Kinsale Capital (KNSL) 10-Q 25 Jul 24 2024 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	6 Months Ended
	Jun. 30, 2024	Jul. 19, 2024
Document and Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2024
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		23,286,423
Entity Central Index Key	0001669162
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Amendment Flag	false

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets
Fixed-maturity securities, available for sale, at fair value (amortized cost: $3,214,692, allowance for credit losses: $67 – 2024; $2,834,463 and $553 –2023)	$ 3,072,718	$ 2,711,759
Equity securities, at fair value (cost: $255,000 – 2024; $193,543 – 2023)	317,482	234,813
Real Estate Investments, Net	15,045	14,791
Short-term investments	6,908	5,589
Total investments	3,412,153	2,966,952
Cash and Cash Equivalents, at Carrying Value	171,021	126,694
Investment income due and accrued	25,112	21,689
Premiums and fees receivable, net of allowance for credit losses of $21,226 – 2024; $13,383 – 2023	171,815	143,212
Reinsurance recoverables, net	302,092	247,836
Ceded unearned premiums	58,492	52,516
Deferred policy acquisition costs, net of ceding commissions	109,358	88,395
Intangible assets	3,538	3,538
Deferred Income Tax Assets, Net	57,410	55,699
Other assets	84,300	66,443
Total assets	4,395,291	3,772,974
Liabilities
Reserves for unpaid losses and loss adjustment expenses	2,013,055	1,692,875
Unearned premiums	846,638	701,351
Payable to reinsurers	48,397	47,582
Accounts payable and accrued expenses	27,188	44,922
Debt	183,984	183,846
Other liabilities	18,826	15,566
Total liabilities	3,138,088	2,686,142
Stockholders' Equity
Common stock, $0.01 par value, 400,000,000 shares authorized, 23,286,248 and 23,181,919 shares issued and outstanding at June 30, 2024 and December 31, 2023 respectively	233	232
Additional paid-in capital	354,389	352,970
Retained earnings	1,012,796	828,247
Accumulated other comprehensive loss	(110,215)	(94,617)
Total stockholders’ equity	1,257,203	1,086,832
Total liabilities and stockholders’ equity	$ 4,395,291	$ 3,772,974

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets [Abstract]
Fixed-maturity securities, available for sale, amortized cost	$ 3,214,692	$ 2,834,463
Allowance for Credit Losses	(67)	(553)
Equity securities - cost	255,000	193,543
Premium Receivable, Allowance for Credit Loss	21,226	13,383
Reinsurance Recoverable, Allowance for Credit Loss	$ (841)	$ (744)
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)	23,286,248	23,181,919
Common stock, shares outstanding (in shares)	23,286,248	23,181,919

Consolidated Statements of Inco

Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues:
Gross written premiums	$ 529,770	$ 438,222	$ 978,414	$ 795,810
Ceded written premiums	(99,534)	(73,181)	(197,124)	(131,739)
Net written premiums	430,236	365,041	781,290	664,071
Change in unearned premiums	(97,775)	(107,995)	(139,311)	(169,867)
Net earned premiums	332,461	257,046	641,979	494,204
Fee income	8,991	6,986	17,083	13,187
Net investment income	35,847	24,172	68,780	44,867
Change in the fair value of equity securities	3,159	5,811	21,212	9,329
Net realized investment gains (losses)	2,879	1,291	6,745	(3,361)
Change in allowance for credit losses on investments	476	25	486	(56)
Other income	740	435	1,059	741
Total revenues	384,553	295,766	757,344	558,911
Expenses:
Losses and loss adjustment expenses	193,325	147,042	380,111	286,076
Underwriting, acquisition and insurance expenses	72,068	55,473	137,821	108,219
Interest Expense	2,564	2,724	4,986	5,294
Other expenses	796	417	2,759	819
Total expenses	268,753	205,656	525,677	400,408
Income before income taxes	115,800	90,110	231,667	158,503
Total income tax expense	23,221	17,319	40,147	29,912
Net income	92,579	72,791	191,520	128,591
Other comprehensive income (loss):
Change in net unrealized losses on available-for-sale investments, net of taxes	(5,658)	(14,107)	(15,598)	3,402
Total comprehensive income	$ 86,921	$ 58,684	$ 175,922	$ 131,993
Earnings per share:
Basic	$ 4	$ 3.16	$ 8.28	$ 5.59
Diluted	$ 3.97	$ 3.12	$ 8.21	$ 5.52
Weighted average shares outstanding:
Basic	23,165	23,040	23,137	23,024
Diluted	23,329	23,301	23,332	23,293

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, 2022		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
Balance, shares at Jun. 30, 2023	23,162,175
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	3,402
Net income	128,591
Balance at Jun. 30, 2023	$ 871,815	$ 232	347,865	655,234	(131,516)
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)
Balance, shares at Dec. 31, 2023	23,181,919	23,181,919
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)		105,314
Restricted shares withheld for taxes (shares)		(11,318)
Balance, shares at Mar. 31, 2024		23,275,915
Balance at Dec. 31, 2023	$ 1,086,832	$ 232	352,970	828,247	(94,617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	933	1	932
Stock-based compensation expense	3,524		3,524
Restricted shares withheld for taxes	(5,842)		(5,842)
Dividends declared	(3,479)			(3,479)
Other comprehensive income (loss), net of tax	(9,940)				(9,940)
Net income	98,941			98,941
Balance at Mar. 31, 2024	$ 1,170,969	$ 233	351,584	923,709	(104,557)
Balance, shares at Dec. 31, 2023	23,181,919	23,181,919
Balance, shares at Jun. 30, 2024	23,286,248
Balance at Dec. 31, 2023	$ 1,086,832	$ 232	352,970	828,247	(94,617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss), net of tax	(15,598)
Net income	191,520
Balance at Jun. 30, 2024	$ 1,257,203	$ 233	354,389	1,012,796	(110,215)
Balance, shares at Mar. 31, 2024		23,275,915
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)	13,249
Restricted shares withheld for taxes (shares)	(2,916)
Balance, shares at Jun. 30, 2024	23,286,248
Balance at Mar. 31, 2024	$ 1,170,969	$ 233	351,584	923,709	(104,557)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	219	0	219
Stock-based compensation expense	3,709		3,709
Restricted shares withheld for taxes	(1,123)		(1,123)
Dividends declared	(3,492)			(3,492)
Other comprehensive income (loss), net of tax	(5,658)				(5,658)
Net income	92,579			92,579
Balance at Jun. 30, 2024	$ 1,257,203	$ 233	$ 354,389	$ 1,012,796	$ (110,215)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023
Statement of Stockholders' Equity [Abstract]
Dividends declared, per share	$ 0.15	$ 0.15	$ 0.14	$ 0.14

Condensed Consolidated Statemen

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating Activities
Net cash provided by operating activities	$ 489,293	$ 423,577
Investing Activities
Purchase of property and equipment	(7,329)	(4,219)
Purchase of real estate investment	(312)	(1,085)
Change in short-term investments, net	(1,233)	13,071
Purchases – fixed-maturity securities	(759,799)	(667,804)
Purchases - equity securities	(84,229)	(40,535)
Sales – fixed-maturity securities	189,284	187,418
Sales – equity securities	30,880	6,251
Maturities and calls – fixed-maturity securities	200,573	62,284
Net cash used in investing activities	(432,165)	(444,619)
Financing Activities
Payroll taxes withheld and remitted on share-based payments	(6,965)	(4,234)
Proceeds from stock options exercised	1,152	554
Dividends paid	(6,988)	(6,495)
Net cash used in financing activities	(12,801)	(10,175)
Net change in cash and cash equivalents	44,327	(31,217)
Cash and cash equivalents	171,021	$ 125,057
Cash and cash equivalents at beginning of year	126,694
Cash and cash equivalents at end of period	$ 171,021

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2024
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, 2023. 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 ASU 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures In November 2023, the FASB issued ASU 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures," which expands reportable segment disclosure requirements by requiring disclosures of significant reportable segment expenses that are regularly provided to the Chief Operating Decision Maker ("CODM") and included within each reported measure of a segment's profit or loss. The ASU also requires disclosure of the title and position of the individual identified as the CODM and an explanation of how the CODM uses the reported measures of a segment's profit or loss in assessing segment performance and deciding how to allocate resources. Additionally, ASU 2023-07 requires all segment profit or loss and assets disclosures to be provided on an annual and interim basis. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning one year later. Early adoption is permitted and the amendments must be applied retrospectively to all prior periods presented. The Company does not expect the adoption of this guidance to materially affect the consolidated financial statements, and the Company is currently evaluating the effect the guidance will have on its disclosures.

Investments

Investments	6 Months Ended
	Jun. 30, 2024
Investments [Abstract]
Investments	Investments Available-for-sale investments The following tables summarize the available-for-sale investments at June 30, 2024 and December 31, 2023: June 30, 2024 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 $ 15,151 $ — $ (710) $ — $ 14,441 Obligations of states, municipalities and political subdivisions 173,760 25 (21,947) — 151,838 Corporate and other securities 1,762,577 1,617 (59,390) (67) 1,704,737 Asset-backed securities 699,739 1,571 (2,697) — 698,613 Residential mortgage-backed securities 460,923 614 (55,954) — 405,583 Commercial mortgage-backed securities 102,542 134 (5,170) — 97,506 Total fixed-maturity investments $ 3,214,692 $ 3,961 $ (145,868) $ (67) $ 3,072,718 December 31, 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 $ 28,003 $ 57 $ (806) $ — $ 27,254 Obligations of states, municipalities and political subdivisions 191,080 212 (20,248) — 171,044 Corporate and other securities 1,437,468 5,532 (54,755) (552) 1,387,693 Asset-backed securities 641,700 2,833 (2,773) — 641,760 Residential mortgage-backed securities 463,904 1,732 (48,530) — 417,106 Commercial mortgage-backed securities 72,308 11 (5,416) (1) 66,902 Total fixed-maturity investments $ 2,834,463 $ 10,377 $ (132,528) $ (553) $ 2,711,759 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 June 30, 2024, the Company's credit loss review resulted in an allowance for credit losses on three securities. The following table presents changes in the allowance for expected credit losses on available-for-sale securities for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Beginning balance $ 543 $ 447 $ 553 $ 366 Increase to allowance from securities for which credit losses were not previously recorded — — — — Reduction from securities sold during the period (479) (12) (479) (12) Net (decrease) increase from securities that had an allowance at the beginning of the period 3 (13) (7) 68 Ending balance $ 67 $ 422 $ 67 $ 422 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: June 30, 2024 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 $ 549 $ (1) $ 13,893 $ (709) $ 14,442 $ (710) Obligations of states, municipalities and political subdivisions 14,753 (164) 133,181 (21,783) 147,934 (21,947) Corporate and other securities 649,409 (3,640) 724,778 (55,750) 1,374,187 (59,390) Asset-backed securities 216,615 (731) 141,705 (1,966) 358,320 (2,697) Residential mortgage-backed securities 105,217 (1,286) 248,896 (54,668) 354,113 (55,954) Commercial mortgage-backed securities 19,746 (110) 56,994 (5,060) 76,740 (5,170) Total fixed-maturity investments $ 1,006,289 $ (5,932) $ 1,319,447 $ (139,936) $ 2,325,736 $ (145,868) At June 30, 2024, the Company held 1,253 fixed-maturity securities in an unrealized loss position with a total estimated fair value of $2.3 billion and gross unrealized losses of $145.9 million. Of these securities, 789 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 June 30, 2024, except for securities previously discussed, unrealized losses were caused by interest rate changes or other market factors and were not credit-specific issues. At June 30, 2024, 79.4% 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, 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 U.S. government agencies $ — $ — $ 15,484 $ (806) $ 15,484 $ (806) Obligations of states, municipalities and political subdivisions 20,886 (221) 121,911 (20,027) 142,797 (20,248) Corporate and other securities 246,355 (1,444) 651,525 (53,311) 897,880 (54,755) Asset-backed securities 142,287 (872) 217,401 (1,901) 359,688 (2,773) Residential mortgage-backed securities 26,158 (49) 268,891 (48,481) 295,049 (48,530) Commercial mortgage-backed securities 8,775 (55) 56,731 (5,361) 65,506 (5,416) Total fixed-maturity investments $ 444,461 $ (2,641) $ 1,331,943 $ (129,887) $ 1,776,404 $ (132,528) Contractual maturities of available-for-sale fixed-maturity securities The amortized cost and estimated fair value of available-for-sale fixed-maturity securities at June 30, 2024 are summarized, by contractual maturity, as follows: June 30, 2024 Amortized Estimated Cost Fair Value (in thousands) Due in one year or less $ 296,969 $ 295,225 Due after one year through five years 1,087,876 1,067,641 Due after five years through ten years 350,584 333,550 Due after ten years 216,059 174,600 Asset-backed securities 699,739 698,613 Residential mortgage-backed securities 460,923 405,583 Commercial mortgage-backed securities 102,542 97,506 Total fixed-maturity securities $ 3,214,692 $ 3,072,718 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 Real estate investments represents directly owned property held for investment purposes and consisted of land with a carrying value of $15.0 million and $14.8 million at June 30, 2024 and December 31, 2023, respectively. There was no accumulated depreciation on real estate investments at June 30, 2024 and December 31, 2023. Net investment income The following table presents the components of net investment income for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Interest: Taxable bonds $ 34,471 $ 20,924 $ 65,862 $ 39,028 Tax exempt municipal bonds 395 546 834 1,182 Cash equivalents and short-term investments 568 866 1,111 1,579 Dividends on equity securities 1,461 1,278 2,837 2,421 Real estate investment income — 1,356 153 2,714 Gross investment income 36,895 24,970 70,797 46,924 Investment expenses (1,048) (798) (2,017) (2,057) Net investment income $ 35,847 $ 24,172 $ 68,780 $ 44,867 There was no depreciation expense related to real estate investments for the three and six months ended June 30, 2024 or three months ended June 30, 2023 as the Company sold the related assets during 2023. Investment expenses included depreciation expense related to real estate investments of $0.5 million for the six months ended June 30, 2023. Realized investment gains and losses The following table presents realized investment gains and losses for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Fixed-maturity securities: Realized gains $ 846 $ 1,338 $ 941 $ 1,737 Realized losses (933) (958) (1,039) (2,217) Net realized (losses) gains from fixed-maturity securities (87) 380 (98) (480) Equity securities: Realized gains 3,390 1,611 7,271 1,626 Realized losses (424) (687) (424) (4,487) Net realized gains (losses) from equity securities 2,966 924 6,847 (2,861) Realized gains (losses) from the sales of short-term investments 1 (13) 1 (20) Realized loss on sale of real estate investments (1) — (5) — Net realized investment gains (losses) $ 2,879 $ 1,291 $ 6,745 $ (3,361) 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 (losses) gains on fixed-maturity securities For the three months ended June 30, 2024 and 2023, the change in net unrealized losses for fixed-maturity securities was $(7.2) million and $(17.8) million respectively. For the six months ended June 30, 2024 and 2023, the change in net unrealized (losses) gains for fixed-maturity securities was $(19.7) million and $4.4 million, respectively. Insurance – statutory deposits The Company had invested assets with a fair value of $3.5 million and $5.8 million on deposit with state regulatory authorities at June 30, 2024 and December 31, 2023, respectively. Payable for investments purchased The Company recorded a payable for investments purchased, not yet settled, of $16.7 million and $12.3 million at June 30, 2024 and December 31, 2023, respectively. The payable balance was included in the "other liabilities" line item of the consolidated balance sheet.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2024
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 June 30, 2024 and December 31, 2023, by level within the fair value hierarchy: June 30, 2024 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 14,441 $ — $ — $ 14,441 Obligations of states, municipalities and political subdivisions — 151,838 — 151,838 Corporate and other securities — 1,704,737 — 1,704,737 Asset-backed securities — 698,613 — 698,613 Residential mortgage-backed securities — 405,583 — 405,583 Commercial mortgage-backed securities — 97,506 — 97,506 Total fixed-maturity securities 14,441 3,058,277 — 3,072,718 Equity securities: Exchange traded funds 119,612 — — 119,612 Non-redeemable preferred stock — 28,964 — 28,964 Common stocks 168,906 — — 168,906 Total equity securities 288,518 28,964 — 317,482 Short-term investments 3,627 3,281 — 6,908 Total $ 306,586 $ 3,090,522 $ — $ 3,397,108 December 31, 2023 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 22,235 $ 5,019 $ — $ 27,254 Obligations of states, municipalities and political subdivisions — 171,044 — 171,044 Corporate and other securities — 1,387,693 — 1,387,693 Asset-backed securities — 641,760 — 641,760 Residential mortgage-backed securities — 417,106 — 417,106 Commercial mortgage-backed securities — 66,902 — 66,902 Total fixed-maturity securities 22,235 2,689,524 — 2,711,759 Equity securities: Exchange traded funds 106,300 — — 106,300 Non-redeemable preferred stock — 33,173 — 33,173 Common stocks 95,340 — — 95,340 Total equity securities 201,640 33,173 — 234,813 Short-term investments 1,862 3,727 — 5,589 Total $ 225,737 $ 2,726,424 $ — $ 2,952,161 There were no assets or liabilities measured at fair value on a nonrecurring basis as of June 30, 2024 or December 31, 2023. The carrying amount of the Company's fixed-rate senior notes was $175.0 million, less debt issuance costs, and the corresponding estimated fair value was $168.3 million and $171.6 million at June 30, 2024 and December 31, 2023, 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 June 30, 2024 and December 31, 2023. See Note 13 for further information regarding the Company's debt arrangements.

Credit Losses

Credit Losses	6 Months Ended
	Jun. 30, 2024
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 six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Beginning balance $ 15,482 $ 10,127 $ 13,383 $ 8,067 Current period change for estimated uncollectible premiums 6,079 2,711 10,342 5,118 Write-offs of uncollectible premiums receivable (335) (671) (2,499) (1,018) Ending balance $ 21,226 $ 12,167 $ 21,226 $ 12,167

Deferred Policy Acquisition Cos

Deferred Policy Acquisition Costs	6 Months Ended
	Jun. 30, 2024
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 six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Balance, beginning of period $ 94,489 $ 69,444 $ 88,395 $ 61,594 Policy acquisition costs deferred: Direct commissions 77,818 63,279 143,373 114,643 Ceding commissions (29,869) (21,171) (58,315) (38,549) Other underwriting and policy acquisition costs 3,512 3,242 6,653 5,888 Policy acquisition costs deferred 51,461 45,350 91,711 81,982 Amortization of net policy acquisition costs (36,592) (29,468) (70,748) (58,250) Balance, end of period $ 109,358 $ 85,326 $ 109,358 $ 85,326 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	6 Months Ended
	Jun. 30, 2024
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: June 30, 2024 December 31, 2023 (in thousands) Building $ 37,190 $ 37,181 Parking deck 5,072 5,072 Land 3,068 3,068 Equipment 4,250 3,958 Software 17,597 15,375 Furniture and fixtures 3,093 3,065 Land improvements 474 474 Leasehold improvements 153 153 Construction in progress - building 11,145 6,623 Property and equipment 82,042 74,969 Accumulated depreciation (13,878) (11,565) Total property and equipment, net $ 68,164 $ 63,404

Underwriting, Acquisition and I

Underwriting, Acquisition and Insurance Expenses	6 Months Ended
	Jun. 30, 2024
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 six months ended June 30, 2024 and 2023 consist of the following: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Underwriting, acquisition and insurance expenses incurred: Direct commissions $ 62,764 $ 46,977 $ 121,130 $ 90,146 Ceding commissions (29,359) (19,927) (56,186) (36,486) Other underwriting expenses 38,663 28,423 72,877 54,559 Total $ 72,068 $ 55,473 $ 137,821 $ 108,219

Stock-based Compensation

Stock-based Compensation	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-based Compensation	Stock-based Compensation On 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 $7.2 million and $4.5 million for the six months ended June 30, 2024 and 2023, respectively. Restricted Stock Awards During the six months ended June 30, 2024, 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 six months ended June 30, 2024 is as follows: Six Months Ended June 30, 2024 Number of Shares Weighted Average Grant Date Fair Value per Share Non-vested outstanding at the beginning of the period 107,822 $ 250.86 Granted 47,689 $ 502.43 Vested (41,502) $ 231.05 Forfeited (1,139) $ 272.22 Non-vested outstanding at the end of the period 112,870 $ 365.35 Employees surrender shares to pay for withholding tax obligations resulting from any vesting of restricted stock awards. During the six months ended June 30, 2024, shares withheld for taxes in connection with the vesting of restricted stock awards totaled 14,234. The weighted average grant-date fair value per share of the Company's restricted stock awards granted during the six months ended June 30, 2024 and 2023 was $502.43 and $313.35, respectively. The fair value of restricted stock awards that vested during the six months ended June 30, 2024 and 2023 was $19.8 million and $12.6 million, respectively. As of June 30, 2024, the Company had $36.0 million of total unrecognized stock-based compensation expense expected to be charged to earnings over a weighted-average period of 2.6 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 June 30, 2024, 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, 2024 201,560 $ 16.00 Granted — — Forfeited — — Exercised (72,013) 16.00 Outstanding at June 30, 2024 129,547 $ 16.00 2.1 $ 47,839 Exercisable at June 30, 2024 129,547 $ 16.00 2.1 $ 47,839

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2024
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 June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands, except per share data) Net income $ 92,579 $ 72,791 $ 191,520 $ 128,591 Weighted average common shares outstanding - basic 23,165 23,040 23,137 23,024 Effect of potential dilutive securities: Conversion of stock options 130 217 150 225 Conversion of restricted stock 34 44 45 44 Weighted average common shares outstanding - diluted 23,329 23,301 23,332 23,293 Earnings per common share: Basic $ 4.00 $ 3.16 $ 8.28 $ 5.59 Diluted $ 3.97 $ 3.12 $ 8.21 $ 5.52

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2024
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

Reserves for Unpaid Losses and

Reserves for Unpaid Losses and Loss Adjustment Expenses	6 Months Ended
	Jun. 30, 2024
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: June 30, 2024 2023 (in thousands) Gross reserves for unpaid losses and loss adjustment expenses, beginning of year $ 1,692,875 $ 1,238,402 Less: reinsurance recoverable on unpaid losses 241,357 177,039 Net reserves for unpaid losses and loss adjustment expenses, beginning of year 1,451,518 1,061,363 Incurred losses and loss adjustment expenses: Current year 398,058 305,536 Prior years (17,947) (19,460) Total net losses and loss adjustment expenses incurred 380,111 286,076 Payments: Current year 8,114 8,058 Prior years 102,829 92,055 Total payments 110,943 100,113 Net reserves for unpaid losses and loss adjustment expenses, end of period 1,720,686 1,247,326 Reinsurance recoverable on unpaid losses 292,369 208,408 Gross reserves for unpaid losses and loss adjustment expenses, end of period $ 2,013,055 $ 1,455,734 During the six months ended June 30, 2024, the reserves for unpaid losses and loss adjustment expenses held at December 31, 2023 developed favorably by $17.9 million, of which $30.7 million was attributable to the 2021 through 2023 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 primarily from the 2017 through 2019 accident years due to construction defect claims that are more exposed to inflation and from the 2020 accident year due to a large property claim.

Reinsurance

Reinsurance	6 Months Ended
	Jun. 30, 2024
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance The following table summarizes the effect of reinsurance on premiums written and earned for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Premiums written: Direct $ 529,770 $ 438,222 $ 978,414 $ 795,810 Ceded (99,534) (73,181) (197,124) (131,739) Net written $ 430,236 $ 365,041 $ 781,290 $ 664,071 Premiums earned: Direct $ 430,535 $ 326,697 $ 833,127 $ 620,233 Ceded (98,074) (69,651) (191,148) (126,029) Net earned $ 332,461 $ 257,046 $ 641,979 $ 494,204 The following table summarizes ceded losses and loss adjustment expenses for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Ceded incurred losses and loss adjustment expenses $ 40,944 $ 25,981 $ 70,205 $ 61,990 The following table presents reinsurance recoverables on paid and unpaid losses as of June 30, 2024 and December 31, 2023: June 30, 2024 December 31, 2023 (in thousands) Reinsurance recoverables on paid losses $ 9,723 $ 6,479 Reinsurance recoverables on unpaid losses, net 292,369 241,357 Reinsurance recoverables, net $ 302,092 $ 247,836

Debt

Debt	6 Months Ended
	Jun. 30, 2024
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 (as subsequently amended, the "Note Purchase Agreement") with PGIM, Inc. ("Prudential") and the purchasers of the Series A and Series B Senior Notes (as defined below). The Note Purchase Agreement provides for issuance of senior promissory notes with an aggregate principal amount of up to $200.0 million through September 18, 2026. 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”), and on September 18, 2023, the Company issued a $50.0 million aggregate principal amount 6.21% Series B Senior Note ("Series B Note") due July 22, 2034. 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. Principal payments on the Series A Notes are required annually beginning on July 22, 2030 in equal installments of $25.0 million through July 22, 2034. Principal payments on the Series B Note are required annually beginning on July 22, 2030 in equal installments of $10.0 million through July 22, 2034. Credit Agreement 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 provides the Company with a $100.0 million senior unsecured revolving credit facility (the "Credit Facility"), with the option to increase the aggregate commitment by $30.0 million. 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). 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 six months ended June 30, 2024, the annual weighted-average interest rate of borrowings under the Credit Facility was 7.07%. The following table presents the Company's outstanding debt as of June 30, 2024 and December 31, 2023: Issuance Maturities June 30, December 31, 2023 (in thousands) Credit Facility Various 7/22/2027 $ 11,000 $ 11,000 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 50,000 Less: Unamortized debt issuance costs (2,016) (2,154) Total debt $ 183,984 $ 183,846

Other Comprehensive (Loss) Inco

Other Comprehensive (Loss) Income	6 Months Ended
	Jun. 30, 2024
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income	Other Comprehensive (Loss) Income The following table summarizes the components of other comprehensive (loss) income for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Unrealized (losses) gains on fixed-maturity securities arising during the period, before income taxes $ (6,892) $ (18,236) $ (19,476) $ 2,934 Income tax benefit (expense) 1,447 3,830 4,090 (616) Unrealized (losses) gains arising during the period, net of income taxes (5,445) (14,406) (15,386) 2,318 Less reclassification adjustment: Net realized losses on fixed-maturity securities, before income taxes (207) (404) (218) (1,316) Income tax benefit 44 85 46 276 Reclassification adjustment included in net income (163) (319) (172) (1,040) Change in allowance for credit losses on investments, before income taxes 476 25 486 (56) Income tax (expense) benefit (100) (5) (102) 12 Reclassification adjustment included in net income 376 20 384 (44) Other comprehensive (loss) income $ (5,658) $ (14,107) $ (15,598) $ 3,402 The sale or credit loss of an available-for-sale fixed-maturity security results in amounts being reclassified from accumulated other comprehensive (loss) income 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.

Commitment and Contingencies

Commitment and Contingencies	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure	Contingencies Contingencies arise in the normal conduct of the Company’s operations and are not expected to have a material effect on the Company’s financial condition or results of operations. However, adverse outcomes are possible and could negatively affect the Company’s financial condition and results of operations. In June 2019, Marie Hughes, as authorized administrator for the estate of George Hughes, filed a wrongful death claim against Venetian Hills Apartments, LLC ("Venetian Hills") in DeKalb County in Georgia state court. On December 20, 2023, the jury awarded a verdict to the plaintiff of $140.0 million. Venetian Hills was a policyholder of a $1.0 million general liability policy issued by Kinsale Insurance. The Company believes exclusions in the policy apply to the claim and intends to defend any action related to this proceeding vigorously. The Company expects to appeal the verdict at the conclusion of post trial motions and does not expect a resolution as to the Company’s liability, if any, with respect to this matter in the foreseeable future, and potentially for multiple years. The Company does not believe this legal proceeding will have a material adverse effect on its results of operations or business. The Company believes adequate provision has been made in its consolidated financial statements and its existing reserves account for liabilities to the Company relating to claims such as this legal proceeding.
Legal Matters and Contingencies	In June 2019, Marie Hughes, as authorized administrator for the estate of George Hughes, filed a wrongful death claim against Venetian Hills Apartments, LLC ("Venetian Hills") in DeKalb County in Georgia state court. On December 20, 2023, the jury awarded a verdict to the plaintiff of $140.0 million. Venetian Hills was a policyholder of a $1.0 million general liability policy issued by Kinsale Insurance. The Company believes exclusions in the policy apply to the claim and intends to defend any action related to this proceeding vigorously. The Company expects to appeal the verdict at the conclusion of post trial motions and does not expect a resolution as to the Company’s liability, if any, with respect to this matter in the foreseeable future, and potentially for multiple years.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net income	$ 92,579	$ 98,941	$ 72,791	$ 55,800	$ 191,520	$ 128,591

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2024
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 second quarter of 2024, 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)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	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, 2023. 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 estimates
New Accounting Pronouncements, Policy	Prospective accounting pronouncements ASU 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures In November 2023, the FASB issued ASU 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures," which expands reportable segment disclosure requirements by requiring disclosures of significant reportable segment expenses that are regularly provided to the Chief Operating Decision Maker ("CODM") and included within each reported measure of a segment's profit or loss. The ASU also requires disclosure of the title and position of the individual identified as the CODM and an explanation of how the CODM uses the reported measures of a segment's profit or loss in assessing segment performance and deciding how to allocate resources. Additionally, ASU 2023-07 requires all segment profit or loss and assets disclosures to be provided on an annual and interim basis. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning one year later. Early adoption is permitted and the amendments must be applied retrospectively to all prior periods presented. The Company does not expect the adoption of this guidance to materially affect the consolidated financial statements, and the Company is currently evaluating the effect the guidance will have on its disclosures.

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2024
Investments [Abstract]
Available-for-sale Investments	The following tables summarize the available-for-sale investments at June 30, 2024 and December 31, 2023: June 30, 2024 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 $ 15,151 $ — $ (710) $ — $ 14,441 Obligations of states, municipalities and political subdivisions 173,760 25 (21,947) — 151,838 Corporate and other securities 1,762,577 1,617 (59,390) (67) 1,704,737 Asset-backed securities 699,739 1,571 (2,697) — 698,613 Residential mortgage-backed securities 460,923 614 (55,954) — 405,583 Commercial mortgage-backed securities 102,542 134 (5,170) — 97,506 Total fixed-maturity investments $ 3,214,692 $ 3,961 $ (145,868) $ (67) $ 3,072,718 December 31, 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 $ 28,003 $ 57 $ (806) $ — $ 27,254 Obligations of states, municipalities and political subdivisions 191,080 212 (20,248) — 171,044 Corporate and other securities 1,437,468 5,532 (54,755) (552) 1,387,693 Asset-backed securities 641,700 2,833 (2,773) — 641,760 Residential mortgage-backed securities 463,904 1,732 (48,530) — 417,106 Commercial mortgage-backed securities 72,308 11 (5,416) (1) 66,902 Total fixed-maturity investments $ 2,834,463 $ 10,377 $ (132,528) $ (553) $ 2,711,759
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 six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Beginning balance $ 543 $ 447 $ 553 $ 366 Increase to allowance from securities for which credit losses were not previously recorded — — — — Reduction from securities sold during the period (479) (12) (479) (12) Net (decrease) increase from securities that had an allowance at the beginning of the period 3 (13) (7) 68 Ending balance $ 67 $ 422 $ 67 $ 422
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: June 30, 2024 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 $ 549 $ (1) $ 13,893 $ (709) $ 14,442 $ (710) Obligations of states, municipalities and political subdivisions 14,753 (164) 133,181 (21,783) 147,934 (21,947) Corporate and other securities 649,409 (3,640) 724,778 (55,750) 1,374,187 (59,390) Asset-backed securities 216,615 (731) 141,705 (1,966) 358,320 (2,697) Residential mortgage-backed securities 105,217 (1,286) 248,896 (54,668) 354,113 (55,954) Commercial mortgage-backed securities 19,746 (110) 56,994 (5,060) 76,740 (5,170) Total fixed-maturity investments $ 1,006,289 $ (5,932) $ 1,319,447 $ (139,936) $ 2,325,736 $ (145,868) December 31, 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 U.S. government agencies $ — $ — $ 15,484 $ (806) $ 15,484 $ (806) Obligations of states, municipalities and political subdivisions 20,886 (221) 121,911 (20,027) 142,797 (20,248) Corporate and other securities 246,355 (1,444) 651,525 (53,311) 897,880 (54,755) Asset-backed securities 142,287 (872) 217,401 (1,901) 359,688 (2,773) Residential mortgage-backed securities 26,158 (49) 268,891 (48,481) 295,049 (48,530) Commercial mortgage-backed securities 8,775 (55) 56,731 (5,361) 65,506 (5,416) Total fixed-maturity investments $ 444,461 $ (2,641) $ 1,331,943 $ (129,887) $ 1,776,404 $ (132,528)
Contractual Maturities of Available-for-sale Fixed Maturity Securities	The amortized cost and estimated fair value of available-for-sale fixed-maturity securities at June 30, 2024 are summarized, by contractual maturity, as follows: June 30, 2024 Amortized Estimated Cost Fair Value (in thousands) Due in one year or less $ 296,969 $ 295,225 Due after one year through five years 1,087,876 1,067,641 Due after five years through ten years 350,584 333,550 Due after ten years 216,059 174,600 Asset-backed securities 699,739 698,613 Residential mortgage-backed securities 460,923 405,583 Commercial mortgage-backed securities 102,542 97,506 Total fixed-maturity securities $ 3,214,692 $ 3,072,718
Schedule of Real Estate Properties	Real estate investments represents directly owned property held for investment purposes and consisted of land with a carrying value of $15.0 million and $14.8 million at June 30, 2024 and December 31, 2023, respectively. There was no accumulated depreciation on real estate investments at June 30, 2024 and December 31, 2023.
Net Investment Income	The following table presents the components of net investment income for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Interest: Taxable bonds $ 34,471 $ 20,924 $ 65,862 $ 39,028 Tax exempt municipal bonds 395 546 834 1,182 Cash equivalents and short-term investments 568 866 1,111 1,579 Dividends on equity securities 1,461 1,278 2,837 2,421 Real estate investment income — 1,356 153 2,714 Gross investment income 36,895 24,970 70,797 46,924 Investment expenses (1,048) (798) (2,017) (2,057) Net investment income $ 35,847 $ 24,172 $ 68,780 $ 44,867 There was no depreciation expense related to real estate investments for the three and six months ended June 30, 2024 or three months ended June 30, 2023 as the Company sold the related assets during 2023. Investment expenses included depreciation expense related to real estate investments of $0.5 million for the six months ended June 30, 2023.
Realized Gain (Loss) on Investments	The following table presents realized investment gains and losses for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Fixed-maturity securities: Realized gains $ 846 $ 1,338 $ 941 $ 1,737 Realized losses (933) (958) (1,039) (2,217) Net realized (losses) gains from fixed-maturity securities (87) 380 (98) (480) Equity securities: Realized gains 3,390 1,611 7,271 1,626 Realized losses (424) (687) (424) (4,487) Net realized gains (losses) from equity securities 2,966 924 6,847 (2,861) Realized gains (losses) from the sales of short-term investments 1 (13) 1 (20) Realized loss on sale of real estate investments (1) — (5) — Net realized investment gains (losses) $ 2,879 $ 1,291 $ 6,745 $ (3,361) 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)	6 Months Ended
	Jun. 30, 2024
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 June 30, 2024 and December 31, 2023, by level within the fair value hierarchy: June 30, 2024 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 14,441 $ — $ — $ 14,441 Obligations of states, municipalities and political subdivisions — 151,838 — 151,838 Corporate and other securities — 1,704,737 — 1,704,737 Asset-backed securities — 698,613 — 698,613 Residential mortgage-backed securities — 405,583 — 405,583 Commercial mortgage-backed securities — 97,506 — 97,506 Total fixed-maturity securities 14,441 3,058,277 — 3,072,718 Equity securities: Exchange traded funds 119,612 — — 119,612 Non-redeemable preferred stock — 28,964 — 28,964 Common stocks 168,906 — — 168,906 Total equity securities 288,518 28,964 — 317,482 Short-term investments 3,627 3,281 — 6,908 Total $ 306,586 $ 3,090,522 $ — $ 3,397,108 December 31, 2023 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 22,235 $ 5,019 $ — $ 27,254 Obligations of states, municipalities and political subdivisions — 171,044 — 171,044 Corporate and other securities — 1,387,693 — 1,387,693 Asset-backed securities — 641,760 — 641,760 Residential mortgage-backed securities — 417,106 — 417,106 Commercial mortgage-backed securities — 66,902 — 66,902 Total fixed-maturity securities 22,235 2,689,524 — 2,711,759 Equity securities: Exchange traded funds 106,300 — — 106,300 Non-redeemable preferred stock — 33,173 — 33,173 Common stocks 95,340 — — 95,340 Total equity securities 201,640 33,173 — 234,813 Short-term investments 1,862 3,727 — 5,589 Total $ 225,737 $ 2,726,424 $ — $ 2,952,161

Credit Losses (Tables)

Credit Losses (Tables)	6 Months Ended
	Jun. 30, 2024
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 six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Beginning balance $ 15,482 $ 10,127 $ 13,383 $ 8,067 Current period change for estimated uncollectible premiums 6,079 2,711 10,342 5,118 Write-offs of uncollectible premiums receivable (335) (671) (2,499) (1,018) Ending balance $ 21,226 $ 12,167 $ 21,226 $ 12,167

Deferred Policy Acquisition C_2

Deferred Policy Acquisition Costs (Tables)	6 Months Ended
	Jun. 30, 2024
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 six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Balance, beginning of period $ 94,489 $ 69,444 $ 88,395 $ 61,594 Policy acquisition costs deferred: Direct commissions 77,818 63,279 143,373 114,643 Ceding commissions (29,869) (21,171) (58,315) (38,549) Other underwriting and policy acquisition costs 3,512 3,242 6,653 5,888 Policy acquisition costs deferred 51,461 45,350 91,711 81,982 Amortization of net policy acquisition costs (36,592) (29,468) (70,748) (58,250) Balance, end of period $ 109,358 $ 85,326 $ 109,358 $ 85,326

Property and Equipment (Tables)

Property and Equipment (Tables)	6 Months Ended
	Jun. 30, 2024
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: June 30, 2024 December 31, 2023 (in thousands) Building $ 37,190 $ 37,181 Parking deck 5,072 5,072 Land 3,068 3,068 Equipment 4,250 3,958 Software 17,597 15,375 Furniture and fixtures 3,093 3,065 Land improvements 474 474 Leasehold improvements 153 153 Construction in progress - building 11,145 6,623 Property and equipment 82,042 74,969 Accumulated depreciation (13,878) (11,565) Total property and equipment, net $ 68,164 $ 63,404

Underwriting, Acquisition and_2

Underwriting, Acquisition and Insurance Expenses (Tables)	6 Months Ended
	Jun. 30, 2024
Underwriting, Acquisition and Insurance Expenses [Abstract]
Underwriting, acquisition and insurance expenses	Underwriting, acquisition and insurance expenses for the three and six months ended June 30, 2024 and 2023 consist of the following: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Underwriting, acquisition and insurance expenses incurred: Direct commissions $ 62,764 $ 46,977 $ 121,130 $ 90,146 Ceding commissions (29,359) (19,927) (56,186) (36,486) Other underwriting expenses 38,663 28,423 72,877 54,559 Total $ 72,068 $ 55,473 $ 137,821 $ 108,219

Stock-based Compensation (Table

Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Restricted Stock Activity	A summary of restricted stock activity under the 2016 Incentive Plan for the six months ended June 30, 2024 is as follows: Six Months Ended June 30, 2024 Number of Shares Weighted Average Grant Date Fair Value per Share Non-vested outstanding at the beginning of the period 107,822 $ 250.86 Granted 47,689 $ 502.43 Vested (41,502) $ 231.05 Forfeited (1,139) $ 272.22 Non-vested outstanding at the end of the period 112,870 $ 365.35
Stock Options Activity	A summary of option activity as of June 30, 2024, 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, 2024 201,560 $ 16.00 Granted — — Forfeited — — Exercised (72,013) 16.00 Outstanding at June 30, 2024 129,547 $ 16.00 2.1 $ 47,839 Exercisable at June 30, 2024 129,547 $ 16.00 2.1 $ 47,839

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2024
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 June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands, except per share data) Net income $ 92,579 $ 72,791 $ 191,520 $ 128,591 Weighted average common shares outstanding - basic 23,165 23,040 23,137 23,024 Effect of potential dilutive securities: Conversion of stock options 130 217 150 225 Conversion of restricted stock 34 44 45 44 Weighted average common shares outstanding - diluted 23,329 23,301 23,332 23,293 Earnings per common share: Basic $ 4.00 $ 3.16 $ 8.28 $ 5.59 Diluted $ 3.97 $ 3.12 $ 8.21 $ 5.52

Reserves for Unpaid Losses an_2

Reserves for Unpaid Losses and Loss Adjustment Expenses (Tables)	6 Months Ended
	Jun. 30, 2024
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: June 30, 2024 2023 (in thousands) Gross reserves for unpaid losses and loss adjustment expenses, beginning of year $ 1,692,875 $ 1,238,402 Less: reinsurance recoverable on unpaid losses 241,357 177,039 Net reserves for unpaid losses and loss adjustment expenses, beginning of year 1,451,518 1,061,363 Incurred losses and loss adjustment expenses: Current year 398,058 305,536 Prior years (17,947) (19,460) Total net losses and loss adjustment expenses incurred 380,111 286,076 Payments: Current year 8,114 8,058 Prior years 102,829 92,055 Total payments 110,943 100,113 Net reserves for unpaid losses and loss adjustment expenses, end of period 1,720,686 1,247,326 Reinsurance recoverable on unpaid losses 292,369 208,408 Gross reserves for unpaid losses and loss adjustment expenses, end of period $ 2,013,055 $ 1,455,734

Reinsurance (Tables)

Reinsurance (Tables)	6 Months Ended
	Jun. 30, 2024
Reinsurance Disclosures [Abstract]
Effects of Reinsurance	The following table summarizes the effect of reinsurance on premiums written and earned for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Premiums written: Direct $ 529,770 $ 438,222 $ 978,414 $ 795,810 Ceded (99,534) (73,181) (197,124) (131,739) Net written $ 430,236 $ 365,041 $ 781,290 $ 664,071 Premiums earned: Direct $ 430,535 $ 326,697 $ 833,127 $ 620,233 Ceded (98,074) (69,651) (191,148) (126,029) Net earned $ 332,461 $ 257,046 $ 641,979 $ 494,204
Effects of Reinsurance on Losses	The following table summarizes ceded losses and loss adjustment expenses for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Ceded incurred losses and loss adjustment expenses $ 40,944 $ 25,981 $ 70,205 $ 61,990
Reinsurance Recoverables	The following table presents reinsurance recoverables on paid and unpaid losses as of June 30, 2024 and December 31, 2023: June 30, 2024 December 31, 2023 (in thousands) Reinsurance recoverables on paid losses $ 9,723 $ 6,479 Reinsurance recoverables on unpaid losses, net 292,369 241,357 Reinsurance recoverables, net $ 302,092 $ 247,836

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2024
Debt Disclosure [Abstract]
Schedule of Debt	The following table presents the Company's outstanding debt as of June 30, 2024 and December 31, 2023: Issuance Maturities June 30, December 31, 2023 (in thousands) Credit Facility Various 7/22/2027 $ 11,000 $ 11,000 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 50,000 Less: Unamortized debt issuance costs (2,016) (2,154) Total debt $ 183,984 $ 183,846

Other Comprehensive (Loss) In_2

Other Comprehensive (Loss) Income (Tables)	6 Months Ended
	Jun. 30, 2024
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss)	The following table summarizes the components of other comprehensive (loss) income for the three and six months ended June 30, 2024 and 2023: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (in thousands) Unrealized (losses) gains on fixed-maturity securities arising during the period, before income taxes $ (6,892) $ (18,236) $ (19,476) $ 2,934 Income tax benefit (expense) 1,447 3,830 4,090 (616) Unrealized (losses) gains arising during the period, net of income taxes (5,445) (14,406) (15,386) 2,318 Less reclassification adjustment: Net realized losses on fixed-maturity securities, before income taxes (207) (404) (218) (1,316) Income tax benefit 44 85 46 276 Reclassification adjustment included in net income (163) (319) (172) (1,040) Change in allowance for credit losses on investments, before income taxes 476 25 486 (56) Income tax (expense) benefit (100) (5) (102) 12 Reclassification adjustment included in net income 376 20 384 (44) Other comprehensive (loss) income $ (5,658) $ (14,107) $ (15,598) $ 3,402

Investments Investments (Availa

Investments Investments (Available for Sale) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	$ 3,214,692		$ 2,834,463
Gross Unrealized Holding Gains	3,961		10,377
Gross Unrealized Holding Losses	145,868		132,528
Allowance for Credit Losses	(67)	$ (543)	(553)	$ (422)	$ (447)	$ (366)
Estimated Fair Value	3,072,718		2,711,759
U.S. Treasury securities and obligations of U.S. government agencies
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	15,151		28,003
Gross Unrealized Holding Gains	0		57
Gross Unrealized Holding Losses	710		806
Allowance for Credit Losses	0		0
Estimated Fair Value	14,441		27,254
Obligations of states, municipalities and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	173,760		191,080
Gross Unrealized Holding Gains	25		212
Gross Unrealized Holding Losses	21,947		20,248
Allowance for Credit Losses	0		0
Estimated Fair Value	151,838		171,044
Corporate and other securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	1,762,577		1,437,468
Gross Unrealized Holding Gains	1,617		5,532
Gross Unrealized Holding Losses	59,390		54,755
Allowance for Credit Losses	(67)		(552)
Estimated Fair Value	1,704,737		1,387,693
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	699,739		641,700
Gross Unrealized Holding Gains	1,571		2,833
Gross Unrealized Holding Losses	2,697		2,773
Allowance for Credit Losses	0		0
Estimated Fair Value	698,613		641,760
Residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	460,923		463,904
Gross Unrealized Holding Gains	614		1,732
Gross Unrealized Holding Losses	55,954		48,530
Allowance for Credit Losses	0		0
Estimated Fair Value	405,583		417,106
Commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturities, Amortized Cost	102,542		72,308
Gross Unrealized Holding Gains	134		11
Gross Unrealized Holding Losses	5,170		5,416
Allowance for Credit Losses	0		(1)
Estimated Fair Value	$ 97,506		$ 66,902

Investments Available-for-Sale

Investments Available-for-Sale Securities in a Loss Position (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) security	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	$ 1,006,289		$ 1,006,289		$ 444,461
Less than 12 months, gross unrealized holding losses	5,932		5,932		2,641
12 Months or Longer, Estimated Fair Value	1,319,447		1,319,447		1,331,943
12 Months or Longer, Gross Unrealized Holding Losses	139,936		139,936		129,887
Total Estimated Fair Value	2,325,736		2,325,736		1,776,404
Total Gross Unrealized Holding Losses	145,868		145,868		132,528
Beginning balance	543	$ 447	553	$ 366
Increase to allowance from securities for which credit losses were not previously recorded	0	0	0	0
Reduction from securities sold during the period	(479)	(12)	(479)	(12)
Net increase (decrease) from securities that had an allowance at the beginning of the period	3	(13)	(7)	68
Ending balance	67	$ 422	$ 67	$ 422
Debt Securities Available For Sale Allowance For Credit Loss Number Of Securities | security			3
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	549		$ 549		0
Less than 12 months, gross unrealized holding losses	1		1		0
12 Months or Longer, Estimated Fair Value	13,893		13,893		15,484
12 Months or Longer, Gross Unrealized Holding Losses	709		709		806
Total Estimated Fair Value	14,442		14,442		15,484
Total Gross Unrealized Holding Losses	710		710		806
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	14,753		14,753		20,886
Less than 12 months, gross unrealized holding losses	164		164		221
12 Months or Longer, Estimated Fair Value	133,181		133,181		121,911
12 Months or Longer, Gross Unrealized Holding Losses	21,783		21,783		20,027
Total Estimated Fair Value	147,934		147,934		142,797
Total Gross Unrealized Holding Losses	21,947		21,947		20,248
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	649,409		649,409		246,355
Less than 12 months, gross unrealized holding losses	3,640		3,640		1,444
12 Months or Longer, Estimated Fair Value	724,778		724,778		651,525
12 Months or Longer, Gross Unrealized Holding Losses	55,750		55,750		53,311
Total Estimated Fair Value	1,374,187		1,374,187		897,880
Total Gross Unrealized Holding Losses	59,390		59,390		54,755
Beginning balance			552
Ending balance	67		67
Asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	216,615		216,615		142,287
Less than 12 months, gross unrealized holding losses	731		731		872
12 Months or Longer, Estimated Fair Value	141,705		141,705		217,401
12 Months or Longer, Gross Unrealized Holding Losses	1,966		1,966		1,901
Total Estimated Fair Value	358,320		358,320		359,688
Total Gross Unrealized Holding Losses	2,697		2,697		2,773
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	105,217		105,217		26,158
Less than 12 months, gross unrealized holding losses	1,286		1,286		49
12 Months or Longer, Estimated Fair Value	248,896		248,896		268,891
12 Months or Longer, Gross Unrealized Holding Losses	54,668		54,668		48,481
Total Estimated Fair Value	354,113		354,113		295,049
Total Gross Unrealized Holding Losses	55,954		55,954		48,530
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	19,746		19,746		8,775
Less than 12 months, gross unrealized holding losses	110		110		55
12 Months or Longer, Estimated Fair Value	56,994		56,994		56,731
12 Months or Longer, Gross Unrealized Holding Losses	5,060		5,060		5,361
Total Estimated Fair Value	76,740		76,740		65,506
Total Gross Unrealized Holding Losses	5,170		5,170		$ 5,416
Beginning balance			1
Ending balance	$ 0		$ 0

Investments Available-for-Sal_2

Investments Available-for-Sale Securities in a Loss Position Narrative (Details) $ in Thousands	Jun. 30, 2024 USD ($) Rate	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Number of available-for-sale securities in unrealized loss positions	1,253
Total Estimated Fair Value	$ 2,325,736	$ 1,776,404
Gross Unrealized Losses	$ 145,868	$ 132,528
Number of available-for-sale securities in unrealized loss positions, greater than one year	789
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	79.40%

Investments Contractual Maturit

Investments Contractual Maturities of Available-for-Sale Fixed Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Amortized Cost
Due in one year or less, Amortized Cost	$ 296,969
Due after one year through five years, Amortized Cost	1,087,876
Due after five years through ten years, Amortized Cost	350,584
Due after ten years, Amortized Cost	216,059
Total fixed maturities, Amortized Cost	3,214,692	$ 2,834,463
Estimated Fair Value
Due in one year or less, Estimated Fair Value	295,225
Due after one year through five years, Estimated Fair Value	1,067,641
Due after five years through ten years, Estimated Fair Value	333,550
Due after ten years, Estimated Fair Value	174,600
Estimated Fair Value	3,072,718	2,711,759
Asset-backed securities [Member]
Amortized Cost
Without single maturity date, Amortized Cost	699,739
Total fixed maturities, Amortized Cost	699,739	641,700
Estimated Fair Value
Without single maturity date, Estimated Fair Value	698,613
Estimated Fair Value	698,613	641,760
Residential mortgage-backed securities [Member]
Amortized Cost
Without single maturity date, Amortized Cost	460,923
Total fixed maturities, Amortized Cost	460,923	463,904
Estimated Fair Value
Without single maturity date, Estimated Fair Value	405,583
Estimated Fair Value	405,583	417,106
Commercial mortgage-backed securities
Amortized Cost
Without single maturity date, Amortized Cost	102,542
Total fixed maturities, Amortized Cost	102,542	72,308
Estimated Fair Value
Without single maturity date, Estimated Fair Value	97,506
Estimated Fair Value	$ 97,506	$ 66,902

Investments Net Investment Inco

Investments Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Interest Income (Expense), Net [Abstract]
Taxable bonds	$ 34,471	$ 20,924	$ 65,862	$ 39,028
Tax exempt municipal bonds	395	546	834	1,182
Cash equivalents and short-term investments	568	866	1,111	1,579
Dividends on equity securities	1,461	1,278	2,837	2,421
Gross Investment Income, Operating	36,895	24,970	70,797	46,924
Investment Income, Investment Expense	1,048	798	2,017	2,057
Net investment income	35,847	24,172	68,780	44,867
Real Estate Investment
Interest Income (Expense), Net [Abstract]
Gross Investment Income, Operating	0	1,356	153	2,714
Investment Income, Investment Expense	$ 0	$ 0	$ 0	$ 500

Investments Realized Gains (Los

Investments Realized Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Debt and Equity Securities, Realized Gain (Loss) [Abstract]
Realized gains, fixed-maturity securities	$ 846	$ 1,338	$ 941	$ 1,737
Realized losses, fixed-maturity securities	(933)	(958)	(1,039)	(2,217)
Net realized (losses) gains from fixed-maturity securities	(87)	380	(98)	(480)
Realized gains, equity securities	3,390	1,611	7,271	1,626
Realized losses, equity securities	(424)	(687)	(424)	(4,487)
Net realized gains (losses) from equity securities	2,966	924	6,847	(2,861)
Realized gains (losses) from the sales of short-term investments	1	(13)	1	(20)
Gains (Losses) on Sales of Investment Real Estate	(1)	0	(5)	0
Net realized investment gains (losses)	$ 2,879	$ 1,291	$ 6,745	$ (3,361)

Investments Unrealized Gains (L

Investments Unrealized Gains (Losses) on Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Change in net unrealized gains (losses) on fixed-maturity securities	$ (7.2)	$ (17.8)	$ (19.7)	$ 4.4

Investments Investment Narrativ

Investments Investment Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Assets on deposit with state regulatory authorities	$ 3.5	$ 5.8
Payable for investments purchased	$ 16.7	$ 12.3

Investments (Details), Real Est

Investments (Details), Real Estate - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Real Estate Properties [Line Items]
Land	$ 15,000		$ 15,000		$ 14,800
Real Estate Investment Property, Accumulated Depreciation	0		0		$ 0
Gains (Losses) on Sales of Investment Real Estate	(1)	$ 0	(5)	$ 0
Investment Income, Investment Expense	1,048	798	2,017	2,057
Real Estate Investment
Real Estate Properties [Line Items]
Investment Income, Investment Expense	$ 0	$ 0	$ 0	$ 500

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	$ 3,072,718	$ 2,711,759
U.S. Treasury securities and obligations of U.S. government agencies
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	14,441	27,254
Obligations of states, municipalities and political subdivisions [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	151,838	171,044
Corporate and other securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	1,704,737	1,387,693
Asset-backed securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	698,613	641,760
Residential mortgage-backed securities [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	405,583	417,106
Commercial mortgage-backed securities
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	97,506	66,902
Recurring
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	3,397,108	2,952,161
Recurring | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	306,586	225,737
Recurring | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	3,090,522	2,726,424
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	3,072,718	2,711,759
Recurring | Fixed maturities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	14,441	22,235
Recurring | Fixed maturities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Estimated Fair Value	3,058,277	2,689,524
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	14,441	27,254
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	14,441	22,235
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	0	5,019
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	151,838	171,044
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	151,838	171,044
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	1,704,737	1,387,693
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	1,704,737	1,387,693
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	698,613	641,760
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	698,613	641,760
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	405,583	417,106
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	405,583	417,106
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	97,506	66,902
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	97,506	66,902
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	317,482	234,813
Recurring | Equity securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	288,518	201,640
Recurring | Equity securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	28,964	33,173
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	119,612	106,300
Recurring | Exchange traded funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	119,612	106,300
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	28,964	33,173
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	28,964	33,173
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	168,906	95,340
Recurring | Common Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	168,906	95,340
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	6,908	5,589
Recurring | Short-term Investments | Fair Value, Inputs, Level 1 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	3,627	1,862
Recurring | Short-term Investments | Fair Value, Inputs, Level 2 [Member]
Fair Value of Investments Measured on Recurring Basis [Line Items]
Fair value	3,281	3,727
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	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	$ 32,600	$ 11,800
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	175,000
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	$ 168,300	$ 171,600

Credit Losses (Details)

Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Credit Loss [Abstract]
Beginning Balance	$ 15,482	$ 10,127	$ 13,383	$ 8,067
Current period change for estimated uncollectible premiums	6,079	2,711	10,342	5,118
Write-offs of uncollectible premiums receivable	(335)	(671)	(2,499)	(1,018)
Ending Balance	$ 21,226	$ 12,167	$ 21,226	$ 12,167

Deferred Policy Acquisition C_3

Deferred Policy Acquisition Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of period	$ 94,489	$ 69,444	$ 88,395	$ 61,594
Policy acquisition costs deferred:
Direct commissions deferred	77,818	63,279	143,373	114,643
Ceding commissions deferred	(29,869)	(21,171)	(58,315)	(38,549)
Other underwriting and policy acquisition costs	3,512	3,242	6,653	5,888
Policy acquisition costs deferred	51,461	45,350	91,711	81,982
Amortization of net policy acquisition costs	(36,592)	(29,468)	(70,748)	(58,250)
Balance, end of period	$ 109,358	$ 85,326	$ 109,358	$ 85,326

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 82,042	$ 74,969
Accumulated Depreciation	(13,878)	(11,565)
Property, Plant and Equipment, Net	68,164	63,404
Building
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	37,190	37,181
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	4,250	3,958
Software Development
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	17,597	15,375
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,093	3,065
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	153
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 11,145	$ 6,623

Underwriting, Acquisition and_3

Underwriting, Acquisition and Insurance Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Underwriting, Acquisition and Insurance Expenses [Abstract]
Gross commissions	$ 62,764	$ 46,977	$ 121,130	$ 90,146
Ceding commissions	(29,359)	(19,927)	(56,186)	(36,486)
Other operating expenses	38,663	28,423	72,877	54,559
Underwriting, acquisition, and insurance expenses	72,068	55,473	137,821	108,219
Salaries, bonuses and employee benefits	$ 26,000	$ 20,600	$ 50,700	$ 39,900

Stock-based Compensation Narrat

Stock-based Compensation Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 7.2	$ 4.5
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	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value	$ 502.43	$ 313.35
Fair value of restricted stock awards vested	$ 19.8	$ 12.6
Unrecognized stock-based compensation expense	$ 36
Compensation cost not yet recognized, period	2 years 7 months 6 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		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Nonvested Restricted Stock, Weighted Average Grant Date Fair Value [Abstract]
Restricted shares withheld for taxes (shares)	2,916	6,816
Restricted stock [Member]
Nonvested Restricted Stock, Number of Shares [Roll Forward]
Nonvested outstanding at the beginning of the period, shares			107,822
Granted, shares			47,689
Vested, shares			(41,502)
Forfeited, shares			(1,139)
Nonvested outstanding at the end of the period, shares	112,870		112,870
Nonvested Restricted Stock, Weighted Average Grant Date Fair Value [Abstract]
Nonvested outstanding at the beginning of the period			$ 250.86
Granted			502.43	$ 313.35
Vested			231.05
Forfeited			272.22
Nonvested outstanding at the end of the period	$ 365.35		$ 365.35
Restricted shares withheld for taxes (shares)			14,234

Stock-based Compensation Narr_3

Stock-based Compensation Narrative - Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended
	Jul. 27, 2016	Jun. 30, 2024	Jun. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised		$ 33	$ 10.6
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		6 Months Ended
	Jul. 27, 2016	Jun. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding beginning of period, shares		201,560
Granted, shares		0
Forfeited, shares		0
Exercised, shares		(72,013)
Outstanding end of period, shares		129,547
Exercisable, shares		129,547
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 1 month 6 days
Exercisable, weighted average remaining contractual term		2 years 1 month 6 days
Outstanding, aggregate intrinsic value		$ 47,839
Exercisable, aggregate intrinsic value		$ 47,839
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				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share, [Line Items]
Net income	$ 92,579	$ 98,941	$ 72,791	$ 55,800	$ 191,520	$ 128,591
Weighted Average Number of Shares Outstanding, Basic [Abstract]
Weighted average shares outstanding - basic	23,165		23,040		23,137	23,024
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Weighted average shares outstanding - diluted	23,329		23,301		23,332	23,293
Earnings Per Share, Basic [Abstract]
Earnings per share - basic	$ 4		$ 3.16		$ 8.28	$ 5.59
Earnings Per Share, Diluted [Abstract]
Earnings per share - diluted	$ 3.97		$ 3.12		$ 8.21	$ 5.52
Stock option [Member]
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Dilutive effect of shares issued under stock compensation arrangements	130		217		150	225
Restricted stock [Member]
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Dilutive effect of shares issued under stock compensation arrangements	34		44		45	44

Earnings Per Share Narrative (D

Earnings Per Share Narrative (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Restricted stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities	44,000	0	44,000	47,000

Income Taxes (Details)

Income Taxes (Details)	6 Months Ended
	Jun. 30, 2024 Rate	Jun. 30, 2023 Rate
Income Tax Disclosure [Abstract]
Effective tax rate	17.30%	18.90%
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	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves for unpaid losses and loss adjustment expenses, beginning of year	$ 1,692,875	$ 1,238,402
Reinsurance recoverable on unpaid losses	292,369	208,408	$ 241,357	$ 177,039
Net reserves for unpaid losses and loss adjustment expenses, beginning of year	1,451,518	1,061,363
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Current year	398,058	305,536
Prior years	(17,947)	(19,460)
Total net losses and loss adjustment expenses incurred	380,111	286,076
Payments:
Current year	8,114	8,058
Prior years	102,829	92,055
Total payments	110,943	100,113
Net reserves for unpaid losses and loss adjustment expenses, end of period	1,720,686	1,247,326
Reinsurance recoverable on unpaid losses	292,369	208,408	$ 241,357	$ 177,039
Gross reserves for unpaid losses and loss adjustment expenses, end of period	$ 2,013,055	$ 1,455,734

Reserves for Unpaid Losses an_4

Reserves for Unpaid Losses and Loss Adjustment Expenses Narrative (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Claims Development [Line Items]
Adverse (Favorable) development on prior year loss reserves	$ (17,947)	$ (19,460)
Current year	398,058	305,536
Accident Years 2021 and 2022
Claims Development [Line Items]
Adverse (Favorable) development on prior year loss reserves		$ (27,100)
Short Duration Insurance Contract Accident Years 2021 through 2022
Claims Development [Line Items]
Adverse (Favorable) development on prior year loss reserves	$ (30,700)

Reinsurance (Details)

Reinsurance (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Premiums Written, Net [Abstract]
Premiums written - direct	$ 529,770	$ 438,222	$ 978,414	$ 795,810
Premiums written - ceded	(99,534)	(73,181)	(197,124)	(131,739)
Net written premiums	430,236	365,041	781,290	664,071
Premiums Earned, Net [Abstract]
Premiums earned - direct	430,535	326,697	833,127	620,233
Premiums earned - ceded	(98,074)	(69,651)	(191,148)	(126,029)
Net earned premiums	332,461	257,046	641,979	494,204
Ceded incurred losses and loss adjustment expenses	40,944	25,981	70,205	61,990
Reinsurance recoverables on paid losses	9,723		9,723		$ 6,479
Reinsurance recoverable on unpaid losses	292,369	$ 208,408	292,369	$ 208,408	241,357	$ 177,039
Reinsurance recoverables, net	$ 302,092		$ 302,092		$ 247,836

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Debt Issuance Costs, Net	$ (2,016)	$ (2,154)
Debt	183,984	183,846
Senior Notes
Debt Instrument [Line Items]
Debt instrument borrowing capacity	$ 200,000
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	11,000
Weighted Average Interest Rate	7.07%
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	$ 50,000
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				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized (losses) gains on fixed-maturity securities arising during the period, before income taxes	$ (6,892)		$ (18,236)		$ (19,476)	$ 2,934
Income tax benefit (expense)	1,447		3,830		4,090	(616)
Unrealized (losses) gains arising during the period, net of income taxes	(5,445)		(14,406)		(15,386)	2,318
Less reclassification adjustment [Abstract]
Net realized losses on fixed-maturity securities, before income taxes	(207)		(404)		(218)	(1,316)
Income tax benefit	44		85		46	276
Reclassification adjustment included in net income	(163)		(319)		(172)	(1,040)
Change in allowance for credit losses on investments, before income taxes	476		25		486	(56)
Income tax (expense) benefit	(100)		(5)		(102)	12
Reclassification adjustment included in net income	376		20		384	(44)
Other comprehensive (loss) income	$ (5,658)	$ (9,940)	$ (14,107)	$ 17,509	$ (15,598)	$ 3,402

Uncategorized Items - knsl-2024

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 126,694,000
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 156,274,000