
Incurred loss and loss expense, gross	(704)	(562)	(127)
Less: loss and loss expense paid, Gross	(709)	(195)	(44)
Reserve for loss and loss expense at the end of year, gross	27,768	27,773	28,530
Reserve for loss and loss expense at beginning of year, net	21,075	21,421	21,589
Incurred loss and loss expense, Net	(205)	37	(154)
Less: loss and loss expense paid, Net	(541)	(383)	(14)
Reserve for loss and loss expense at the end of year, net	20,329	21,075	21,421
Asbestos [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for loss and loss expense at beginning of year, gross	6,115	6,254	6,288
Incurred loss and loss expense, gross	(8)	(51)	(320)
Less: loss and loss expense paid, Gross	(232)	(190)	(354)
Reserve for loss and loss expense at the end of year, gross	5,891	6,115	6,254
Reserve for loss and loss expense at beginning of year, net	4,884	5,023	5,057
Incurred loss and loss expense, Net	8	51	320
Less: loss and loss expense paid, Net	(232)	(190)	(354)
Reserve for loss and loss expense at the end of year, net	4,660	4,884	5,023
Enviromental [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for loss and loss expense at beginning of year, gross	21,658	22,276	22,413
Incurred loss and loss expense, gross	(696)	(613)	(447)
Less: loss and loss expense paid, Gross	(477)	(5)	(310)
Reserve for loss and loss expense at the end of year, gross	21,877	21,658	22,276
Reserve for loss and loss expense at beginning of year, net	16,191	16,398	16,532
Incurred loss and loss expense, Net	213	14	474
Less: loss and loss expense paid, Net	(309)	(193)	(340)
Reserve for loss and loss expense at the end of year, net	$ 15,669	$ 16,191	$ 16,398

Reserve for Loss and Loss Exp_7

Reserve for Loss and Loss Expense (Claims Development) (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Claims Development [Line Items]
Net outstanding liabilities	$ 13,946,270
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	10,066,069
Liability for Unpaid Claims and Claims Adjustment Expense, Net	4,259,274
Reserve for loss and loss expense	5,144,821	$ 4,580,903
Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	379,073
Short-duration Insurance Contracts, Accident Year 2013 [Member]
Claims Development [Line Items]
Net outstanding liabilities	951,813	957,958	$ 973,739	$ 984,858	$ 987,763	$ 1,002,316	$ 1,021,007	$ 1,047,230	$ 1,062,045	$ 1,044,142
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 33,631
Short-duration Insurance Contract, Cumulative Number of Reported Claims	91,959
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 916,769	911,657	904,825	891,841	872,331	833,823	748,758	644,475	518,872	335,956
Short-duration Insurance Contracts, Accident Year 2014[Member]
Claims Development [Line Items]
Net outstanding liabilities	1,090,345	1,094,367	1,089,529	1,100,208	1,104,218	1,124,014	1,146,990	1,133,798	1,107,513
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 42,087
Short-duration Insurance Contract, Cumulative Number of Reported Claims	95,835
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 1,032,400	1,020,961	1,002,157	981,868	936,425	855,959	736,154	614,075	405,898
Short-duration Insurance Contracts, Accident Year 2015 [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,103,543	1,103,592	1,108,860	1,119,441	1,138,313	1,144,830	1,130,513	1,114,081
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 45,698
Short-duration Insurance Contract, Cumulative Number of Reported Claims	95,173
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 1,018,023	1,000,509	967,857	929,222	845,868	725,385	581,203	376,641
Short-duration Insurance Contracts, Accident Year 2016 [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,167,539	1,171,273	1,180,829	1,199,734	1,227,142	1,203,634	1,188,608
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 67,934
Short-duration Insurance Contract, Cumulative Number of Reported Claims	95,944
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 1,061,952	1,025,264	983,852	892,390	764,331	617,958	387,272
Short-duration Insurance Contracts, Accident Year 2017 [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,273,039	1,268,941	1,288,526	1,313,585	1,313,372	1,270,110
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 84,415
Short-duration Insurance Contract, Cumulative Number of Reported Claims	99,877
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 1,116,336	1,050,258	954,792	829,134	678,453	433,440
Short-duration Insurance Contract, Accident Year 2018 [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,425,540	1,441,303	1,457,415	1,461,603	1,413,800
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 153,214
Short-duration Insurance Contract, Cumulative Number of Reported Claims	107,095
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 1,187,744	1,083,556	942,893	779,466	511,271
Short-Duration Insurance Contract, Accident Year 2019 [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,529,859	1,526,566	1,523,041	1,483,945
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 272,639
Short-duration Insurance Contract, Cumulative Number of Reported Claims	104,096
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 1,109,628	949,996	781,462	510,091
Short-Duration Insurance Contract, Accident Year 2020
Claims Development [Line Items]
Net outstanding liabilities	1,550,195	1,587,607	1,591,972
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 395,519
Short-duration Insurance Contract, Cumulative Number of Reported Claims	94,752
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 988,463	831,976	572,302
Short-Duration Insurance Contract, Accident Year 2021
Claims Development [Line Items]
Net outstanding liabilities	1,781,054	1,784,661
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 636,984
Short-duration Insurance Contract, Cumulative Number of Reported Claims	97,914
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 934,965	609,889
Short-Duration Insurance Contract, Accident Year 2022
Claims Development [Line Items]
Net outstanding liabilities	2,073,343
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 1,089,571
Short-duration Insurance Contract, Cumulative Number of Reported Claims	94,382
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 699,789
Standard Commercial Lines [Member] | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	3,096,166
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	1,520,784
Liability for Unpaid Claims and Claims Adjustment Expense, Net	1,688,645
Standard Commercial Lines [Member] | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,665,144
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	1,086,983
Liability for Unpaid Claims and Claims Adjustment Expense, Net	809,019
Standard Commercial Lines [Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	3,521,080
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	2,677,763
Liability for Unpaid Claims and Claims Adjustment Expense, Net	847,967
Standard Commercial Lines [Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	589,734
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	488,920
Liability for Unpaid Claims and Claims Adjustment Expense, Net	110,471
Standard Commercial Lines [Member] | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,758,159
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	1,628,461
Liability for Unpaid Claims and Claims Adjustment Expense, Net	130,277
Standard Commercial Lines [Member] | Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member] | General Liability [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	113,263
Standard Commercial Lines [Member] | Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member] | Workers Compensation [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	230,858
Standard Commercial Lines [Member] | Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	4,650
Standard Commercial Lines [Member] | Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	9,657
Standard Commercial Lines [Member] | Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member] | Commercial Property [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	579
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2013 [Member] | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	189,594	192,782	195,697	202,697	203,831	210,785	225,709	239,776	251,421	250,609
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 12,561
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,462
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 174,987	172,983	169,847	163,764	153,628	139,114	104,587	72,127	35,113	12,789
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2013 [Member] | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	149,975	153,436	157,645	159,767	162,787	166,662	173,160	187,658	194,318	199,794
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 16,818
Short-duration Insurance Contract, Cumulative Number of Reported Claims	11,385
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 131,390	130,467	129,224	126,822	124,130	118,669	109,739	96,376	74,568	36,829
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2013 [Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	207,564	207,554	208,040	209,602	207,975	210,410	207,994	209,197	205,282	188,289
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 535
Short-duration Insurance Contract, Cumulative Number of Reported Claims	26,221
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 206,641	206,162	205,064	202,622	200,750	189,626	169,850	140,015	109,893	76,469
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2013 [Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	38,984	38,930	39,358	39,699	39,709	41,369	40,624	41,005	42,618	49,617
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 169
Short-duration Insurance Contract, Cumulative Number of Reported Claims	3,484
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 39,445	39,440	39,212	39,085	38,464	37,993	34,760	30,845	26,592	17,412
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2013 [Member] | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	90,799	90,461	90,486	90,218	90,278	90,436	90,005	90,103	90,639	88,101
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 4
Short-duration Insurance Contract, Cumulative Number of Reported Claims	5,716
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 91,206	90,891	90,917	90,646	90,696	90,840	90,350	90,446	87,874	60,244
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2014[Member] | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	228,933	230,247	229,679	237,125	234,082	239,333	257,132	249,946	244,312
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 18,901
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,704
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 204,212	198,772	187,352	179,192	154,957	121,969	79,972	46,825	14,901
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2014[Member] | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	158,479	161,021	159,604	160,646	164,420	172,515	182,579	187,065	199,346
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 17,598
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,498
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 132,809	130,726	127,858	124,077	119,392	113,626	100,876	78,944	35,924
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2014[Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	214,816	214,992	216,461	217,334	218,172	219,925	216,824	212,725	200,534
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 516
Short-duration Insurance Contract, Cumulative Number of Reported Claims	28,263
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 213,847	213,689	212,481	209,655	202,821	180,701	148,884	117,169	80,810
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2014[Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	57,355	57,483	57,302	58,093	58,517	59,806	62,548	60,949	55,962
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 96
Short-duration Insurance Contract, Cumulative Number of Reported Claims	4,067
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 56,861	55,729	55,708	55,458	52,940	49,460	44,911	40,584	28,914
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2014[Member] | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	136,112	136,151	136,237	136,212	138,155	138,751	136,820	136,249	141,192
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 5
Short-duration Insurance Contract, Cumulative Number of Reported Claims	6,517
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 136,107	136,141	135,928	136,008	137,418	137,883	136,634	132,909	101,131
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2015 [Member] | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	210,137	211,768	214,176	219,204	233,249	246,990	245,710	254,720
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 19,932
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,565
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 179,117	173,697	157,071	144,216	116,804	78,668	39,978	14,665
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2015 [Member] | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	169,008	170,577	172,572	176,242	179,642	183,604	194,639	193,729
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 18,790
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,554
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 132,235	129,019	124,046	120,097	112,601	98,195	77,320	33,857
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2015 [Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	262,766	262,054	261,386	260,565	259,495	253,074	240,958	220,994
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 1,627
Short-duration Insurance Contract, Cumulative Number of Reported Claims	30,085
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 257,668	255,600	249,905	238,142	211,515	175,866	132,260	91,347
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2015 [Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	52,514	52,200	52,325	54,454	55,925	57,245	53,768	52,871
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 608
Short-duration Insurance Contract, Cumulative Number of Reported Claims	3,968
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 51,120	50,005	49,839	49,073	46,571	42,710	36,014	24,189
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2015 [Member] | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	112,915	112,937	112,582	112,496	111,566	111,750	109,513	110,270
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 9
Short-duration Insurance Contract, Cumulative Number of Reported Claims	6,407
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 112,391	112,410	112,117	110,969	110,994	109,829	106,182	79,048
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2016 [Member] | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	243,669	246,643	252,733	263,245	277,986	272,048	277,214
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 30,556
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,825
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 199,032	181,770	164,136	133,757	89,431	46,549	15,684
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2016 [Member] | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	151,961	155,210	156,540	166,009	176,248	184,946	196,774
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 21,205
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,586
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 122,186	119,800	115,159	109,166	98,037	78,531	34,525
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2016 [Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	294,297	291,674	290,359	285,304	285,302	274,367	255,187
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 2,635
Short-duration Insurance Contract, Cumulative Number of Reported Claims	32,041
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 284,870	277,242	264,858	233,939	200,701	155,720	106,022
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2016 [Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	53,201	53,147	53,367	53,835	54,993	53,792	52,335
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 828
Short-duration Insurance Contract, Cumulative Number of Reported Claims	3,854
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 52,070	50,536	48,786	45,308	39,973	36,848	24,655
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2016 [Member] | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	123,126	123,005	123,567	124,487	125,937	126,185	121,927
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 14
Short-duration Insurance Contract, Cumulative Number of Reported Claims	6,743
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 123,265	122,909	123,601	123,828	122,930	118,789	83,966
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2017 [Member] | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	283,379	278,607	289,883	301,384	293,128	293,747
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 46,761
Short-duration Insurance Contract, Cumulative Number of Reported Claims	11,324
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 201,948	167,002	131,980	92,355	49,470	17,366
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2017 [Member] | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	151,221	154,159	162,672	175,853	184,306	195,202
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 19,961
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,813
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 120,468	116,426	110,645	100,645	82,216	40,375
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2017 [Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	325,654	326,461	322,197	324,291	329,389	301,274
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 4,664
Short-duration Insurance Contract, Cumulative Number of Reported Claims	33,345
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 309,810	296,600	262,349	220,422	178,823	117,287
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2017 [Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	42,374	43,606	48,067	51,524	48,698	46,624
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 879
Short-duration Insurance Contract, Cumulative Number of Reported Claims	3,895
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 40,845	39,940	40,359	36,950	31,337	21,865
Standard Commercial Lines [Member] | Short-duration Insurance Contracts, Accident Year 2017 [Member] | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	154,942	154,119	153,664	149,044	149,106	138,773
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 20
Short-duration Insurance Contract, Cumulative Number of Reported Claims	6,906
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 154,689	153,750	152,018	148,589	142,338	99,047
Standard Commercial Lines [Member] | Short-duration Insurance Contract, Accident Year 2018 [Member] | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	324,567	332,013	345,224	336,326	317,934
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 92,627
Short-duration Insurance Contract, Cumulative Number of Reported Claims	11,802
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 197,286	155,538	108,421	60,784	19,531
Standard Commercial Lines [Member] | Short-duration Insurance Contract, Accident Year 2018 [Member] | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	167,974	173,428	181,151	193,818	193,894
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 25,963
Short-duration Insurance Contract, Cumulative Number of Reported Claims	11,133
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 126,206	119,904	105,903	84,780	41,122
Standard Commercial Lines [Member] | Short-duration Insurance Contract, Accident Year 2018 [Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	348,202	350,310	345,547	352,487	347,908
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 11,375
Short-duration Insurance Contract, Cumulative Number of Reported Claims	36,002
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 319,819	291,725	243,713	193,788	134,867
Standard Commercial Lines [Member] | Short-duration Insurance Contract, Accident Year 2018 [Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	56,625	60,393	62,427	57,202	55,024
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 3,125
Short-duration Insurance Contract, Cumulative Number of Reported Claims	4,262
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 51,239	48,144	44,316	39,791	29,995
Standard Commercial Lines [Member] | Short-duration Insurance Contract, Accident Year 2018 [Member] | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	196,413	194,016	192,558	190,834	183,177
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 47
Short-duration Insurance Contract, Cumulative Number of Reported Claims	8,293
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 196,376	193,487	192,698	184,813	135,416
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2019 [Member] | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	366,184	358,301	356,363	347,150
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 154,311
Short-duration Insurance Contract, Cumulative Number of Reported Claims	11,575
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 160,680	100,206	58,284	18,097
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2019 [Member] | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	164,940	174,912	188,596	188,625
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 32,088
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,324
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 112,649	100,812	77,878	37,826
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2019 [Member] | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	407,051	404,854	398,346	385,212
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 32,019
Short-duration Insurance Contract, Cumulative Number of Reported Claims	36,375
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 331,152	283,410	221,590	149,538
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2019 [Member] | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	65,762	64,667	59,466	53,531
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 8,181
Short-duration Insurance Contract, Cumulative Number of Reported Claims	3,639
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 52,887	46,113	41,587	27,718
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2019 [Member] | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	180,605	179,574	177,075	173,826
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 230
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,315
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 179,538	177,825	172,768	130,891
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2020 | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	352,834	360,302	361,554
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 201,089
Short-duration Insurance Contract, Cumulative Number of Reported Claims	9,645
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 100,356	58,699	21,858
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2020 | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	159,229	168,594	168,643
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 44,323
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,534
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 87,211	68,277	29,559
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2020 | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	375,636	381,163	381,654
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 70,872
Short-duration Insurance Contract, Cumulative Number of Reported Claims	30,343
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 254,365	198,034	139,016
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2020 | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	73,077	73,680	71,836
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 7,630
Short-duration Insurance Contract, Cumulative Number of Reported Claims	5,421
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 60,596	57,210	43,376
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2020 | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	226,107	225,278	232,060
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 2,023
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,147
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 220,953	215,107	164,613
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2021 | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	414,279	422,748
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 287,278
Short-duration Insurance Contract, Cumulative Number of Reported Claims	10,136
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 71,664	28,069
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2021 | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	185,151	185,198
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 74,474
Short-duration Insurance Contract, Cumulative Number of Reported Claims	8,547
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 76,015	32,918
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2021 | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	512,673	483,831
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 155,984
Short-duration Insurance Contract, Cumulative Number of Reported Claims	36,843
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 283,411	187,200
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2021 | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	63,648	66,312
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 10,539
Short-duration Insurance Contract, Cumulative Number of Reported Claims	3,454
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 47,436	34,412
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2021 | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	239,822	246,319
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 4,672
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,942
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 227,259	161,757
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2022 | General Liability [Member]
Claims Development [Line Items]
Net outstanding liabilities	482,590
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 409,505
Short-duration Insurance Contract, Cumulative Number of Reported Claims	8,988
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 31,502
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2022 | Workers Compensation [Member]
Claims Development [Line Items]
Net outstanding liabilities	207,206
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 116,968
Short-duration Insurance Contract, Cumulative Number of Reported Claims	8,517
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 45,814
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2022 | Commercial Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	572,421
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 278,004
Short-duration Insurance Contract, Cumulative Number of Reported Claims	36,909
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 216,180
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2022 | Business Owners' Policies [Member]
Claims Development [Line Items]
Net outstanding liabilities	86,194
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 33,995
Short-duration Insurance Contract, Cumulative Number of Reported Claims	3,074
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 36,421
Standard Commercial Lines [Member] | Short-Duration Insurance Contract, Accident Year 2022 | Commercial Property [Member]
Claims Development [Line Items]
Net outstanding liabilities	297,318
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 56,716
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,224
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 186,677
Standard Personal Lines | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,065,746
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	972,809
Liability for Unpaid Claims and Claims Adjustment Expense, Net	99,982
Standard Personal Lines | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	792,170
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	752,675
Liability for Unpaid Claims and Claims Adjustment Expense, Net	45,597
Standard Personal Lines | Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member] | Personal Automobile [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	7,045
Standard Personal Lines | Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member] | Homeowners [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	6,102
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2013 [Member] | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	107,758	107,754	107,803	107,916	107,680	107,759	106,703	106,225	109,620	108,417
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 57
Short-duration Insurance Contract, Cumulative Number of Reported Claims	22,376
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 107,417	107,423	107,419	106,876	106,679	105,131	100,528	92,637	80,861	61,384
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2013 [Member] | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	71,960	71,955	71,948	72,318	72,148	71,714	72,145	71,494	72,528	73,670
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 67
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,753
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 72,415	72,447	72,446	72,433	72,197	71,776	69,775	67,838	65,528	50,664
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2014[Member] | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	107,543	107,566	107,106	107,104	106,821	107,452	106,757	109,325	102,250
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 47
Short-duration Insurance Contract, Cumulative Number of Reported Claims	22,509
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 107,325	107,108	106,478	105,709	104,055	99,173	92,589	83,739	62,519
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2014[Member] | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	83,819	83,830	83,525	83,824	83,539	83,844	83,637	82,461	80,111
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 60
Short-duration Insurance Contract, Cumulative Number of Reported Claims	8,776
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 83,782	83,321	82,831	82,836	82,583	81,664	79,751	76,007	61,561
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2015 [Member] | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	98,669	98,596	98,588	98,718	99,570	100,214	99,698	96,387
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 117
Short-duration Insurance Contract, Cumulative Number of Reported Claims	20,865
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 97,920	97,761	97,275	95,997	92,102	87,163	76,470	58,725
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2015 [Member] | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	74,237	74,682	74,673	74,978	74,723	76,559	76,400	76,637
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 20
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,753
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 74,108	74,096	74,052	74,079	72,927	72,202	70,078	52,589
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2016 [Member] | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	100,395	99,858	99,544	101,140	100,202	98,032	92,727
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 409
Short-duration Insurance Contract, Cumulative Number of Reported Claims	19,827
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 99,656	98,977	98,080	94,372	86,752	76,823	57,961
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2016 [Member] | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	60,841	60,855	61,735	61,723	62,391	60,931	60,105
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 438
Short-duration Insurance Contract, Cumulative Number of Reported Claims	6,896
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 60,474	60,449	61,187	60,082	59,546	57,333	42,252
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2017 [Member] | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	105,079	103,557	103,260	103,653	105,139	101,880
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 710
Short-duration Insurance Contract, Cumulative Number of Reported Claims	20,748
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 103,556	100,521	97,628	91,479	82,730	62,854
Standard Personal Lines | Short-duration Insurance Contracts, Accident Year 2017 [Member] | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	68,902	68,938	70,064	70,365	67,978	59,167
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 504
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,389
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 68,282	68,078	67,767	67,193	63,290	45,466
Standard Personal Lines | Short-duration Insurance Contract, Accident Year 2018 [Member] | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	113,647	112,418	112,030	113,569	111,594
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 2,098
Short-duration Insurance Contract, Cumulative Number of Reported Claims	22,684
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 109,644	107,026	99,982	89,628	69,721
Standard Personal Lines | Short-duration Insurance Contract, Accident Year 2018 [Member] | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	68,416	68,931	69,832	68,526	62,961
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 608
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,608
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 67,739	66,634	65,348	64,137	49,430
Standard Personal Lines | Short-Duration Insurance Contract, Accident Year 2019 [Member] | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	118,669	115,993	115,688	114,043
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 4,163
Short-duration Insurance Contract, Cumulative Number of Reported Claims	22,860
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 109,844	102,930	92,162	69,699
Standard Personal Lines | Short-Duration Insurance Contract, Accident Year 2019 [Member] | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	73,070	73,816	72,772	64,306
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 1,412
Short-duration Insurance Contract, Cumulative Number of Reported Claims	7,010
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 70,880	69,911	67,631	49,680
Standard Personal Lines | Short-Duration Insurance Contract, Accident Year 2020 | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	90,179	94,532	95,625
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 6,584
Short-duration Insurance Contract, Cumulative Number of Reported Claims	17,533
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 76,710	68,691	53,407
Standard Personal Lines | Short-Duration Insurance Contract, Accident Year 2020 | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	113,804	112,523	109,033
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 3,611
Short-duration Insurance Contract, Cumulative Number of Reported Claims	9,824
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 109,145	105,690	83,838
Standard Personal Lines | Short-Duration Insurance Contract, Accident Year 2021 | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	102,777	108,244
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 10,411
Short-duration Insurance Contract, Cumulative Number of Reported Claims	19,672
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 84,743	65,325
Standard Personal Lines | Short-Duration Insurance Contract, Accident Year 2021 | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	83,295	82,425
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 3,657
Short-duration Insurance Contract, Cumulative Number of Reported Claims	6,884
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 77,018	59,054
Standard Personal Lines | Short-Duration Insurance Contract, Accident Year 2022 | Personal Automobile [Member]
Claims Development [Line Items]
Net outstanding liabilities	121,030
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 26,632
Short-duration Insurance Contract, Cumulative Number of Reported Claims	20,345
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 75,994
Standard Personal Lines | Short-Duration Insurance Contract, Accident Year 2022 | Homeowners [Member]
Claims Development [Line Items]
Net outstanding liabilities	93,826
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 17,362
Short-duration Insurance Contract, Cumulative Number of Reported Claims	5,819
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 68,832
E&S Lines [Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	1,020,366
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	546,850
Liability for Unpaid Claims and Claims Adjustment Expense, Net	479,507
E&S Lines [Member] | Short-Duration Insurance Contracts, Accident Years Prior to 2013 [Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	5,991
E&S Lines [Member] | Short-duration Insurance Contracts, Accident Year 2013 [Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	60,511	60,349	68,029	68,451	68,972	67,647	69,112	67,099	60,309	55,468
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 3,504
Short-duration Insurance Contract, Cumulative Number of Reported Claims	2,311
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 58,584	57,152	55,988	54,974	51,142	46,108	35,200	21,980	9,470	$ 2,715
E&S Lines [Member] | Short-duration Insurance Contracts, Accident Year 2014[Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	74,538	74,270	70,846	71,153	71,206	71,719	69,929	63,505	55,316
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 4,918
Short-duration Insurance Contract, Cumulative Number of Reported Claims	2,141
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 68,648	66,661	64,698	60,092	53,780	43,877	25,571	12,234	$ 2,353
E&S Lines [Member] | Short-duration Insurance Contracts, Accident Year 2015 [Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	90,263	87,662	90,126	90,355	90,488	82,404	76,432	75,498
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 4,646
Short-duration Insurance Contract, Cumulative Number of Reported Claims	2,887
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 81,396	75,844	71,421	64,529	50,712	29,389	13,057	$ 3,036
E&S Lines [Member] | Short-duration Insurance Contracts, Accident Year 2016 [Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	101,873	102,476	104,730	105,120	104,655	96,416	94,451
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 12,138
Short-duration Insurance Contract, Cumulative Number of Reported Claims	2,998
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 81,932	75,004	69,448	56,581	33,950	16,195	$ 3,720
E&S Lines [Member] | Short-duration Insurance Contracts, Accident Year 2017 [Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	102,045	99,960	99,395	99,866	95,783	91,438
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 11,390
Short-duration Insurance Contract, Cumulative Number of Reported Claims	2,848
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 77,090	68,266	53,238	34,179	14,672	$ 5,057
E&S Lines [Member] | Short-duration Insurance Contract, Accident Year 2018 [Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	105,756	104,983	103,184	103,004	98,324
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 17,093
Short-duration Insurance Contract, Cumulative Number of Reported Claims	2,816
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 73,605	57,962	39,174	21,337	$ 5,509
E&S Lines [Member] | Short-Duration Insurance Contract, Accident Year 2019 [Member] | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	117,113	117,736	118,298	117,087
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 39,429
Short-duration Insurance Contract, Cumulative Number of Reported Claims	2,683
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 57,701	35,844	17,812	$ 4,422
E&S Lines [Member] | Short-Duration Insurance Contract, Accident Year 2020 | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	95,832	103,137	103,872
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 49,633
Short-duration Insurance Contract, Cumulative Number of Reported Claims	1,788
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 27,861	13,064	$ 3,695
E&S Lines [Member] | Short-Duration Insurance Contract, Accident Year 2021 | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	125,436	128,099
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 89,909
Short-duration Insurance Contract, Cumulative Number of Reported Claims	1,751
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 15,835	$ 4,326
E&S Lines [Member] | Short-Duration Insurance Contract, Accident Year 2022 | Casualty Insurance Product Line [Member]
Claims Development [Line Items]
Net outstanding liabilities	146,999
Short-duration Insurance Contracts, Incurred but Not Reported (IBNR) Claims Liability, Net	$ 132,276
Short-duration Insurance Contract, Cumulative Number of Reported Claims	1,285
Short-duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net	$ 4,198

Reserve for Loss and Loss Exp_8

Reserve for Loss and Loss Expense (Reconciliation of Claims Development to Liability) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	$ 4,259,274
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	757,513	$ 578,641	$ 554,269
Unallocated loss expenses	128,034
Gross liability for unpaid loss and loss expenses	5,144,821	$ 4,580,903	$ 4,260,355	$ 4,067,163
Standard Commercial Lines [Member] | General Liability [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	1,688,645
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	246,736
Standard Commercial Lines [Member] | Workers Compensation [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	809,019
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	199,057
Standard Commercial Lines [Member] | Commercial Automobile [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	847,967
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	14,271
Standard Commercial Lines [Member] | Business Owners' Policies [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	110,471
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	19,277
Standard Commercial Lines [Member] | Commercial Property [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	130,277
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	81,970
Standard Commercial Lines [Member] | Other Commercial [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	17,995
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	4,443
Standard Commercial Lines [Member] | Total Standard Commercial Lines [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	3,604,374
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	565,754
Standard Personal Lines | Personal Automobile [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	99,982
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	36,529
Standard Personal Lines | Homeowners [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	45,597
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	7,124
Standard Personal Lines | Other Personal [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	11,739
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	132,525
Standard Personal Lines | Standard Personal Lines
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	157,318
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	176,178
E&S Lines [Member] | Total E&S Lines [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	497,582
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	15,581
E&S Lines [Member] | Standard Commercial Lines [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	4,184
E&S Lines [Member] | Property Insurance [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	18,075
E&S Lines [Member] | Casualty Insurance Product Line [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Net	479,507
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	$ 11,397

Reserve for Loss and Loss Exp_9

Reserve for Loss and Loss Expense (Historical Claims Duration) (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Net outstanding liabilities	$ 13,946,270
Standard Commercial Lines [Member] | General Liability [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	6.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	11.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	15.50%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	17.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	15.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	9.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	7.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	4.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	3%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	2.10%
Standard Commercial Lines [Member] | Workers Compensation [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	22.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	25.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	13.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	8.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	4.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	3%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	1.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	1.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	3.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	2.20%
Standard Commercial Lines [Member] | Commercial Automobile [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	36.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	16.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	14.60%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	13.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	9.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	4.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	1.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	1.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0.10%
Standard Commercial Lines [Member] | Business Owners' Policies [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	49%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	21.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	8.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	8.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	6.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	3.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	1.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0.60%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0.30%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0.20%
Standard Commercial Lines [Member] | Commercial Property [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	68.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	26.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	3.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	1%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	0.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	0%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	0%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0%
Standard Personal Lines | Personal Automobile [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	59.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	18.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	8.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	6.50%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	3.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	1.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	0.50%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0.40%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0.10%
Standard Personal Lines | Homeowners [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	70.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	21.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	3.50%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	1.60%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	1.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	0.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	0.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	0.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	0.10%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	0%
E&S Lines [Member] | Casualty Insurance Product Line [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Short-duration Insurance Contracts, Historical Claims Duration, Year One	3.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Two	11.50%
Short-duration Insurance Contracts, Historical Claims Duration, Year Three	18%
Short-duration Insurance Contracts, Historical Claims Duration, Year Four	21.70%
Short-duration Insurance Contracts, Historical Claims Duration, Year Five	15.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Six	7.90%
Short-duration Insurance Contracts, Historical Claims Duration, Year Seven	6.80%
Short-duration Insurance Contracts, Historical Claims Duration, Year Eight	5.20%
Short-duration Insurance Contracts, Historical Claims Duration, Year Nine	2.60%
Short-duration Insurance Contracts, Historical Claims Duration, Year Ten	3.50%

Indebtedness Indebtedness (Sche

Indebtedness Indebtedness (Schedule of Long-Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Debt Instruments [Line Items]
Long-term debt	$ 504,676	$ 506,050
Unamortized Debt Issuance Costs	2,929
Unamortized Debt Discount	6,113
Finance Lease, Liability	$ 3,718	5,450
Five Point Three Hundred Seventy Five Percent Senior Notes [Member]
Schedule of Debt Instruments [Line Items]
Interest Rate	5.375%
Long-term Debt, Gross	$ 300,000
Unamortized Debt Issuance Costs	2,543
Unamortized Debt Discount	5,576
Long-term Debt	$ 291,881	291,597
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Schedule of Debt Instruments [Line Items]
Interest Rate	3.03%
Long-term Debt, Gross	$ 60,000
Unamortized Debt Issuance Costs	0
Unamortized Debt Discount	0
Long-term Debt	$ 60,000	60,000
Six Point Seventy Percent Senior Notes [Member]
Schedule of Debt Instruments [Line Items]
Interest Rate	6.70%
Long-term Debt, Gross	$ 100,000
Unamortized Debt Issuance Costs	256
Unamortized Debt Discount	458
Long-term Debt	$ 99,286	99,233
Seven Point Twenty Five Percent Senior Notes [Member]
Schedule of Debt Instruments [Line Items]
Interest Rate	7.25%
Long-term Debt, Gross	$ 50,000
Unamortized Debt Issuance Costs	130
Unamortized Debt Discount	79
Long-term Debt	49,791	49,770
Finance lease obligation [Member]
Schedule of Debt Instruments [Line Items]
Finance Lease, Liability	$ 3,718	$ 5,450

Indebtedness (Narrative) (Detai

Indebtedness (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2005	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2004
Maximum borrowing percentage		10%
Borrowing threshold of FHLBI		20
Debt Issuance Costs, Gross		$ 3,300
Long-term debt		504,676	$ 506,050
Five Point Three Hundred Seventy Five Percent Senior Notes [Member]
Long-term Debt, Gross		$ 300,000
Interest Rate		5.375%
Discount for notes issued		$ 5,900
Net proceeds from the issuance		290,800
Five Point Eight Hundred Seventy Five Percent Senior Notes [Member]
Long-term Debt, Gross		$ 185,000
Interest Rate		5.875%
Debt Retirement Costs Before Tax		$ 4,200
Debt Retirement Costs Net of Tax		3,300
Proceeds From Debt Issuance After Redemption		106,000
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Long-term Debt, Gross		$ 60,000
Interest Rate		3.03%
Federal Home Loan Bank Advances			45,000
Net proceeds from the issuance			15,000
Six Point Seventy Percent Senior Notes due 2035 [Member]
Long-term Debt, Gross		$ 100,000
Interest Rate		6.70%
Acceleration of principal		$ 10,000
Discount for notes issued	$ 700
Effective yield	6.754%
Net proceeds from the issuance	$ 50,000
Seven Point Twenty Five Percent Senior Notes due 2034 [Member]
Long-term Debt, Gross		$ 50,000
Interest Rate		7.25%
Acceleration of principal		$ 10,000
Discount for notes issued					$ 100
Effective yield					7.27%
Bond proceeds to Insurance Subsidiaries as capital					$ 25,000
Line of Credit [Member]
Line of credit borrowing capacity		50,000		$ 50,000
Line of credit, maximum borrowing capacity		125,000		$ 125,000
Acceleration of principal		$ 30,000
Maximum borrowing percentage		10%
Zero Point Seventy Percent Borrowing from FHLBNY Due June 27, 2022. [Member]
Federal Home Loan Bank Advances		$ 35,000
Federal Home Loan Bank, Advances, Interest Rate		0.70%
One Point One Percent Borrowing From Federal Home Loan Bank Due June 27, 2022 [Member]
Federal Home Loan Bank, Advances, Interest Rate		1.10%
Three Point Twenty One Percent Borrowing from Federal Home Loan Bank Due November 3, 2022.
Federal Home Loan Bank Advances			$ 25,000
Federal Home Loan Bank, Advances, Interest Rate			3.21%
Federal Home Loan Bank of Indianapolis [Member]
Aggregate investment in FHLBI		$ 5,200	$ 5,700

Indebtedness (Covenants in the

Indebtedness (Covenants in the Line of Credit) (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Debt Disclosure [Abstract]
Consolidated net worth, minimum requirement	$ 1,900,000
Consolidated net worth, actual	$ 3,000,000
Debt-to-capitalization ratio, maximum requirement	35%
Debt-to-capitalization ratio, actual	14.30%

Segment Information (Narrative)

Segment Information (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting [Abstract]
Number of Operating Segments	4
Goodwill	$ 7,849	$ 7,849
Percentage of net premiums written related to insurance policies written in New Jersey	17%

Segment Information (Revenue Fr

Segment Information (Revenue From Continuing Operations by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue from External Customer [Line Items]
Net premiums earned	$ 3,373,380	$ 3,017,253	$ 2,681,814
Other income	11,335	17,723	17,570
Net investment income earned	288,155	326,589	227,107
Net realized and unrealized investment (losses) gains	(114,808)	17,599	(4,217)
Total investment revenues	173,347	344,188	222,890
Total revenues	3,558,062	3,379,164	2,922,274
Standard Commercial Lines [Member]
Revenue from External Customer [Line Items]
Other income	9,519	16,056	15,512
Total revenues	2,749,338	2,459,941	2,158,696
Standard Personal Lines
Revenue from External Customer [Line Items]
Other income	1,816	1,667	2,058
Total revenues	301,221	295,226	301,198
E&S Lines [Member]
Revenue from External Customer [Line Items]
Total revenues	334,156	279,809	239,490
Commercial Automobile [Member] | Standard Commercial Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	495,647	436,412	388,120
Workers Compensation [Member] | Standard Commercial Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	335,955	306,428	278,062
General Liability [Member] | Standard Commercial Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	902,428	807,158	694,019
Commercial Property [Member] | Standard Commercial Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	812,306	724,398	615,181
Business Owners' Policies [Member] | Standard Commercial Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	124,474	110,622	110,210
Bonds Segment [Member] | Standard Commercial Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	43,354	35,762	36,742
Other Commercial [Member] | Standard Commercial Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	25,655	23,105	20,850
Personal Automobile [Member] | Standard Personal Lines
Revenue from External Customer [Line Items]
Net premiums earned	162,899	163,007	165,020
Homeowners [Member] | Standard Personal Lines
Revenue from External Customer [Line Items]
Net premiums earned	128,222	122,526	125,405
Other Personal [Member] | Standard Personal Lines
Revenue from External Customer [Line Items]
Net premiums earned	8,284	8,026	8,715
Casualty Insurance Product Line [Member] | E&S Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	233,086	197,779	174,408
Property Insurance [Member] | E&S Lines [Member]
Revenue from External Customer [Line Items]
Net premiums earned	$ 101,070	$ 82,030	$ 65,082

Segment Information (Income Fro

Segment Information (Income From Continuing Operations, Before and After Federal Income Tax) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net investment income earned	$ 288,155	$ 326,589	$ 227,107
Net realized and unrealized investment (losses) gains	(114,808)	17,599	(4,217)
Total investment revenues	173,347	344,188	222,890
Tax on investment income	31,846	67,284	41,609
Total investment income, after federal income tax	141,501	276,904	181,281
Standard Commercial Lines [Member]
Underwriting income (loss), before federal income tax	143,696	198,596	151,731
Underwriting income (loss), after federal income tax	$ 113,520	$ 156,891	$ 119,867
Combined ratio	94.80%	91.90%	92.90%
Return on equity contribution	4.60%	5.90%	5.10%
Standard Personal Lines
Underwriting income (loss), before federal income tax	$ (7,193)	$ 3,966	$ (15,508)
Underwriting income (loss), after federal income tax	$ (5,682,000)	$ 3,133	$ (12,251)
Combined ratio	102.40%	98.60%	105.20%
Return on equity contribution	(0.20%)	0.10%	(0.50%)
E&S Lines [Member]
Underwriting income (loss), before federal income tax	$ 30,299	$ 16,030	$ 126
Underwriting income (loss), after federal income tax	$ 23,936,000	$ 12,664	$ 100
Combined ratio	90.90%	94.30%	99.90%
Return on equity contribution	1%	0.50%	0%
Investments SIGI
Return on equity contribution	9.40%	9.90%	7.80%

Segment Information (Reconcilia

Segment Information (Reconciliation of Segment Results to Income from Continuing Operations, before Federal Income Tax) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total investment revenues	$ 173,347	$ 344,188	$ 222,890
Interest expense	(28,847)	(29,165)	(30,839)
Corporate expenses	(31,116)	(28,305)	(25,412)
Income before federal income tax	280,186	505,310	302,988
Preferred stock dividends	(9,200)	(9,353)	0
Income available to common stockholders, before federal income tax	270,986	495,957	302,988
Standard Commercial Lines [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Underwriting income (loss), before federal income tax	143,696	198,596	151,731
Standard Personal Lines
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Underwriting income (loss), before federal income tax	(7,193)	3,966	(15,508)
E&S Lines [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Underwriting income (loss), before federal income tax	30,299	16,030	126
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total all segments	$ 340,149	$ 562,780	$ 359,239

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income available to common stockholders	$ 215,686	$ 394,484	$ 246,355
Weighted average common shares outstanding - basic	60,407,000	60,183,000	59,862,000
Effect of dilutive securities - stock compensation plans	468,000	484,000	431,000
Weighted Average Common Shares Outstanding, Diluted	60,875,000	60,667,000	60,293,000
Earnings per common share - net income available to common stockholders - Basic	$ 3.57	$ 6.55	$ 4.12
Earnings per common share - net income available to common stockholders - Diluted	$ 3.54	$ 6.50	$ 4.09

Federal Income Taxes (Reconcili

Federal Income Taxes (Reconciliation of Federal Income Tax on Income at the Corporate Rate to the Effective Tax Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Tax at statutory rate	$ 58,839	$ 106,115	$ 63,627
Tax-advantaged interest	(4,087)	(4,514)	(4,730)
Dividends received deduction	(469)	(558)	(514)
Executive compensation	1,848	2,469	2,246
Stock-based compensation	(893)	(693)	(1,846)
Other	62	(1,346)	(2,150)
Total federal income tax expense	55,300	101,473	56,633
Income available to common stockholders, before federal income tax	$ 270,986	$ 495,957	$ 302,988
Effective Income Tax Rate Reconciliation, Percent	20.40%	20.50%	18.70%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21%

Federal Income Taxes (Deferred

Federal Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Net loss reserve discounting	$ 65,907	$ 60,227
Net unearned premiums	76,513	68,086
Employee benefits	7,064	2,787
Long-term incentive compensation plans	6,384	5,904
Unrealized losses on AFS securities	110,857	0
Temporary investment write-downs	12,480	4,314
Other	9,824	2,245
Total deferred tax assets	289,029	143,563
Deferred policy acquisition costs	77,411	68,652
Unrealized gains on investment securities	0	48,082
Other investment-related items, net	26,713	27,044
Accelerated depreciation and amortization	12,172	13,198
Deferred Tax Liabilities, Total	116,296	156,976
Deferred federal income tax	(172,733)	0
Net deferred federal income tax	0	(13,413)
Deferred tax liability
Net deferred federal income tax	$ (172,733)	$ (13,413)

Retirement Plans (Deferred Comp

Retirement Plans (Deferred Compensation Plan) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Savings Plan [Member]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 19.8	$ 19.2	$ 18.6

Retirement Plans (Funded Status

Retirement Plans (Funded Status of Retirement Income Plan and Retirement Life Plan) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Income Plan [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		5.21%	2.98%
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	[1]	$ (10,738)	$ (11,882)	$ (7,778)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of year		407,758	425,161
Interest cost		9,944	8,593	11,312
Actuarial losses (gains)		(91,653)	(12,844)
Benefits paid		(14,104)	(13,152)
Benefit obligation, end of year		311,945	407,758	425,161
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of assets, beginning of year		450,305	432,716
Actual return on plan assets, net of expenses		(93,227)	30,741
Benefits paid		(14,104)	(13,152)
Fair value of assets, end of year		342,974	450,305	432,716
Funded status		31,029	42,547
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position		31,029	42,547
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net actuarial loss		100,561	78,304
Weighted-Average Liability Asumptions
Accumulated benefit obligation		311,945	407,758
Retirement Life Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Contributions by the employer to funded plans		$ 19,800	$ 19,200	$ 18,600
[1]The components of net periodic pension cost (benefit) are included within "Loss and loss expense incurred" and "Other insurance expenses" on the Consolidated Statements of Income.

Retirement Plans (Components of

Retirement Plans (Components of Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Income) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net actuarial loss (gain)		$ 20,941	$ (21,636)	$ (1,515)
Reversal of amortization of net actuarial loss		$ (1,668)	$ (2,772)	(3,015)
Retirement Income Plan [Member]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		5.21%	2.98%
Interest cost		$ 9,944	$ 8,593	11,312
Expected return on plan assets		(22,147)	(22,976)	(21,907)
Amortization of unrecognized actuarial loss		1,465	2,501	2,817
Total net periodic pension cost (benefit)	[1]	(10,738)	(11,882)	(7,778)
Net actuarial loss (gain)		23,722	(20,609)	(2,894)
Reversal of amortization of net actuarial loss		(1,465)	(2,501)	(2,817)
Total recognized in other comprehensive income		22,257	(23,110)	(5,711)
Total recognized in net periodic benefit cost and OCI		$ 11,519	$ (34,992)	$ (13,489)
[1]The components of net periodic pension cost (benefit) are included within "Loss and loss expense incurred" and "Other insurance expenses" on the Consolidated Statements of Income.

Retirement Plans (Weighted-Aver

Retirement Plans (Weighted-Average Expense Assumptions) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Discount rate	2.48%	2.06%	2.95%
Change in Defined Benefit Plan Discount Rate	$ 223
Retirement Income Plan [Member]
Discount rate	2.98%	2.68%	3.33%
Expected return on plan assets	5%	5.40%	5.80%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	5.21%	2.98%

Retirement Plans (Plan's Alloca

Retirement Plans (Plan's Allocated Target Ranges and Actual Weighted Average Asset Allocation by Investment Categories) (Details)		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021
Percent Hedge Against Projected Benefit Obligation		77%
Actual percentage		100%	100%
Return Seeking Assets [Member]
Actual percentage	[1]	71%	66%
Liability Hedging Assets [Member]
Actual percentage		27%	33%
Short-term Investments [Member]
Actual percentage		2%	1%
Minimum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage
Minimum [Member] | Return Seeking Assets [Member]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description		50
Minimum [Member] | Liability Hedging Assets [Member]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description		20
Minimum [Member] | Short-term Investments [Member]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description		-
Maximum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage
Maximum [Member] | Return Seeking Assets [Member]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description		80
Maximum [Member] | Liability Hedging Assets [Member]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description		50
Maximum [Member] | Short-term Investments [Member]
Defined Benefit Plan, Plan Assets, Investment Policy and Strategy, Description		-
[1]Includes limited partnerships.

Retirement Plans (Quantitative

Retirement Plans (Quantitative Disclosures of Retirement Income Plan's Invested Assets that are Measured at Fair Value on a Recurring Basis) (Details) - Retirement Income Plan [Member] - USD ($) $ in Thousands		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Total Assets		$ 342,974	$ 450,305	$ 432,716
Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		341,826	456,502
Total Equities [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		241,987	300,389
Return Seeking Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		242,345	300,849
Liability Hedging Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		91,633	151,487
Cash And Short Term Investments [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		7,848	4,166
Alternative Investments [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	358	460
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		338,728	453,620
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Total Equities [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		241,987	300,389
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Return Seeking Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		241,987	300,389
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Liability Hedging Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		91,633	151,487
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Cash And Short Term Investments [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		5,108	1,744
Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		2,740	2,422
Significant Other Observable Inputs (Level 2) [Member] | Total Equities [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Significant Other Observable Inputs (Level 2) [Member] | Return Seeking Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Significant Other Observable Inputs (Level 2) [Member] | Liability Hedging Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Significant Other Observable Inputs (Level 2) [Member] | Cash And Short Term Investments [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		2,740	2,422
Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Significant Unobservable Inputs (Level 3) [Member] | Total Equities [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Significant Unobservable Inputs (Level 3) [Member] | Return Seeking Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Significant Unobservable Inputs (Level 3) [Member] | Liability Hedging Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Significant Unobservable Inputs (Level 3) [Member] | Cash And Short Term Investments [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Global Equity [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		63,852	144,634
Global Equity [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		63,852	144,634
Global Equity [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Global Equity [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Diversified Credit [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		58,761	66,165
Diversified Credit [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		58,761	66,165
Diversified Credit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Diversified Credit [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Real Assets Equity [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		95,396	89,590
Real Assets Equity [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		95,396	89,590
Real Assets Equity [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Real Assets Equity [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Liquid diversifiers | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[2]	23,978
Liquid diversifiers | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[2]	23,978
Liquid diversifiers | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[2]	0
Liquid diversifiers | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[2]	0
Real Assets [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	27	47
Real Assets [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Real Assets [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Real Assets [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Private Equity Funds [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	331	413
Private Equity Funds [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Private Equity Funds [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Private Equity Funds [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Alternative Investments [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Alternative Investments [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Alternative Investments [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets	[1]	0	0
Fixed Income Securities [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		35,378	86,183
Fixed Income Securities [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		35,378	86,183
Fixed Income Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Fixed Income Securities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
US Treasury Securities [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		56,255	65,304
US Treasury Securities [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		56,255	65,304
US Treasury Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
US Treasury Securities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Short-term Investments [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		5,108	1,744
Short-term Investments [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		5,108	1,744
Short-term Investments [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Short-term Investments [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Deposit Administration Contracts [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		2,740	2,422
Deposit Administration Contracts [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		0	0
Deposit Administration Contracts [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		2,740	2,422
Deposit Administration Contracts [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value, recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Assets		$ 0	$ 0
[1] In accordance with the FASB issued ASU 2015-07, Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent) , certain investments that are measured at fair value using the net asset value per share (or its practical expedient) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total Pension Plan invested assets.

Retirement Plans (Benefit Payme

Retirement Plans (Benefit Payments) (Details) - Retirement Income Plan [Member] $ in Thousands	Dec. 31, 2022 USD ($)
2023	$ 16,925
2024	17,265
2025	18,317
2026	19,391
2027	20,328
2028 - 2032	$ 111,842

Share-Based Payments (Summary o

Share-Based Payments (Summary of Shares Available for Issuance) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Dividend Equivalent Units [Member]
Schedule of Share-Based Compensation Shares Available for Issuance [Line Items]
Total intrinsic value of shares vested	$ 0.7	$ 0.6	$ 0.7
Omnibus Stock Plan 2014 [Member]
Schedule of Share-Based Compensation Shares Available for Issuance [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	4,750,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2,474,585
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	657,311
Employee Stock [Member]
Schedule of Share-Based Compensation Shares Available for Issuance [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	5,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,116,863
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	0
Agent Stock Purchase Plan [Member]
Schedule of Share-Based Compensation Shares Available for Issuance [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	3,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,551,498
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	0

Shared-Based Payments (Summary

Shared-Based Payments (Summary of Retired Plans) (Details)	Dec. 31, 2022 shares
Omnibus Stock Plan [Member]
Schedule of Share-Based Compensation Retired Plans [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,954,922
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	29,522	[1]
Stock Compensation Plan For Non Employee Directors [Member]
Schedule of Share-Based Compensation Retired Plans [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	40,940
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	40,940	[1]
[1]Awards outstanding under the 2005 Stock Plan represent shares deferred by our non-employee directors.

Share-Based Payments (Summary_2

Share-Based Payments (Summary of the Restricted Stock Unit Transactions under Share-Based Payment Plans) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Incentive Plan [Member]
Weighted average remaining expense life	1 year 1 month 6 days
Share Based Compensation Liability Awards Amount Of Liability	$ 11.1	$ 11
Cash incentive unit payments made	$ 2.9	$ 2.2	$ 2.3
Restricted Stock Units (RSUs) [Member]
Unvested RSU awards at December 31, 2021, number of shares	641,636
Granted in 2022, number of shares	248,619
Vested in 2022, number of shares	(232,742)
Forfeited in 2022, number of shares	(20,451)
Unvested RSU awards at December 31, 2022, number of shares	637,062	641,636
Unvested RSU awards at December 31, 2021, weighted average grant date fair value	$ 63.73
Granted in 2022, weighted average grant date market value	76.09	$ 64.03	$ 62.91
Vested in 2022, weighted average grant date value	63.79
Forfeited in 2022, weighted average grant date fair value	66.77
Unvested RSU awards at December 31, 2022, weighted average grant date fair value	$ 68.84	$ 63.73
Total unrecognized compensation cost related to unvested RSU awards	$ 11.3
Weighted average remaining expense life	1 year 8 months 12 days
Total intrinsic value of shares vested	$ 18.1	$ 17.2	$ 20.6
Dividend Equivalent Units [Member]
Total intrinsic value of shares vested	$ 0.7	$ 0.6	$ 0.7

Shared-Based Payments (Summar_2

Shared-Based Payments (Summary of ESPP and ASPP Shares Issued) (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule of Share-Based Compensation ESPP and ASPP Shares Granted [Line Items]
Stock Issued During Period Shares	374,102	395,018	519,863
Employee Stock [Member]
Schedule of Share-Based Compensation ESPP and ASPP Shares Granted [Line Items]
Stock Issued During Period Shares	67,986	72,239	99,141
Agent Stock Purchase Plan [Member]
Schedule of Share-Based Compensation ESPP and ASPP Shares Granted [Line Items]
Stock Issued During Period Shares	56,736	50,999	69,238

Share-Based Payments (Weighted

Share-Based Payments (Weighted Average Assumptions for Employee Stock Purchase Plan and Other Options) (Details) - Employee Stock Purchase Plan [Member]	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Risk-free interest rate	1.42%	0.07%	0.76%
Expected term	6 months	6 months	6 months
Dividend yield	1.30%	1.40%	1.60%
Expected volatility	21%	28%	37%

Share-Based Payments (Weighted-

Share-Based Payments (Weighted-Average Fair Value of Options and Stock Per Share) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Restricted Stock Units (RSUs) [Member]
Stock, weighted average grant date fair value	$ 76.09	$ 64.03	$ 62.91
Employee Stock Purchase Plan [Member]
Options, weighted average grant date fair value	4.43	4.69	4.82
Discount of grant date market value	12.61	10.98	8.61
Total ESPP	17.04	15.67	13.43
Agent Stock Purchase Plan [Member]
Stock, weighted average grant date fair value	$ 8.28	$ 7.57	$ 5.73

Shared-Based Payments (Summar_3

Shared-Based Payments (Summary of Share-Based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disclosure of Share-Based Compensation Expenses [Abstract]
Share-based compensation expense, pre-tax	$ 23.6	$ 22.3	$ 19.8
Income tax benefit, including the benefit related to stock grants that vested during the year	(5.6)	(5.1)	(5.7)
Share-based Compensation Expense, Net of Tax	$ 18	$ 17.2	$ 14.1

Preferred Stock Text Block List

Preferred Stock Text Block List (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Preferred Stock Shares Issued	8,000,000
Preferred Stock, Liquidation Preference, Value	$ 25
Preferred stock issued, net of issuance costs	$ 0	$ (479)	$ 195,063
Equity Text Block	Preferred Stock We have 5,000,000 shares of preferred stock authorized, with no par value, of which (i) 300,000 shares are designated Series A junior preferred stock, which have not been issued, and (ii) 8,000 shares were issued as Series B in 2020 as discussed below. On December 2, 2020, we issued 8.0 million depository shares, each representing a 1/1,000th interest in a share of our perpetual 4.60% Non-Cumulative Preferred Stock, Series B, without par value, with a liquidation preference of $25,000 per share (equivalent to $25.00 per depository share) (“Preferred Stock”), for net proceeds of $194.6 million. Dividends are recorded when declared and, if declared, are payable quarterly in arrears on the 15th day of March, June, September, and December. If a dividend is not declared and paid or made payable on all outstanding shares of the Preferred Stock for the latest completed dividend period, no dividends may be declared or paid on our common stock and we may not purchase, redeem, or otherwise acquire our outstanding common stock. The Preferred Stock is redeemable at our option in whole or in part, from time to time, on or after December 15, 2025 at a redemption price equal to $25,000 per share of Preferred Stock (equivalent to $25.00 per depository share), plus unpaid dividends attributable to the then current dividend period. Prior to December 15, 2025, the Preferred Stock is redeemable at the Company’s option, in whole but not in part, within 90 days of the occurrence of (a) a rating agency event at a redemption price equal to $25,500 per share of Preferred Stock (equivalent to $25.50 per depository share), plus unpaid dividends attributable to the current dividend period in circumstances where a rating agency changes its criteria used to assign equity credit to securities like the Preferred Stock; or (b) a regulatory capital event at a redemption price equal to $25,000 per share of Preferred Stock (equivalent to $25.00 per depository share), plus unpaid dividends attributable to the current dividend period in circumstances where a capital regulator such as a state insurance regulator changes or proposes to change capital adequacy rules. Share Repurchase Program On December 2, 2020, we announced that our Board authorized a $100 million share repurchase program, with no set expiration or termination date. Our repurchase program does not obligate us to acquire any particular amount of our common stock. Management will determine the timing and amount of any share repurchases under the authorization at its discretion based on market conditions and other considerations. For the year ended December 31, 2022, 165,159 shares were repurchased under the share repurchase program at a total cost of $12.4 million, including commissions. We had $84.2 million of remaining capacity under our share repurchase program as of December 31, 2022.
Rating Agency Event [Member]
Class of Stock [Line Items]
Depositary Share Price	$ 25.50
Preferred Stock, Redemption Price Per Share	25,500
Regulatory Capital Event [Member]
Class of Stock [Line Items]
Depositary Share Price	25
Preferred Stock, Redemption Price Per Share	$ 25,000
Proceeds from preferred stock offering; less issuance costs [Member]
Class of Stock [Line Items]
Preferred stock issued, net of issuance costs	$ 194,600
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Issued	8,000	8,000
Series A [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	300,000	300,000
Series B [Member]
Class of Stock [Line Items]
Depositary Share Price	$ 25
Preferred Stock, Dividend Rate, Percentage	4.60%

Equity (Details)

Equity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Stock Repurchase Program, Authorized Amount	$ 100,000
Treasury Stock, Shares, Acquired	165,159	52,781	0
Treasury stock, share repurchase authorization, cost	$ 12,400
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 84,200

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 31, 2023
Investments	$ 7,837,469	$ 8,026,988
Direct premiums written	4,068,518	3,656,537	$ 3,204,512
Contributions to the Selective Insurance Group Foundation	300	1,300	500
Costs and Expenses, Related Party - BlackRock	1,800	1,800	2,000
Due to Related Parties	$ 800	500	1,300
Related Party Insurance Agency [Member]
Equity ownership percentage of director of parent of general independent retail insurance agency	10%
Equity Ownership Percentage Of Son Of Director Of Parent	10%
Equity Ownership Percentage Of Daughter Of Director Of Parent	10%
Direct premiums written	$ 14,300	12,800	11,000
Commissions paid to Rue Insurance	2,700	2,000	1,800
Due to Related Parties, Current	$ 700	$ 700
Vanguard Group
Percentage of investments in related party funds to total invested assets	1%	3%
BlackRock Inc [Member]
Percentage Common Stock Owned by Related Party	11.80%
Related Party Transaction, Purchases from Related Party	$ 18,500	$ 16,500	62,200
Sale of Related Party Investments	32,300	32,500
Net realized and unrealized gain (loss)	(6,900)	(600)	(200)
Investment Income (Loss), Net	$ (1,800)	$ (900)	(400)
Percentage of investments in related party funds to total invested assets	1%	1%
Vanguard Group
Net realized and unrealized gain (loss)	$ 10,400	$ 17,700	10,200
Investment Income (Loss), Net	(4,700)	(7,500)	(2,400)
Vanguard Group | Subsequent Event
Percentage Common Stock Owned by Related Party				10.03%
Retirement Income Plan [Member] | BlackRock Inc [Member]
Investments	120,100	209,900
Related Party Transaction, Purchases from Related Party	56,400	18,000	56,700
Sale of Related Party Investments	65,700	18,100	44,900
Investment Income (Loss), Net	80,500	(18,200)	(35,800)
Retirement Income Plan [Member] | Vanguard Group
Related Party Transaction, Purchases from Related Party	3,500	19,300	$ 150,900
Sale of Related Party Investments	$ 125,200	$ 23,600

Leases (Components of Lease Exp

Leases (Components of Lease Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Lease Expense [Line Items]
Operating lease cost	$ 8,148	$ 7,935
Finance lease cost: Amortization of assets	2,440	1,765
Finance lease cost: Interest on lease liabilities	46	35
Total finance lease cost	2,486	1,800
Variable lease cost	1,384	291
Short-term lease cost	$ 166	$ 832

Leases (Supplemental Informatio

Leases (Supplemental Information on Operating and Finance Leases) (Details)	Dec. 31, 2022	Dec. 31, 2021
Supplemental Lease Information [Line Items]
Weighted average remaining lease term, operating leases	8 years	7 years
Weighted average remaining lease term, finance leases	2 years	2 years
Weighted average discount rate, operating leases	2.60%	2.10%
Weighted average discount rate, finance leases	1.20%	0.80%

Leases (Lease Assets and Liabil

Leases (Lease Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Lease Assets and Liabilities [Abstract]
Operating leases, Other assets	$ 42,403	$ 35,644
Operating leases, Other liabilities	44,505	37,296
Finance leases, Property and equipment - at cost, net of accumulated depreciation and amortization	3,713	5,446
Finance lease obligations	3,718	5,450
Operating Lease, Liability	$ 44,505	$ 37,296
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Finance Lease, Right-of-Use Asset, Accumulated Amortization	Property and equipment - at cost, net of accumulated depreciation and amortization	Property and equipment - at cost, net of accumulated depreciation and amortization
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Long-term debt (Note 11)	Long-term debt (Note 11)

Leases (Maturities of Lease Lia

Leases (Maturities of Lease Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Finance Lease Liability, Due Year One	$ 2,490
Finance Lease Liability, Due Year Two	1,029
Finance Lease Liability, Due Year Three	190
Finance Lease Liability, Due Year Four	54
Finance Lease Liability, Due Year Five	2
Total finance leases due thereafter	0
Finance Lease, Liability, total payments	3,765
Finance Lease imputed interest	47
Leases that have not yet commenced	0
Finance Lease, Liability	3,718	$ 5,450
Operating Lease Liability, Due Year One	7,290
Operating Lease Liability, Due Year Two	6,943
Operating Lease Liability, Due Year Three	6,649
Operating Lease Liability, Due Year Four	6,156
Operating Lease Liability, Due Year Five	6,053
Total operating lease due thereafter	18,832
Operating Lease Liability, total payments	51,923
Operating Lease imputed interest	4,496
Operating Lease Liability Not Yet Commenced	2,922
Operating Lease, Liability	44,505	$ 37,296
Total Lease Liability, Due Year One	9,780
Total Lease Liability, Due Year Two	7,972
Total Lease Liability, Due Year Three	6,839
Total Lease Liability, Due Year Four	6,210
Total Lease Liability, Due Year Five	6,055
Total Lease Due Thereafter	18,832
Total Lease Liability, total payments	55,688
Total imputed interest	4,543
Total leases that have not yet commenced	2,922
Total lease liabilities	$ 48,223

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Total contractually obligated investments
Contractual Obligation Additional Investment in Alternative or Other Investments	$ 412,700
Alternative and Other Investments
Contractual Obligation Additional Investment in Alternative or Other Investments	246,100
Non-publicly traded collateralized loan obligations in our fixed income securities portfolio
Contractual Obligation	106,600
Non-publicly traded common stock within our equity portfolio
Contractual Obligation	35,000
Commercial Mortgage Loans SIGI
Contractual Obligation	4,900
Privately placed corporate securities
Contractual Obligation	$ 20,100

Commitments and Contingencies S

Commitments and Contingencies Stuctured Settlement Annuity (Details) $ in Millions	Dec. 31, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Purchase Amount Of Annuities	$ 31

Statutory Financial Informati_3

Statutory Financial Information, Capital Requirements and Restrictions on Dividends and Transfers of Funds (Statutory Financial Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statutory unassigned surplus	$ 1,908.1	$ 1,825.4
Statutory surplus	2,473.7	2,391
Statutory net income	264.4	338.3	$ 242.4
Selective Insurace Company of America (SICA) [Member]
Statutory unassigned surplus	686.6	673.1
Statutory surplus	851.8	838.3
Statutory net income	103.1	134.7	81.8
Selective Way Insurance Company (SWIC) [Member]
Statutory unassigned surplus	461.9	436.4
Statutory surplus	517.8	492.4
Statutory net income	69.6	74.5	54
Selective Insurance Company of South Carolina (SICSC) [Member]
Statutory unassigned surplus	164.1	166.3
Statutory surplus	198.4	200.6
Statutory net income	17	24.2	20.8
Selective Insurance Company of the Southeast (SICSE) [Member]
Statutory unassigned surplus	135.9	132.7
Statutory surplus	163.5	160.3
Statutory net income	14.2	19.4	16.8
Selective Insurance Company of New York (SICNY) [Member]
Statutory unassigned surplus	137.4	127
Statutory surplus	165.1	154.7
Statutory net income	13.2	18.6	15.3
Selective Insurance Company of New England (SICNE) [Member]
Statutory unassigned surplus	38.2	34.5
Statutory surplus	69.3	65.6
Statutory net income	5.1	7.5	6.8
Selective Auto Insurance Company of New Jersey (SAICNJ) [Member]
Statutory unassigned surplus	102.2	90.4
Statutory surplus	147.1	135.2
Statutory net income	12.7	16.7	12.9
Mesa Underwriting Specialty Insurance Company (MUSIC) [Member]
Statutory unassigned surplus	52.8	47.4
Statutory surplus	122.3	116.9
Statutory net income	9.7	13.9	11.4
Selective Casualty Insurance Company (SCIC) [Member]
Statutory unassigned surplus	91.4	83.4
Statutory surplus	167.9	159.9
Statutory net income	14	20.6	16.2
Selective Fire and Casualty Insurance Company (SFCIC) [Member]
Statutory unassigned surplus	37.6	34.2
Statutory surplus	70.5	67.1
Statutory net income	$ 5.8	$ 8.2	$ 6.4

Statutory Financial Informati_4

Statutory Financial Information, Capital Requirements, and Restrictions on Dividends and Transfers of Funds (Dividends) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Retained Earnings	$ 2,749,703	$ 2,603,472
Ordinary dividends paid	120,000
Insurance subsidiaries ability to provide annual dividends	$ 283,100
Maximum borrowing percentage	10%
New Jersey Dividend Restriction	10%
New York Dividend Restriction on Insurer's Statutory Surplus	10%
New York Dividend Restriction on Adjusted Net Investment Income	100%
Selective Insurace Company of America (SICA) [Member]
Ordinary dividends paid	$ 62,300
Insurance subsidiaries ability to provide annual dividends	103,100
Selective Way Insurance Company (SWIC) [Member]
Ordinary dividends paid	24,300
Insurance subsidiaries ability to provide annual dividends	69,600
Selective Insurance Company of South Carolina (SICSC) [Member]
Ordinary dividends paid	5,600
Insurance subsidiaries ability to provide annual dividends	19,800
Selective Insurance Company of the Southeast (SICSE) [Member]
Ordinary dividends paid	6,600
Insurance subsidiaries ability to provide annual dividends	16,400
Selective Insurance Company of New York (SICNY) [Member]
Ordinary dividends paid	3,000
Insurance subsidiaries ability to provide annual dividends	16,500
Selective Insurance Company of New England (SICNE) [Member]
Ordinary dividends paid	1,500
Insurance subsidiaries ability to provide annual dividends	6,900
Selective Auto Insurance Company of New Jersey (SAICNJ) [Member]
Ordinary dividends paid	1,300
Insurance subsidiaries ability to provide annual dividends	14,700
Mesa Underwriting Specialty Insurance Company (MUSIC) [Member]
Ordinary dividends paid	5,300
Insurance subsidiaries ability to provide annual dividends	12,200
Selective Casualty Insurance Company (SCIC) [Member]
Ordinary dividends paid	7,800
Insurance subsidiaries ability to provide annual dividends	16,800
Selective Fire and Casualty Insurance Company (SFCIC) [Member]
Ordinary dividends paid	2,300
Insurance subsidiaries ability to provide annual dividends	7,100
Parent Company [Member]
Investments and Cash Available to fund future dividend and interest payments	484,300
Retained Earnings	2,700,000
Additional Borrowing Capacity for Parent	$ 121,500

Schedule I - Summary of Inves_2

Schedule I - Summary of Investments - Other Than Investments in Related Parties (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Amortized Cost or Cost	$ 8,045,330
Carrying Amount	7,837,469
Short-term Investments [Member]
Amortized Cost or Cost	440,439
Carrying Amount	440,456
Other Investments [Member]
Amortized Cost or Cost	71,244
Carrying Amount	71,244
Alternative Investments [Member]
Amortized Cost or Cost	371,316
Carrying Amount	371,316
Held-to-maturity Securities [Member] | Obligations of States and Political Subdivisions [Member]
Amortized Cost or Cost	3,405
Fair Value	3,405
Carrying Amount	3,405
Held-to-maturity Securities [Member] | Public Utilities
Amortized Cost or Cost	0
Fair Value	0
Carrying Amount	0
Held-to-maturity Securities [Member] | All other corporate securities
Amortized Cost or Cost	27,752
Fair Value	26,432
Carrying Amount	27,752
Held-to-maturity Securities [Member] | Fixed Income Securities [Member]
Amortized Cost or Cost	31,157
Fair Value	29,837
Carrying Amount	31,157
AFS Fixed Income Securities [Member] | US Government Agencies Debt Securities [Member]
Amortized Cost or Cost	209,528
Fair Value	189,239
Carrying Amount	189,239
AFS Fixed Income Securities [Member] | Foreign Government
Amortized Cost or Cost	11,199
Fair Value	9,608
Carrying Amount	9,608
AFS Fixed Income Securities [Member] | Obligations of States and Political Subdivisions [Member]
Amortized Cost or Cost	965,231
Fair Value	918,018
Carrying Amount	918,018
AFS Fixed Income Securities [Member] | Public Utilities
Amortized Cost or Cost	110,544
Fair Value	97,717
Carrying Amount	97,717
AFS Fixed Income Securities [Member] | All other corporate securities
Amortized Cost or Cost	2,448,111
Fair Value	2,237,308
Carrying Amount	2,237,308
AFS Fixed Income Securities [Member] | CLO and Other ABS
Amortized Cost or Cost	1,607,660
Fair Value	1,485,973
Carrying Amount	1,485,973
AFS Fixed Income Securities [Member] | Commercial Mortgage-backed Securities (CMBS) [Member]
Amortized Cost or Cost	1,169,546
Fair Value	1,059,832
Carrying Amount	1,059,832
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities [Member]
Amortized Cost or Cost	663,935
Fair Value	614,412
Carrying Amount	614,412
AFS Fixed Income Securities [Member] | Fixed Income Securities [Member]
Amortized Cost or Cost	7,185,754
Fair Value	6,612,107
Carrying Amount	6,612,107
Equity Securities [Member] | Banks, trusts, and insurance companies
Amortized Cost or Cost	22,579
Fair Value	20,201
Carrying Amount	20,201
Equity Securities [Member] | Industrial, miscellaneous and all other
Amortized Cost or Cost	142,892
Fair Value	140,154
Carrying Amount	140,154
Equity Securities [Member] | Preferred Stock [Member]
Amortized Cost or Cost	1,960
Fair Value	1,645
Carrying Amount	1,645
Equity Securities [Member] | Equity Securities [Member]
Amortized Cost or Cost	167,431
Fair Value	162,000
Carrying Amount	162,000
Commercial Mortgage Loans [Member]
Amortized Cost or Cost	149,305
Carrying Amount	$ 149,189

Parent Corporation Balance Shee

Parent Corporation Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Debt Securities, Available-for-sale, Fair Value	$ 6,612,107	$ 6,709,976
Equity securities	162,000	335,537
Short-term investments	440,456	447,863
Other investments	71,244	49,300
Cash	26	455
Current federal income tax	3,545	772
Deferred federal income tax	172,733	0
Other assets	202,491	195,240
Total assets	10,802,261	10,461,389
Liabilities:
Long-term debt	504,676	506,050
Other liabilities	517,234	453,874
Total liabilities	8,274,697	7,478,504
Stockholders’ Equity:
Preferred stock of $0 par value per share (Note 17): Authorized shares: 5,000,000; Issued shares: 8,000 with $25,000 liquidation preference per share - 2022 and 2021	200,000	200,000
Common stock of $2 par value per share: Authorized shares: 360,000,000 Issued: 104,847,111 - 2022; 104,450,916 - 2021	209,694	208,902
Additional paid-in capital	493,488	464,347
Retained earnings	2,749,703	2,603,472
Accumulated other comprehensive (loss) income	(498,042)	115,099
Treasury stock, at cost (shares: 44,508,211 - 2022; 44,266,534 - 2021)	(627,279)	(608,935)
Total stockholders’ equity	2,527,564	2,982,885	$ 2,738,889
Total liabilities and stockholders’ equity	10,802,261	10,461,389
Parent Company [Member]
ASSETS
Debt Securities, Available-for-sale, Fair Value	387,535	325,014
Equity securities	48,095	136,362
Short-term investments	33,008	56,042
Other investments	15,631	9,241
Cash	26	455	$ 394	$ 300
Investment in subsidiaries	2,524,448	2,954,725
Current federal income tax	8,894	7,208
Deferred federal income tax	14,733	4,487
Other assets	11,104	9,178
Total assets	3,043,474	3,502,712
Liabilities:
Long-term debt	440,958	440,600
Intercompany notes payable	56,266	57,980
Accrued long-term stock compensation	11,101	10,965
Other liabilities	7,585	10,282
Total liabilities	515,910	519,827
Stockholders’ Equity:
Preferred stock of $0 par value per share (Note 17): Authorized shares: 5,000,000; Issued shares: 8,000 with $25,000 liquidation preference per share - 2022 and 2021	200,000	200,000
Common stock of $2 par value per share: Authorized shares: 360,000,000 Issued: 104,847,111 - 2022; 104,450,916 - 2021	209,694	208,902
Additional paid-in capital	493,488	464,347
Retained earnings	2,749,703	2,603,472
Accumulated other comprehensive (loss) income	(498,042)	115,099
Treasury stock, at cost (shares: 44,508,211 - 2022; 44,266,534 - 2021)	(627,279)	(608,935)
Total stockholders’ equity	2,527,564	2,982,885
Total liabilities and stockholders’ equity	$ 3,043,474	$ 3,502,712

Parent Corporation Balance Sh_2

Parent Corporation Balance Sheets (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Fixed income securities, available-for-sale, amortized cost	$ 7,185,754	$ 6,490,753
Fixed income securities, available-for-sale, allowance for credit loss	$ 45,721	$ 9,724	$ 3,969
Common Stock [Member]
Common Stock, Par or Stated Value (in dollars per share)	$ 2	$ 2
Common Stock, Shares Authorized	360,000,000	360,000,000
Common Stock, Shares, Issued	104,847,111	104,450,916
Preferred Stock [Member]
Preferred Stock, Par or Stated Value (in dollars per share)	$ 0	$ 0
Preferred Stock, Liquidation Preference (in dollars per share)	$ 25,000	$ 25,000
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Issued	8,000	8,000
Parent Company [Member]
Fixed income securities, available-for-sale, amortized cost	$ 418,588	$ 317,703
Fixed income securities, available-for-sale, allowance for credit loss	$ 1,194	$ 542

Parent Corporation Statements o

Parent Corporation Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Net investment income earned	$ 288,155	$ 326,589	$ 227,107
Total revenues	3,558,062	3,379,164	2,922,274
Expenses:
Interest expense	28,847	29,165	30,839
Total expenses	3,277,876	2,873,854	2,619,286
Income before federal income tax	280,186	505,310	302,988
Federal income tax (benefit) expense:
Current	78,308	87,335	60,059
Deferred	(23,008)	14,138	(3,426)
Total federal income tax benefit	55,300	101,473	56,633
Net income	224,886	403,837	246,355
Preferred stock dividends	9,200	9,353	0
Net Income available to common stockholders	215,686	394,484	246,355
Parent Company [Member]
Revenues:
Dividends from subsidaries	120,007	140,018	104,992
Net investment income earned	18,622	15,454	7,579
Net realized and unrealized investment (losses) gains	(17,855)	1,898	1,756
Total revenues	120,774	157,370	114,327
Expenses:
Interest expense	28,897	28,988	29,220
Other expenses	31,116	28,305	25,412
Total expenses	60,013	57,293	54,632
Income before federal income tax	60,761	100,077	59,695
Federal income tax (benefit) expense:
Current	(9,381)	(6,552)	(10,987)
Deferred	(2,189)	12	473
Total federal income tax benefit	(11,570)	(6,540)	(10,514)
Net income before equity in undistributed income of subsidiaries	72,331	106,617	70,209
Equity In Undistributed Income Of Continuing Subsidiaries, Net Of Tax	152,555	297,220	176,146
Net income	224,886	403,837	246,355
Preferred stock dividends	9,200	9,353	0
Net Income available to common stockholders	$ 215,686	$ 394,484	$ 246,355

Parent Corporation Statements_2

Parent Corporation Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities
Net income	$ 224,886	$ 403,837	$ 246,355
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Stock-based compensation expense	18,428	15,893	16,227
Undistributed losses of equity method investments	(12,946)	(69,873)	(12,408)
Amortization - other	42,336	55,109	59,350
Changes in assets and liabilities:
Decrease in net federal income taxes	(25,932)	(542)	7,708
Increase in other assets	(37,561)	(33,379)	(27,927)
Decrease in other liabilities	49,869	78,121	27,897
Investing Activities
Purchases of fixed income securities, available-for-sale	(2,648,974)	(2,165,555)	(1,723,818)
Purchases of short-term investments	(4,506,500)	(4,345,140)	(5,762,725)
Purchase of other investments	(73,408)	(85,044)	(79,598)
Redemption and maturities of fixed income securities, available-for-sale	669,211	1,217,555	1,019,132
Sales of fixed income securities, available-for-sale	1,211,739	502,911	487,087
Sales of equity securities	186,144	99,235	1,320
Sales of short-term investments	4,513,940	4,306,684	5,635,463
Proceeds from Limited Partnership Investments	0	959	0
Financing Activities
Dividends to preferred stockholders	(9,200)	(9,353)	0
Dividends to common stockholders	(66,920)	(60,136)	(54,486)
Acquisition of treasury stock	(18,344)	(9,050)	(7,053)
Net proceeds from stock purchase and compensation plans	9,086	7,976	8,411
Preferred stock issued, net of issuance costs	0	(479)	195,063
Cash, beginning of year	455
Cash, end of year	26	455
Purchases of equity securities	(26,675)	(88,640)	(230,813)
Parent Company [Member]
Operating Activities
Net income	224,886	403,837	246,355
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Equity in undistributed income of subsidiaries, net of tax	(152,555)	(297,220)	(176,146)
Stock-based compensation expense	18,428	15,893	16,227
Net realized and unrealized investment losses (gains)	17,855	(1,898)	(1,756)
Undistributed losses of equity method investments	(2,240)	(1,859)	672
Amortization - other	(154)	1,076	1,080
Changes in assets and liabilities:
Increase (decrease) in accrued long-term stock compensation	136	2,727	(366)
Decrease in net federal income taxes	(3,875)	3,843	5,549
Increase in other assets	(1,961)	(7,251)	(317)
Decrease in other liabilities	(2,813)	(1,742)	(390)
Net cash provided by operating activities	97,707	117,406	90,908
Investing Activities
Purchases of fixed income securities, available-for-sale	(208,512)	(113,829)	(89,726)
Purchases of short-term investments	(362,213)	(330,843)	(523,961)
Purchase of other investments	(4,149)	(4,949)	4,065
Redemption and maturities of fixed income securities, available-for-sale	35,527	51,524	26,877
Sales of fixed income securities, available-for-sale	66,725	15,713	23,276
Sales of equity securities	77,971	31,204	0
Sales of short-term investments	385,254	311,225	523,813
Capital contribution to subsidiaries	0	0	30,000
Net cash used in investing activities	(11,044)	(44,672)	(231,197)
Financing Activities
Dividends to preferred stockholders	(9,200)	9,353	0
Dividends to common stockholders	(66,920)	(60,136)	(54,486)
Acquisition of treasury stock	(18,344)	(9,050)	(7,053)
Proceeds from borrowings	0	0	50,000
Repayment of borrowings	0	0	(50,000)
Net proceeds from stock purchase and compensation plans	9,086	7,976	8,411
Preferred stock issued, net of issuance costs	0	(479)	195,063
Principal payments of borrowings from subsidiaries	(1,714)	(1,631)	(1,552)
Net cash (used in) provided by financing activities	(87,092)	(72,673)	140,383
Net (decrease) increase in cash	(429)	61	94
Cash, beginning of year	455	394	300
Cash, end of year	26	455	394
Purchases of equity securities	$ (1,647)	$ (5,676)	$ (157,411)

Schedule III - Supplementary _2

Schedule III - Supplementary Insurance Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Deferred policy acquisition costs		$ 368,624		$ 326,915		$ 288,578
Reserve for loss and loss expenses		5,144,821		4,580,903		4,260,355
Unearned premiums		1,992,781		1,803,207		1,618,271
Net premiums earned		3,373,380		3,017,253		2,681,814
Net investment income	[1]	173,347		344,188		222,890
Loss and loss expense incurred		2,111,778		1,813,984		1,635,823
Amortization of deferred policy acquisition costs		705,822		626,469		560,271
Other operating expenses		388,978	[2]	358,208	[3]	349,371	[4]
Net premiums written		3,573,590		3,189,713		2,773,092
Other insurance expenses		400,313		375,931		366,941
Other income		11,335		17,723		17,570
Standard Commercial Lines [Member]
Deferred policy acquisition costs		311,535		279,850		246,494
Reserve for loss and loss expenses		4,275,002		3,832,151		3,596,340
Unearned premiums		1,511,447		1,346,809		1,196,243
Net premiums earned		2,739,819		2,443,885		2,143,184
Net investment income		0		0		0
Loss and loss expense incurred		1,683,988		1,426,768		1,245,627
Amortization of deferred policy acquisition costs		605,845		539,606		474,322
Other operating expenses		306,290		278,915		271,504
Net premiums written		2,901,984		2,593,018		2,230,636
Other income		9,519		16,056		15,512
E&S Lines [Member]
Deferred policy acquisition costs		39,272		34,154		28,281
Reserve for loss and loss expenses		529,517		478,686		435,667
Unearned premiums		158,666		139,122		113,845
Net premiums earned		334,156		279,809		239,490
Net investment income		0		0		0
Loss and loss expense incurred		196,677		175,100		156,936
Amortization of deferred policy acquisition costs		72,848		60,945		55,255
Other operating expenses		34,332		27,734		27,173
Net premiums written		352,547		304,430		247,290
Miscellaneous Income [Member]
Other income		11,335		17,723		17,570
Standard Personal Lines
Deferred policy acquisition costs		17,817		12,911		13,803
Reserve for loss and loss expenses		340,302		270,066		228,348
Unearned premiums		322,668		317,276		308,183
Net premiums earned		299,405		293,559		299,140
Net investment income		0		0		0
Loss and loss expense incurred		231,113		212,116		233,260
Amortization of deferred policy acquisition costs		27,129		25,918		30,694
Other operating expenses		48,356		51,559		50,694
Net premiums written		319,059		292,265		295,166
Other income		1,816		1,667		2,058
Investments SIGI
Deferred policy acquisition costs		0		0		0
Reserve for loss and loss expenses		0		0		0
Unearned premiums		0		0		0
Net premiums earned		0		0		0
Net investment income	[1]	173,347		344,188		222,890
Loss and loss expense incurred		0		0		0
Amortization of deferred policy acquisition costs		0		0		0
Other operating expenses		0		0		0
Net premiums written		$ 0		$ 0		$ 0
[1]Includes “Net investment income earned” and “Net realized and unrealized investment (losses) gains” on the Consolidated Statements of Income.[2]“Other operating expenses” of $388,978 reconciles to the Consolidated Statements of Income[3]“Other operating expenses” of $358,208 reconciles to the Consolidated Statements of Income[4]“Other operating expenses” of $349,371 reconciles to the Consolidated Statements of Income

Schedule IV - Reinsurance (Deta

Schedule IV - Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Direct Amount	$ 3,880,522	$ 3,472,715	$ 3,108,687
Assumed From Other Companies	30,742	21,550	25,010
Ceded to Other Companies	537,884	477,012	451,883
Net premiums earned	$ 3,373,380	$ 3,017,253	$ 2,681,814
Percentage of Amount Assumed to Net	1%	1%	1%
Accident and Health Insurance Segment [Member]
Direct Amount	$ 0	$ 2	$ 13
Assumed From Other Companies	0	0	0
Ceded to Other Companies	0	2	13
Net premiums earned	$ 0	$ 0	$ 0
Percentage of Amount Assumed to Net	0%	0%	0%
Property and liability insurance [Member]
Direct Amount	$ 3,880,522	$ 3,472,713	$ 3,108,674
Assumed From Other Companies	30,742	21,550	25,010
Ceded to Other Companies	537,884	477,010	451,870
Net premiums earned	$ 3,373,380	$ 3,017,253	$ 2,681,814
Percentage of Amount Assumed to Net	1%	1%	1%

Schedule V - Allowance for Cr_2

Schedule V - Allowance for Credit Losses on Premiums and Other Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance, January 1	$ 15,200	$ 22,777	$ 10,800
Additions	7,478	1,766	17,576
Deductions	(4,978)	(9,343)	(3,754)
Balance, December 31	17,700	15,200	22,777
Accounting Standards Update 2016-13 [Member]
Cumulative effect adjustment		0	0	$ (1,845)
Accounting Standards Update 2016-13 [Member] | Premiums Receivable [Member]
Balance, January 1	$ 15,200	22,777	8,955
Balance, December 31		$ 15,200	$ 22,777