Kinsale Capital (KNSL) 10-Q 26 Oct 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	9 Months Ended
	Sep. 30, 2023	Oct. 20, 2023
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2023
Entity Registrant Name	KINSALE CAPITAL GROUP, INC.
Entity File Number	001-37848
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	98-0664337
Entity Address, Address Line One	2035 Maywill Street
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Richmond
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	23230
Entity Current Reporting Status	Yes
City Area Code	804
Local Phone Number	289-1300
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	KNSL
Security Exchange Name	NYSE
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		23,173,468
Entity Central Index Key	0001669162
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Assets
Fixed-maturity securities, available for sale, at fair value (amortized cost: $2,563,914, allowance for credit losses: $565 – 2023; $1,933,632 and $366 –2022)	$ 2,364,759	$ 1,760,100
Equity securities, at fair value (cost: $178,162 – 2023; $126,478 – 2022)	207,951	152,471
Real Estate Investments, Net	14,372	76,387
Short-term investments	29,065	41,337
Total investments	2,616,147	2,030,295
Cash and Cash Equivalents, at Carrying Value	162,944	156,274
Investment income due and accrued	19,028	14,451
Premiums and fees receivable, net of allowance for credit losses of $14,379 – 2023; $8,067 – 2022	124,087	105,754
Reinsurance recoverables, net	240,852	220,454
Ceded unearned premiums	50,967	42,935
Deferred policy acquisition costs, net of ceding commissions	86,181	61,594
Intangible assets	3,538	3,538
Deferred Income Tax Assets, Net	68,535	56,983
Other assets	70,257	54,844
Total assets	3,442,536	2,747,122
Liabilities
Reserves for unpaid losses and loss adjustment expenses	1,564,907	1,238,402
Unearned premiums	690,354	499,677
Payable to reinsurers	45,853	32,024
Accounts payable and accrued expenses	32,758	31,361
Debt	183,777	195,747
Other liabilities	1,125	4,462
Total liabilities	2,518,774	2,001,673
Stockholders' Equity
Common stock, $0.01 par value, 400,000,000 shares authorized, 23,172,925 and 23,090,526 shares issued and outstanding at September 30, 2023 and December 31, 2022 respectively	232	231
Additional paid-in capital	350,452	347,015
Retained earnings	728,105	533,121
Accumulated other comprehensive loss	(155,027)	(134,918)
Total stockholders’ equity	923,762	745,449
Total liabilities and stockholders’ equity	$ 3,442,536	$ 2,747,122

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Assets [Abstract]
Fixed-maturity securities, available for sale, amortized cost	$ 2,563,914	$ 1,933,632
Allowance for Credit Losses	(565)	(366)
Equity securities - cost	178,162	126,478
Premium Receivable, Allowance for Credit Loss	14,379	8,067
Reinsurance Recoverable, Allowance for Credit Loss	$ (459)	$ (459)
Stockholders' Equity
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	23,172,925	23,090,526
Common stock, shares outstanding (in shares)	23,172,925	23,090,526

Consolidated Statements of Inco

Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenues:
Gross written premiums	$ 377,789	$ 284,111	$ 1,173,599	$ 806,625
Ceded written premiums	(83,509)	(48,212)	(215,248)	(111,885)
Net written premiums	294,280	235,899	958,351	694,740
Change in unearned premiums	(12,778)	(26,640)	(182,645)	(116,761)
Net earned premiums	281,502	209,259	775,706	577,979
Fee income	6,841	5,099	20,028	14,363
Net investment income	27,086	13,858	71,953	33,540
Change in the fair value of equity securities	(5,533)	(6,095)	3,796	(37,199)
Net realized investment gains (losses)	4,274	(173)	913	1,535
Change in allowance for credit losses on investments	(143)	0	(199)	0
Other income	340	112	1,081	381
Total revenues	314,367	222,060	873,278	590,599
Expenses:
Losses and loss adjustment expenses	155,552	134,788	441,628	344,333
Underwriting, acquisition and insurance expenses	60,348	45,244	168,567	132,025
Interest Expense	2,573	1,716	7,867	2,306
Other expenses	401	212	1,220	521
Total expenses	218,874	181,960	619,282	479,185
Income before income taxes	95,493	40,100	253,996	111,414
Total income tax expense	19,378	7,116	49,290	19,549
Net income	76,115	32,984	204,706	91,865
Other comprehensive income (loss):
Change in net unrealized losses on available-for-sale investments, net of taxes	(23,511)	(46,652)	(20,109)	(165,464)
Total comprehensive income (loss)	$ 52,604	$ (13,668)	$ 184,597	$ (73,599)
Earnings per share:
Basic	$ 3.30	$ 1.45	$ 8.89	$ 4.03
Diluted	$ 3.26	$ 1.43	$ 8.79	$ 3.98
Weighted average shares outstanding:
Basic	23,058	22,813	23,036	22,783
Diluted	23,315	23,114	23,298	23,099

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance, shares at Dec. 31, 2021		22,834,377
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)		75,630
Restricted shares withheld for taxes (shares)		(2,459)
Balance, shares at Mar. 31, 2022		22,907,548
Balance at Dec. 31, 2021	$ 699,335	$ 228	$ 295,040	$ 385,942	$ 18,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	378	1	377
Stock-based compensation expense	1,489		1,489
Restricted shares withheld for taxes	(516)		(516)
Dividends declared	(2,977)			(2,977)
Other comprehensive income (loss), net of tax	(63,930)				(63,930)
Net income	31,791			31,791
Balance at Mar. 31, 2022	$ 665,570	$ 229	296,390	414,756	(45,805)
Balance, shares at Dec. 31, 2021		22,834,377
Balance, shares at Sep. 30, 2022	22,924,522
Balance at Dec. 31, 2021	$ 699,335	$ 228	295,040	385,942	18,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss), net of tax	(165,464)
Net income	91,865
Balance at Sep. 30, 2022	$ 619,455	$ 229	297,692	468,873	(147,339)
Balance, shares at Mar. 31, 2022		22,907,548
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)	8,630
Restricted shares withheld for taxes (shares)	(12,420)
Balance, shares at Jun. 30, 2022	22,903,758
Balance at Mar. 31, 2022	$ 665,570	$ 229	296,390	414,756	(45,805)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	150	0	150
Stock-based compensation expense	1,857		1,857
Restricted shares withheld for taxes	(2,741)		(2,741)
Dividends declared	(2,978)			(2,978)
Other comprehensive income (loss), net of tax	(54,882)				(54,882)
Net income	27,090			27,090
Balance at Jun. 30, 2022	$ 634,066	229	295,656	438,868	(100,687)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)	20,764
Balance, shares at Sep. 30, 2022	22,924,522
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	$ 373	0	373
Stock-based compensation expense	1,663		1,663
Dividends declared	(2,979)			(2,979)
Other comprehensive income (loss), net of tax	(46,652)				(46,652)
Net income	32,984			32,984
Balance at Sep. 30, 2022	$ 619,455	$ 229	297,692	468,873	(147,339)
Balance, shares at Dec. 31, 2022	23,090,526	23,090,526
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)		70,047
Restricted shares withheld for taxes (shares)		(6,628)
Balance, shares at Mar. 31, 2023		23,153,945
Balance at Dec. 31, 2022	$ 745,449	$ 231	347,015	533,121	(134,918)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	324	1	323
Stock-based compensation expense	1,988		1,988
Restricted shares withheld for taxes	(2,104)		(2,104)
Dividends declared	(3,235)			(3,235)
Other comprehensive income (loss), net of tax	17,509				17,509
Net income	55,800			55,800
Balance at Mar. 31, 2023	$ 815,731	$ 232	347,222	585,686	(117,409)
Balance, shares at Dec. 31, 2022	23,090,526	23,090,526
Balance, shares at Sep. 30, 2023	23,172,925
Balance at Dec. 31, 2022	$ 745,449	$ 231	347,015	533,121	(134,918)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss), net of tax	(20,109)
Net income	204,706
Balance at Sep. 30, 2023	$ 923,762	$ 232	350,452	728,105	(155,027)
Balance, shares at Mar. 31, 2023		23,153,945
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)	15,046
Restricted shares withheld for taxes (shares)	(6,816)
Balance, shares at Jun. 30, 2023	23,162,175
Balance at Mar. 31, 2023	$ 815,731	$ 232	347,222	585,686	(117,409)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	230	0	230
Stock-based compensation expense	2,543		2,543
Restricted shares withheld for taxes	(2,130)		(2,130)
Dividends declared	(3,243)			(3,243)
Other comprehensive income (loss), net of tax	(14,107)				(14,107)
Net income	72,791			72,791
Balance at Jun. 30, 2023	$ 871,815	232	347,865	655,234	(131,516)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)	10,750
Balance, shares at Sep. 30, 2023	23,172,925
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	$ 172	0	172
Stock-based compensation expense	2,415		2,415
Dividends declared	(3,244)			(3,244)
Other comprehensive income (loss), net of tax	(23,511)				(23,511)
Net income	76,115			76,115
Balance at Sep. 30, 2023	$ 923,762	$ 232	$ 350,452	$ 728,105	$ (155,027)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Statement of Stockholders' Equity [Abstract]
Dividends declared, per share	$ 0.14	$ 0.14	$ 0.14	$ 0.13	$ 0.13	$ 0.13

Condensed Consolidated Statemen

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating Activities
Net cash provided by operating activities	$ 648,308	$ 456,699
Investing Activities
Purchase of property and equipment	(5,501)	(4,744)
Purchase of real estate investment	(1,733)	0
Sale of real estate investment	62,036	0
Change in short-term investments, net	13,071	(81,113)
Purchases – fixed-maturity securities	(947,920)	(599,735)
Purchases - equity securities	(62,047)	(1,098)
Sales – fixed-maturity securities	204,416	73,066
Sales – equity securities	7,503	3,990
Maturities and calls – fixed-maturity securities	113,811	89,783
Net cash used in investing activities	(616,364)	(519,851)
Financing Activities
Proceeds from Issuance of Long-Term Debt	50,000	125,000
Repayments of Long-Term Lines of Credit	(62,000)	(43,000)
Payments of Debt Issuance Costs	(43)	(2,381)
Payroll taxes withheld and remitted on share-based payments	(4,234)	(3,257)
Proceeds from stock options exercised	726	901
Dividends paid	(9,723)	(8,938)
Net cash (used in) provided by financing activities	(25,274)	68,325
Net change in cash and cash equivalents	6,670	5,173
Cash and cash equivalents	162,944	$ 126,213
Cash and cash equivalents at beginning of year	156,274
Cash and cash equivalents at end of period	$ 162,944

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of presentation The unaudited condensed consolidated financial statements and notes have been prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") for interim financial information and do not contain all of the information and footnotes required by U.S. GAAP for complete financial statements. As such, these unaudited condensed consolidated interim financial statements should be read in conjunction with the audited consolidated financial statements of Kinsale Capital Group, Inc. and its subsidiaries ("the Company") included in the Annual Report on Form 10-K for the year ended December 31, 2022. In the opinion of management, all adjustments necessary for a fair presentation of the condensed consolidated financial statements have been included. Such adjustments consist only of normal recurring items. All significant intercompany balances and transactions have been eliminated in consolidation. Interim results are not necessarily indicative of results of operations for the full year. Use of estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, if any, at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Prospective accounting pronouncements There are no prospective accounting standards which, upon their effective date, would have a material impact on the Company's condensed consolidated financial statements.

Investments

Investments	9 Months Ended
	Sep. 30, 2023
Investments [Abstract]
Investments	Investments Available-for-sale investments The following tables summarize the available-for-sale investments at September 30, 2023 and December 31, 2022: September 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Allowance for Credit Losses Estimated Fair Value (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 42,705 $ — $ (1,200) $ — $ 41,505 Obligations of states, municipalities and political subdivisions 190,263 22 (30,339) — 159,946 Corporate and other securities 1,299,277 34 (87,518) (564) 1,211,229 Asset-backed securities 599,813 703 (6,822) — 593,694 Residential mortgage-backed securities 361,833 44 (66,329) — 295,548 Commercial mortgage-backed securities 70,023 — (7,185) (1) 62,837 Total fixed-maturity investments $ 2,563,914 $ 803 $ (199,393) $ (565) $ 2,364,759 December 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Allowance for Credit Losses Estimated Fair Value (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 17,934 $ — $ (1,193) $ — $ 16,741 Obligations of states, municipalities and political subdivisions 230,746 330 (26,444) — 204,632 Corporate and other securities 909,285 730 (76,757) (366) 832,892 Asset-backed securities 361,248 292 (8,534) — 353,006 Residential mortgage-backed securities 349,066 52 (55,156) — 293,962 Commercial mortgage-backed securities 65,353 — (6,486) — 58,867 Total fixed-maturity investments $ 1,933,632 $ 1,404 $ (174,570) $ (366) $ 1,760,100 Available-for-sale securities in a loss position The Company regularly reviews all its available-for-sale investments with unrealized losses to assess whether the decline in the fair value is deemed to be a credit loss. The Company considers a number of factors in completing its review of credit losses, including the extent to which a security's fair value has been below cost and the financial condition of an issuer. In addition to specific issuer information, the Company also evaluates the current market and interest rate environment. Generally, a decline in a security’s value caused by a change in the market or interest rate environment does not constitute a credit loss. For fixed-maturity securities, the Company also considers whether it intends to sell the security or, if it is more likely than not that it will be required to sell the security before recovery, and its ability to recover all amounts outstanding when contractually due. When assessing whether it intends to sell a fixed-maturity security or, if it is likely to be required to sell a fixed-maturity security before recovery of its amortized cost, the Company evaluates facts and circumstances including, but not limited to, decisions to reposition the investment portfolio, potential sales of investments to meet cash flow needs and potential sales of investments to capitalize on favorable pricing. For fixed-maturity securities where a decline in fair value is below the amortized cost basis and the Company intends to sell the security, or it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost, an impairment is recognized in net income based on the fair value of the security at the time of assessment. For fixed-maturity securities that the Company does not intend to sell or for which it is more likely than not that the Company would not be required to sell before recovery of its amortized cost, the Company compares the estimated present value of the cash flows expected to be collected to the amortized cost of the security. Inputs into the cash flow analysis include default rates and recoverability rates based on credit rating. The extent to which the estimated present value of the cash flows expected to be collected is less than the amortized cost of the security represents the credit-related portion of the impairment, which is recognized in net income through an allowance for credit losses. Any remaining decline in fair value represents the noncredit portion of the impairment, which is recognized in other comprehensive income. The Company reports investment income due and accrued separately from available-for-sale investments and has elected not to measure an allowance for credit losses for investment income due and accrued. Investment income due and accrued is written off through earnings at the time the issuer of the bond defaults or is expected to default on payments. At September 30, 2023, the Company's credit loss review resulted in an allowance for credit losses on 6 securities. The following table presents changes in the allowance for expected credit losses on available-for-sale securities for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Beginning balance $ 422 $ — $ 366 $ — Increase to allowance from securities for which credit losses were not previously recorded 1 — 1 — Reduction from securities sold during the period — — (12) — Net increase from securities that had an allowance at the beginning of the period 142 — 210 — Ending balance $ 565 $ — $ 565 $ — The following tables summarize gross unrealized losses and estimated fair value for available-for-sale investments by length of time that the securities have continuously been in an unrealized loss position: September 30, 2023 Less than 12 Months 12 Months or Longer Total Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses (in thousands) Fixed maturities: U.S. Treasury securities and obligations of the U.S. government agencies $ 26,341 $ (84) $ 15,164 $ (1,116) $ 41,505 $ (1,200) Obligations of states, municipalities and political subdivisions 42,151 (1,046) 116,398 (29,293) 158,549 (30,339) Corporate and other securities 564,003 (9,918) 643,417 (77,600) 1,207,420 (87,518) Asset-backed securities 273,264 (3,895) 245,476 (2,927) 518,740 (6,822) Residential mortgage-backed securities 36,467 (326) 257,041 (66,003) 293,508 (66,329) Commercial mortgage-backed securities 5,953 (129) 56,884 (7,056) 62,837 (7,185) Total fixed-maturity investments $ 948,179 $ (15,398) $ 1,334,380 $ (183,995) $ 2,282,559 $ (199,393) At September 30, 2023, the Company held 1,233 fixed-maturity securities in an unrealized loss position with a total estimated fair value of $2.3 billion and gross unrealized losses of $199.4 million. Of these securities, 782 were in a continuous unrealized loss position for greater than one year. As discussed above, the Company regularly reviews all fixed-maturity securities within its investment portfolio to determine whether a credit loss has occurred. Based on the Company's review as of September 30, 2023, except for securities previously discussed, unrealized losses were caused by interest rate changes or other market factors and were not credit-specific issues. At September 30, 2023, 82.0% of the Company’s fixed-maturity securities were rated "A-" or better and all of the Company’s fixed-maturity securities made expected coupon payments under the contractual terms of the securities. December 31, 2022 Less than 12 Months 12 Months or Longer Total Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 10,538 $ (447) $ 6,204 $ (746) $ 16,742 $ (1,193) Obligations of states, municipalities and political subdivisions 141,460 (20,347) 17,314 (6,097) 158,774 (26,444) Corporate and other securities 583,619 (42,675) 156,148 (34,082) 739,767 (76,757) Asset-backed securities 216,487 (5,429) 97,703 (3,105) 314,190 (8,534) Residential mortgage-backed securities 98,909 (12,324) 194,773 (42,832) 293,682 (55,156) Commercial mortgage-backed securities 50,666 (4,732) 8,201 (1,754) 58,867 (6,486) Total fixed-maturity investments $ 1,101,679 $ (85,954) $ 480,343 $ (88,616) $ 1,582,022 $ (174,570) Contractual maturities of available-for-sale fixed-maturity securities The amortized cost and estimated fair value of available-for-sale fixed-maturity securities at September 30, 2023 are summarized, by contractual maturity, as follows: September 30, 2023 Amortized Estimated Cost Fair Value (in thousands) Due in one year or less $ 184,335 $ 181,981 Due after one year through five years 923,152 889,587 Due after five years through ten years 194,507 167,015 Due after ten years 230,251 174,097 Asset-backed securities 599,813 593,694 Residential mortgage-backed securities 361,833 295,548 Commercial mortgage-backed securities 70,023 62,837 Total fixed-maturity securities $ 2,563,914 $ 2,364,759 Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties, and the lenders may have the right to put the securities back to the borrower. Real estate investments In December 2022, the Company completed the purchase of a real estate investment property. Real estate investments consisted of the following: September 30, 2023 December 31, 2022 (in thousands) Building $ — $ 44,931 Land 14,372 17,946 Intangible in-place lease — 9,749 Site improvements — 2,686 Parking deck — 1,311 14,372 76,623 Accumulated depreciation — (236) Total real estate investments, net $ 14,372 $ 76,387 During the third quarter of 2023, the Company sold the parking deck, one of the office buildings and the related in-place leases of its real estate investment property for approximately $62.0 million in cash, net of seller’s costs. The Company recognized a gain on the sale of $4.3 million, which is included in net realized investment gains on the consolidated statement of income. The Company used the net sale proceeds to pay down a portion of its Credit Facility. Concurrent with the sale of the investment property, the Company refined its plans for the remainder of the property and determined the predominant use of the remaining office building would be for future office space expansion. Upon this determination, the Company reclassified the carrying value of the building to construction in progress within property and equipment. Net investment income The following table presents the components of net investment income for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Interest: Taxable bonds $ 24,644 $ 12,041 $ 63,672 $ 29,015 Tax exempt municipal bonds 522 849 1,704 2,558 Cash equivalents and short-term investments 758 475 2,337 598 Dividends on equity securities 1,271 1,085 3,692 3,208 Real estate investment income 851 — 3,565 — Gross investment income 28,046 14,450 74,970 35,379 Investment expenses (960) (592) (3,017) (1,839) Net investment income $ 27,086 $ 13,858 $ 71,953 $ 33,540 Investment expenses included depreciation expense related to real estate investments of $0.5 million for the nine months ended September 30, 2023. There was no depreciation of real estate investments for the three months ended September 30, 2023 as the related depreciable real estate investments were reclassified to held for sale prior to being sold during the period. There was no depreciation of real estate investments for the three and nine months ended September 30, 2022. Realized investment gains and losses The following table presents realized investment gains and losses for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Fixed-maturity securities: Realized gains $ 74 $ — $ 1,811 $ 1,076 Realized losses (51) (177) (2,268) (720) Net realized (losses) gains from fixed-maturity securities 23 (177) (457) 356 Equity securities: Realized gains — — 1,626 1,363 Realized losses — — (4,487) (148) Net realized (losses) gains from equity securities — — (2,861) 1,215 Realized (losses) gains from the sales of short-term investments 1 4 (19) (36) Realized gain on sale of real estate investments 4,250 — 4,250 — Net realized investment gains (losses) $ 4,274 $ (173) $ 913 $ 1,535 The net realized gains or losses on sales of equity securities represent the total gains or losses from the purchase dates of the equity securities. The change in unrealized gains (losses) in the consolidated statement of income consists of two components: (1) the reversal of the gain or loss recognized in previous periods on equity securities sold and (2) the change in unrealized gain or loss resulting from mark-to-market adjustments on equity securities still held. Change in net unrealized gains (losses) on fixed-maturity securities For the three months ended September 30, 2023 and 2022, the changes in net unrealized losses for fixed-maturity securities were $(29.8) million and $(59.1) million, respectively. For the nine months ended September 30, 2023 and 2022, the changes in net unrealized losses for fixed-maturity securities were $(25.4) million and $(209.4) million, respectively. Insurance – statutory deposits The Company had invested assets with a fair value of $5.7 million and $5.9 million on deposit with state regulatory authorities at September 30, 2023 and December 31, 2022, respectively. Payable for investments purchased The Company recorded a payable for investments purchased, not yet settled, of $1.0 million and $1.8 million at September 30, 2023 and December 31, 2022, respectively. The payable balance was included in the "other liabilities" line item of the consolidated balance sheet.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is estimated for each class of financial instrument based on the framework established in the fair value accounting guidance. Fair value is defined as the price in the principal market that would be received for an asset or paid to transfer a liability to facilitate an orderly transaction between market participants on the measurement date. Market participants are assumed to be independent, knowledgeable, able and willing to transact an exchange and not acting under duress. Fair value hierarchy disclosures are based on the quality of inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Adjustments to transaction prices or quoted market prices may be required in illiquid or disorderly markets in order to estimate fair value. The three levels of the fair value hierarchy are defined as follows: Level 1 - Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities traded in active markets. Level 2 - Inputs to the valuation methodology include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and market-corroborated inputs. Level 3 - Inputs to the valuation methodology are unobservable for the asset or liability and are significant to the fair value measurement. Fair values of the Company's investment portfolio are estimated using unadjusted prices obtained by its investment accounting vendor from nationally recognized third-party pricing services, where available. Values for U.S. Treasuries, exchange traded funds and common stocks are generally based on Level 1 inputs, which use quoted prices in active markets for identical assets. For other fixed-maturity securities and non-redeemable preferred stock, the pricing vendors use a pricing methodology involving the market approach, including pricing models which use prices and relevant market information regarding a particular security or securities with similar characteristics to establish a valuation. The estimates of fair value of these investments are included in the amounts disclosed as Level 2. For those investments where significant inputs are unobservable, the Company's investment accounting vendor obtains valuations from pricing vendors or brokers using the market approach and income approach valuation techniques and are disclosed as Level 3. Management performs several procedures to ascertain the reasonableness of investment values included in the condensed consolidated financial statements, including 1) obtaining and reviewing internal control reports from the Company's investment accounting vendor that assess fair values from third party pricing services, 2) discussing with the Company's investment accounting vendor its process for reviewing and validating pricing obtained from third party pricing services and 3) reviewing the security pricing received from the Company's investment accounting vendor and monitoring changes in unrealized gains and losses at the individual security level. The Company has evaluated the various types of securities in its investment portfolio to determine an appropriate fair value hierarchy level based upon trading activity and the observability of market inputs. The following tables present the balances of assets measured at fair value on a recurring basis as of September 30, 2023 and December 31, 2022, by level within the fair value hierarchy: September 30, 2023 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 36,537 $ 4,968 $ — $ 41,505 Obligations of states, municipalities and political subdivisions — 159,946 — 159,946 Corporate and other securities — 1,211,229 — 1,211,229 Asset-backed securities — 593,694 — 593,694 Residential mortgage-backed securities — 295,548 — 295,548 Commercial mortgage-backed securities — 62,837 — 62,837 Total fixed-maturity securities 36,537 2,328,222 — 2,364,759 Equity securities: Exchange traded funds 106,565 — — 106,565 Non-redeemable preferred stock — 31,755 — 31,755 Common stocks 69,631 — — 69,631 Total equity securities 176,196 31,755 — 207,951 Short-term investments 4,725 24,340 — 29,065 Total $ 217,458 $ 2,384,317 $ — $ 2,601,775 December 31, 2022 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 16,741 $ — $ — $ 16,741 Obligations of states, municipalities and political subdivisions — 204,632 — 204,632 Corporate and other securities — 832,892 — 832,892 Asset-backed securities — 353,006 — 353,006 Residential mortgage-backed securities — 293,962 — 293,962 Commercial mortgage-backed securities — 58,867 — 58,867 Total fixed-maturity securities 16,741 1,743,359 — 1,760,100 Equity securities: Exchange traded funds 104,202 — — 104,202 Non-redeemable preferred stock — 38,162 — 38,162 Common stocks 10,107 — — 10,107 Total equity securities 114,309 38,162 — 152,471 Short-term investments 31,366 9,971 — 41,337 Total $ 162,416 $ 1,791,492 $ — $ 1,953,908 There were no assets or liabilities measured at fair value on a nonrecurring basis as of September 30, 2023 or December 31, 2022. The carrying amount of the Company's fixed-rate senior notes was $175.0 million and $125.0 million, less debt issuance costs, and the corresponding estimated fair value was $159.5 million and $117.2 million at September 30, 2023 and December 31, 2022, respectively. The fair value measurement was determined using a discounted cash flow analysis that factors in current market yields for comparable borrowing arrangements under the Company's credit profile. Since this methodology is based upon market yields for comparable arrangements, the measurement is categorized as Level 2. The estimated fair value of outstanding borrowings under the Company's revolving Credit Facility approximated its carrying value at September 30, 2023 and December 31, 2022. See Note 13 for further information regarding the Company's debt arrangements.

Credit Losses

Credit Losses	9 Months Ended
	Sep. 30, 2023
Credit Loss [Abstract]
Credit Loss, Financial Instrument	Premiums receivable Premiums receivable balances are carried at face value, net of any allowance for credit losses. The allowance for credit losses represents an estimate of amounts considered uncollectible based on the Company’s assessment of the collectability of receivables that are past due. The estimate considers historical loss data, current and future economic conditions and specific identification of collectability concerns, where applicable. The following table presents the change in the allowance for credit losses for premiums receivable for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Beginning balance $ 12,167 $ 5,612 $ 8,067 $ 3,391 Current period change for estimated uncollectible premiums 2,341 1,874 7,459 4,818 Write-offs of uncollectible premiums receivable (129) (195) (1,147) (918) Ending balance $ 14,379 $ 7,291 $ 14,379 $ 7,291

Deferred Policy Acquisition Cos

Deferred Policy Acquisition Costs	9 Months Ended
	Sep. 30, 2023
Deferred Policy Acquisition Costs Disclosures [Abstract]
Deferred Policy Acquisition Costs	Deferred Policy Acquisition Costs The following table presents the amounts of policy acquisition costs deferred and amortized for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Balance, beginning of period $ 85,326 $ 54,806 $ 61,594 $ 41,968 Policy acquisition costs deferred: Direct commissions 54,580 41,525 169,223 117,621 Ceding commissions (24,230) (13,886) (62,779) (32,678) Other underwriting and policy acquisition costs 1,623 2,302 7,511 6,534 Policy acquisition costs deferred 31,973 29,941 113,955 91,477 Amortization of net policy acquisition costs (31,118) (26,302) (89,368) (75,000) Balance, end of period $ 86,181 $ 58,445 $ 86,181 $ 58,445 Amortization of net policy acquisition costs is included in the line item "Underwriting, acquisition and insurance expenses" in the accompanying consolidated statements of income and comprehensive income.

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2023
Property and Equipment [Abstract]
Property and Equipment Disclosure [Text Block]	Property and Equipment, Net Property and equipment are included in "other assets" in the accompanying consolidated balance sheets and consist of the following: September 30, 2023 December 31, 2022 (in thousands) Building $ 37,107 $ 33,065 Parking deck 5,072 5,072 Land 3,068 3,068 Equipment 3,859 3,444 Software 14,402 11,410 Furniture and fixtures 3,049 2,615 Land improvements 474 474 Leasehold improvements 153 — Construction in progress - building 5,700 2,618 72,884 61,766 Accumulated depreciation (10,620) (8,291) Total property and equipment, net $ 62,264 $ 53,475

Underwriting, Acquisition and I

Underwriting, Acquisition and Insurance Expenses	9 Months Ended
	Sep. 30, 2023
Underwriting, Acquisition and Insurance Expenses [Abstract]
Underwriting, acquisition and insurance expenses	Underwriting, Acquisition and Insurance Expenses Underwriting, acquisition and insurance expenses for the three and nine months ended September 30, 2023 and 2022 consist of the following: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Underwriting, acquisition and insurance expenses incurred: Direct commissions $ 53,035 $ 37,177 $ 143,181 $ 99,540 Ceding commissions (23,396) (12,939) (59,882) (30,069) Other underwriting expenses 30,709 21,006 85,268 62,554 Total $ 60,348 $ 45,244 $ 168,567 $ 132,025 Other underwriting expenses within underwriting, acquisition and insurance expenses include salaries, bonus and employee benefits expenses of $23.1 million and $15.4 million for the three months ended September 30, 2023 and 2022, respectively. Other underwriting expenses within underwriting, acquisition and insurance expenses included salaries, bonus and employee benefits expenses of $63.0 million and $46.1 million for the nine months ended September 30, 2023 and 2022, respectively. See Note 15 for further information regarding underwriting, acquisition and insurance expenses.

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-based Compensation	Stock-based CompensationOn July 27, 2016, the Kinsale Capital Group, Inc. 2016 Omnibus Incentive Plan (the "2016 Incentive Plan") became effective. The 2016 Incentive Plan, which is administered by the Compensation, Nominating and Corporate Governance Committee of the Company’s Board of Directors, provides for grants of stock options, restricted stock, restricted stock units and other stock-based awards to officers, employees, directors, independent contractors and consultants. The number of shares of common stock available for issuance under the 2016 Incentive Plan may not exceed 2,073,832. The total compensation cost that has been charged against income for share-based compensation arrangements was $6.9 million and $5.0 million for the nine months ended September 30, 2023 and 2022, respectively. Restricted Stock Awards During the nine months ended September 30, 2023, the Company granted restricted stock awards under the 2016 Incentive Plan. The restricted stock awards were valued on the date of grant and will vest over a period of 1 to 4 years corresponding to the anniversary date of the grants. The fair value of restricted stock awards was determined based on the closing trading price of the Company’s shares on the grant date or, if no shares were traded on the grant date, the last preceding date for which there was a sale of shares. Except for restrictions placed on the transferability of restricted stock, holders of unvested restricted stock have full stockholder’s rights, including voting rights and the right to receive dividends. Unvested shares of restricted stock awards and accrued dividends, if any, are forfeited upon the termination of service to or employment with the Company. A summary of restricted stock activity under the 2016 Incentive Plan for the nine months ended September 30, 2023 is as follows: For the Nine Months Ended September 30, 2023 Number of Shares Weighted Average Grant Date Fair Value per Share Non-vested outstanding at the beginning of the period 98,621 $ 182.37 Granted 51,176 $ 313.35 Vested (40,582) $ 163.62 Forfeited (725) $ 225.64 Non-vested outstanding at the end of the period 108,490 $ 250.88 Employees surrender shares to pay for withholding tax obligations resulting from any vesting of restricted stock awards. During the nine months ended September 30, 2023, shares withheld for taxes in connection with the vesting of restricted stock awards totaled 13,444. The weighted average grant-date fair value per share of the Company's restricted stock awards granted during the nine months ended September 30, 2023 and 2022 was $313.35 and $211.86, respectively. The fair value of restricted stock awards that vested during the nine months ended September 30, 2023 and 2022 was $12.6 million and $9.9 million, respectively. As of September 30, 2023, the Company had $21.7 million of total unrecognized stock-based compensation expense expected to be charged to earnings over a weighted-average period of 2.8 years. Stock Options On July 27, 2016, the Board of Directors approved, and the Company granted, 1,036,916 stock options with an exercise price equal to the initial public offering price of $16.00 per share and a weighted-average grant-date fair value of $2.71 per share. The options have a maximum contractual term of 10 years and vested in 4 equal annual installments following the date of the grant. The value of the options granted was estimated at the date of grant using the Black-Scholes pricing model. A summary of option activity as of September 30, 2023, and changes during the period then ended is presented below: Number of Shares Weighted-Average Exercise Price Weighted-Average Remaining Years of Contractual Term Aggregate Intrinsic Value (in thousands) Outstanding at January 1, 2023 256,357 $ 16.00 Granted — — Forfeited — — Exercised (45,392) 16.00 Outstanding at September 30, 2023 210,965 $ 16.00 2.8 $ 83,991 Exercisable at September 30, 2023 210,965 $ 16.00 2.8 $ 83,991

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following represents a reconciliation of the numerator and denominator of the basic and diluted earnings per share computations contained in the condensed consolidated financial statements: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands, except per share data) Net income $ 76,115 $ 32,984 $ 204,706 $ 91,865 Weighted average common shares outstanding - basic 23,058 22,813 23,036 22,783 Effect of potential dilutive securities: Conversion of stock options 208 262 220 276 Conversion of restricted stock 49 39 42 40 Weighted average common shares outstanding - diluted 23,315 23,114 23,298 23,099 Earnings per common share: Basic $ 3.30 $ 1.45 $ 8.89 $ 4.03 Diluted $ 3.26 $ 1.43 $ 8.79 $ 3.98

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company uses the estimated annual effective tax rate method for calculating its tax provision in interim periods, which represents the Company's best estimate of the effective tax rate expected for the full year. The estimated annual effective tax rate typically differs from the U.S. statutory tax rate, primarily as a result of tax-exempt investment income and any discrete items recognized during the period. The Company's effective tax rates were 19.4% and 17.5% for the nine months ended September 30, 2023 and 2022, respectively. The effective tax rates were lower than the federal statutory rate of 21% due primarily to the tax benefits from stock-based compensation and from income generated by certain tax-exempt investments.

Reserves for Unpaid Losses and

Reserves for Unpaid Losses and Loss Adjustment Expenses	9 Months Ended
	Sep. 30, 2023
Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract]
Reserves for Unpaid Losses and Loss Adjustment Expenses	Reserves For Unpaid Losses and Loss Adjustment Expenses The following table presents a reconciliation of consolidated beginning and ending reserves for unpaid losses and loss adjustment expenses: September 30, 2023 2022 (in thousands) Gross reserves for unpaid losses and loss adjustment expenses, beginning of year $ 1,238,402 $ 881,344 Less: reinsurance recoverable on unpaid losses 177,039 117,561 Net reserves for unpaid losses and loss adjustment expenses, beginning of year 1,061,363 763,783 Incurred losses and loss adjustment expenses: Current year 470,235 373,183 Prior years (28,607) (28,850) Total net losses and loss adjustment expenses incurred 441,628 344,333 Payments: Current year 22,156 13,028 Prior years 136,380 84,827 Total payments 158,536 97,855 Net reserves for unpaid losses and loss adjustment expenses, end of period 1,344,455 1,010,261 Reinsurance recoverable on unpaid losses 220,452 187,056 Gross reserves for unpaid losses and loss adjustment expenses, end of period $ 1,564,907 $ 1,197,317 During the nine months ended September 30, 2023, the reserves for unpaid losses and loss adjustment expenses held at December 31, 2022 developed favorably by $28.6 million, of which $39.0 million was attributable to the 2021 and 2022 accident years due to lower emergence of reported losses than expected across most lines of business. This favorable development was offset in part by adverse development largely from the 2017 through 2019 accident years due to long-tailed property damage claims within the construction-related primary casualty business that are more exposed to the increase in inflation. During the nine months ended September 30, 2022, the reserves for unpaid losses and loss adjustment expenses held at December 31, 2021 developed favorably by $28.9 million, of which $32.0 million was attributable to the 2020 and 2021 accident years due to lower emergence of reported losses than expected across most lines of business. This favorable development was offset in part by adverse development largely from the 2018 accident year due to routine variability in reported losses and modest adjustments in actuarial assumptions. Current accident year incurred losses and loss adjustment expenses for the nine months ended September 30, 2022 included $26.2 million of catastrophe losses primarily related to Hurricane Ian.

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2023
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance The following table summarizes the effect of reinsurance on premiums written and earned for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Premiums written: Direct $ 377,789 $ 284,111 $ 1,173,599 $ 806,625 Ceded (83,509) (48,212) (215,248) (111,885) Net written $ 294,280 $ 235,899 $ 958,351 $ 694,740 Premiums earned: Direct $ 362,689 $ 254,855 $ 982,922 $ 682,619 Ceded (81,187) (45,596) (207,216) (104,640) Net earned $ 281,502 $ 209,259 $ 775,706 $ 577,979 The following table summarizes ceded losses and loss adjustment expenses for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Ceded incurred losses and loss adjustment expenses $ 27,381 $ 56,774 $ 89,371 $ 79,790 The following table presents reinsurance recoverables on paid and unpaid losses as of September 30, 2023 and December 31, 2022: September 30, 2023 December 31, 2022 (in thousands) Reinsurance recoverables on paid losses $ 20,400 $ 43,415 Reinsurance recoverables on unpaid losses, net 220,452 177,039 Reinsurance recoverables, net $ 240,852 $ 220,454

Debt

Debt	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Debt	Debt Note Purchase and Private Shelf Agreement On July 22, 2022, the Company entered into a Note Purchase and Private Shelf Agreement (the “Note Purchase Agreement”) with PGIM, Inc. (“Prudential”) and the purchasers of the Series A Notes (as defined below), named in the Purchaser Schedule attached thereto (collectively, the “Note Purchasers”). Pursuant to the Note Purchase Agreement, on July 22, 2022, the Company issued $125.0 million aggregate principal amount of 5.15% Series A Senior Notes Due July 22, 2034 (collectively, the "Series A Notes”) to the Note Purchasers. The Note Purchase Agreement also provides for the issuance of additional shelf notes issued thereunder (the “Shelf Notes” and, together with the Series A Notes, the “Notes”) not to exceed $150.0 million of Notes outstanding thereunder. On September 18, 2023, the Company entered into a First Amendment to the Note Purchase Agreement and increased the additional Shelf Notes limit to $200.0 million. Pursuant to the First Amendment to the Note Purchase Agreement, on September 18, 2023, the Company issued a $50.0 million aggregate principal amount 6.21% Series B Senior Note due July 22, 2034 to the note purchaser. The Series A and B Notes are senior unsecured obligations of the Company and rank pari passu with the Company’s Amended and Restated Credit Agreement. The Series A Notes bear interest at 5.15% per annum and mature on July 22, 2034, unless paid earlier by the Company. Should the Company elect to prepay the Series A Notes, such aggregate prepayment will include the applicable make-whole amount(s), as defined within the applicable Note Purchase Agreement. Principal payments are required annually beginning on July 22, 2030 in equal installments of $25.0 million through July 22, 2034. The Series B Note bears interest at 6.21% per annum and matures on July 22, 2034, unless paid earlier by the Company. Should the Company elect to prepay the Series B Note, such aggregate prepayment will include the applicable make-whole amount(s), as defined within the applicable Note Purchase Agreement. Principal payments are required annually beginning on July 22, 2030 in equal installments of $10.0 million through July 22, 2034. Credit Agreement On May 28, 2019, the Company entered into a Credit Agreement (the “Credit Agreement”) that provided the Company with a $50.0 million senior unsecured revolving credit facility (the “Credit Facility”) and an uncommitted accordion feature that permits the Company to increase the commitments by an additional $30.0 million. On July 22, 2022, the Company entered into an Amended and Restated Credit Agreement, with JPMorgan Chase Bank, N.A., as administrative agent and as issuing bank, Truist Bank, as syndication agent, and the lenders party thereto (collectively, the “Lenders”). The Amended and Restated Credit Agreement extended the maturity date to July 22, 2027, and increased the aggregate commitment to $100.0 million, with the option to increase the aggregate commitment by $30.0 million, subject to the Company obtaining commitments from existing or new lenders and satisfying other conditions specified in the Amended and Restated Credit Agreement. The Company is required to pay a Commitment Fee Rate (as defined therein) of 0.25% on the average daily amount of the Available Revolving Commitment (as defined therein). Borrowings under the Amended and Restated Credit Agreement may be used for general corporate purposes (which may include, without limitation, to fund future growth, to finance working capital needs, to fund capital expenditures, and to refinance, redeem or repay indebtedness). In September 2023, the Company used proceeds from the sale of its real estate investment property to pay down $62.0 million from the Credit Facility. The loans under the Amended and Restated Credit Agreement bear interest, at the Company's option, at a rate equal to the Adjusted Term SOFR Rate (as defined therein) plus 1.625% or the Alternate Base Rate (as defined therein) plus 0.625%. For the nine months ended September 30, 2023, the annual weighted-average interest rate of borrowings under the Credit Facility was 6.75%. The following table presents the Company's outstanding debt as of September 30, 2023 and December 31, 2022: Issuance Maturities September 30, 2023 December 31, 2022 (in thousands) Credit Facility Various 7/22/2027 $ 11,000 $ 73,000 5.15% Series A Notes 7/22/2022 7/22/2034 125,000 125,000 6.21% Series B Note 9/18/2023 7/22/2034 50,000 — Less: Unamortized debt issuance costs (2,223) (2,253) Total debt $ 183,777 $ 195,747

Other Comprehensive (Loss) Inco

Other Comprehensive (Loss) Income	9 Months Ended
	Sep. 30, 2023
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income	Other Comprehensive Loss The following table summarizes the components of other comprehensive loss for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Unrealized losses on fixed-maturity securities arising during the period, before income taxes $ (29,931) $ (59,230) $ (26,997) $ (209,198) Income tax benefit 6,286 12,439 5,670 43,932 Unrealized losses arising during the period, net of income taxes (23,645) (46,791) (21,327) (165,266) Less reclassification adjustment: Net realized (losses) gains on fixed-maturity securities, before income taxes (27) (177) (1,343) 250 Income tax benefit (expense) 6 38 282 (52) Reclassification adjustment included in net income (21) (139) (1,061) 198 Change in allowance for credit losses on investments, before income taxes (143) — (199) — Income tax benefit 30 — 42 — Reclassification adjustment included in net income (113) — (157) — Other comprehensive loss $ (23,511) $ (46,652) $ (20,109) $ (165,464) The sale or credit loss of an available-for-sale fixed-maturity security results in amounts being reclassified from accumulated other comprehensive loss to realized gains or losses in current period earnings. The related tax effect of the reclassification adjustment is recorded in income tax expense in current period earnings. See Note 2 for additional information.

Accounting Changes and Error Co

Accounting Changes and Error Corrections	9 Months Ended
	Sep. 30, 2023
Accounting Changes and Error Corrections [Abstract]
Immaterial Correction to Prior Period Financial Statements for Accounting Policy Change	Immaterial Correction to Prior Period Financial Statements for Accounting Policy Change The Company charges insureds certain policy fees and recognizes such fees into earnings when the related premium is written. Previously, the Company presented these fees as a reduction of underwriting, acquisition and insurance expenses. Effective April 1, 2023, the Company corrected its accounting policy to present these fees as fee income in the consolidated statements of income and comprehensive income in accordance with ASC 944, Financial Services–Insurance. The Company presented $6.8 million and $20.0 million as fee income for the three and nine months ended September 30, 2023, respectively, in the consolidated statements of income and comprehensive income. The Company reclassified $5.1 million and $14.4 million to fee income from underwriting, acquisition and insurance expenses in the previously issued financial statements on Form 10-Q for the three and nine months ended September 30, 2022, respectively, to correct prior periods’ presentation. The Company considered the qualitative and quantitative impacts and determined that the correction was not material to the Company's previously issued consolidated financial statements.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net income	$ 76,115	$ 72,791	$ 55,800	$ 32,984	$ 27,090	$ 31,791	$ 204,706	$ 91,865

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		Securities Trading Plans of Directors and Executive Officers Transactions in our securities by our non-employee directors and executive officers are required to be made in accordance with our Policy on the Prevention of Insider Trading and Selective Disclosure (the “Insider Trading Policy”), which, among other things, requires that the transactions be in accordance with applicable U.S. federal securities laws that prohibit trading while in possession of material nonpublic information. Rule 10b5-1 under the Exchange Act provides an affirmative defense that enables prearranged transactions in securities in a manner that avoids concerns about initiating transactions at a future date while possibly in possession of material nonpublic information. Our Insider Trading Policy permits our non-employee directors and executive officers to enter into trading plans designed to comply with Rule 10b5-1. During the third quarter of 2023, none of our non-employee directors or executive officers adopted, modified or terminated a Rule 10b5-1 trading plan or adopted, modified or terminated a non-Rule 10b5-1 trading arrangement (as defined in Item 408(c) of Regulation S-K).
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of presentationThe unaudited condensed consolidated financial statements and notes have been prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") for interim financial information and do not contain all of the information and footnotes required by U.S. GAAP for complete financial statements. As such, these unaudited condensed consolidated interim financial statements should be read in conjunction with the audited consolidated financial statements of Kinsale Capital Group, Inc. and its subsidiaries ("the Company") included in the Annual Report on Form 10-K for the year ended December 31, 2022. In the opinion of management, all adjustments necessary for a fair presentation of the condensed consolidated financial statements have been included. Such adjustments consist only of normal recurring items. All significant intercompany balances and transactions have been eliminated in consolidation. Interim results are not necessarily indicative of results of operations for the full year.
Use of Estimates	Use of estimatesThe preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities, if any, at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
New Accounting Pronouncements, Policy	Prospective accounting pronouncements There are no prospective accounting standards which, upon their effective date, would have a material impact on the Company's condensed consolidated financial statements.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2023
Investments [Abstract]
Available-for-sale Investments	The following tables summarize the available-for-sale investments at September 30, 2023 and December 31, 2022: September 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Allowance for Credit Losses Estimated Fair Value (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 42,705 $ — $ (1,200) $ — $ 41,505 Obligations of states, municipalities and political subdivisions 190,263 22 (30,339) — 159,946 Corporate and other securities 1,299,277 34 (87,518) (564) 1,211,229 Asset-backed securities 599,813 703 (6,822) — 593,694 Residential mortgage-backed securities 361,833 44 (66,329) — 295,548 Commercial mortgage-backed securities 70,023 — (7,185) (1) 62,837 Total fixed-maturity investments $ 2,563,914 $ 803 $ (199,393) $ (565) $ 2,364,759 December 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Allowance for Credit Losses Estimated Fair Value (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 17,934 $ — $ (1,193) $ — $ 16,741 Obligations of states, municipalities and political subdivisions 230,746 330 (26,444) — 204,632 Corporate and other securities 909,285 730 (76,757) (366) 832,892 Asset-backed securities 361,248 292 (8,534) — 353,006 Residential mortgage-backed securities 349,066 52 (55,156) — 293,962 Commercial mortgage-backed securities 65,353 — (6,486) — 58,867 Total fixed-maturity investments $ 1,933,632 $ 1,404 $ (174,570) $ (366) $ 1,760,100
Debt Securities, Available-for-Sale, Allowance for Credit Loss	The following table presents changes in the allowance for expected credit losses on available-for-sale securities for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Beginning balance $ 422 $ — $ 366 $ — Increase to allowance from securities for which credit losses were not previously recorded 1 — 1 — Reduction from securities sold during the period — — (12) — Net increase from securities that had an allowance at the beginning of the period 142 — 210 — Ending balance $ 565 $ — $ 565 $ —
Available-for-sale Securities in an Unrealized Loss Position	The following tables summarize gross unrealized losses and estimated fair value for available-for-sale investments by length of time that the securities have continuously been in an unrealized loss position: September 30, 2023 Less than 12 Months 12 Months or Longer Total Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses (in thousands) Fixed maturities: U.S. Treasury securities and obligations of the U.S. government agencies $ 26,341 $ (84) $ 15,164 $ (1,116) $ 41,505 $ (1,200) Obligations of states, municipalities and political subdivisions 42,151 (1,046) 116,398 (29,293) 158,549 (30,339) Corporate and other securities 564,003 (9,918) 643,417 (77,600) 1,207,420 (87,518) Asset-backed securities 273,264 (3,895) 245,476 (2,927) 518,740 (6,822) Residential mortgage-backed securities 36,467 (326) 257,041 (66,003) 293,508 (66,329) Commercial mortgage-backed securities 5,953 (129) 56,884 (7,056) 62,837 (7,185) Total fixed-maturity investments $ 948,179 $ (15,398) $ 1,334,380 $ (183,995) $ 2,282,559 $ (199,393) December 31, 2022 Less than 12 Months 12 Months or Longer Total Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses Estimated Fair Value Gross Unrealized Losses (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 10,538 $ (447) $ 6,204 $ (746) $ 16,742 $ (1,193) Obligations of states, municipalities and political subdivisions 141,460 (20,347) 17,314 (6,097) 158,774 (26,444) Corporate and other securities 583,619 (42,675) 156,148 (34,082) 739,767 (76,757) Asset-backed securities 216,487 (5,429) 97,703 (3,105) 314,190 (8,534) Residential mortgage-backed securities 98,909 (12,324) 194,773 (42,832) 293,682 (55,156) Commercial mortgage-backed securities 50,666 (4,732) 8,201 (1,754) 58,867 (6,486) Total fixed-maturity investments $ 1,101,679 $ (85,954) $ 480,343 $ (88,616) $ 1,582,022 $ (174,570)
Contractual Maturities of Available-for-sale Fixed Maturity Securities	The amortized cost and estimated fair value of available-for-sale fixed-maturity securities at September 30, 2023 are summarized, by contractual maturity, as follows: September 30, 2023 Amortized Estimated Cost Fair Value (in thousands) Due in one year or less $ 184,335 $ 181,981 Due after one year through five years 923,152 889,587 Due after five years through ten years 194,507 167,015 Due after ten years 230,251 174,097 Asset-backed securities 599,813 593,694 Residential mortgage-backed securities 361,833 295,548 Commercial mortgage-backed securities 70,023 62,837 Total fixed-maturity securities $ 2,563,914 $ 2,364,759
Schedule of Real Estate Properties	Real estate investments consisted of the following: September 30, 2023 December 31, 2022 (in thousands) Building $ — $ 44,931 Land 14,372 17,946 Intangible in-place lease — 9,749 Site improvements — 2,686 Parking deck — 1,311 14,372 76,623 Accumulated depreciation — (236) Total real estate investments, net $ 14,372 $ 76,387
Net Investment Income	The following table presents the components of net investment income for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Interest: Taxable bonds $ 24,644 $ 12,041 $ 63,672 $ 29,015 Tax exempt municipal bonds 522 849 1,704 2,558 Cash equivalents and short-term investments 758 475 2,337 598 Dividends on equity securities 1,271 1,085 3,692 3,208 Real estate investment income 851 — 3,565 — Gross investment income 28,046 14,450 74,970 35,379 Investment expenses (960) (592) (3,017) (1,839) Net investment income $ 27,086 $ 13,858 $ 71,953 $ 33,540 Investment expenses included depreciation expense related to real estate investments of $0.5 million for the nine months ended September 30, 2023. There was no depreciation of real estate investments for the three months ended September 30, 2023 as the related depreciable real estate investments were reclassified to held for sale prior to being
Realized Gain (Loss) on Investments	The following table presents realized investment gains and losses for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Fixed-maturity securities: Realized gains $ 74 $ — $ 1,811 $ 1,076 Realized losses (51) (177) (2,268) (720) Net realized (losses) gains from fixed-maturity securities 23 (177) (457) 356 Equity securities: Realized gains — — 1,626 1,363 Realized losses — — (4,487) (148) Net realized (losses) gains from equity securities — — (2,861) 1,215 Realized (losses) gains from the sales of short-term investments 1 4 (19) (36) Realized gain on sale of real estate investments 4,250 — 4,250 — Net realized investment gains (losses) $ 4,274 $ (173) $ 913 $ 1,535 The net realized gains or losses on sales of equity securities represent the total gains or losses from the purchase dates of the equity securities. The change in unrealized gains (losses) in the consolidated statement of income consists of two components: (1) the reversal of the gain or loss recognized in previous periods on equity securities sold and (2) the change in unrealized gain or loss resulting from mark-to-market adjustments on equity securities still held.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Assets Measured at Fair Value on a Recurring Basis	The following tables present the balances of assets measured at fair value on a recurring basis as of September 30, 2023 and December 31, 2022, by level within the fair value hierarchy: September 30, 2023 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 36,537 $ 4,968 $ — $ 41,505 Obligations of states, municipalities and political subdivisions — 159,946 — 159,946 Corporate and other securities — 1,211,229 — 1,211,229 Asset-backed securities — 593,694 — 593,694 Residential mortgage-backed securities — 295,548 — 295,548 Commercial mortgage-backed securities — 62,837 — 62,837 Total fixed-maturity securities 36,537 2,328,222 — 2,364,759 Equity securities: Exchange traded funds 106,565 — — 106,565 Non-redeemable preferred stock — 31,755 — 31,755 Common stocks 69,631 — — 69,631 Total equity securities 176,196 31,755 — 207,951 Short-term investments 4,725 24,340 — 29,065 Total $ 217,458 $ 2,384,317 $ — $ 2,601,775 December 31, 2022 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 16,741 $ — $ — $ 16,741 Obligations of states, municipalities and political subdivisions — 204,632 — 204,632 Corporate and other securities — 832,892 — 832,892 Asset-backed securities — 353,006 — 353,006 Residential mortgage-backed securities — 293,962 — 293,962 Commercial mortgage-backed securities — 58,867 — 58,867 Total fixed-maturity securities 16,741 1,743,359 — 1,760,100 Equity securities: Exchange traded funds 104,202 — — 104,202 Non-redeemable preferred stock — 38,162 — 38,162 Common stocks 10,107 — — 10,107 Total equity securities 114,309 38,162 — 152,471 Short-term investments 31,366 9,971 — 41,337 Total $ 162,416 $ 1,791,492 $ — $ 1,953,908

Credit Losses (Tables)

Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2023
Credit Loss [Abstract]
Premium Receivable, Allowance for Credit Loss	The following table presents the change in the allowance for credit losses for premiums receivable for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Beginning balance $ 12,167 $ 5,612 $ 8,067 $ 3,391 Current period change for estimated uncollectible premiums 2,341 1,874 7,459 4,818 Write-offs of uncollectible premiums receivable (129) (195) (1,147) (918) Ending balance $ 14,379 $ 7,291 $ 14,379 $ 7,291

Deferred Policy Acquisition C_2

Deferred Policy Acquisition Costs (Tables)	9 Months Ended
	Sep. 30, 2023
Deferred Policy Acquisition Costs Disclosures [Abstract]
Deferred Policy Acquisition Costs	The following table presents the amounts of policy acquisition costs deferred and amortized for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Balance, beginning of period $ 85,326 $ 54,806 $ 61,594 $ 41,968 Policy acquisition costs deferred: Direct commissions 54,580 41,525 169,223 117,621 Ceding commissions (24,230) (13,886) (62,779) (32,678) Other underwriting and policy acquisition costs 1,623 2,302 7,511 6,534 Policy acquisition costs deferred 31,973 29,941 113,955 91,477 Amortization of net policy acquisition costs (31,118) (26,302) (89,368) (75,000) Balance, end of period $ 86,181 $ 58,445 $ 86,181 $ 58,445

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2023
Property and Equipment [Abstract]
Property and Equipment	Property and equipment are included in "other assets" in the accompanying consolidated balance sheets and consist of the following: September 30, 2023 December 31, 2022 (in thousands) Building $ 37,107 $ 33,065 Parking deck 5,072 5,072 Land 3,068 3,068 Equipment 3,859 3,444 Software 14,402 11,410 Furniture and fixtures 3,049 2,615 Land improvements 474 474 Leasehold improvements 153 — Construction in progress - building 5,700 2,618 72,884 61,766 Accumulated depreciation (10,620) (8,291) Total property and equipment, net $ 62,264 $ 53,475

Underwriting, Acquisition and_2

Underwriting, Acquisition and Insurance Expenses (Tables)	9 Months Ended
	Sep. 30, 2023
Underwriting, Acquisition and Insurance Expenses [Abstract]
Underwriting, acquisition and insurance expenses	Underwriting, acquisition and insurance expenses for the three and nine months ended September 30, 2023 and 2022 consist of the following: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Underwriting, acquisition and insurance expenses incurred: Direct commissions $ 53,035 $ 37,177 $ 143,181 $ 99,540 Ceding commissions (23,396) (12,939) (59,882) (30,069) Other underwriting expenses 30,709 21,006 85,268 62,554 Total $ 60,348 $ 45,244 $ 168,567 $ 132,025

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Restricted Stock Activity	A summary of restricted stock activity under the 2016 Incentive Plan for the nine months ended September 30, 2023 is as follows: For the Nine Months Ended September 30, 2023 Number of Shares Weighted Average Grant Date Fair Value per Share Non-vested outstanding at the beginning of the period 98,621 $ 182.37 Granted 51,176 $ 313.35 Vested (40,582) $ 163.62 Forfeited (725) $ 225.64 Non-vested outstanding at the end of the period 108,490 $ 250.88
Stock Options Activity	A summary of option activity as of September 30, 2023, and changes during the period then ended is presented below: Number of Shares Weighted-Average Exercise Price Weighted-Average Remaining Years of Contractual Term Aggregate Intrinsic Value (in thousands) Outstanding at January 1, 2023 256,357 $ 16.00 Granted — — Forfeited — — Exercised (45,392) 16.00 Outstanding at September 30, 2023 210,965 $ 16.00 2.8 $ 83,991 Exercisable at September 30, 2023 210,965 $ 16.00 2.8 $ 83,991

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Earnings Per Share	The following represents a reconciliation of the numerator and denominator of the basic and diluted earnings per share computations contained in the condensed consolidated financial statements: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands, except per share data) Net income $ 76,115 $ 32,984 $ 204,706 $ 91,865 Weighted average common shares outstanding - basic 23,058 22,813 23,036 22,783 Effect of potential dilutive securities: Conversion of stock options 208 262 220 276 Conversion of restricted stock 49 39 42 40 Weighted average common shares outstanding - diluted 23,315 23,114 23,298 23,099 Earnings per common share: Basic $ 3.30 $ 1.45 $ 8.89 $ 4.03 Diluted $ 3.26 $ 1.43 $ 8.79 $ 3.98

Reserves for Unpaid Losses an_2

Reserves for Unpaid Losses and Loss Adjustment Expenses (Tables)	9 Months Ended
	Sep. 30, 2023
Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract]
Schedule of Unpaid Losses and Loss Adjustment Expenses	The following table presents a reconciliation of consolidated beginning and ending reserves for unpaid losses and loss adjustment expenses: September 30, 2023 2022 (in thousands) Gross reserves for unpaid losses and loss adjustment expenses, beginning of year $ 1,238,402 $ 881,344 Less: reinsurance recoverable on unpaid losses 177,039 117,561 Net reserves for unpaid losses and loss adjustment expenses, beginning of year 1,061,363 763,783 Incurred losses and loss adjustment expenses: Current year 470,235 373,183 Prior years (28,607) (28,850) Total net losses and loss adjustment expenses incurred 441,628 344,333 Payments: Current year 22,156 13,028 Prior years 136,380 84,827 Total payments 158,536 97,855 Net reserves for unpaid losses and loss adjustment expenses, end of period 1,344,455 1,010,261 Reinsurance recoverable on unpaid losses 220,452 187,056 Gross reserves for unpaid losses and loss adjustment expenses, end of period $ 1,564,907 $ 1,197,317

Reinsurance (Tables)

Reinsurance (Tables)	9 Months Ended
	Sep. 30, 2023
Reinsurance Disclosures [Abstract]
Effects of Reinsurance	The following table summarizes the effect of reinsurance on premiums written and earned for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Premiums written: Direct $ 377,789 $ 284,111 $ 1,173,599 $ 806,625 Ceded (83,509) (48,212) (215,248) (111,885) Net written $ 294,280 $ 235,899 $ 958,351 $ 694,740 Premiums earned: Direct $ 362,689 $ 254,855 $ 982,922 $ 682,619 Ceded (81,187) (45,596) (207,216) (104,640) Net earned $ 281,502 $ 209,259 $ 775,706 $ 577,979
Effects of Reinsurance on Losses	The following table summarizes ceded losses and loss adjustment expenses for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Ceded incurred losses and loss adjustment expenses $ 27,381 $ 56,774 $ 89,371 $ 79,790
Reinsurance Recoverables	The following table presents reinsurance recoverables on paid and unpaid losses as of September 30, 2023 and December 31, 2022: September 30, 2023 December 31, 2022 (in thousands) Reinsurance recoverables on paid losses $ 20,400 $ 43,415 Reinsurance recoverables on unpaid losses, net 220,452 177,039 Reinsurance recoverables, net $ 240,852 $ 220,454

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Schedule of Debt	The following table presents the Company's outstanding debt as of September 30, 2023 and December 31, 2022: Issuance Maturities September 30, 2023 December 31, 2022 (in thousands) Credit Facility Various 7/22/2027 $ 11,000 $ 73,000 5.15% Series A Notes 7/22/2022 7/22/2034 125,000 125,000 6.21% Series B Note 9/18/2023 7/22/2034 50,000 — Less: Unamortized debt issuance costs (2,223) (2,253) Total debt $ 183,777 $ 195,747

Other Comprehensive (Loss) In_2

Other Comprehensive (Loss) Income (Tables)	9 Months Ended
	Sep. 30, 2023
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss)	The following table summarizes the components of other comprehensive loss for the three and nine months ended September 30, 2023 and 2022: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) Unrealized losses on fixed-maturity securities arising during the period, before income taxes $ (29,931) $ (59,230) $ (26,997) $ (209,198) Income tax benefit 6,286 12,439 5,670 43,932 Unrealized losses arising during the period, net of income taxes (23,645) (46,791) (21,327) (165,266) Less reclassification adjustment: Net realized (losses) gains on fixed-maturity securities, before income taxes (27) (177) (1,343) 250 Income tax benefit (expense) 6 38 282 (52) Reclassification adjustment included in net income (21) (139) (1,061) 198 Change in allowance for credit losses on investments, before income taxes (143) — (199) — Income tax benefit 30 — 42 — Reclassification adjustment included in net income (113) — (157) — Other comprehensive loss $ (23,511) $ (46,652) $ (20,109) $ (165,464)

Investments Investments (Availa

Investments Investments (Available for Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	$ 2,563,914		$ 1,933,632
Gross Unrealized Holding Gains	803		1,404
Gross Unrealized Holding Losses	199,393		174,570
Allowance for Credit Losses	(565)	$ (422)	(366)	$ 0	$ 0	$ 0
Estimated Fair Value	2,364,759		1,760,100
U.S. Treasury securities and obligations of U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	42,705		17,934
Gross Unrealized Holding Gains	0		0
Gross Unrealized Holding Losses	1,200		1,193
Allowance for Credit Losses	0		0
Estimated Fair Value	41,505		16,741
Obligations of states, municipalities and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	190,263		230,746
Gross Unrealized Holding Gains	22		330
Gross Unrealized Holding Losses	30,339		26,444
Allowance for Credit Losses	0		0
Estimated Fair Value	159,946		204,632
Corporate and other securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	1,299,277		909,285
Gross Unrealized Holding Gains	34		730
Gross Unrealized Holding Losses	87,518		76,757
Allowance for Credit Losses	(564)		(366)
Estimated Fair Value	1,211,229		832,892
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	599,813		361,248
Gross Unrealized Holding Gains	703		292
Gross Unrealized Holding Losses	6,822		8,534
Allowance for Credit Losses	0		0
Estimated Fair Value	593,694		353,006
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	361,833		349,066
Gross Unrealized Holding Gains	44		52
Gross Unrealized Holding Losses	66,329		55,156
Allowance for Credit Losses	0		0
Estimated Fair Value	295,548		293,962
Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	70,023		65,353
Gross Unrealized Holding Gains	0		0
Gross Unrealized Holding Losses	7,185		6,486
Allowance for Credit Losses	(1)		0
Estimated Fair Value	$ 62,837		$ 58,867

Investments Available-for-Sale

Investments Available-for-Sale Securities in a Loss Position (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) security	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	$ 948,179		$ 948,179		$ 1,101,679
Less than 12 months, gross unrealized holding losses	15,398		15,398		85,954
12 Months or Longer, Estimated Fair Value	1,334,380		1,334,380		480,343
12 Months or Longer, Gross Unrealized Holding Losses	183,995		183,995		88,616
Total Estimated Fair Value	2,282,559		2,282,559		1,582,022
Total Gross Unrealized Holding Losses	199,393		199,393		174,570
Beginning balance	422	$ 0	366	$ 0
Increase to allowance from securities for which credit losses were not previously recorded	1	0	1	0
Reduction from securities sold during the period	0	0	(12)	0
Net increase (decrease) from securities that had an allowance at the beginning of the period	142	0	210	0
Ending balance	565	$ 0	$ 565	$ 0
Debt Securities Available For Sale Allowance For Credit Loss Number Of Securities | security			6
U.S. Treasury securities and obligations of U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	26,341		$ 26,341		10,538
Less than 12 months, gross unrealized holding losses	84		84		447
12 Months or Longer, Estimated Fair Value	15,164		15,164		6,204
12 Months or Longer, Gross Unrealized Holding Losses	1,116		1,116		746
Total Estimated Fair Value	41,505		41,505		16,742
Total Gross Unrealized Holding Losses	1,200		1,200		1,193
Beginning balance			0
Ending balance	0		0
Obligations of states, municipalities and political subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	42,151		42,151		141,460
Less than 12 months, gross unrealized holding losses	1,046		1,046		20,347
12 Months or Longer, Estimated Fair Value	116,398		116,398		17,314
12 Months or Longer, Gross Unrealized Holding Losses	29,293		29,293		6,097
Total Estimated Fair Value	158,549		158,549		158,774
Total Gross Unrealized Holding Losses	30,339		30,339		26,444
Beginning balance			0
Ending balance	0		0
Corporate and other securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	564,003		564,003		583,619
Less than 12 months, gross unrealized holding losses	9,918		9,918		42,675
12 Months or Longer, Estimated Fair Value	643,417		643,417		156,148
12 Months or Longer, Gross Unrealized Holding Losses	77,600		77,600		34,082
Total Estimated Fair Value	1,207,420		1,207,420		739,767
Total Gross Unrealized Holding Losses	87,518		87,518		76,757
Beginning balance			366
Ending balance	564		564
Asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	273,264		273,264		216,487
Less than 12 months, gross unrealized holding losses	3,895		3,895		5,429
12 Months or Longer, Estimated Fair Value	245,476		245,476		97,703
12 Months or Longer, Gross Unrealized Holding Losses	2,927		2,927		3,105
Total Estimated Fair Value	518,740		518,740		314,190
Total Gross Unrealized Holding Losses	6,822		6,822		8,534
Beginning balance			0
Ending balance	0		0
Residential mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	36,467		36,467		98,909
Less than 12 months, gross unrealized holding losses	326		326		12,324
12 Months or Longer, Estimated Fair Value	257,041		257,041		194,773
12 Months or Longer, Gross Unrealized Holding Losses	66,003		66,003		42,832
Total Estimated Fair Value	293,508		293,508		293,682
Total Gross Unrealized Holding Losses	66,329		66,329		55,156
Beginning balance			0
Ending balance	0		0
Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	5,953		5,953		50,666
Less than 12 months, gross unrealized holding losses	129		129		4,732
12 Months or Longer, Estimated Fair Value	56,884		56,884		8,201
12 Months or Longer, Gross Unrealized Holding Losses	7,056		7,056		1,754
Total Estimated Fair Value	62,837		62,837		58,867
Total Gross Unrealized Holding Losses	7,185		7,185		$ 6,486
Beginning balance			0
Ending balance	$ 1		$ 1

Investments Available-for-Sal_2

Investments Available-for-Sale Securities in a Loss Position Narrative (Details) $ in Thousands	Sep. 30, 2023 USD ($) Rate	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-sale [Line Items]
Number of available-for-sale securities in unrealized loss positions	1,233
Total Estimated Fair Value	$ 2,282,559	$ 1,582,022
Gross Unrealized Losses	$ 199,393	$ 174,570
Number of available-for-sale securities in unrealized loss positions, greater than one year	782
Fixed maturities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale securities, percentage of securities with ratings of A minus or better | Rate	82%

Investments Contractual Maturit

Investments Contractual Maturities of Available-for-Sale Fixed Maturity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Amortized Cost
Due in one year or less, Amortized Cost	$ 184,335
Due after one year through five years, Amortized Cost	923,152
Due after five years through ten years, Amortized Cost	194,507
Due after ten years, Amortized Cost	230,251
Total fixed maturities, Amortized Cost	2,563,914	$ 1,933,632
Estimated Fair Value
Due in one year or less, Estimated Fair Value	181,981
Due after one year through five years, Estimated Fair Value	889,587
Due after five years through ten years, Estimated Fair Value	167,015
Due after ten years, Estimated Fair Value	174,097
Estimated Fair Value	2,364,759	1,760,100
Asset-backed securities [Member]
Amortized Cost
Without single maturity date, Amortized Cost	599,813
Total fixed maturities, Amortized Cost	599,813	361,248
Estimated Fair Value
Without single maturity date, Estimated Fair Value	593,694
Estimated Fair Value	593,694	353,006
Residential mortgage-backed securities [Member]
Amortized Cost
Without single maturity date, Amortized Cost	361,833
Total fixed maturities, Amortized Cost	361,833	349,066
Estimated Fair Value
Without single maturity date, Estimated Fair Value	295,548
Estimated Fair Value	295,548	293,962
Commercial mortgage-backed securities
Amortized Cost
Without single maturity date, Amortized Cost	70,023
Total fixed maturities, Amortized Cost	70,023	65,353
Estimated Fair Value
Without single maturity date, Estimated Fair Value	62,837
Estimated Fair Value	$ 62,837	$ 58,867

Investments Net Investment Inco

Investments Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Components of Net Investment Income [Abstract]
Taxable bonds	$ 24,644	$ 12,041	$ 63,672	$ 29,015
Tax exempt municipal bonds	522	849	1,704	2,558
Cash equivalents and short-term investments	758	475	2,337	598
Dividends on equity securities	1,271	1,085	3,692	3,208
Real estate investment income	851	0	3,565	0
Gross investment income	28,046	14,450	74,970	35,379
Investment expenses	(960)	(592)	(3,017)	(1,839)
Net investment income	$ 27,086	$ 13,858	$ 71,953	$ 33,540

Investments Realized Gains (Los

Investments Realized Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Debt and Equity Securities, Realized Gain (Loss) [Abstract]
Realized gains, fixed-maturity securities	$ 74	$ 0	$ 1,811	$ 1,076
Realized losses, fixed-maturity securities	(51)	(177)	(2,268)	(720)
Net realized (losses) gains from fixed-maturity securities	23	(177)	(457)	356
Realized gains, equity securities	0	0	1,626	1,363
Realized losses, equity securities	0	0	(4,487)	(148)
Net realized (losses) gains from equity securities	0	0	(2,861)	1,215
Realized (losses) gains from the sales of short-term investments	1	4	(19)	(36)
Gains (Losses) on Sales of Investment Real Estate	4,250	0	4,250	0
Net realized investment gains (losses)	$ 4,274	$ (173)	$ 913	$ 1,535

Investments Unrealized Gains (L

Investments Unrealized Gains (Losses) on Investments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Change in net unrealized gains (losses) on fixed-maturity securities	$ (29.8)	$ (59.1)	$ (25.4)	$ (209.4)

Investments Investment Narrativ

Investments Investment Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Assets on deposit with state regulatory authorities	$ 5.7	$ 5.9
Payable for investments purchased	$ 1	$ 1.8

Investments (Details), Real Est

Investments (Details), Real Estate - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Real Estate Properties [Line Items]
Investment Building and Building Improvements	$ 0		$ 0		$ 44,931
Land	14,372		14,372		17,946
Finite-Lived Intangible Asset, Acquired-in-Place Leases	0		0		9,749
Land Improvements	0		0		2,686
Investment in Real Estate - Parking Deck	0		0		1,311
Real Estate Investment Property, at Cost	14,372		14,372		76,623
Real Estate Investment Property, Accumulated Depreciation	0		0		(236)
Real Estate Investments, Net	14,372		14,372		$ 76,387
Proceeds from Sale, Real Estate, Held-for-Investment			62,000
Gains (Losses) on Sales of Investment Real Estate	4,250	$ 0	4,250	$ 0
Real Estate Investment
Real Estate Properties [Line Items]
Depreciation, Depletion and Amortization	$ 0	$ 0	$ 500	$ 0

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	$ 2,364,759	$ 1,760,100
U.S. Treasury securities and obligations of U.S. government agencies
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	41,505	16,741
Obligations of states, municipalities and political subdivisions [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	159,946	204,632
Corporate and other securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	1,211,229	832,892
Asset-backed securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	593,694	353,006
Residential mortgage-backed securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	295,548	293,962
Commercial mortgage-backed securities
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	62,837	58,867
Recurring
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	2,601,775	1,953,908
Recurring | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	217,458	162,416
Recurring | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	2,384,317	1,791,492
Recurring | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	0	0
Recurring | Fixed maturities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	2,364,759	1,760,100
Recurring | Fixed maturities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	36,537	16,741
Recurring | Fixed maturities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	2,328,222	1,743,359
Recurring | Fixed maturities [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | U.S. Treasury securities and obligations of U.S. government agencies
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	41,505	16,741
Recurring | U.S. Treasury securities and obligations of U.S. government agencies | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	36,537	16,741
Recurring | U.S. Treasury securities and obligations of U.S. government agencies | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	4,968	0
Recurring | U.S. Treasury securities and obligations of U.S. government agencies | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Obligations of states, municipalities and political subdivisions [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	159,946	204,632
Recurring | Obligations of states, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Obligations of states, municipalities and political subdivisions [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	159,946	204,632
Recurring | Obligations of states, municipalities and political subdivisions [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Corporate and other securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	1,211,229	832,892
Recurring | Corporate and other securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Corporate and other securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	1,211,229	832,892
Recurring | Corporate and other securities [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Asset-backed securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	593,694	353,006
Recurring | Asset-backed securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Asset-backed securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	593,694	353,006
Recurring | Asset-backed securities [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Residential mortgage-backed securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	295,548	293,962
Recurring | Residential mortgage-backed securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Residential mortgage-backed securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	295,548	293,962
Recurring | Residential mortgage-backed securities [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Commercial mortgage-backed securities
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	62,837	58,867
Recurring | Commercial mortgage-backed securities | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Commercial mortgage-backed securities | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	62,837	58,867
Recurring | Commercial mortgage-backed securities | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	0	0
Recurring | Equity securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	207,951	152,471
Recurring | Equity securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	176,196	114,309
Recurring | Equity securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	31,755	38,162
Recurring | Equity securities [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	0	0
Recurring | Exchange traded funds [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	106,565	104,202
Recurring | Exchange traded funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	106,565	104,202
Recurring | Exchange traded funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	0	0
Recurring | Exchange traded funds [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	0	0
Recurring | Nonredeemable preferred stock [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	31,755	38,162
Recurring | Nonredeemable preferred stock [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	0	0
Recurring | Nonredeemable preferred stock [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	31,755	38,162
Recurring | Nonredeemable preferred stock [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	0	0
Recurring | Common Stock [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	69,631	10,107
Recurring | Common Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	69,631	10,107
Recurring | Common Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	0	0
Recurring | Common Stock [Member] | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	0	0
Recurring | Short-term Investments
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	29,065	41,337
Recurring | Short-term Investments | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	4,725	31,366
Recurring | Short-term Investments | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	24,340	9,971
Recurring | Short-term Investments | Level 3
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	$ 0	$ 0

Fair Value Measures and Disclos

Fair Value Measures and Disclosures Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	$ 5,400	$ 58,000
Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Liabilities measured at fair value	0	0
Reported Value Measurement | Senior Notes
Fair Value of Investments Measured on Recurring Basis [Line Items]
Long-Term Debt, Fair Value	175,000	125,000
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2 [Member] | Senior Notes
Fair Value of Investments Measured on Recurring Basis [Line Items]
Long-Term Debt, Fair Value	$ 159,500	$ 117,200

Credit Losses (Details)

Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Credit Loss [Abstract]
Beginning Balance	$ 12,167	$ 5,612	$ 8,067	$ 3,391
Current period change for estimated uncollectible premiums	2,341	1,874	7,459	4,818
Write-offs of uncollectible premiums receivable	(129)	(195)	(1,147)	(918)
Ending Balance	$ 14,379	$ 7,291	$ 14,379	$ 7,291

Deferred Policy Acquisition C_3

Deferred Policy Acquisition Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of period	$ 85,326	$ 54,806	$ 61,594	$ 41,968
Policy acquisition costs deferred:
Direct commissions deferred	54,580	41,525	169,223	117,621
Ceding commissions deferred	(24,230)	(13,886)	(62,779)	(32,678)
Other underwriting and policy acquisition costs	1,623	2,302	7,511	6,534
Policy acquisition costs deferred	31,973	29,941	113,955	91,477
Amortization of net policy acquisition costs	(31,118)	(26,302)	(89,368)	(75,000)
Balance, end of period	$ 86,181	$ 58,445	$ 86,181	$ 58,445

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 72,884	$ 61,766
Accumulated Depreciation	(10,620)	(8,291)
Property, Plant and Equipment, Net	62,264	53,475
Building
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	37,107	33,065
Parking
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	5,072	5,072
Land
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,068	3,068
Equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,859	3,444
Software Development
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	14,402	11,410
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,049	2,615
Land Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	474	474
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	153	0
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 5,700	$ 2,618

Underwriting, Acquisition and_3

Underwriting, Acquisition and Insurance Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Underwriting, Acquisition and Insurance Expenses [Abstract]
Gross commissions	$ 53,035	$ 37,177	$ 143,181	$ 99,540
Ceding commissions	(23,396)	(12,939)	(59,882)	(30,069)
Other operating expenses	30,709	21,006	85,268	62,554
Underwriting, acquisition, and insurance expenses	60,348	45,244	168,567	132,025
Salaries, bonuses and employee benefits	$ 23,100	$ 15,400	$ 63,000	$ 46,100

Stock-based Compensation Narrat

Stock-based Compensation Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 6.9	$ 5
Maximum [Member] | 2016 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance	2,073,832

Stock-based Compensation Narr_2

Stock-based Compensation Narrative - Restricted Stock Awards (Details) - Restricted stock [Member] - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value	$ 313.35	$ 211.86
Fair value of restricted stock awards vested	$ 12.6	$ 9.9
Unrecognized stock-based compensation expense	$ 21.7
Compensation cost not yet recognized, period	2 years 9 months 18 days
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

Stock-based Compensation Restri

Stock-based Compensation Restrictive Stock Awards (Details) - $ / shares	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Nonvested Restricted Stock, Weighted Average Grant Date Fair Value [Abstract]
Restricted shares withheld for taxes (shares)	6,816	12,420
Restricted stock [Member]
Nonvested Restricted Stock, Number of Shares [Roll Forward]
Nonvested outstanding at the beginning of the period, shares			98,621
Granted, shares			51,176
Vested, shares			(40,582)
Forfeited, shares			(725)
Nonvested outstanding at the end of the period, shares			108,490
Nonvested Restricted Stock, Weighted Average Grant Date Fair Value [Abstract]
Nonvested outstanding at the beginning of the period			$ 182.37
Granted			313.35	$ 211.86
Vested			163.62
Forfeited			225.64
Nonvested outstanding at the end of the period			$ 250.88
Restricted shares withheld for taxes (shares)			13,444

Stock-based Compensation Narr_3

Stock-based Compensation Narrative - Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions		9 Months Ended
	Jul. 27, 2016	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised		$ 14.6	$ 12.2
Weighted average exercise price, granted		$ 0
Stock option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price, granted	$ 16
Weighted average grant date fair value	$ 2.71
Contractual term	10 years
Vesting period	4 years

Stock-based Compensation Stock

Stock-based Compensation Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands		9 Months Ended
	Jul. 27, 2016	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding beginning of period, shares		256,357
Granted, shares		0
Forfeited, shares		0
Exercised, shares		(45,392)
Outstanding end of period, shares		210,965
Exercisable, shares		210,965
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding beginning of period		$ 16
Granted		0
Forfeited		0
Exercised		16
Outstanding end of period		16
Exercisable end of period		$ 16
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted average remaining contractual term		2 years 9 months 18 days
Exercisable, weighted average remaining contractual term		2 years 9 months 18 days
Outstanding, aggregate intrinsic value		$ 83,991
Exercisable, aggregate intrinsic value		$ 83,991
Stock option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Granted, shares	1,036,916
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Granted	$ 16

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share, [Line Items]
Net income	$ 76,115	$ 72,791	$ 55,800	$ 32,984	$ 27,090	$ 31,791	$ 204,706	$ 91,865
Weighted Average Number of Shares Outstanding, Basic [Abstract]
Weighted average shares outstanding - basic	23,058			22,813			23,036	22,783
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Weighted average shares outstanding - diluted	23,315			23,114			23,298	23,099
Earnings Per Share, Basic [Abstract]
Earnings per share - basic	$ 3.30			$ 1.45			$ 8.89	$ 4.03
Earnings Per Share, Diluted [Abstract]
Earnings per share - diluted	$ 3.26			$ 1.43			$ 8.79	$ 3.98
Stock option [Member]
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Dilutive effect of shares issued under stock compensation arrangements	208			262			220	276
Restricted stock [Member]
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Dilutive effect of shares issued under stock compensation arrangements	49			39			42	40

Earnings Per Share Narrative (D

Earnings Per Share Narrative (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Restricted stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities	0	0	47,000	48,000

Income Taxes (Details)

Income Taxes (Details)	9 Months Ended
	Sep. 30, 2023 Rate	Sep. 30, 2022 Rate
Income Tax Disclosure [Abstract]
Effective tax rate	19.40%	17.50%
Federal statutory income tax rate	21%	21%

Reserves for Unpaid Losses an_3

Reserves for Unpaid Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves for unpaid losses and loss adjustment expenses, beginning of year	$ 1,238,402	$ 881,344
Reinsurance recoverable on unpaid losses	220,452	187,056	$ 177,039	$ 117,561
Net reserves for unpaid losses and loss adjustment expenses, beginning of year	1,061,363	763,783
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Current year	470,235	373,183
Prior years	(28,607)	(28,850)
Total net losses and loss adjustment expenses incurred	441,628	344,333
Payments:
Current year	22,156	13,028
Prior years	136,380	84,827
Total payments	158,536	97,855
Net reserves for unpaid losses and loss adjustment expenses, end of period	1,344,455	1,010,261
Reinsurance recoverable on unpaid losses	220,452	187,056	$ 177,039	$ 117,561
Gross reserves for unpaid losses and loss adjustment expenses, end of period	$ 1,564,907	$ 1,197,317

Reserves for Unpaid Losses an_4

Reserves for Unpaid Losses and Loss Adjustment Expenses Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Claims Development [Line Items]
Adverse (Favorable) development on prior year loss reserves	$ (28,607)	$ (28,850)
Current year	470,235	373,183
Catastrophe losses [Member]
Claims Development [Line Items]
Current year		26,200
Accident Years 2021 and 2020
Claims Development [Line Items]
Adverse (Favorable) development on prior year loss reserves		$ (32,000)
Accident Years 2021 and 2022
Claims Development [Line Items]
Adverse (Favorable) development on prior year loss reserves	$ (39,000)

Reinsurance (Details)

Reinsurance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Premiums Written, Net [Abstract]
Premiums written - direct	$ 377,789	$ 284,111	$ 1,173,599	$ 806,625
Premiums written - ceded	(83,509)	(48,212)	(215,248)	(111,885)
Net written premiums	294,280	235,899	958,351	694,740
Premiums Earned, Net [Abstract]
Premiums earned - direct	362,689	254,855	982,922	682,619
Premiums earned - ceded	(81,187)	(45,596)	(207,216)	(104,640)
Net earned premiums	281,502	209,259	775,706	577,979
Ceded incurred losses and loss adjustment expenses	27,381	56,774	89,371	79,790
Reinsurance recoverables on paid losses	20,400		20,400		$ 43,415
Reinsurance recoverable on unpaid losses	220,452	$ 187,056	220,452	$ 187,056	177,039	$ 117,561
Reinsurance recoverables, net	$ 240,852		$ 240,852		$ 220,454

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Debt Instrument [Line Items]
Debt Issuance Costs, Net	$ (2,223)		$ (2,253)
Lines of Credit, Maximum Borrowing Capacity under former agreement	50,000
Debt	183,777		195,747
Repayments of Long-Term Lines of Credit	62,000	$ 43,000
Amended debt instrument borrowing capacity	200,000
Senior Notes
Debt Instrument [Line Items]
Debt instrument borrowing capacity	$ 150,000
Line of Credit
Debt Instrument [Line Items]
Maturity Date	Jul. 22, 2027
Current Borrowing Capacity	$ 100,000
Credit Facility Accordion Feature	$ 30,000
Line of Credit Facility, Commitment Fee Percentage	0.25%
Interest Rate Description	The loans under the Amended and Restated Credit Agreement bear interest, at the Company's option, at a rate equal to the Adjusted Term SOFR Rate (as defined therein) plus 1.625% or the Alternate Base Rate (as defined therein) plus 0.625%.
Credit facility	$ 11,000		73,000
Weighted Average Interest Rate	6.75%
2034 Series A Notes | Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Issuance Date	Jul. 22, 2022
Debt Instrument, Face Amount	$ 125,000		125,000
Debt Instrument, Interest Rate, Stated Percentage	5.15%
Debt Instrument, Maturity Date	Jul. 22, 2034
Debt Instrument, Date of First Required Payment	Jul. 22, 2030
Debt Instrument, Periodic Payment, Principal	$ 25,000
2034 Series B Notes | Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Issuance Date	Sep. 18, 2023
Debt Instrument, Face Amount	$ 50,000		$ 0
Debt Instrument, Interest Rate, Stated Percentage	6.21%
Debt Instrument, Maturity Date	Jul. 22, 2034
Debt Instrument, Date of First Required Payment	Jul. 22, 2030
Debt Instrument, Periodic Payment, Principal	$ 10,000

Other Comprehensive (Loss) In_3

Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized losses on fixed-maturity securities arising during the period, before income taxes	$ (29,931)			$ (59,230)			$ (26,997)	$ (209,198)
Income tax benefit	6,286			12,439			5,670	43,932
Unrealized losses arising during the period, net of income taxes	(23,645)			(46,791)			(21,327)	(165,266)
Less reclassification adjustment [Abstract]
Net realized (losses) gains on fixed-maturity securities, before income taxes	(27)			(177)			(1,343)	250
Income tax benefit (expense)	6			38			282	(52)
Reclassification adjustment included in net income	(21)			(139)			(1,061)	198
Change in allowance for credit losses on investments, before income taxes	(143)			0			(199)	0
Income tax benefit	30			0			42	0
Reclassification adjustment included in net income	(113)			0			(157)	0
Other comprehensive loss	$ (23,511)	$ (14,107)	$ 17,509	$ (46,652)	$ (54,882)	$ (63,930)	$ (20,109)	$ (165,464)

Accounting Changes and Error _2

Accounting Changes and Error Corrections (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accounting Changes and Error Corrections [Abstract]
Fee income	$ 6.8	$ 5.1	$ 20	$ 14.4

Uncategorized Items - knsl-2023

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 121,040,000
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 156,274,000