Kinsale Capital (KNSL) 10-K 25 Feb 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 18, 2021	Jun. 30, 2020
Document and Entity Information [Abstract]
Entity Registrant Name	KINSALE CAPITAL GROUP, INC.
Trading Symbol	KNSL
Entity Listing, Description	Common Stock, par value $0.01
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
City Area Code	804
Local Phone Number	289-1300
Entity Incorporation, State or Country Code	DE
Entity Central Index Key	0001669162
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-37848
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		22,773,134
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Public Float			$ 3,241,859,629
Security Exchange Name	NASDAQ
Entity Tax Identification Number	98-0664337
ICFR Auditor Attestation Flag	true

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Investments:
Fixed-maturity securities available-for-sale, at fair value (amortized cost: $1,031,817 at 2020; $714,817 at 2019)	$ 1,081,800	$ 729,532
Equity securities, at fair value (cost: $98,758 in 2020; $64,245 in 2019)	129,662	78,294
Total investments	1,211,462	807,826
Cash and cash equivalents	77,093	100,408
Investment income due and accrued	6,637	4,743
Premiums receivable, net	48,641	34,483
Reinsurance recoverables	93,215	72,574
Ceded unearned premiums	24,265	16,118
Deferred policy acquisition costs, net of ceding commissions	31,912	23,564
Intangible assets	3,538	3,538
Deferred income tax asset, net	0	3,374
Other assets	50,133	23,922
Total assets	1,546,896	1,090,550
Liabilities:
Gross reserves for unpaid losses and loss adjustment expenses, beginning of year	636,013	460,058
Unearned premiums	260,986	187,374
Payable to reinsurers	12,672	7,151
Accounts payable and accrued expenses	13,651	12,366
Credit facility	42,570	16,744
Deferred income tax liability, net	4,648	0
Other liabilities	118	977
Total liabilities	970,658	684,670
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value, 400,000,000 shares authorized, 22,757,251 shares issued and outstanding at December 31, 2020; 22,205,665 shares issued and outstanding at December 31, 2019	228	222
Additional paid-in capital	291,315	229,229
Retained earnings	243,315	162,911
Accumulated other comprehensive income	41,380	13,518
Stockholders' equity	576,238	405,880
Total liabilities and stockholders' equity	$ 1,546,896	$ 1,090,550

Consolidated Balance Sheets - (

Consolidated Balance Sheets - (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Investments:
Fixed maturity securities available-for-sale, amortized cost	$ 1,031,817	$ 714,817
Equity securities - cost	$ 98,758	$ 64,245
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)	22,757,251	22,205,665
Common stock, shares outstanding (in shares)	22,757,251	22,205,665

Consolidated Statements of Inco

Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Gross written premiums	$ 552,814	$ 389,694	$ 275,538
Ceded written premiums	(74,595)	(47,633)	(39,924)
Net written premiums	478,219	342,061	235,614
Change in unearned premiums	(65,465)	(59,080)	(22,926)
Net earned premiums	412,754	282,981	212,688
Net investment income	26,110	20,133	15,688
Change in the fair value of equity securities	16,855	12,389
Change in fair value of equity securities			(6,555)
Net realized investment gains	3,533	359	281
Other income	634	26	12
Total revenues	459,886	315,888	222,114
Expenses:
Losses and loss adjustment expenses	263,802	169,563	128,041
Underwriting, acquisition and insurance expenses	94,296	70,217	53,425
Other expenses	1,375	57	168
Total expenses	359,473	239,837	181,634
Income before income taxes	100,413	76,051	40,480
Income tax expense	11,994	12,735	6,693
Net income	88,419	63,316	33,787
Other comprehensive income (loss):
Change in unrealized gains (losses) on available-for-sale investments, net of taxes	27,862	14,774	(5,469)
Total comprehensive income	$ 116,281	$ 78,090	$ 28,318
Earnings per share:
Basic	$ 3.96	$ 2.94	$ 1.60
Diluted	$ 3.87	$ 2.86	$ 1.56
Weighted-average common shares outstanding:
Basic	22,319	21,528	21,090
Diluted	22,852	22,136	21,685

Consolidated Statements of In_2

Consolidated Statements of Income and Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other comprehensive income (loss):
Change in unrealized gains (losses), taxes	$ 7,406	$ 3,927	$ (1,453)

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings [Member]Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss) [Member]Cumulative Effect, Period of Adoption, Adjusted Balance
Balance, shares at Dec. 31, 2017	21,036,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, shares	206,000
Balance, shares at Dec. 31, 2018	21,242,000
Balance at Dec. 31, 2017	$ 238,189	$ 210	$ 155,082	$ 73,502			$ 9,395
Balance (Accounting Standards Update 2016-01 [Member]) at Dec. 31, 2017					$ 6,490	$ 79,992		$ (6,490)	$ 2,905
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification of tax effect of TCJA | Accounting Standards Update 2018-02 [Member]				(1,308)			1,308
Issuance of stock under stock-based compensation plan	1,808	2	1,806
Stock-based compensation expense	1,597		1,597
Dividends declared	(5,926)			(5,926)
Other comprehensive income (loss), net of income tax	(5,469)						(5,469)
Net income	33,787			33,787
Balance at Dec. 31, 2018	$ 263,986	212	158,485	106,545			(1,256)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued, shares	742,000
Stock-based compensation, shares	229,000
Restricted shares withheld for taxes, shares	(7,000)
Balance, shares at Dec. 31, 2019	22,205,665
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance costs	$ 65,879	8	65,871
Issuance of stock under stock-based compensation plan	2,750	2	2,748
Stock-based compensation expense	2,742		2,742
Restricted shares withheld for taxes	(617)		(617)
Dividends declared	(6,950)			(6,950)
Other comprehensive income (loss), net of income tax	14,774						14,774
Net income	63,316			63,316
Balance at Dec. 31, 2019	$ 405,880	222	229,229	162,911			13,518
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued, shares	311,000
Stock-based compensation, shares	252,000
Restricted shares withheld for taxes, shares	(12,000)
Balance, shares at Dec. 31, 2020	22,757,251
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standard for credit losses | Accounting Standards Update 2016-13 [Member]	$ 78			78
Issuance of common stock, net of issuance costs	56,698	3	56,695
Issuance of stock under stock-based compensation plan	3,622	3	3,619
Stock-based compensation expense	3,575		3,575
Restricted shares withheld for taxes	(1,803)		(1,803)
Dividends declared	(8,093)			(8,093)
Other comprehensive income (loss), net of income tax	27,862						27,862
Net income	88,419			88,419
Balance at Dec. 31, 2020	$ 576,238	$ 228	$ 291,315	$ 243,315			$ 41,380

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared, per share	$ 0.36	$ 0.32	$ 0.28

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net income	$ 88,419	$ 63,316	$ 33,787
Adjustments to reconcile net income to net cash provided by operating activities:
Change in the fair value of equity securities	(16,855)	(12,389)
Change in fair value of equity securities			6,555
Net investment gains	(3,533)	(359)	(281)
Deferred tax (benefit) expense	616	(125)	(3,230)
Depreciation and amortization	1,574	682	631
Stock compensation expense	3,575	2,742	1,597
Change in operating assets and liabilities:
Investment income due and accrued	(1,894)	(960)	(706)
Premiums receivable, net	(14,158)	(10,230)	(4,466)
Reserves for unpaid loss and loss adjustment expenses	175,955	90,906	53,435
Unearned premiums	73,612	59,124	25,140
Reinsurance balances, net	(23,267)	(13,246)	(8,070)
Deferred policy acquisition costs	(8,348)	(8,763)	(3,026)
Income taxes (recoverable) payable	(1,611)	1,221	18
Accounts payable and accrued expenses	3,087	2,972	464
Other	2,802	3,466	2,132
Net cash provided by operating activities	279,974	178,357	103,980
Investing Activities:
Purchase of property and equipment	(32,875)	(19,622)	(1,273)
Sale of property and equipment	5,077	0	0
Purchases - fixed-maturity securities	(530,732)	(306,203)	(194,989)
Purchases - equity securities	(36,822)	(29,887)	(12,656)
Sales - fixed-maturity securities	119,749	35,526	10,427
Sales - equity securities	2,367	21,459	2,429
Maturities and calls - fixed-maturity securities	93,803	67,934	89,522
Net cash used in investing activities	(379,433)	(230,793)	(106,540)
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	56,698	65,879	0
Proceeds from credit facility	25,700	17,300	0
Debt issuance costs	0	(628)	0
Payroll taxes withheld and remitted on share-based payments	(1,803)	(617)	0
Common stock issued, stock options exercised	3,622	2,750	1,808
Dividends paid	(8,073)	(6,929)	(5,906)
Net cash provided by (used in) financing activities	76,144	77,755	(4,098)
Net change in cash and cash equivalents	(23,315)	25,319	(6,658)
Cash and cash equivalents at beginning of period	100,408	75,089	81,747
Cash and cash equivalents at end of period	$ 77,093	$ 100,408	$ 75,089

Description of business

Description of business	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of business	Description of businessKinsale Capital Group, Inc., an insurance holding company, is a Delaware corporation that was formed in 2009 and conducts its operations through its wholly-owned subsidiaries ("KCGI" and together with its subsidiaries, the "Company"). Kinsale Capital Group, Inc. writes excess and surplus lines insurance on a non-admitted basis principally through its insurance subsidiary, Kinsale Insurance Company ("Kinsale Insurance"), which is authorized to write business in 50 states, the District of Columbia, the Commonwealth of Puerto Rico and the U.S. Virgin Islands. Kinsale Capital Group, Inc. also markets certain products through its subsidiary, Aspera Insurance Services, Inc. ("Aspera"), an insurance broker.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of significant accounting policies	Summary of significant accounting policies Principles of consolidation The accompanying consolidated financial statements include the accounts of Kinsale Capital Group, Inc. and its wholly-owned subsidiaries (referred to as "Kinsale" or, with its subsidiaries, the "Company"). All significant intercompany balances and transactions have been eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the current year's presentation. Use of estimates The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles ("U.S. GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Management periodically reviews its estimates and assumptions. These reviews include evaluating the adequacy of reserves for unpaid losses and loss adjustment expenses, allowance for doubtful accounts and uncollectible reinsurance, fair value of investments, as well as evaluating the investment portfolio for credit impairments. Cash and cash equivalents The Company considers all highly liquid investments with an original maturity of three months or less to be cash equivalents. Short-term investments Short-term investments are carried at cost, which approximates fair value. Short-term investments have maturities greater than three months but less than one year at the date of purchase. There were no short-term investments at December 31, 2020 or December 31, 2019. Fixed-maturity and equity securities Fixed-maturity securities are classified as available-for-sale and reported at fair value. Unrealized gains and losses on these securities are excluded from net earnings but are recorded as a separate component of other comprehensive income and stockholders' equity, net of deferred income taxes. Equity securities are reported at fair value. Changes in unrealized gains and losses in fair value of these investments are recognized in net income. 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. See Note 2 for further discussion of credit losses. Interest on fixed-maturity securities is credited to earnings as it accrues. Premiums and discounts are amortized or accreted using the effective interest method over the lives of the related fixed maturities, or to the earliest call date for securities purchased at a premium. Dividends on equity securities are included in earnings on the ex-dividend date. Realized gains and losses on disposition of investments are based on specific identification of the investments sold on the trade date. Reinsurance Reinsurance premiums, commissions, and ceded unearned premiums on reinsured business are accounted for on a basis consistent with that used in accounting for the original policies issued and the terms of the reinsurance contracts. The Company receives ceding commissions in accordance with certain reinsurance treaties. The ceding commissions are capitalized and amortized as a reduction of underwriting, acquisition and insurance expenses. Reinsurance recoverables represent paid losses and loss adjustment expenses and reserves for unpaid losses and loss adjustment expenses ceded to reinsurers that are subject to reimbursement under reinsurance treaties. The method for determining reinsurance recoverables for unpaid losses and loss adjustment expenses involves reviewing actuarial estimates of gross unpaid losses and loss adjustment expenses to determine the Company's ability to cede unpaid losses and loss adjustment expenses under the Company's existing reinsurance contracts. This method is continually reviewed and updated and any resulting adjustments are reflected in earnings in the period identified. See Note 8 for a further discussion of the Company's reinsurance program. Premiums receivable, net Premiums receivable balances are carried at face value, net of any allowance for doubtful accounts. The allowance for doubtful accounts represents an estimate of amounts considered uncollectible based on the Company’s assessment of the collectability of receivables that are past due. The Company recorded an allowance for doubtful accounts of $3.1 million and $2.7 million at December 31, 2020 and 2019, respectively, and believes that all other amounts due are collectible. Deferred policy acquisition costs, net of ceding commissions The Company defers commissions, net of ceding commissions, and certain other costs that are directly related to the successful acquisition of insurance contracts. All eligible costs are capitalized and charged to expense in proportion to premium earned over the estimated policy life. To the extent that unearned premiums on existing policies are not adequate to cover the related costs and expenses, referred to as a premium deficiency, deferred policy acquisition costs are charged to earnings. The Company considers anticipated investment income in determining whether a premium deficiency exists. Property and equipment, net Property and equipment are stated at cost less accumulated depreciation. Depreciation of property and equipment is calculated using the straight-line method over the estimated useful lives of the assets. The estimated useful lives range from 39 years for the parking deck and building, 15 to 20 years for land improvements, 7 to 10 years for furniture and equipment, 3 to 7 years for electronic data processing hardware and software, and from 2 to 5 years for leasehold improvements, which is the shorter of the estimated useful life or the lease term. Property and equipment are included in "other assets" in the accompanying consolidated balance sheets and consists of the following: December 31, 2020 2019 (in thousands) Building $ 31,675 $ — Parking deck 5,072 — Land 3,068 — Equipment 2,770 2,353 Software 4,815 2,356 Furniture and fixtures 1,731 1,025 Leasehold improvements — 984 Land improvements 317 — Construction in progress - corporate headquarters — 19,789 49,448 26,507 Accumulated depreciation (3,262) (3,873) Total property and equipment, net $ 46,186 $ 22,634 At December 31, 2019, construction in progress includes the purchased land and capitalized expenses related to the construction of the new corporate headquarters' building and parking deck. During 2020, the construction of the headquarters and parking deck was substantially completed and the related fixed assets were placed into service. During 2020, the Company sold a portion of both the land and parking deck for approximately $6.5 million to a real estate developer for the development of an apartment building. At December 31, 2020, the Company received $5.0 million of the proceeds from the sale and is expected to receive the remaining $1.5 million upon completion of the apartment building. This receivable is included in "other assets" on the accompanying consolidated balance sheet. Intangible assets Intangible assets are recorded at fair value at the date of acquisition. The Company's intangible assets are comprised solely of indefinite-lived intangible assets, which arose from regulatory approvals granted by the various state insurance departments to write insurance business in the respective states on a non-admitted basis. In accordance with U.S. GAAP, amortization of indefinite-lived intangible assets is not permitted. Indefinite-lived intangible assets are tested for impairment during the fourth quarter on an annual basis, or earlier if there is reason to suspect that their values may have been diminished or impaired. There were no impairments recognized in 2020, 2019, or 2018. In addition, as of December 31, 2020, no triggering events occurred that suggested an updated review was necessary. Reserves for unpaid losses and loss adjustment expenses Reserves for unpaid losses and loss adjustment expenses represent management's best estimate of ultimate unpaid cost of all reported and unreported losses and loss adjustment expenses incurred prior to the financial statement date. The estimates are based on an actuarial method that uses management’s initial expected loss ratios, expected reporting patterns for losses based on industry data and the Company’s actual reported losses and loss adjustment expenses. All estimates are regularly reviewed and, as experience develops and new information becomes known, the reserves for unpaid losses and loss adjustment expenses are adjusted as necessary. Such adjustments are reflected in the results of operations in the period in which they are determined. Although management believes that the reserves for losses and loss adjustment expenses are reasonable, due to the inherent uncertainty in estimating reserves for unpaid losses and loss adjustment expenses, it is possible that the Company’s actual incurred losses and loss adjustment expenses will not develop in a manner consistent with the assumptions inherent in the determination of these reserves. If actual liabilities exceed recorded amounts, there will be an increase to the Company’s reserves resulting in a reduction in net income and stockholders’ equity in the period in which the deficiency is identified. Furthermore, management may determine that recorded reserves are more than adequate to cover expected losses which will result in a reduction to the reserves. The Company believes that the reserves for unpaid losses and loss adjustment expenses at December 31, 2020 and 2019 are adequate and represent a reasonable estimate of the Company's future obligations. See Note 7 for a further discussion of reserves for unpaid losses and loss adjustment expenses. Revenue recognition Premiums are recognized as revenue ratably over the term of the insurance contracts, net of ceded reinsurance. Unearned premiums are calculated on a daily pro rata basis. Income taxes Deferred income tax assets and liabilities are determined based on the difference between the recorded amounts and the tax bases of assets and liabilities, using enacted tax rates expected to be in effect during the year in which the basis differences reverse. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are recorded when it is more likely than not that some portion, or all, of the deferred tax assets will not be realizable. Management evaluates the realizability of the deferred tax assets and assesses the need for any valuation allowance adjustment. Valuation allowances on deferred tax assets are estimated based on the Company's assessment of the realizability of such amounts. The Company provides for uncertain tax positions, and the related interest and penalties, based upon management’s assessment of whether a tax benefit is more likely than not to be sustained upon examination by tax authorities. To the extent that the anticipated tax outcome of these uncertain tax positions changes, such changes in estimate will impact the income tax provision in the period in which such determination is made. The Company recognizes accrued interest and penalties related to uncertain tax positions as a component of income tax expense. The Company uses the portfolio approach to release stranded tax effects in accumulated other comprehensive income ("AOCI") related to its available-for-sale fixed-maturity securities. Under this approach, stranded tax effects remaining in AOCI are released only when the entire portfolio of the available-for-sale fixed-maturity securities are liquidated, sold or extinguished. Commitments and contingencies Liabilities for loss contingencies, arising from noninsurance policy claims, assessments, litigation, fines, and penalties and other sources, are recorded when it is probable that a liability has been incurred and the amount of the assessment and/or remediation can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred. Fair value of financial instruments The fair values of certain financial instruments are determined based on the fair value hierarchy. U.S. GAAP guidance requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The guidance also describes three levels of inputs that may be used to measure fair value. The following was considered in the estimation of fair value for each class of financial instruments for which it was practicable to estimate that value. The Company’s investment accounting vendor uses independent pricing vendors to estimate the fair value of fixed-maturity securities and the Company’s management reviews these prices for reasonableness. U.S. Treasury securities that have quoted prices in active markets are included in the amounts disclosed as Level 1. For other fixed-maturity securities, 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 fixed-maturity securities are included in the amounts disclosed as Level 2. For those fixed-maturity securities where significant inputs are unobservable, Level 3 inputs, the Company's investment accounting vendor obtains valuations from pricing vendors using the market approach and income approach valuation techniques. For equity securities, the Company’s investment accounting vendor uses prices from independent pricing vendors to estimate fair value. The fair value estimates of exchange traded funds are based on quoted prices in an active market and are disclosed as Level 1. The fair value estimates of preferred stock are based on observable market data and, as a result, are disclosed as Level 2. Fair value disclosures for investments are included in Notes 2 and 3. Stock-based compensation Stock-based compensation is expensed based upon the estimated fair value of employee stock awards. Compensation cost for awards of equity instruments to employees is measured based on the grant-date fair value of those awards and compensation expense is recognized over the service period that the awards vest. Forfeitures of stock-based compensation awards are recognized as they occur. See Note 9 for further discussion and related disclosures regarding stock-based compensation. Recently adopted accounting pronouncements Accounting Standards Update ("ASU") 2016-13, Financial Instruments – Credit Losses (Topic 326) On June 16, 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326)" to provide more useful information about the expected credit losses on financial instruments. The update requires a financial asset measured at amortized cost to be presented at the net amount expected to be collected by means of an allowance for credit losses that runs through net income. Credit losses relating to available-for-sale fixed-maturity securities must also be recorded through an allowance for credit losses. However, the amendments limit the amount of the allowance to the amount by which fair value is below amortized cost. The measurement of credit losses on available-for-sale securities is similar under previous U.S. GAAP, but the update requires the use of the allowance account through which amounts can be reversed, rather than through an irreversible write-down. The FASB has issued additional ASUs on Topic 326 that do not change the core principle of the guidance in ASU 2016-13 but clarify certain aspects of it. Effective January 1, 2020, the Company adopted this ASU using the modified-retrospective approach and recorded a cumulative effect adjustment to beginning retained earnings. The adoption of this ASU resulted in the recognition of an allowance for credit loss related to the Company’s reinsurance recoverables. However, since the Company enters into contracts with reinsurers that have A.M. Best ratings of “A” (Excellent) or better, the allowance was not material to the Company’s consolidated financial statements. ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract On August 29, 2018, the FASB issued new guidance on a customer's accounting for implementation, set-up and other up-front costs incurred in a cloud computing arrangement hosted by the vendor. The new guidance requires an entity to determine the stage of a project that the implementation activity relates to and the nature of the associated costs in order to determine whether those costs should be expensed as incurred or capitalized. The new guidance also requires the entity to amortize the capitalized implementation costs as an expense over the term of the hosting arrangement. Effective January 1, 2020, the Company adopted ASU 2018-15 using a modified-retrospective approach. The adoption of ASU 2018-15 did not have a material impact on the Company's consolidated financial statements. Prospective accounting pronouncements ASU 2019-12, Income Taxes - Simplifying the Accounting for Income Taxes In December 2019, the FASB issued updated guidance for the accounting for income taxes. The updated guidance is intended to simplify the accounting for income taxes by removing several exceptions contained in existing guidance and amending other existing guidance to simplify several other income tax accounting matters. The updated guidance is effective for annual reporting periods beginning after December 15, 2020. Early adoption is permitted. The adoption of the guidance will not have a material effect on the Company’s consolidated financial statements. There are no other prospective accounting standards which, upon their effective date, would have a material impact on the Company's consolidated financial statements.

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Investments	Investments Available-for-sale investments The following tables summarize the Company’s available-for-sale investments at December 31, 2020 and 2019: December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (in thousands) Fixed maturities: Obligations of states, municipalities and political subdivisions $ 216,181 $ 14,792 $ (67) $ 230,906 Corporate and other securities 294,854 21,840 (86) 316,608 Asset-backed securities 236,813 4,230 (382) 240,661 Commercial mortgage-backed securities 66,110 4,886 (27) 70,969 Residential mortgage-backed securities 217,859 4,938 (141) 222,656 Total fixed-maturity investments $ 1,031,817 $ 50,686 $ (703) $ 1,081,800 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 110 $ 2 $ — $ 112 Obligations of states, municipalities and political subdivisions 166,312 7,542 (961) 172,893 Corporate and other securities 180,287 4,736 (255) 184,768 Asset-backed securities 141,123 1,272 (471) 141,924 Commercial mortgage-backed securities 54,627 1,658 (239) 56,046 Residential mortgage-backed securities 172,358 1,819 (388) 173,789 Total fixed-maturity investments $ 714,817 $ 17,029 $ (2,314) $ 729,532 Available-for-sale investments 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 change 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 the 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. 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. Beginning on January 1, 2020, credit losses are recognized through an allowance account. See Note 1 - Recently adopted accounting pronouncements - ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) for additional information. The Company reports investment income due and accrued separately from fixed-maturity securities, available for sale, 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 net realized gains (losses) on investments at the time the issuer of the bond defaults or is expected to default on payments. 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: December 31, 2020 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: Obligations of states, municipalities and political subdivisions $ 6,412 $ (67) $ — $ — $ 6,412 $ (67) Corporate and other securities 3,829 (86) — — 3,829 (86) Asset-backed securities 57,750 (149) 23,825 (233) 81,575 (382) Commercial mortgage-backed securities 4,971 (27) — — 4,971 (27) Residential mortgage-backed securities 46,869 (129) 266 (12) 47,135 (141) Total fixed-maturity investments $ 119,831 $ (458) $ 24,091 $ (245) $ 143,922 $ (703) At December 31, 2020, the Company held 60 fixed-maturity securities with a total estimated fair value of $143.9 million and gross unrealized losses of $0.7 million. Of those securities, 12 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 December 31, 2020, unrealized losses were caused by interest rate changes or other market factors and were not credit-specific issues. At December 31, 2020, 81.6% of the Company’s fixed-maturity securities were rated "A-" or better and all of Company's fixed-maturity securities made expected coupon payments under the contractual terms of the securities. Based on its review, the Company concluded that there were no credit losses from fixed-maturity securities with unrealized losses for the year ended December 31, 2020. December 31, 2019 Less than 12 Months 12 Months or Longer Total Estimated Fair Value Gross Unrealized Holding Losses Estimated Fair Value Gross Unrealized Holding Losses Estimated Fair Value Gross Unrealized Holding Losses (in thousands) Fixed maturities: Obligations of states, municipalities and political subdivisions $ 28,997 $ (961) $ 254 $ — $ 29,251 $ (961) Corporate and other securities 22,409 (251) 1,509 (4) 23,918 (255) Asset-backed securities 21,371 (79) 44,115 (392) 65,486 (471) Commercial mortgage-backed securities 16,352 (224) 2,508 (15) 18,860 (239) Residential mortgage-backed securities 36,986 (148) 24,815 (240) 61,801 (388) Total fixed-maturity investments $ 126,115 $ (1,663) $ 73,201 $ (651) $ 199,316 $ (2,314) Contractual maturities of available-for-sale fixed-maturity securities The amortized cost and estimated fair value of available-for-sale fixed-maturity securities at December 31, 2020 are summarized, by contractual maturity, as follows: Amortized Estimated Cost Fair Value (in thousands) Due in one year or less $ 15,545 $ 15,782 Due after one year through five years 107,150 115,390 Due after five years through ten years 156,958 169,711 Due after ten years 231,382 246,631 Asset-backed securities 236,813 240,661 Commercial mortgage-backed securities 66,110 70,969 Residential mortgage-backed securities 217,859 222,656 Total fixed maturities $ 1,031,817 $ 1,081,800 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. Net investment income The following table presents the components of net investment income: Year Ended December 31, 2020 2019 2018 (in thousands) Interest: Taxable bonds $ 20,493 $ 14,853 $ 9,474 Municipal bonds (tax exempt) 3,618 3,692 4,298 Cash equivalents and short-term investments 262 842 1,017 Dividends on equity securities 3,512 2,136 2,014 Gross investment income 27,885 21,523 16,803 Investment expenses (1,775) (1,390) (1,115) Net investment income $ 26,110 $ 20,133 $ 15,688 Realized investment gains and losses The following table presents realized investment gains and losses: Year Ended December 31, 2020 2019 2018 (in thousands) Fixed-maturity securities: Realized gains $ 4,022 $ 567 $ 263 Realized losses (383) (79) (17) Net realized gains from fixed-maturity securities 3,639 488 246 Equity securities: Realized gains — 556 57 Realized losses (119) (688) (22) Net realized (losses) gains from equity securities (119) (132) 35 Short-term securities - realized gains 13 3 — Net realized investment gains $ 3,533 $ 359 $ 281 Change in net unrealized gains (losses) on investments The change in net unrealized gains for fixed-maturity securities was $35.3 million and $18.7 million for the years ended December 31, 2020 and 2019, respectively. The change in net unrealized losses for fixed-maturity securities was $6.9 million for the year ended December 31, 2018. Insurance – statutory deposits The Company had invested assets with a carrying value of $6.9 million on deposit with state regulatory authorities at both December 31, 2020 and 2019.

Fair value measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurementsFair value is estimated for each class of financial instrument for which it was practical to estimate fair value. 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. Treasury and exchange traded funds are generally based on Level 1 inputs which use quoted prices in active markets for identical assets. For other fixed-maturity securities and 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 consolidated financial statements at December 31, 2020 and 2019, 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 December 31, 2020 and 2019, by level within the fair value hierarchy. December 31, 2020 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: Obligations of states, municipalities and political subdivisions $ — $ 230,906 $ — $ 230,906 Corporate and other securities — 316,608 — 316,608 Asset-backed securities — 240,661 — 240,661 Commercial mortgage-backed securities — 70,969 — 70,969 Residential mortgage-backed securities — 222,656 — 222,656 Total fixed maturities — 1,081,800 — 1,081,800 Equity securities: Exchange traded funds 98,050 — — 98,050 Nonredeemable preferred stock — 31,612 — 31,612 Total equity securities 98,050 31,612 — 129,662 Total $ 98,050 $ 1,113,412 $ — $ 1,211,462 December 31, 2019 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 112 $ — $ — $ 112 Obligations of states, municipalities and political subdivisions — 172,893 — 172,893 Corporate and other securities — 184,768 — 184,768 Asset-backed securities — 141,924 — 141,924 Commercial mortgage-backed securities — 56,046 — 56,046 Residential mortgage-backed securities — 173,789 — 173,789 Total fixed maturities 112 729,420 — 729,532 Equity securities: Exchange traded funds 54,463 — — 54,463 Nonredeemable preferred stock — 23,831 — 23,831 Total equity securities 54,463 23,831 — 78,294 Total $ 54,575 $ 753,251 $ — $ 807,826 There were no assets or liabilities measured at fair value on a nonrecurring basis as of December 31, 2020 or 2019. The carrying value of cash equivalents approximates its fair value at December 31, 2020 and 2019, due to the short-term maturities of these assets. In addition, the estimated fair value of the Credit Facility approximated its carrying value as of December 31, 2020 and 2019. See Note 11 for further information regarding the Credit Facility.

Deferred policy acquisition cos

Deferred policy acquisition costs	12 Months Ended
	Dec. 31, 2020
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 years ended: Year Ended December 31, 2020 2019 2018 (in thousands) Balance, beginning of year $ 23,564 $ 14,801 $ 11,775 Policy acquisition costs deferred: Direct commissions 80,682 56,841 40,546 Ceding commissions (18,879) (12,373) (11,239) Other underwriting and policy acquisition costs 4,478 3,727 3,141 Policy acquisition costs deferred 66,281 48,195 32,448 Amortization of net policy acquisition costs (57,933) (39,432) (29,422) Balance, end of year $ 31,912 $ 23,564 $ 14,801 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.

Underwriting, acquisition and i

Underwriting, acquisition and insurance expenses	12 Months Ended
	Dec. 31, 2020
Underwriting, Acquisition and Insurance Expenses [Abstract]
Underwriting, acquisition and insurance expenses	Underwriting, acquisition and insurance expenses Underwriting, acquisition and insurance expenses consist of the following: Year Ended December 31, 2020 2019 2018 (in thousands) Underwriting, acquisition and insurance expenses incurred: Direct commissions $ 69,922 $ 48,382 $ 36,885 Ceding commissions (16,145) (12,347) (10,448) Other operating expenses 40,519 34,182 26,988 Total $ 94,296 $ 70,217 $ 53,425 Other operating expenses within underwriting, acquisition and insurance expenses included salaries, employee benefits and bonus expense of $35.9 million, $27.8 million and $19.7 million, for the years ended December 31, 2020, 2019 and 2018, respectively.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income taxes	Income taxes The Company’s subsidiaries file a consolidated U.S. federal income tax return. Under a tax sharing agreement, KCGI collects from or refunds to its subsidiaries the amount of taxes determined as if KCGI and the subsidiaries filed separate returns. The Company is no longer subject to income tax examination by tax authorities for the years ended before January 1, 2017. The Coronavirus Aid, Relief, and Economic Security (“CARES”) Act was enacted on March 27, 2020. The purpose of the CARES Act is to provide emergency assistance and health care response for individuals, families, and businesses affected by the 2020 coronavirus pandemic. The CARES Act builds on and clarifies a number of changes in corporate tax law implemented by the Tax Cuts and Jobs Act. The CARES Act will not have a significant impact on the Company's consolidated financial statements. Income tax expense includes the following components for the years ending December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 (in thousands) Current federal income tax expense $ 11,378 $ 12,860 $ 9,923 Deferred federal income tax (benefit) expense 616 (125) (3,230) Income tax expense $ 11,994 $ 12,735 $ 6,693 The Company paid $13.0 million, $11.6 million and $9.9 million in federal income taxes during the years ended December 31, 2020, 2019 and 2018, respectively. Current income taxes recoverable was $1.2 million at December 31, 2020, and included in "other assets" in the accompanying consolidated balance sheets. Current income taxes payable was $0.4 million at December 31, 2019, and included in "other liabilities" in the accompanying consolidated balance sheets. The prevailing federal income tax rate was 21% in 2020, 2019 and 2018. The Company’s effective income tax rate on income before income taxes differs from the prevailing federal income tax rate and is summarized as follows: Year ended December 31, 2020 2019 2018 (in thousands) Income tax expense at federal income tax rate $ 21,087 $ 15,971 $ 8,501 Stock options exercised (7,634) (2,411) (918) Tax-exempt investment income (565) (577) (672) Restricted stock award vesting (658) (153) — Other (236) (95) (218) Total $ 11,994 $ 12,735 $ 6,693 The significant components of the net deferred tax (liability) asset are summarized as follows: December 31, 2020 2019 (in thousands) Deferred tax assets: Unpaid losses and loss adjustment expenses $ 11,736 $ 8,199 Unearned premiums 9,942 7,193 Organizational costs 128 162 Stock compensation 865 765 State operating loss carryforwards 3,833 1,497 Allowance for doubtful accounts 649 570 Other 126 256 Deferred tax assets before allowance 27,279 18,642 Less: valuation allowance (3,491) (1,592) Total deferred tax assets 23,788 17,050 Deferred tax liabilities: Unrealized gains on fixed-maturity securities 10,497 3,090 Unrealized gains on equity securities 6,552 2,995 Deferred policy acquisition costs, net of ceding commissions 6,701 4,949 Property and equipment 2,433 10 Intangible assets 743 743 Transition adjustment for loss reserve discount 1,281 1,537 Other 229 352 Total deferred tax liabilities 28,436 13,676 Net deferred tax (liability) asset $ (4,648) $ 3,374 At December 31, 2020 and 2019, the Company had state net operating losses ("NOLs") of $80.9 million and $31.6 million, respectively. The state NOLs are available to offset future taxable income or reduce taxes payable and begin expiring in 2029. Management evaluates the need for a valuation allowance related to its deferred tax assets. At December 31, 2020 and 2019, the Company recorded a tax valuation allowance equal to the state NOLs and the deferred tax assets, net of existing deferred tax liabilities that were expected to reverse in future periods, related to certain state jurisdictions. No other valuation allowances were established against the Company’s deferred tax assets at December 31, 2020 and 2019, as the Company believes that it is more likely than not that the remaining deferred tax assets will be realized given the carry back availability, reversal of existing temporary differences and future taxable income. The Company did not have any material uncertain tax positions in 2020 or 2019. Management is not aware of any events that would give rise to any uncertain tax positions.

Reserves for unpaid losses and

Reserves for unpaid losses and loss adjustment expenses	12 Months Ended
	Dec. 31, 2020
Liability for Claims and Claims Adjustment Expense [Abstract]
Reserves for unpaid losses and loss adjustment expenses	Reserves for unpaid losses and loss adjustment expenses The reserves for unpaid losses and loss adjustment expenses represent the Company's estimated ultimate cost of all unreported and reported but unpaid insured claims and the cost to adjust these losses that have occurred as of or before the balance sheet date. Reserves are estimated using individual case-basis valuations of reported claims and statistical analyses. Case reserves are established for individual claims that have been reported to the Company, typically by the Company's insureds or their brokers. Based on the information provided, case reserves are established by estimating the ultimate losses from the claim, including defense costs associated with the ultimate settlement of the claim. Incurred-but-not-reported ("IBNR") reserves are determined using actuarial methods to estimate losses that have occurred but have not yet been reported to the Company. The incurred Bornhuetter-Ferguson actuarial method ("BF method") is used to arrive at the Company's loss reserve estimates for each line of business. This method estimates the reserves based on the initial expected loss ratio and expected reporting patterns for losses. Because the Company has a limited number of years of loss experience compared to the period over which losses are expected to be reported, the Company uses industry and peer-group data, in addition to its own data, as a basis for selecting its expected reporting patterns. As part of the reserving process, the Company reviews historical data and considers the effect of various factors on claims development patterns including polices written on a "claims made" versus "occurrence" basis. Policies written on a claims made basis provide coverage to the insured only for losses incurred during the coverage period, and only if the claim was reported during a specified reporting period. Policies written on an occurrence basis provide coverage to the insured for liabilities arising from events occurring during the term of the policy, regardless of when a claim is actually made. Accordingly, claims related to policies written on an occurrence basis may arise many years after a policy has lapsed. Property losses, while written on an occurrence basis, are generally reported within a short time from the date of loss, and in most instances, property claims are settled and paid within a relatively short period of time. The following table presents a reconciliation of consolidated beginning and ending reserves for unpaid losses and loss adjustment expenses: December 31, 2020 2019 2018 (in thousands) Gross reserves for unpaid losses and loss adjustment expenses, beginning of year $ 460,058 $ 369,152 $ 315,717 Less: reinsurance recoverable on unpaid losses 69,792 55,389 48,224 Adoption of new accounting standard for credit losses (282) — — Net reserves for unpaid losses and loss adjustment expenses, beginning of year 390,548 313,763 267,493 Incurred losses and loss adjustment expenses: Current year 277,140 178,986 135,078 Prior year (13,338) (9,423) (7,037) Total net losses and loss adjustment expenses incurred 263,802 169,563 128,041 Payments: Current year 27,664 19,054 14,118 Prior year 74,403 74,006 67,653 Total payments 102,067 93,060 81,771 Net reserves for unpaid losses and loss adjustment expenses, end of year 552,283 390,266 313,763 Reinsurance recoverable on unpaid losses, net of allowance 83,730 69,792 55,389 Gross reserves for unpaid losses and loss adjustment expenses, end of year $ 636,013 $ 460,058 $ 369,152 During the year ended December 31, 2020, our net incurred losses for accident years 2019 and prior developed favorably by $13.3 million. This favorable development included $10.5 million for the 2019 accident year and $1.8 million for accident year 2018. This favorable development was primarily due to reported losses emerging at a lower level than expected, largely across the other liability and excess lines of business. Current year incurred losses and loss adjustment expenses for the year ended December 31, 2020 included $23.2 million of catastrophe losses primarily related to Hurricane Laura, Hurricane Sally and the California wildfires. During the year ended December 31, 2019, our net incurred losses for accident years 2018 and prior developed favorably by $9.4 million. This favorable development included $13.0 million for the 2018 accident year and $1.6 million for the 2017 accident year. This favorable development was primarily due to reported losses emerging at a lower level than expected, on the other liability and products liability lines of business. The favorable development was offset by adverse development of $5.2 million for the 2011 through 2015 accident years. The unfavorable development was primarily attributable to the other liability occurrence line of business. This adverse development largely resulted from management’s decision to lengthen the actuarial loss development factors to provide for emergence of reported losses over a longer period of time based on trends observed in loss experience, which added a modest amount of conservatism to the Company’s IBNR reserves. During the year ended December 31, 2018, our net incurred losses for accident years 2017 and prior developed favorably by $7.0 million. This favorable development included $6.8 million for the 2017 accident year, $3.8 million for the 2016 accident year. This favorable development was primarily due to reported losses emerging at a lower level than expected, across most lines of business. The favorable development was offset in part by adverse development of $3.6 million for the 2011 through 2015 accident years. The unfavorable development was primarily attributable to the other liability occurrence line of business. Incurred and Paid Claims Development The following is information about incurred and paid claims development as of December 31, 2020, net of reinsurance, as well as cumulative claim frequency and the total of IBNR liabilities plus expected development on reported claims included within the net incurred claims amounts. The development and claims duration tables below exclude commuted multi-line quota-share reinsurance treaty ("MLQS") contracts, which would distort development patterns related to those transactions. Cumulative number of reported claims is reported on a per claim basis. The information about incurred and paid claims development for the years ended December 31, 2011 to December 31, 2019, is presented as unaudited supplementary information. Property Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2020 Accident Year 2016 2017 2018 2019 2020 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims ($ in thousands) 2016 $ 4,177 $ 3,392 $ 3,301 $ 3,278 $ 3,270 $ — 286 2017 12,473 11,705 11,676 11,631 19 1,041 2018 11,559 12,004 12,698 88 649 2019 14,914 13,909 430 636 2020 40,612 7,139 2,189 Total $ 82,120 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2016 2017 2018 2019 2020 ($ in thousands) 2016 $ 1,867 $ 3,257 $ 3,265 $ 3,265 $ 3,270 2017 9,938 11,233 11,602 11,608 2018 9,132 11,646 12,599 2019 9,852 12,581 2020 19,897 Total 59,955 All outstanding liabilities before 2016, net of reinsurance — Liabilities for claims and claim adjustment expenses, net of reinsurance $ 22,165 Historical Claims Duration The following is supplementary information about average historical claims duration as of December 31, 2020: Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance (Unaudited) Years 1 2 3 4 5 Property 66.9 % 23.3 % 3.6 % — % 0.2 % Casualty - Claims Made Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2020 Accident Year 2011 2012 2013 2014 Unaudited 2015 2016 2017 2018 2019 Unaudited 2020 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims 2011 $ 4,246 $ 3,844 $ 3,646 $ 3,609 $ 3,560 $ 3,374 $ 3,261 $ 3,225 $ 3,206 $ 3,177 $ 73 76 2012 7,913 5,749 4,205 3,102 2,845 2,477 2,314 2,207 2,136 190 138 2013 15,238 11,639 9,113 7,917 7,002 6,463 6,128 6,087 465 228 2014 18,847 14,289 11,748 11,217 10,948 10,988 10,620 824 273 2015 18,883 16,777 14,896 13,583 13,942 13,548 1,378 258 2016 19,170 14,693 14,675 14,322 13,583 2,116 310 2017 18,116 17,097 16,120 15,794 3,703 369 2018 22,429 20,234 18,612 7,275 458 2019 34,693 29,056 17,500 538 2020 55,630 48,966 738 Total $ 168,243 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 139 $ 1,037 $ 1,392 $ 2,116 $ 3,044 $ 3,042 $ 3,042 $ 3,065 $ 3,104 $ 3,104 2012 153 475 877 1,024 1,090 1,882 1,946 1,946 1,946 2013 499 1,915 4,436 5,070 5,320 5,439 5,482 5,612 2014 435 1,865 5,039 6,385 8,290 9,415 9,491 2015 217 4,496 7,563 9,238 11,372 11,522 2016 1,158 3,015 6,907 9,839 11,381 2017 340 4,897 8,252 10,484 2018 507 5,030 8,931 2019 2,487 6,005 2020 1,002 Total 69,478 All outstanding liabilities before 2011, net of reinsurance 9 Liabilities for claims and claim adjustment expenses, net of reinsurance $ 98,774 Casualty - Occurrence Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2020 Accident Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims 2011 $ 5,839 $ 5,940 $ 5,757 $ 7,340 $ 7,613 $ 8,142 $ 8,375 $ 9,023 $ 9,379 $ 9,318 $ 360 227 2012 16,977 17,436 18,803 20,401 20,579 22,001 22,401 23,223 23,197 1,288 586 2013 30,616 28,771 28,037 29,039 31,731 33,248 33,973 33,128 2,978 856 2014 47,805 40,668 38,049 36,678 39,313 41,859 42,434 5,843 1,196 2015 59,717 51,739 49,122 52,100 54,697 54,090 9,323 1,496 2016 61,440 55,680 53,549 55,534 57,401 13,928 1,434 2017 71,126 67,151 68,985 70,641 24,096 1,632 2018 86,157 78,331 78,386 44,307 1,606 2019 112,266 109,994 81,322 1,644 2020 154,619 146,945 1,076 Total $ 633,208 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 207 $ 1,596 $ 2,519 $ 3,788 $ 4,575 $ 6,363 $ 6,868 $ 8,510 $ 8,693 $ 8,745 2012 757 4,441 7,850 11,238 14,382 16,474 19,383 20,707 21,408 2013 1,099 4,469 7,957 14,890 21,348 26,715 28,248 29,610 2014 698 3,081 8,489 17,576 23,771 31,026 34,338 2015 941 3,161 12,685 28,385 37,690 41,724 2016 1,099 6,015 17,225 28,924 34,437 2017 1,581 9,352 22,407 37,736 2018 2,638 10,995 22,860 2019 3,944 16,687 2020 2,400 Total 249,945 All outstanding liabilities before 2011, net of reinsurance 46 Liabilities for claims and claim adjustment expenses, net of reinsurance $ 383,309 Historical Claims Duration The following is supplementary information about average historical claims duration as of December 31, 2020: Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance (Unaudited) Years 1 2 3 4 5 6 7 8 9 10 Casualty - claims made 4.9 % 21.2 % 24.3 % 14.4 % 13.6 % 10.1 % 1.1 % 1.0 % 0.6 % — % Casualty - occurrence 2.5 % 10.3 % 14.8 % 20.2 % 13.8 % 13.8 % 7.6 % 9.1 % 2.5 % 0.6 % Reconciliation of Incurred and Paid Claims Development to the Liability for Unpaid Claims and Claim Adjustment Expenses The reconciliation of the net incurred and paid claims development tables to the liability for unpaid claims and claim adjustment expenses in the consolidated statement of financial position is as follows: (in thousands) December 31, 2020 Net outstanding liabilities Property $ 22,165 Casualty - claims made 98,774 Casualty - occurrence 383,309 Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance 504,248 Reinsurance recoverable on unpaid claims Property 10,800 Casualty - claims made 61,100 Casualty - occurrence 11,830 Total reinsurance recoverable on unpaid claims 83,730 Unallocated claims adjustment expenses 48,035 Gross liability for unpaid claims and claim adjustment expense $ 636,013

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2020
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance The Company purchases reinsurance from other insurance companies ("reinsurers") in order to limit its exposure to large losses and enable it to underwrite policies with sufficient limits to meet policyholder needs. In a reinsurance transaction, an insurance company transfers, or cedes, part or all of its exposure to the reinsurer that receives a portion of the premium. The ceding of insurance does not legally discharge the Company from its primary liability for the full amount of the policy coverage, and therefore the Company will be required to pay the loss and bear collection risk if the reinsurer fails to meet its obligations under the reinsurance agreement. The following table summarizes the effect of reinsurance on premiums written and earned: Year Ended December 31, 2020 2019 2018 (in thousands) Written: Direct $ 552,814 $ 389,569 $ 275,538 Assumed — 125 — Ceded (74,595) (47,633) (39,924) Net written $ 478,219 $ 342,061 $ 235,614 Earned: Direct $ 479,181 $ 330,464 $ 250,397 Assumed 21 104 — Ceded (66,448) (47,587) (37,709) Net earned $ 412,754 $ 282,981 $ 212,688 Incurred losses and loss adjustment expenses were net of reinsurance recoverables (ceded incurred losses and loss adjustment expenses) of $42.0 million, $27.2 million and $25.5 million for the years ended December 31, 2020, 2019 and 2018, respectively. Reinsurance balances The following table presents reinsurance recoverables on paid and unpaid losses as of December 31, 2020 and 2019: December 31, 2020 December 31, 2019 (in thousands) Reinsurance recoverables on paid losses $ 9,485 $ 2,782 Reinsurance recoverables on unpaid losses 83,730 69,792 Reinsurance recoverables $ 93,215 $ 72,574 Credit risk exists with reinsurance ceded to the extent that any reinsurer is unable to meet the obligations assumed under the reinsurance agreements. Allowances are established for amounts deemed uncollectible. The Company evaluates the financial condition of its reinsurers and monitors concentration of credit risk arising from its exposure to individual reinsurers. All reinsurance receivables are from companies with A.M. Best ratings of "A" (Excellent) or better. To further reduce credit exposure to reinsurance recoverable balances, the Company has received letters of credit from certain reinsurers that are not authorized as reinsurers under U.S. state insurance regulations. After adoption of ASU 2016-13, the Company recorded an allowance for doubtful accounts of $0.3 million related to its reinsurance balances at December 31, 2020; however, the deterioration in the credit quality of existing reinsurers or disputes over reinsurance agreements could result in future charges. See Note 1 - Recently adopted accounting pronouncements - ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) for additional information. The Company did not record an allowance for doubtful accounts related to its reinsurance balances at December 31, 2019 and believed this was appropriate after consideration of all currently available information. At December 31, 2020, reinsurance recoverables on paid and unpaid losses from the Company’s five largest reinsurers were $26.3 million, $19.7 million, $11.9 million, $8.6 million and $6.5 million, representing 78.4% of the total balance. At December 31, 2020, prepaid reinsurance premiums ceded to five reinsurers were $6.1 million, $4.0 million, $2.7 million, $2.4 million and $2.3 million, representing 71.8% of the total balance.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Attributable to Parent [Abstract]
Stockholders' equity	Stockholders’ equity Capital Stock The Company’s authorized capital stock consists of 400,000,000 shares of common stock, par value $0.01 per share, and 100,000,000 shares of preferred stock, par value $0.01 per share. There were no shares of preferred stock issued or outstanding at December 31, 2020 or 2019. Public Offerings On August 7, 2020, the Company completed an underwritten public offering and sold and issued 310,500 shares of its common stock at a price of $190.00 per share. After deducting underwriting discounts and commissions and offering expenses, the Company received net proceeds of $56.7 million. The proceeds from the public offering were used for general corporate purposes, including to fund organic growth. On August 12, 2019, the Company completed an underwritten public offering and sold and issued 741,750 shares of its common stock at a price of $93.00 per share. After deducting underwriter discounts and commissions and offering expenses, the Company received net proceeds from the offering of approximately $65.9 million. Equity-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 Company recognized total equity-based compensation expense of $3.6 million, $2.7 million and $1.6 million for the years ended December 31, 2020, 2019 and 2018, respectively. 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. The options have a maximum contractual term of 10 years and vested in 4 equal annual installments following the date of the grant. The weighted average grant date fair value of options granted during 2016 was $2.71 per share. The value of the options granted was estimated at the date of grant using the Black-Scholes pricing model using the following assumptions: Risk-free rate of return 1.26 % Dividend yield 1.25 % Expected share price volatility (1) 18.50 % Expected life in years (2) 6.3 years (1) Expected volatility was based on the Company’s competitors within the industry. (2) Expected life was calculated using the simplified method, which was an average of the contractual term of the option and its ordinary vesting period, as the Company did not have sufficient historical data for determining the expected term of our stock option awards. A summary of option activity as of December 31, 2020, and changes during the year then ended is presented below: Number of Shares Weighted-average exercise price Weighted-average remaining years of contractual life Aggregate intrinsic value (in thousands) Outstanding at December 31, 2019 614,345 $ 16.00 Granted — — Forfeited (234) 16.00 Exercised (226,373) 16.00 Outstanding at December 31, 2020 387,738 $ 16.00 5.6 $ 71,394 Exercisable at December 31, 2020 387,738 $ 16.00 5.6 $ 71,394 The total intrinsic value of options exercised was $37.0 million during the year ended December 31, 2020 and $11.9 million during the year ended December 31, 2019. Restricted Stock Awards During 2020, the Board of Directors approved, and 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 common stock on the grant date or, if no common stock was traded on the grant date, the last preceding date for which there was a sale of common stock. 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 cash dividends. Unvested 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 equity compensation plans for the year ended is as follows: December 31, 2020 Number of Shares Weighted Average Grant Date Fair Value per Share Nonvested outstanding at the beginning of the period 122,723 $ 67.01 Granted 42,694 $ 147.45 Vested (41,010) $ 63.86 Forfeited (16,015) $ 83.79 Nonvested outstanding at the end of the period 108,392 $ 97.40 Employees surrender restricted stock awards to pay for withholding tax obligations resulting from any vesting of those awards. During the year ended December 31, 2020, restricted stock awards withheld for taxes in connection with the vesting of those awards totaled 11,966. The weighted average grant-date fair value of the Company's restricted stock awards granted during the years ended December 31, 2020, 2019, and 2018 was $147.45, $80.59 and $52.99, respectively. The fair value of restricted stock awards that vested during the year ended December 31, 2020 and 2019 was $5.8 million and $2.1 million, respectively. There were no restricted stock awards that vested during the year ended December 31, 2018. As of December 31, 2020, the Company had $8.3 million of total unrecognized stock-based compensation expense expected to be charged to earnings over a weighted-average period of 2.8 years. Subsequent Events The Board of Directors granted 3,200 restricted stock awards on January 1, 2021 under the 2016 Incentive Plan to the Company’s non-employee directors. The restricted stock awards had a fair value on the date of grant of $200.13 per share and will vest on a straight-line basis over a 1 year period. On February 11, 2021, the Company’s Board of Directors declared a cash dividend of $0.11 per share of common stock. This dividend is payable on March 12, 2021 to all stockholders of record on February 26, 2021.

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings per share	Earnings per share The following table represents a reconciliation of the numerator and denominator of the basic and diluted earnings per share computations contained in the consolidated financial statements: Year ended December 31, 2020 2019 2018 (in thousands, except per share data) Net income $ 88,419 $ 63,316 $ 33,787 Weighted average common shares outstanding - basic 22,319 21,528 21,090 Dilutive effect of shares issued under stock compensation arrangements: Stock options 469 570 591 Restricted stock awards 64 38 4 Total dilutive effect of shares issued under stock compensation arrangements 533 608 595 Weighted average common shares outstanding - diluted 22,852 22,136 21,685 Earnings per common share: Basic $ 3.96 $ 2.94 $ 1.60 Diluted $ 3.87 $ 2.86 $ 1.56 There were 35 thousand, 54 thousand and 86 thousand anti-dilutive stock awards for the years ended December 31, 2020, 2019 and 2018, respectively.

Credit Agreement

Credit Agreement	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Credit Agreement	Credit agreement On May 28, 2019, the Company entered into a Credit Agreement (the “Credit Agreement”) that provided the Company with a $50.0 million senior unsecured revolving credit facility (the “Credit Facility”) and an uncommitted accordion feature that permits the Company to increase the commitments by an additional $30.0 million. The Credit Facility has a maturity of May 28, 2024. Borrowings under the Credit Facility were used to fund construction of the Company’s new headquarters but may also be used for working capital and general corporate purposes. Loans under the Credit Facility may be subject to varying rates of interest depending on whether the loan is a Eurodollar loan or an alternate base rate (ABR) loan, at the Company's election. Eurodollar loans bear an interest rate per annum equal to adjusted LIBOR for the applicable interest period plus a margin of 1.75%. ABR loans bear an interest rate per annum equal to the higher of the prime rate, the New York Federal Reserve Board Rate or the one-month adjusted LIBOR, plus the applicable margin of 0.75% to 1.75%, depending on which interest option was applicable for the particular ABR loan. During the year ended December 31, 2020, the Company drew down $25.7 million on its Credit Facility. As of December 31, 2020, there was $42.6 million outstanding under the Credit Facility, net of debt issuance cost of $0.4 million, with a weighted average interest rate of 1.98%. For the year ended December 31, 2020, total interest expense under the Credit Facility was $1.0 million, of which $0.8 million was capitalized as part of the real estate project under construction. See Note 1 for further details. Interest paid was $0.8 million and $0.1 million for the years ended December 31, 2020 and 2019, respectively. There were no credit agreements outstanding at December 31, 2018. The Credit Agreement also contains representations and warranties and affirmative and negative covenants customary for financings of this type, as well as customary events of default. As of December 31, 2020, the Company was in compliance with all of its financial covenants under the Credit Facility.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingencies	ContingenciesContingencies 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.

Employee benefit plan

Employee benefit plan	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Employee benefit plan	Employee benefit planThe Company has established a defined contribution employee retirement plan ("Plan") in accordance with Section 401(k) of the Internal Revenue Code. Expenses related to the Plan were $1.7 million, $1.3 million and $1.0 million in 2020, 2019 and 2018, respectively.

Other comprehensive income (los

Other comprehensive income (loss)	12 Months Ended
	Dec. 31, 2020
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other comprehensive income (loss)	Other comprehensive income (loss) The following table summarizes the components of other comprehensive income (loss): Year Ending December 31, 2020 2019 2018 (in thousands) Unrealized gains (losses) on fixed-maturity securities arising during the period, before income taxes: $ 37,387 $ 19,190 $ (6,664) Income tax (expense) benefit (7,851) (4,029) 1,399 Unrealized gains (losses) arising during the period, net of income taxes 29,536 15,161 (5,265) Less reclassification adjustment: Net realized investment gains on available-for-sale investments 2,119 489 258 Income tax benefit (445) (102) (54) Reclassification adjustment included in net income 1,674 387 204 Other comprehensive income (loss) $ 27,862 $ 14,774 $ (5,469) The sale of an available-for-sale security results in amounts being reclassified from accumulated other comprehensive 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.

Underwriting information

Underwriting information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Underwriting information	Underwriting informationThe Company has one reportable segment, the Excess and Surplus Lines Insurance segment, which primarily offers commercial excess and surplus lines liability and property insurance products through its underwriting divisions. Gross written premiums by underwriting division are presented below: Year Ended December 31, 2020 2019 2018 (in thousands) Commercial: Construction $ 87,206 $ 71,035 $ 50,879 Small business 83,289 63,181 44,368 Excess casualty 76,715 51,225 37,398 Commercial property 51,789 29,115 9,166 Product liability 38,306 26,333 20,049 Allied health 37,562 23,962 16,815 Life sciences 31,027 17,821 14,505 General casualty 29,205 23,279 17,625 Professional liability 27,051 20,029 16,717 Management liability 24,061 14,820 8,161 Energy 16,985 15,371 15,586 Environmental 8,568 5,179 2,205 Health care 7,666 5,963 5,725 Inland marine 6,910 3,467 2,046 Public entity 3,007 580 1,193 Commercial insurance 1,757 1,674 1,096 Total commercial 531,104 373,034 263,534 Personal: Personal insurance 21,710 16,660 12,004 Total $ 552,814 $ 389,694 $ 275,538 Construction underwrites commercial general liability coverage on contractors focusing on new residential construction, residential remodeling and renovation and commercial construction. Small business underwrites commercial general liability on smaller risks with an emphasis on artisan contractors and premises related exposures. Excess casualty underwrites excess liability over risks that would fit within the general casualty, construction, products liability and small business divisions. Coverage is written over the Company's primary liability policies as well as those of other insurers. This division also writes excess liability over primary commercial auto liability policies written by other carriers. Commercial property underwrites first-party coverage on manufacturing facilities, government and municipal buildings, professional buildings, offices and general commercial properties, vacant properties, as well as entertainment and retail facilities. Products liability underwrites commercial general liability on manufacturers, distributors and importers of a wide array of consumer, commercial and industrial products. Allied health underwrites commercial general liability, professional liability and excess liability on allied health and social service risks including assisted living facilities, home health care agencies and outpatient medical facilities. Life sciences underwrites general liability, products liability and professional liability coverage for manufacturers, distributors and developers of dietary supplements, medical devices, pharmaceuticals, biologics, health and beauty products, durable medical equipment and clinical trials. General casualty underwrites general liability and liquor liability on hospitality, habitational and retail risks, among others, with similar premises liability loss exposures. Professional liability underwrites small-to-medium sized non-medical professional liability risks. The classes of risks include accountants, architects and engineers, financial planners, insurance agents, lawyers, realtors, and certain other professions. Management liability underwrites directors and officers liability, employment practices liability and fiduciary liability coverage on a variety of commercial and government risks. Energy underwrites commercial general liability, pollution liability, professional liability and excess liability on enterprises engaged in the business of energy production or distribution or mining including drillers, lease operators, contractors, product manufacturers and alternative energy. Environmental underwrites commercial general liability, pollution liability and professional liability on a wide range of commercial risks where environmental exposures exist that are operational in nature or related to the premises. Health care underwrites medical professional liability for physicians, surgeons, dentists, chiropractors and podiatrists. Policies cover both individuals and small practice groups. Inland marine underwrites a variety of inland marine coverages including builders risk, contractors' equipment, transportation risks and mobile equipment. Public entity underwrites law enforcement professional liability and school board liability. Commercial insurance underwrites commercial general liability on small accounts, through the Company's wholly-owned broker, Aspera. Personal insurance writes homeowners coverage on manufactured homes with a catastrophe exposure due to coastal location. The Company does business with three unaffiliated insurance brokers that generated $72.1 million, $63.8 million and $56.5 million of gross written premiums for the year ended December 31, 2020, representing 13.0%, 11.5% and 10.2% of gross written premiums, respectively. No other broker generated 10.0% or more of the gross written premiums for the year ended December 31, 2020.

Statutory financial information

Statutory financial information	12 Months Ended
	Dec. 31, 2020
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments [Abstract]
Statutory financial information	Statutory financial information Kinsale Insurance maintains its accounts in conformity with accounting practices prescribed or permitted by state regulatory authorities that vary in certain respects from U.S. GAAP. In converting from statutory accounting principles to U.S. GAAP, typical adjustments include deferral of policy acquisition costs, the inclusion of statutory nonadmitted assets and the inclusion of net unrealized gains or losses relating to fixed maturities in stockholders’ equity. The Company does not use any permitted practices that are different from prescribed statutory accounting practices. Statutory net income and statutory capital and surplus for Kinsale Insurance as of December 31, 2020, 2019, and 2018 and for the years then ended are summarized as follows: Year ended December 31, 2020 2019 2018 (in thousands) Statutory net income $ 54,338 $ 40,917 $ 34,206 Statutory capital and surplus $ 476,066 $ 348,811 $ 233,500 Kinsale Insurance is subject to risk-based capital ("RBC") requirements. RBC is a method developed by the National Association of Insurance Commissioners ("NAIC") to determine the minimum amount of statutory capital appropriate for an insurance company to support its overall business operations in consideration of its size and risk profile. The formula for determining the amount of RBC is calculated using various factors, weighted based on the perceived degree of risk, which are applied to certain financial balances and financial activity. The adequacy of a company’s actual capital is evaluated by a comparison to the RBC results, as determined by the formula. Companies that do not maintain statutory capital and surplus at a level in excess of the company action level RBC are required to take specified actions. At December 31, 2020 and 2019, actual statutory capital and surplus for Kinsale Insurance substantially exceeded the regulatory requirements.

Unaudited Selected Quarterly Fi

Unaudited Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information	Unaudited selected quarterly financial data The following is a summary of the unaudited quarterly results of operations: 2020 Quarter (in thousands, except per share data) First Second Third Fourth Gross written premiums $ 124,036 $ 134,091 $ 144,777 $ 149,910 Total revenues 80,346 117,707 122,501 139,332 Net income 5,086 30,262 14,890 38,181 Comprehensive (loss) income (4,137) 57,270 21,444 41,704 Earnings per share - basic $ 0.23 $ 1.37 $ 0.66 $ 1.69 Earnings per share - diluted $ 0.22 $ 1.33 $ 0.65 $ 1.65 2019 Quarter (in thousands, except per share data) First Second Third Fourth Gross written premiums $ 84,626 $ 94,947 $ 97,984 $ 112,137 Total revenues 72,185 72,572 78,327 92,804 Net income 18,720 13,767 12,976 17,853 Comprehensive income 25,500 20,322 16,218 16,050 Earnings per share - basic $ 0.88 $ 0.65 $ 0.60 $ 0.81 Earnings per share - diluted $ 0.86 $ 0.63 $ 0.58 $ 0.79 Due to differences in weighted average common shares outstanding, quarterly earnings per share may not add up to the totals reported for the full year.

SEC Schedule, Article 12-15, Su

SEC Schedule, Article 12-15, Summary of Investments - Other than Investments in Related Parties	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Abstract]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties	Schedule I KINSALE CAPITAL GROUP, INC. AND SUBSIDIARIES Summary of Investments—Other than Investments in Related Parties Type of Investment Cost or Amortized Cost Fair Value Amount at which shown on Balance Sheet (in thousands) Fixed maturities: Obligations of states, municipalities and political subdivisions $ 216,181 $ 230,906 $ 230,906 Corporate and other securities 294,854 316,608 316,608 Asset-backed securities 236,813 240,661 240,661 Commercial mortgage-backed securities 66,110 70,969 70,969 Residential mortgage-backed securities 217,859 222,656 222,656 Total fixed maturities 1,031,817 1,081,800 1,081,800 Equity securities: Exchange traded funds 68,032 98,050 98,050 Nonredeemable preferred stock 30,726 31,612 31,612 Total equity securities 98,758 129,662 129,662 Total investments $ 1,130,575 $ 1,211,462 $ 1,211,462

Schedule II - Condensed Financi

Schedule II - Condensed Financial Information of Registrant	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Information of Parent Company Only Disclosure	Schedule II KINSALE CAPITAL GROUP, INC. AND SUBSIDIARIES Condensed Financial Information of Registrant Balance Sheets (Parent Company Only) December 31, 2020 2019 (in thousands) Assets Cash and cash equivalents $ 8,395 $ 14,726 Due from subsidiaries 7,792 16,836 Investment in subsidiaries 600,931 391,071 Deferred income tax asset, net 587 519 Income taxes recoverable 1,177 — Other assets 290 208 Total assets $ 619,172 $ 423,360 Liabilities and Stockholders' Equity Liabilities: Accounts payable and accrued expenses $ 302 $ 260 Income taxes payable — 434 Credit facility 42,570 16,744 Other liabilities 62 42 Total liabilities 42,934 17,480 Stockholders’ equity: Common stock 228 222 Additional paid-in capital 291,315 229,229 Retained earnings 243,315 162,911 Accumulated other comprehensive income 41,380 13,518 Stockholders’ equity 576,238 405,880 Total liabilities and stockholders’ equity $ 619,172 $ 423,360 See accompanying notes to condensed financial information. See accompanying Report of Independent Registered Public Accounting Firm. Schedule II KINSALE CAPITAL GROUP, INC. AND SUBSIDIARIES Condensed Financial Information of Registrant Statements of Income and Comprehensive Income (Parent Company Only) Years Ended December 31, 2020 2019 2018 (in thousands) Revenues: Management fees from subsidiaries $ 5,709 $ 4,502 $ 3,215 Total revenues 5,709 4,502 3,215 Expenses: Other operating expenses 6,624 5,215 4,055 Other expenses 1,332 — — Total expenses 7,956 5,215 4,055 Loss before income taxes (2,247) (713) (840) Income tax benefit (8,779) (2,714) (1,158) Income before equity in net income of subsidiaries 6,532 2,001 318 Equity in net income of subsidiaries 81,887 61,315 33,469 Net income 88,419 63,316 33,787 Other comprehensive income (loss): Equity in other comprehensive earnings (losses) of subsidiaries 27,862 14,774 (5,469) Total comprehensive income $ 116,281 $ 78,090 $ 28,318 See accompanying notes to condensed financial information. See accompanying Report of Independent Registered Public Accounting Firm. Schedule II KINSALE CAPITAL GROUP, INC. AND SUBSIDIARIES Condensed Financial Information of Registrant Statements of Cash Flows (Parent Company Only) Years Ended December 31, 2020 2019 2018 (in thousands) Operating activities Net income $ 88,419 $ 63,316 $ 33,787 Adjustments to reconcile net income to net cash provided by (used in) operating activities: Deferred tax benefit (68) (150) (170) Stock compensation expense 3,575 2,742 1,597 Equity in undistributed earnings of subsidiaries (81,887) (61,315) (33,469) Changes in operating assets and liabilities 7,520 (14,247) (633) Dividends received from subsidiary — 5,000 11,500 Net cash provided by (used in) operating activities 17,559 (4,654) 12,612 Investing activities Contributions to subsidiary (100,034) (68,391) — Net cash used in investing activities (100,034) (68,391) — Financing activities Common stock issued, net of transaction costs 56,698 65,879 — Common stock issued, stock options exercised 3,622 2,750 1,808 Payroll taxes withheld and remitted on share-based payments (1,803) (617) — Dividends paid (8,073) (6,929) (5,906) Proceeds from credit facility 25,700 17,300 — Debt issuance costs — (628) — Net cash provided by (used in) financing activities 76,144 77,755 (4,098) Net change in cash and cash equivalents (6,331) 4,710 8,514 Cash and cash equivalents at beginning of year 14,726 10,016 1,502 Cash and cash equivalents at end of year $ 8,395 $ 14,726 $ 10,016 See accompanying notes to condensed financial information. See accompanying Report of Independent Registered Public Accounting Firm. KINSALE CAPITAL GROUP, INC. Condensed Financial Information of Registrant Notes to Condensed Financial Information (Parent Company Only) 1. Accounting policies Organization Kinsale Capital Group, Inc. (the "Company"), a Delaware domiciled insurance holding company, was formed on June 3, 2009 for the purpose of acquiring and managing insurance entities. Basis of presentation The accompanying condensed financial statements have been prepared using the equity method. Under the equity method, the investment in consolidated subsidiaries is stated at cost plus equity in undistributed earnings of consolidated subsidiaries since the date of acquisition. These condensed financial statements should be read in conjunction with the Company’s consolidated financial statements. Certain prior year amounts have been reclassified to conform to the current year's presentation. Estimates and assumptions Preparation of the condensed financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed financial statements and accompanying disclosures. Those estimates are inherently subject to change, and actual results may ultimately differ from those estimates. Credit agreement On May 28, 2019, the Company entered into a Credit Agreement (the “Credit Agreement”) that provided the Company with a $50.0 million senior unsecured revolving credit facility (the “Credit Facility”) and an uncommitted accordion feature that permits the Company to increase the commitments by an additional $30.0 million. The Credit Facility has a maturity of May 28, 2024. Borrowings under the Credit Facility were used to fund construction of the Company’s new headquarters but may also be used for working capital and general corporate purposes. Loans under the Credit Facility may be subject to varying rates of interest depending on whether the loan is a Eurodollar loan or an alternate base rate (ABR) loan, at the Company's election. Eurodollar loans bear an interest rate per annum equal to adjusted LIBOR for the applicable interest period plus a margin of 1.75%. ABR loans bear an interest rate per annum equal to the higher of the prime rate, the New York Federal Reserve Board Rate or the one-month adjusted LIBOR, plus the applicable margin of 0.75% to 1.75%, depending on which interest option was applicable for the particular ABR loan. During the year ended December 31, 2020, the Company drew down $25.7 million on its Credit Facility. As of December 31, 2020, there was $42.6 million outstanding under the Credit Facility, net of debt issuance cost of $0.4 million, with a weighted average interest rate of 1.98%. For the year ended December 31, 2020, total interest expense under the Credit Facility was $1.0 million, of which $0.8 million was capitalized as part of the real estate project under construction. Interest paid was $0.8 million and $0.1 million for the years ending December 31, 2020 and 2019, respectively. There were no credit agreements outstanding at December 31, 2018. The Credit Agreement also contains representations and warranties and affirmative and negative covenants customary for financings of this type, as well as customary events of default. As of December 31, 2020, the Company was in compliance with all of its financial covenants under the Credit Facility. Dividends from subsidiary Cash dividends paid to Kinsale Capital Group, Inc. by its wholly-owned subsidiary, Kinsale Insurance Company, were $5.0 million for the year ended December 31, 2019, and $11.5 million for the year ended December 31, 2018. There were no cash dividends paid by the insurance subsidiary for the year ended December 31, 2020.

Schedule V - Valuation and Qual

Schedule V - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule V - Valuation and Qualifying Accounts	Schedule V KINSALE CAPITAL GROUP, INC. AND SUBSIDIARIES Valuation and Qualifying Accounts Additions Deductions (in thousands) Balance at Beginning of Period (1) Amounts Amounts Balance Year Ended December 31, 2020: Allowance for premiums receivable $ 2,345 $ 1,240 $ 498 $ 3,087 Valuation allowance for deferred tax assets 1,592 1,899 — 3,491 Allowance for reinsurance recoverables 282 — — 282 Year Ended December 31, 2019: Allowance for premiums receivable 2,615 835 745 2,705 Valuation allowance for deferred tax assets 780 812 — 1,592 Year Ended December 31, 2018: Allowance for premiums receivable 2,112 663 160 2,615 Valuation allowance for deferred tax assets 690 90 — 780 See accompanying Report of Independent Registered Public Accounting Firm.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of consolidation	Principles of consolidation The accompanying consolidated financial statements include the accounts of Kinsale Capital Group, Inc. and its wholly-owned subsidiaries (referred to as "Kinsale" or, with its subsidiaries, the "Company"). All significant intercompany balances and transactions have been eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the current year's presentation.
Use of estimates	Use of estimatesThe preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles ("U.S. GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Management periodically reviews its estimates and assumptions. These reviews include evaluating the adequacy of reserves for unpaid losses and loss adjustment expenses, allowance for doubtful accounts and uncollectible reinsurance, fair value of investments, as well as evaluating the investment portfolio for credit impairments.
Cash and cash equivalents	Cash and cash equivalents The Company considers all highly liquid investments with an original maturity of three months or less to be cash equivalents.
Short-term investments	Short-term investments Short-term investments are carried at cost, which approximates fair value. Short-term investments have maturities greater than three months but less than one year at the date of purchase. There were no short-term investments at December 31, 2020 or December 31, 2019.
Fixed maturity and equity securities	Fixed-maturity and equity securities Fixed-maturity securities are classified as available-for-sale and reported at fair value. Unrealized gains and losses on these securities are excluded from net earnings but are recorded as a separate component of other comprehensive income and stockholders' equity, net of deferred income taxes. Equity securities are reported at fair value. Changes in unrealized gains and losses in fair value of these investments are recognized in net income. 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. See Note 2 for further discussion of credit losses.
Reinsurance	Reinsurance Reinsurance premiums, commissions, and ceded unearned premiums on reinsured business are accounted for on a basis consistent with that used in accounting for the original policies issued and the terms of the reinsurance contracts. The Company receives ceding commissions in accordance with certain reinsurance treaties. The ceding commissions are capitalized and amortized as a reduction of underwriting, acquisition and insurance expenses. Reinsurance recoverables represent paid losses and loss adjustment expenses and reserves for unpaid losses and loss adjustment expenses ceded to reinsurers that are subject to reimbursement under reinsurance treaties. The method for determining reinsurance recoverables for unpaid losses and loss adjustment expenses involves reviewing actuarial estimates of gross unpaid losses and loss adjustment expenses to determine the Company's ability to cede unpaid losses and loss adjustment expenses under the Company's existing reinsurance contracts. This method is continually reviewed and updated and any resulting adjustments are reflected in earnings in the period identified. See Note 8 for a further discussion of the Company's reinsurance program.
Premiums receivable, net	Premiums receivable, net Premiums receivable balances are carried at face value, net of any allowance for doubtful accounts. The allowance for doubtful accounts represents an estimate of amounts considered uncollectible based on the Company’s assessment of the collectability of receivables that are past due. The Company recorded an allowance for doubtful accounts of $3.1 million and $2.7 million at December 31, 2020 and 2019, respectively, and believes that all other amounts due are collectible.
Deferred policy acquisition costs, net of ceding commissions	Deferred policy acquisition costs, net of ceding commissions The Company defers commissions, net of ceding commissions, and certain other costs that are directly related to the successful acquisition of insurance contracts. All eligible costs are capitalized and charged to expense in proportion to premium earned over the estimated policy life. To the extent that unearned premiums on existing policies are not adequate to cover the related costs and expenses, referred to as a premium deficiency, deferred policy acquisition costs are charged to earnings. The Company considers anticipated investment income in determining whether a premium deficiency exists.
Property and equipment, net	Property and equipment, net Property and equipment are stated at cost less accumulated depreciation. Depreciation of property and equipment is calculated using the straight-line method over the estimated useful lives of the assets. The estimated useful lives range from 39 years for the parking deck and building, 15 to 20 years for land improvements, 7 to 10 years for furniture and equipment, 3 to 7 years for electronic data processing hardware and software, and from 2 to 5 years for leasehold improvements, which is the shorter of the estimated useful life or the lease term. Property and equipment are included in "other assets" in the accompanying consolidated balance sheets and consists of the following: December 31, 2020 2019 (in thousands) Building $ 31,675 $ — Parking deck 5,072 — Land 3,068 — Equipment 2,770 2,353 Software 4,815 2,356 Furniture and fixtures 1,731 1,025 Leasehold improvements — 984 Land improvements 317 — Construction in progress - corporate headquarters — 19,789 49,448 26,507 Accumulated depreciation (3,262) (3,873) Total property and equipment, net $ 46,186 $ 22,634 At December 31, 2019, construction in progress includes the purchased land and capitalized expenses related to the construction of the new corporate headquarters' building and parking deck. During 2020, the construction of the headquarters and parking deck was substantially completed and the related fixed assets were placed into service.
Intangible assets	Intangible assets Intangible assets are recorded at fair value at the date of acquisition. The Company's intangible assets are comprised solely of indefinite-lived intangible assets, which arose from regulatory approvals granted by the various state insurance departments to write insurance business in the respective states on a non-admitted basis. In accordance with U.S. GAAP, amortization of indefinite-lived intangible assets is not permitted. Indefinite-lived intangible assets are tested for impairment during the fourth quarter on an annual basis, or earlier if there is reason to suspect that their values may have been diminished or impaired. There were no impairments recognized in 2020, 2019, or 2018. In addition, as of December 31, 2020, no triggering events occurred that suggested an updated review was necessary.
Reserves for unpaid losses and loss adjustment expenses	Reserves for unpaid losses and loss adjustment expenses Reserves for unpaid losses and loss adjustment expenses represent management's best estimate of ultimate unpaid cost of all reported and unreported losses and loss adjustment expenses incurred prior to the financial statement date. The estimates are based on an actuarial method that uses management’s initial expected loss ratios, expected reporting patterns for losses based on industry data and the Company’s actual reported losses and loss adjustment expenses. All estimates are regularly reviewed and, as experience develops and new information becomes known, the reserves for unpaid losses and loss adjustment expenses are adjusted as necessary. Such adjustments are reflected in the results of operations in the period in which they are determined. Although management believes that the reserves for losses and loss adjustment expenses are reasonable, due to the inherent uncertainty in estimating reserves for unpaid losses and loss adjustment expenses, it is possible that the Company’s actual incurred losses and loss adjustment expenses will not develop in a manner consistent with the assumptions inherent in the determination of these reserves. If actual liabilities exceed recorded amounts, there will be an increase to the Company’s reserves resulting in a reduction in net income and stockholders’ equity in the period in which the deficiency is identified. Furthermore, management may determine that recorded reserves are more than adequate to cover expected losses which will result in a reduction to the reserves. The
Revenue recognition	Revenue recognition Premiums are recognized as revenue ratably over the term of the insurance contracts, net of ceded reinsurance. Unearned premiums are calculated on a daily pro rata basis.
Income taxes	Income taxes Deferred income tax assets and liabilities are determined based on the difference between the recorded amounts and the tax bases of assets and liabilities, using enacted tax rates expected to be in effect during the year in which the basis differences reverse. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are recorded when it is more likely than not that some portion, or all, of the deferred tax assets will not be realizable. Management evaluates the realizability of the deferred tax assets and assesses the need for any valuation allowance adjustment. Valuation allowances on deferred tax assets are estimated based on the Company's assessment of the realizability of such amounts. The Company provides for uncertain tax positions, and the related interest and penalties, based upon management’s assessment of whether a tax benefit is more likely than not to be sustained upon examination by tax authorities. To the extent that the anticipated tax outcome of these uncertain tax positions changes, such changes in estimate will impact the income tax provision in the period in which such determination is made. The Company recognizes accrued interest and penalties related to uncertain tax positions as a component of income tax expense. The Company uses the portfolio approach to release stranded tax effects in accumulated other comprehensive income ("AOCI") related to its available-for-sale fixed-maturity securities. Under this approach, stranded tax effects remaining in AOCI are released only when the entire portfolio of the available-for-sale fixed-maturity securities are liquidated, sold or extinguished.
Commitments and contingencies	Commitments and contingencies Liabilities for loss contingencies, arising from noninsurance policy claims, assessments, litigation, fines, and penalties and other sources, are recorded when it is probable that a liability has been incurred and the amount of the assessment and/or remediation can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred.
Fair value of financial instruments	Fair value of financial instruments The fair values of certain financial instruments are determined based on the fair value hierarchy. U.S. GAAP guidance requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The guidance also describes three levels of inputs that may be used to measure fair value. The following was considered in the estimation of fair value for each class of financial instruments for which it was practicable to estimate that value. The Company’s investment accounting vendor uses independent pricing vendors to estimate the fair value of fixed-maturity securities and the Company’s management reviews these prices for reasonableness. U.S. Treasury securities that have quoted prices in active markets are included in the amounts disclosed as Level 1. For other fixed-maturity securities, 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 fixed-maturity securities are included in the amounts disclosed as Level 2. For those fixed-maturity securities where significant inputs are unobservable, Level 3 inputs, the Company's investment accounting vendor obtains valuations from pricing vendors using the market approach and income approach valuation techniques. For equity securities, the Company’s investment accounting vendor uses prices from independent pricing vendors to estimate fair value. The fair value estimates of exchange traded funds are based on quoted prices in an active market and are disclosed as Level 1. The fair value estimates of preferred stock are based on observable market data and, as a result, are disclosed as Level 2. Fair value disclosures for investments are included in Notes 2 and 3.
Stock-based compensation	Stock-based compensation Stock-based compensation is expensed based upon the estimated fair value of employee stock awards. Compensation cost for awards of equity instruments to employees is measured based on the grant-date fair value of those awards and compensation expense is recognized over the service period that the awards vest. Forfeitures of stock-based compensation awards are recognized as they occur. See Note 9 for further discussion and related disclosures regarding stock-based compensation.
Recently adopted accounting pronouncements	Recently adopted accounting pronouncements Accounting Standards Update ("ASU") 2016-13, Financial Instruments – Credit Losses (Topic 326) On June 16, 2016, the Financial Accounting Standards Board ("FASB") issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326)" to provide more useful information about the expected credit losses on financial instruments. The update requires a financial asset measured at amortized cost to be presented at the net amount expected to be collected by means of an allowance for credit losses that runs through net income. Credit losses relating to available-for-sale fixed-maturity securities must also be recorded through an allowance for credit losses. However, the amendments limit the amount of the allowance to the amount by which fair value is below amortized cost. The measurement of credit losses on available-for-sale securities is similar under previous U.S. GAAP, but the update requires the use of the allowance account through which amounts can be reversed, rather than through an irreversible write-down. The FASB has issued additional ASUs on Topic 326 that do not change the core principle of the guidance in ASU 2016-13 but clarify certain aspects of it. Effective January 1, 2020, the Company adopted this ASU using the modified-retrospective approach and recorded a cumulative effect adjustment to beginning retained earnings. The adoption of this ASU resulted in the recognition of an allowance for credit loss related to the Company’s reinsurance recoverables. However, since the Company enters into contracts with reinsurers that have A.M. Best ratings of “A” (Excellent) or better, the allowance was not material to the Company’s consolidated financial statements. ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract On August 29, 2018, the FASB issued new guidance on a customer's accounting for implementation, set-up and other up-front costs incurred in a cloud computing arrangement hosted by the vendor. The new guidance requires an entity to determine the stage of a project that the implementation activity relates to and the nature of the associated costs in order to determine whether those costs should be expensed as incurred or capitalized. The new guidance also requires the entity to amortize the capitalized implementation costs as an expense over the term of the hosting arrangement. Effective January 1, 2020, the Company adopted ASU 2018-15 using a modified-retrospective approach. The adoption of ASU 2018-15 did not have a material impact on the Company's consolidated financial statements.
Prospective accounting pronouncements	Prospective accounting pronouncements ASU 2019-12, Income Taxes - Simplifying the Accounting for Income Taxes In December 2019, the FASB issued updated guidance for the accounting for income taxes. The updated guidance is intended to simplify the accounting for income taxes by removing several exceptions contained in existing guidance and amending other existing guidance to simplify several other income tax accounting matters. The updated guidance is effective for annual reporting periods beginning after December 15, 2020. Early adoption is permitted. The adoption of the guidance will not have a material effect on the Company’s consolidated financial statements. There are no other prospective accounting standards which, upon their effective date, would have a material impact on the Company's consolidated financial statements.

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment [Table Text Block]	Property and equipment are included in "other assets" in the accompanying consolidated balance sheets and consists of the following: December 31, 2020 2019 (in thousands) Building $ 31,675 $ — Parking deck 5,072 — Land 3,068 — Equipment 2,770 2,353 Software 4,815 2,356 Furniture and fixtures 1,731 1,025 Leasehold improvements — 984 Land improvements 317 — Construction in progress - corporate headquarters — 19,789 49,448 26,507 Accumulated depreciation (3,262) (3,873) Total property and equipment, net $ 46,186 $ 22,634

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Available-for-sale Investments	The following tables summarize the Company’s available-for-sale investments at December 31, 2020 and 2019: December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (in thousands) Fixed maturities: Obligations of states, municipalities and political subdivisions $ 216,181 $ 14,792 $ (67) $ 230,906 Corporate and other securities 294,854 21,840 (86) 316,608 Asset-backed securities 236,813 4,230 (382) 240,661 Commercial mortgage-backed securities 66,110 4,886 (27) 70,969 Residential mortgage-backed securities 217,859 4,938 (141) 222,656 Total fixed-maturity investments $ 1,031,817 $ 50,686 $ (703) $ 1,081,800 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 110 $ 2 $ — $ 112 Obligations of states, municipalities and political subdivisions 166,312 7,542 (961) 172,893 Corporate and other securities 180,287 4,736 (255) 184,768 Asset-backed securities 141,123 1,272 (471) 141,924 Commercial mortgage-backed securities 54,627 1,658 (239) 56,046 Residential mortgage-backed securities 172,358 1,819 (388) 173,789 Total fixed-maturity investments $ 714,817 $ 17,029 $ (2,314) $ 729,532
Available-for-sale Securities in a Unrealized Loss Position	December 31, 2020 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: Obligations of states, municipalities and political subdivisions $ 6,412 $ (67) $ — $ — $ 6,412 $ (67) Corporate and other securities 3,829 (86) — — 3,829 (86) Asset-backed securities 57,750 (149) 23,825 (233) 81,575 (382) Commercial mortgage-backed securities 4,971 (27) — — 4,971 (27) Residential mortgage-backed securities 46,869 (129) 266 (12) 47,135 (141) Total fixed-maturity investments $ 119,831 $ (458) $ 24,091 $ (245) $ 143,922 $ (703) December 31, 2019 Less than 12 Months 12 Months or Longer Total Estimated Fair Value Gross Unrealized Holding Losses Estimated Fair Value Gross Unrealized Holding Losses Estimated Fair Value Gross Unrealized Holding Losses (in thousands) Fixed maturities: Obligations of states, municipalities and political subdivisions $ 28,997 $ (961) $ 254 $ — $ 29,251 $ (961) Corporate and other securities 22,409 (251) 1,509 (4) 23,918 (255) Asset-backed securities 21,371 (79) 44,115 (392) 65,486 (471) Commercial mortgage-backed securities 16,352 (224) 2,508 (15) 18,860 (239) Residential mortgage-backed securities 36,986 (148) 24,815 (240) 61,801 (388) Total fixed-maturity investments $ 126,115 $ (1,663) $ 73,201 $ (651) $ 199,316 $ (2,314)
Contractual Maturities of Available-for-sale Fixed Maturity Securities	The amortized cost and estimated fair value of available-for-sale fixed-maturity securities at December 31, 2020 are summarized, by contractual maturity, as follows: Amortized Estimated Cost Fair Value (in thousands) Due in one year or less $ 15,545 $ 15,782 Due after one year through five years 107,150 115,390 Due after five years through ten years 156,958 169,711 Due after ten years 231,382 246,631 Asset-backed securities 236,813 240,661 Commercial mortgage-backed securities 66,110 70,969 Residential mortgage-backed securities 217,859 222,656 Total fixed maturities $ 1,031,817 $ 1,081,800
Net Investment Income	The following table presents the components of net investment income: Year Ended December 31, 2020 2019 2018 (in thousands) Interest: Taxable bonds $ 20,493 $ 14,853 $ 9,474 Municipal bonds (tax exempt) 3,618 3,692 4,298 Cash equivalents and short-term investments 262 842 1,017 Dividends on equity securities 3,512 2,136 2,014 Gross investment income 27,885 21,523 16,803 Investment expenses (1,775) (1,390) (1,115) Net investment income $ 26,110 $ 20,133 $ 15,688
Schedule of Realized Gain (Loss)	The following table presents realized investment gains and losses: Year Ended December 31, 2020 2019 2018 (in thousands) Fixed-maturity securities: Realized gains $ 4,022 $ 567 $ 263 Realized losses (383) (79) (17) Net realized gains from fixed-maturity securities 3,639 488 246 Equity securities: Realized gains — 556 57 Realized losses (119) (688) (22) Net realized (losses) gains from equity securities (119) (132) 35 Short-term securities - realized gains 13 3 — Net realized investment gains $ 3,533 $ 359 $ 281

Fair value measurements (Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2020
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 December 31, 2020 and 2019, by level within the fair value hierarchy. December 31, 2020 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: Obligations of states, municipalities and political subdivisions $ — $ 230,906 $ — $ 230,906 Corporate and other securities — 316,608 — 316,608 Asset-backed securities — 240,661 — 240,661 Commercial mortgage-backed securities — 70,969 — 70,969 Residential mortgage-backed securities — 222,656 — 222,656 Total fixed maturities — 1,081,800 — 1,081,800 Equity securities: Exchange traded funds 98,050 — — 98,050 Nonredeemable preferred stock — 31,612 — 31,612 Total equity securities 98,050 31,612 — 129,662 Total $ 98,050 $ 1,113,412 $ — $ 1,211,462 December 31, 2019 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 112 $ — $ — $ 112 Obligations of states, municipalities and political subdivisions — 172,893 — 172,893 Corporate and other securities — 184,768 — 184,768 Asset-backed securities — 141,924 — 141,924 Commercial mortgage-backed securities — 56,046 — 56,046 Residential mortgage-backed securities — 173,789 — 173,789 Total fixed maturities 112 729,420 — 729,532 Equity securities: Exchange traded funds 54,463 — — 54,463 Nonredeemable preferred stock — 23,831 — 23,831 Total equity securities 54,463 23,831 — 78,294 Total $ 54,575 $ 753,251 $ — $ 807,826

Deferred policy acquisition c_2

Deferred policy acquisition costs (Tables)	12 Months Ended
	Dec. 31, 2020
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 years ended: Year Ended December 31, 2020 2019 2018 (in thousands) Balance, beginning of year $ 23,564 $ 14,801 $ 11,775 Policy acquisition costs deferred: Direct commissions 80,682 56,841 40,546 Ceding commissions (18,879) (12,373) (11,239) Other underwriting and policy acquisition costs 4,478 3,727 3,141 Policy acquisition costs deferred 66,281 48,195 32,448 Amortization of net policy acquisition costs (57,933) (39,432) (29,422) Balance, end of year $ 31,912 $ 23,564 $ 14,801

Underwriting, acquisition and_2

Underwriting, acquisition and insurance expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Underwriting, Acquisition and Insurance Expenses [Abstract]
Underwriting, Acquisition and Insurance Expenses	Underwriting, acquisition and insurance expenses consist of the following: Year Ended December 31, 2020 2019 2018 (in thousands) Underwriting, acquisition and insurance expenses incurred: Direct commissions $ 69,922 $ 48,382 $ 36,885 Ceding commissions (16,145) (12,347) (10,448) Other operating expenses 40,519 34,182 26,988 Total $ 94,296 $ 70,217 $ 53,425

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Components of Income Tax Expense (Benefit)	Income tax expense includes the following components for the years ending December 31, 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 (in thousands) Current federal income tax expense $ 11,378 $ 12,860 $ 9,923 Deferred federal income tax (benefit) expense 616 (125) (3,230) Income tax expense $ 11,994 $ 12,735 $ 6,693
Effective Income Tax Rate Reconciliation	The Company’s effective income tax rate on income before income taxes differs from the prevailing federal income tax rate and is summarized as follows: Year ended December 31, 2020 2019 2018 (in thousands) Income tax expense at federal income tax rate $ 21,087 $ 15,971 $ 8,501 Stock options exercised (7,634) (2,411) (918) Tax-exempt investment income (565) (577) (672) Restricted stock award vesting (658) (153) — Other (236) (95) (218) Total $ 11,994 $ 12,735 $ 6,693
Deferred Tax Assets and Liabilities	The significant components of the net deferred tax (liability) asset are summarized as follows: December 31, 2020 2019 (in thousands) Deferred tax assets: Unpaid losses and loss adjustment expenses $ 11,736 $ 8,199 Unearned premiums 9,942 7,193 Organizational costs 128 162 Stock compensation 865 765 State operating loss carryforwards 3,833 1,497 Allowance for doubtful accounts 649 570 Other 126 256 Deferred tax assets before allowance 27,279 18,642 Less: valuation allowance (3,491) (1,592) Total deferred tax assets 23,788 17,050 Deferred tax liabilities: Unrealized gains on fixed-maturity securities 10,497 3,090 Unrealized gains on equity securities 6,552 2,995 Deferred policy acquisition costs, net of ceding commissions 6,701 4,949 Property and equipment 2,433 10 Intangible assets 743 743 Transition adjustment for loss reserve discount 1,281 1,537 Other 229 352 Total deferred tax liabilities 28,436 13,676 Net deferred tax (liability) asset $ (4,648) $ 3,374

Reserves for unpaid losses an_2

Reserves for unpaid losses and loss adjustment expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Claims Development
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability	The reconciliation of the net incurred and paid claims development tables to the liability for unpaid claims and claim adjustment expenses in the consolidated statement of financial position is as follows: (in thousands) December 31, 2020 Net outstanding liabilities Property $ 22,165 Casualty - claims made 98,774 Casualty - occurrence 383,309 Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance 504,248 Reinsurance recoverable on unpaid claims Property 10,800 Casualty - claims made 61,100 Casualty - occurrence 11,830 Total reinsurance recoverable on unpaid claims 83,730 Unallocated claims adjustment expenses 48,035 Gross liability for unpaid claims and claim adjustment expense $ 636,013
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: December 31, 2020 2019 2018 (in thousands) Gross reserves for unpaid losses and loss adjustment expenses, beginning of year $ 460,058 $ 369,152 $ 315,717 Less: reinsurance recoverable on unpaid losses 69,792 55,389 48,224 Adoption of new accounting standard for credit losses (282) — — Net reserves for unpaid losses and loss adjustment expenses, beginning of year 390,548 313,763 267,493 Incurred losses and loss adjustment expenses: Current year 277,140 178,986 135,078 Prior year (13,338) (9,423) (7,037) Total net losses and loss adjustment expenses incurred 263,802 169,563 128,041 Payments: Current year 27,664 19,054 14,118 Prior year 74,403 74,006 67,653 Total payments 102,067 93,060 81,771 Net reserves for unpaid losses and loss adjustment expenses, end of year 552,283 390,266 313,763 Reinsurance recoverable on unpaid losses, net of allowance 83,730 69,792 55,389 Gross reserves for unpaid losses and loss adjustment expenses, end of year $ 636,013 $ 460,058 $ 369,152
Property [Member]
Claims Development
Short-duration Insurance Contracts, Claims Development	Property Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2020 Accident Year 2016 2017 2018 2019 2020 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims ($ in thousands) 2016 $ 4,177 $ 3,392 $ 3,301 $ 3,278 $ 3,270 $ — 286 2017 12,473 11,705 11,676 11,631 19 1,041 2018 11,559 12,004 12,698 88 649 2019 14,914 13,909 430 636 2020 40,612 7,139 2,189 Total $ 82,120 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2016 2017 2018 2019 2020 ($ in thousands) 2016 $ 1,867 $ 3,257 $ 3,265 $ 3,265 $ 3,270 2017 9,938 11,233 11,602 11,608 2018 9,132 11,646 12,599 2019 9,852 12,581 2020 19,897 Total 59,955 All outstanding liabilities before 2016, net of reinsurance — Liabilities for claims and claim adjustment expenses, net of reinsurance $ 22,165
Short-duration Insurance Contracts, Schedule of Historical Claims Duration	The following is supplementary information about average historical claims duration as of December 31, 2020: Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance (Unaudited) Years 1 2 3 4 5 Property 66.9 % 23.3 % 3.6 % — % 0.2 %
Casualty - claims made [Member]
Claims Development
Short-duration Insurance Contracts, Claims Development	Casualty - Claims Made Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2020 Accident Year 2011 2012 2013 2014 Unaudited 2015 2016 2017 2018 2019 Unaudited 2020 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims 2011 $ 4,246 $ 3,844 $ 3,646 $ 3,609 $ 3,560 $ 3,374 $ 3,261 $ 3,225 $ 3,206 $ 3,177 $ 73 76 2012 7,913 5,749 4,205 3,102 2,845 2,477 2,314 2,207 2,136 190 138 2013 15,238 11,639 9,113 7,917 7,002 6,463 6,128 6,087 465 228 2014 18,847 14,289 11,748 11,217 10,948 10,988 10,620 824 273 2015 18,883 16,777 14,896 13,583 13,942 13,548 1,378 258 2016 19,170 14,693 14,675 14,322 13,583 2,116 310 2017 18,116 17,097 16,120 15,794 3,703 369 2018 22,429 20,234 18,612 7,275 458 2019 34,693 29,056 17,500 538 2020 55,630 48,966 738 Total $ 168,243 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 139 $ 1,037 $ 1,392 $ 2,116 $ 3,044 $ 3,042 $ 3,042 $ 3,065 $ 3,104 $ 3,104 2012 153 475 877 1,024 1,090 1,882 1,946 1,946 1,946 2013 499 1,915 4,436 5,070 5,320 5,439 5,482 5,612 2014 435 1,865 5,039 6,385 8,290 9,415 9,491 2015 217 4,496 7,563 9,238 11,372 11,522 2016 1,158 3,015 6,907 9,839 11,381 2017 340 4,897 8,252 10,484 2018 507 5,030 8,931 2019 2,487 6,005 2020 1,002 Total 69,478 All outstanding liabilities before 2011, net of reinsurance 9 Liabilities for claims and claim adjustment expenses, net of reinsurance $ 98,774
Casualty - occurrence [Member]
Claims Development
Short-duration Insurance Contracts, Claims Development	Casualty - Occurrence Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2020 Accident Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims 2011 $ 5,839 $ 5,940 $ 5,757 $ 7,340 $ 7,613 $ 8,142 $ 8,375 $ 9,023 $ 9,379 $ 9,318 $ 360 227 2012 16,977 17,436 18,803 20,401 20,579 22,001 22,401 23,223 23,197 1,288 586 2013 30,616 28,771 28,037 29,039 31,731 33,248 33,973 33,128 2,978 856 2014 47,805 40,668 38,049 36,678 39,313 41,859 42,434 5,843 1,196 2015 59,717 51,739 49,122 52,100 54,697 54,090 9,323 1,496 2016 61,440 55,680 53,549 55,534 57,401 13,928 1,434 2017 71,126 67,151 68,985 70,641 24,096 1,632 2018 86,157 78,331 78,386 44,307 1,606 2019 112,266 109,994 81,322 1,644 2020 154,619 146,945 1,076 Total $ 633,208 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 207 $ 1,596 $ 2,519 $ 3,788 $ 4,575 $ 6,363 $ 6,868 $ 8,510 $ 8,693 $ 8,745 2012 757 4,441 7,850 11,238 14,382 16,474 19,383 20,707 21,408 2013 1,099 4,469 7,957 14,890 21,348 26,715 28,248 29,610 2014 698 3,081 8,489 17,576 23,771 31,026 34,338 2015 941 3,161 12,685 28,385 37,690 41,724 2016 1,099 6,015 17,225 28,924 34,437 2017 1,581 9,352 22,407 37,736 2018 2,638 10,995 22,860 2019 3,944 16,687 2020 2,400 Total 249,945 All outstanding liabilities before 2011, net of reinsurance 46 Liabilities for claims and claim adjustment expenses, net of reinsurance $ 383,309
Casualty [Member]
Claims Development
Short-duration Insurance Contracts, Schedule of Historical Claims Duration	The following is supplementary information about average historical claims duration as of December 31, 2020: Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance (Unaudited) Years 1 2 3 4 5 6 7 8 9 10 Casualty - claims made 4.9 % 21.2 % 24.3 % 14.4 % 13.6 % 10.1 % 1.1 % 1.0 % 0.6 % — % Casualty - occurrence 2.5 % 10.3 % 14.8 % 20.2 % 13.8 % 13.8 % 7.6 % 9.1 % 2.5 % 0.6 %

Reinsurance (Tables)

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2020
Reinsurance Disclosures [Abstract]
Effects of Reinsurance on Premiums Written and Earned	The following table summarizes the effect of reinsurance on premiums written and earned: Year Ended December 31, 2020 2019 2018 (in thousands) Written: Direct $ 552,814 $ 389,569 $ 275,538 Assumed — 125 — Ceded (74,595) (47,633) (39,924) Net written $ 478,219 $ 342,061 $ 235,614 Earned: Direct $ 479,181 $ 330,464 $ 250,397 Assumed 21 104 — Ceded (66,448) (47,587) (37,709) Net earned $ 412,754 $ 282,981 $ 212,688
Reinsurance Recoverables	The following table presents reinsurance recoverables on paid and unpaid losses as of December 31, 2020 and 2019: December 31, 2020 December 31, 2019 (in thousands) Reinsurance recoverables on paid losses $ 9,485 $ 2,782 Reinsurance recoverables on unpaid losses 83,730 69,792 Reinsurance recoverables $ 93,215 $ 72,574

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Attributable to Parent [Abstract]
Assumptions Used in Estimating Fair Value of Options Granted	The value of the options granted was estimated at the date of grant using the Black-Scholes pricing model using the following assumptions: Risk-free rate of return 1.26 % Dividend yield 1.25 % Expected share price volatility (1) 18.50 % Expected life in years (2) 6.3 years
Share-based Compensation, Stock Options, Activity	A summary of option activity as of December 31, 2020, and changes during the year then ended is presented below: Number of Shares Weighted-average exercise price Weighted-average remaining years of contractual life Aggregate intrinsic value (in thousands) Outstanding at December 31, 2019 614,345 $ 16.00 Granted — — Forfeited (234) 16.00 Exercised (226,373) 16.00 Outstanding at December 31, 2020 387,738 $ 16.00 5.6 $ 71,394 Exercisable at December 31, 2020 387,738 $ 16.00 5.6 $ 71,394
Nonvested Restricted Stock Shares Activity	A summary of restricted stock activity under the equity compensation plans for the year ended is as follows: December 31, 2020 Number of Shares Weighted Average Grant Date Fair Value per Share Nonvested outstanding at the beginning of the period 122,723 $ 67.01 Granted 42,694 $ 147.45 Vested (41,010) $ 63.86 Forfeited (16,015) $ 83.79 Nonvested outstanding at the end of the period 108,392 $ 97.40

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	The following table represents a reconciliation of the numerator and denominator of the basic and diluted earnings per share computations contained in the consolidated financial statements: Year ended December 31, 2020 2019 2018 (in thousands, except per share data) Net income $ 88,419 $ 63,316 $ 33,787 Weighted average common shares outstanding - basic 22,319 21,528 21,090 Dilutive effect of shares issued under stock compensation arrangements: Stock options 469 570 591 Restricted stock awards 64 38 4 Total dilutive effect of shares issued under stock compensation arrangements 533 608 595 Weighted average common shares outstanding - diluted 22,852 22,136 21,685 Earnings per common share: Basic $ 3.96 $ 2.94 $ 1.60 Diluted $ 3.87 $ 2.86 $ 1.56

Other comprehensive income (l_2

Other comprehensive income (loss) (Tables)	12 Months Ended
	Dec. 31, 2020
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss)	The following table summarizes the components of other comprehensive income (loss): Year Ending December 31, 2020 2019 2018 (in thousands) Unrealized gains (losses) on fixed-maturity securities arising during the period, before income taxes: $ 37,387 $ 19,190 $ (6,664) Income tax (expense) benefit (7,851) (4,029) 1,399 Unrealized gains (losses) arising during the period, net of income taxes 29,536 15,161 (5,265) Less reclassification adjustment: Net realized investment gains on available-for-sale investments 2,119 489 258 Income tax benefit (445) (102) (54) Reclassification adjustment included in net income 1,674 387 204 Other comprehensive income (loss) $ 27,862 $ 14,774 $ (5,469)

Underwriting information (Table

Underwriting information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Gross Written Premiums by Underwriting Division	Gross written premiums by underwriting division are presented below: Year Ended December 31, 2020 2019 2018 (in thousands) Commercial: Construction $ 87,206 $ 71,035 $ 50,879 Small business 83,289 63,181 44,368 Excess casualty 76,715 51,225 37,398 Commercial property 51,789 29,115 9,166 Product liability 38,306 26,333 20,049 Allied health 37,562 23,962 16,815 Life sciences 31,027 17,821 14,505 General casualty 29,205 23,279 17,625 Professional liability 27,051 20,029 16,717 Management liability 24,061 14,820 8,161 Energy 16,985 15,371 15,586 Environmental 8,568 5,179 2,205 Health care 7,666 5,963 5,725 Inland marine 6,910 3,467 2,046 Public entity 3,007 580 1,193 Commercial insurance 1,757 1,674 1,096 Total commercial 531,104 373,034 263,534 Personal: Personal insurance 21,710 16,660 12,004 Total $ 552,814 $ 389,694 $ 275,538

Statutory financial informati_2

Statutory financial information (Tables)	12 Months Ended
	Dec. 31, 2020
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments [Abstract]
Statutory Net Income and Statutory Capital and Surplus	Statutory net income and statutory capital and surplus for Kinsale Insurance as of December 31, 2020, 2019, and 2018 and for the years then ended are summarized as follows: Year ended December 31, 2020 2019 2018 (in thousands) Statutory net income $ 54,338 $ 40,917 $ 34,206 Statutory capital and surplus $ 476,066 $ 348,811 $ 233,500

Unaudited Seleted Quarterly Fin

Unaudited Seleted Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Table Text Block]	The following is a summary of the unaudited quarterly results of operations: 2020 Quarter (in thousands, except per share data) First Second Third Fourth Gross written premiums $ 124,036 $ 134,091 $ 144,777 $ 149,910 Total revenues 80,346 117,707 122,501 139,332 Net income 5,086 30,262 14,890 38,181 Comprehensive (loss) income (4,137) 57,270 21,444 41,704 Earnings per share - basic $ 0.23 $ 1.37 $ 0.66 $ 1.69 Earnings per share - diluted $ 0.22 $ 1.33 $ 0.65 $ 1.65 2019 Quarter (in thousands, except per share data) First Second Third Fourth Gross written premiums $ 84,626 $ 94,947 $ 97,984 $ 112,137 Total revenues 72,185 72,572 78,327 92,804 Net income 18,720 13,767 12,976 17,853 Comprehensive income 25,500 20,322 16,218 16,050 Earnings per share - basic $ 0.88 $ 0.65 $ 0.60 $ 0.81 Earnings per share - diluted $ 0.86 $ 0.63 $ 0.58 $ 0.79

Schedule II - Condensed Finan_2

Schedule II - Condensed Financial Information of Registrant (Tables)	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheet	December 31, 2020 2019 (in thousands) Assets Cash and cash equivalents $ 8,395 $ 14,726 Due from subsidiaries 7,792 16,836 Investment in subsidiaries 600,931 391,071 Deferred income tax asset, net 587 519 Income taxes recoverable 1,177 — Other assets 290 208 Total assets $ 619,172 $ 423,360 Liabilities and Stockholders' Equity Liabilities: Accounts payable and accrued expenses $ 302 $ 260 Income taxes payable — 434 Credit facility 42,570 16,744 Other liabilities 62 42 Total liabilities 42,934 17,480 Stockholders’ equity: Common stock 228 222 Additional paid-in capital 291,315 229,229 Retained earnings 243,315 162,911 Accumulated other comprehensive income 41,380 13,518 Stockholders’ equity 576,238 405,880 Total liabilities and stockholders’ equity $ 619,172 $ 423,360
Condensed Income Statement	Years Ended December 31, 2020 2019 2018 (in thousands) Revenues: Management fees from subsidiaries $ 5,709 $ 4,502 $ 3,215 Total revenues 5,709 4,502 3,215 Expenses: Other operating expenses 6,624 5,215 4,055 Other expenses 1,332 — — Total expenses 7,956 5,215 4,055 Loss before income taxes (2,247) (713) (840) Income tax benefit (8,779) (2,714) (1,158) Income before equity in net income of subsidiaries 6,532 2,001 318 Equity in net income of subsidiaries 81,887 61,315 33,469 Net income 88,419 63,316 33,787 Other comprehensive income (loss): Equity in other comprehensive earnings (losses) of subsidiaries 27,862 14,774 (5,469) Total comprehensive income $ 116,281 $ 78,090 $ 28,318
Condensed Cash Flow Statement	Years Ended December 31, 2020 2019 2018 (in thousands) Operating activities Net income $ 88,419 $ 63,316 $ 33,787 Adjustments to reconcile net income to net cash provided by (used in) operating activities: Deferred tax benefit (68) (150) (170) Stock compensation expense 3,575 2,742 1,597 Equity in undistributed earnings of subsidiaries (81,887) (61,315) (33,469) Changes in operating assets and liabilities 7,520 (14,247) (633) Dividends received from subsidiary — 5,000 11,500 Net cash provided by (used in) operating activities 17,559 (4,654) 12,612 Investing activities Contributions to subsidiary (100,034) (68,391) — Net cash used in investing activities (100,034) (68,391) — Financing activities Common stock issued, net of transaction costs 56,698 65,879 — Common stock issued, stock options exercised 3,622 2,750 1,808 Payroll taxes withheld and remitted on share-based payments (1,803) (617) — Dividends paid (8,073) (6,929) (5,906) Proceeds from credit facility 25,700 17,300 — Debt issuance costs — (628) — Net cash provided by (used in) financing activities 76,144 77,755 (4,098) Net change in cash and cash equivalents (6,331) 4,710 8,514 Cash and cash equivalents at beginning of year 14,726 10,016 1,502 Cash and cash equivalents at end of year $ 8,395 $ 14,726 $ 10,016

Description of business - (Deta

Description of business - (Details)	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of states in which company is authorized to write business	50

Summary of significant accoun_3

Summary of significant accounting policies (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Allowance for doubtful accounts	$ 3,100	$ 2,700
Short-term Investments	$ 0	$ 0

Intangible assets and other inf

Intangible assets and other information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Excess and surplus lines insurance authorization [Member]
Indefinite-lived Intangible Assets [Line Items]
Impairment of intangible assets	$ 0	$ 0	$ 0

Summary of significant accoun_4

Summary of significant accounting policies Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 49,448	$ 26,507
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(3,262)	(3,873)
Property, Plant and Equipment, Net	46,186	22,634
Transaction price of sale of land and parking deck	6,500
Proceeds receivable from sale of land and parking deck	1,500
Proceeds received from sale of land and parking deck	5,000
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	2,770	2,353
Software Development [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 4,815	2,356
Technology Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Technology Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 0	984
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	2 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 0	19,789
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,068	0
Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 31,675	0
Building [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	39 years
Parking [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 5,072	0
Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 317	0
Land Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Land Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	20 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 1,731	$ 1,025
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years

Investments, Available-for-sale

Investments, Available-for-sale Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,031,817	$ 714,817
Gross Unrealized Gains	50,686	17,029
Gross Unrealized Losses	703	2,314
Estimated Fair Value	1,081,800	729,532
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		110
Gross Unrealized Gains		2
Gross Unrealized Losses		0
Estimated Fair Value		112
Obligations of states, municipalities and political subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	216,181	166,312
Gross Unrealized Gains	14,792	7,542
Gross Unrealized Losses	67	961
Estimated Fair Value	230,906	172,893
Corporate and other securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	294,854	180,287
Gross Unrealized Gains	21,840	4,736
Gross Unrealized Losses	86	255
Estimated Fair Value	316,608	184,768
Asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	236,813	141,123
Gross Unrealized Gains	4,230	1,272
Gross Unrealized Losses	382	471
Estimated Fair Value	240,661	141,924
Commercial mortgage-backed aecurities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	66,110	54,627
Gross Unrealized Gains	4,886	1,658
Gross Unrealized Losses	27	239
Estimated Fair Value	70,969	56,046
Residential mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	217,859	172,358
Gross Unrealized Gains	4,938	1,819
Gross Unrealized Losses	141	388
Estimated Fair Value	$ 222,656	$ 173,789

Investments, Available-for-sa_2

Investments, Available-for-sale Securities in a Loss Position (Details) $ in Thousands	Dec. 31, 2020USD ($)Rate	Dec. 31, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	$ 119,831	$ 126,115
Less than 12 months, Gross Unrealized Losses	458	1,663
12 Months or Longer, Estimated Fair Value	24,091	73,201
12 Months or Longer, Gross Unrealized Losses	245	651
Total Estimated Fair Value	143,922	199,316
Total Gross Unrealized Losses	$ (703)	(2,314)
Number of available-for-sale securities in unrealized loss positions	60
Number of available-for-sale securities in unrealized loss positions, greater than one year	12
Fixed Maturities [Member]
Debt Securities, Available-for-sale [Line Items]
Percentage of securities rated A- or better | Rate	81.60%
Credit losses	$ 0
Obligations of states, municipalities and political subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	6,412	28,997
Less than 12 months, Gross Unrealized Losses	67	961
12 Months or Longer, Estimated Fair Value	0	254
12 Months or Longer, Gross Unrealized Losses	0	0
Total Estimated Fair Value	6,412	29,251
Total Gross Unrealized Losses	(67)	(961)
Corporate and other securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	3,829	22,409
Less than 12 months, Gross Unrealized Losses	86	251
12 Months or Longer, Estimated Fair Value	0	1,509
12 Months or Longer, Gross Unrealized Losses	0	4
Total Estimated Fair Value	3,829	23,918
Total Gross Unrealized Losses	(86)	(255)
Asset-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	57,750	21,371
Less than 12 months, Gross Unrealized Losses	149	79
12 Months or Longer, Estimated Fair Value	23,825	44,115
12 Months or Longer, Gross Unrealized Losses	233	392
Total Estimated Fair Value	81,575	65,486
Total Gross Unrealized Losses	(382)	(471)
Commercial mortgage-backed aecurities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	4,971	16,352
Less than 12 months, Gross Unrealized Losses	27	224
12 Months or Longer, Estimated Fair Value	0	2,508
12 Months or Longer, Gross Unrealized Losses	0	15
Total Estimated Fair Value	4,971	18,860
Total Gross Unrealized Losses	(27)	(239)
Residential mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	46,869	36,986
Less than 12 months, Gross Unrealized Losses	129	148
12 Months or Longer, Estimated Fair Value	266	24,815
12 Months or Longer, Gross Unrealized Losses	12	240
Total Estimated Fair Value	47,135	61,801
Total Gross Unrealized Losses	$ (141)	$ (388)

Investments, Contractual Maturi

Investments, Contractual Maturities of Available-for-sale Fixed Maturity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Amortized Cost [Abstract]
Due in one year or less, Amortized Cost	$ 15,545
Due after one year through five years, Amortized Cost	107,150
Due after five years through ten years, Amortized Cost	156,958
Due after ten years, Amortized Cost	231,382
Total fixed maturities, Amortized Cost	1,031,817	$ 714,817
Estimated Fair Value [Abstract]
Due in one year or less, Estimated Fair Value	15,782
Due after one year through five years, Estimated Fair Value	115,390
Due after five years through ten years, Estimated Fair Value	169,711
Due after ten years, Estimated Fair Value	246,631
Estimated Fair Value	1,081,800	729,532
Asset-backed securities [Member]
Amortized Cost [Abstract]
Without single maturity date, Amortized Cost	236,813
Total fixed maturities, Amortized Cost	236,813	141,123
Estimated Fair Value [Abstract]
Without single maturity date, Estimated Fair Value	240,661
Estimated Fair Value	240,661	141,924
Residential mortgage-backed securities [Member]
Amortized Cost [Abstract]
Without single maturity date, Amortized Cost	217,859
Total fixed maturities, Amortized Cost	217,859	172,358
Estimated Fair Value [Abstract]
Without single maturity date, Estimated Fair Value	222,656
Estimated Fair Value	222,656	173,789
Commercial mortgage-backed aecurities [Member]
Amortized Cost [Abstract]
Without single maturity date, Amortized Cost	66,110
Total fixed maturities, Amortized Cost	66,110	54,627
Estimated Fair Value [Abstract]
Without single maturity date, Estimated Fair Value	70,969
Estimated Fair Value	$ 70,969	$ 56,046

Investments, Net Investment Inc

Investments, Net Investment Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest [Abstract]
Taxable bonds	$ 20,493	$ 14,853	$ 9,474
Municipal bonds (tax exempt)	3,618	3,692	4,298
Cash equivalents and short-term investments	262	842	1,017
Dividends on equity securities	3,512	2,136	2,014
Gross investment income	27,885	21,523	16,803
Investment expenses	(1,775)	(1,390)	(1,115)
Net investment income	$ 26,110	$ 20,133	$ 15,688

Investments Realized Investment

Investments Realized Investment Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fixed-maturity securities - realized gains (losses) [Abstract]
Realized gains	$ 4,022	$ 567	$ 263
Realized losses	(383)	(79)	(17)
Net realized gains from fixed-maturity securities	3,639	488	246
Equity securities - realized gains (losses) [Abstract]
Realized gains	0	556	57
Realized losses	(119)	(688)	(22)
Net realized gains (losses) from equity securities	(119)	(132)	35
Short-term securities - realized gain	13	3	0
Net realized investment gains	$ 3,533	$ 359	$ 281

Investments, Unrealized Gain (L

Investments, Unrealized Gain (Losses) on Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Change in unrealized gains (losses), fixed-maturity securities	$ 35.3	$ 18.7	$ (6.9)

Investments Investment Deposits

Investments Investment Deposits and Payables (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Invested assets on deposit with state regulatory authorities	$ 6.9	$ 6.9

Fair value measurements (Detail

Fair value measurements (Details) - Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1,211,462	$ 807,826
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	98,050	54,575
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	1,113,412	753,251
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Fixed Maturities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	1,081,800	729,532
Fixed Maturities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	112
Fixed Maturities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	1,081,800	729,420
Fixed Maturities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale		112
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale		112
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale		0
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale		0
Obligations of states, municipalities and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	230,906	172,893
Obligations of states, municipalities and political subdivisions [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Obligations of states, municipalities and political subdivisions [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	230,906	172,893
Obligations of states, municipalities and political subdivisions [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Corporate and other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	316,608	184,768
Corporate and other securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Corporate and other securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	316,608	184,768
Corporate and other securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	240,661	141,924
Asset-backed securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Asset-backed securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	240,661	141,924
Asset-backed securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Commercial mortgage-backed aecurities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	70,969	56,046
Commercial mortgage-backed aecurities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Commercial mortgage-backed aecurities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	70,969	56,046
Commercial mortgage-backed aecurities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Residential mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	222,656	173,789
Residential mortgage-backed securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Residential mortgage-backed securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	222,656	173,789
Residential mortgage-backed securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	0	0
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	129,662	78,294
Equity Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	98,050	54,463
Equity Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	31,612	23,831
Equity Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Exchange Traded Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	98,050	54,463
Exchange Traded Fund [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	98,050	54,463
Exchange Traded Fund [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Exchange Traded Fund [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Nonredeemable Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	31,612	23,831
Nonredeemable Preferred Stock [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Nonredeemable Preferred Stock [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	31,612	23,831
Nonredeemable Preferred Stock [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 0	$ 0

Fair value measurements 2 (Deta

Fair value measurements 2 (Details) - Fair Value, Nonrecurring [Member] - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on a nonrecurring basis	$ 0	$ 0
Liabilities measured at fair value on a nonrecurring basis	$ 0	$ 0

Deferred policy acquisition c_3

Deferred policy acquisition costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Movement analysis of deferred policy acquisition costs [Roll Forward]
Balance, beginning of period	$ 23,564	$ 14,801	$ 11,775
Policy acquisition costs deferred:
Direct commissions deferred	80,682	56,841	40,546
Ceding commissions deferred	(18,879)	(12,373)	(11,239)
Other underwriting and policy acquisition costs deferred	4,478	3,727	3,141
Policy acquisition costs deferred	66,281	48,195	32,448
Amortization of net policy acquisition costs	(57,933)	(39,432)	(29,422)
Balance, end of period	$ 31,912	$ 23,564	$ 14,801

Underwriting, acquisition and_3

Underwriting, acquisition and insurance expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Underwriting, Acquisition and Insurance Expenses [Abstract]
Direct commissions	$ 69,922	$ 48,382	$ 36,885
Ceding commissions	(16,145)	(12,347)	(10,448)
Other expenses	40,519	34,182	26,988
Total	94,296	70,217	53,425
Salaries, employee benefits and bonus expense	$ 35,900	$ 27,800	$ 19,700

Income taxes (Details)

Income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of income tax expense
Current federal income tax expense	$ 11,378	$ 12,860	$ 9,923
Deferred federal income tax benefit	616	(125)	(3,230)
Income tax expense	11,994	12,735	6,693
Federal income taxes paid	13,000	11,600	$ 9,900
Income taxes receivable	$ 1,200
Income tax payable		$ 400
Statutory income tax rate, percent	21.00%	21.00%	21.00%
Effective income tax rate reconciliation, amount [Abstract]
Income tax expense at federal income tax	$ 21,087	$ 15,971	$ 8,501
Stock options exercised	(7,634)	(2,411)	918
Tax-exempt investment income	(565)	(577)	(672)
Restricted stock award vesting	(658)	(153)	0
Other	(236)	(95)	(218)
Income tax expense	11,994	12,735	$ 6,693
Unrecognized tax positions	$ 0	$ 0

Income taxes - Deferred Tax Ass

Income taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets [Abstract]
Unpaid losses and loss adjustment expenses	$ 11,736	$ 8,199
Unearned premiums	9,942	7,193
Organizational costs	128	162
Stock compensation	865	765
State operating loss carryforwards	3,833	1,497
Allowance for doubtful accounts	649	570
Other	126	256
Deferred tax assets before allowance	27,279	18,642
Less: valuation allowance	(3,491)	(1,592)
Total deferred tax assets	23,788	17,050
Deferred tax liabilities [Abstract]
Unrealized gains on fixed-maturity securities	10,497	3,090
Unrealized gains on equity securities	6,552	2,995
Deferred policy acquisition costs, net of ceding commissions	6,701	4,949
Property and equipment	2,433	10
Intangible assets	743	743
Transition adjustment for loss discounting	1,281	1,537
Other	229	352
Total deferred tax liabilities	28,436	13,676
Net deferred tax liabilities	(4,648)
Net deferred tax assets		3,374
State Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 80,900	$ 31,600

Reserves for unpaid losses an_3

Reserves for unpaid losses and loss adjustment expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of consolidated beginning and ending reserves for unpaid losses and loss adjustment expenses [Roll Forward]
Gross reserves for unpaid losses and loss adjustment expenses, beginning of year	$ 636,013	$ 460,058	$ 369,152	$ 315,717
Reinsurance recoverables on unpaid losses, beginning of period	69,792	55,389	48,224
Adoption of new accounting standard for credit losses, allowance for reinsurance recoverables	282	0	0
Net reserves for unpaid losses and loss adjustment expenses, beginning of period	390,266	313,763	267,493
Incurred losses and loss adjustment expenses [Abstract]
Current year	277,140	178,986	135,078
Prior year losses and loss adjustment expense	(13,338)	(9,423)	(7,037)
Total net losses and loss adjustment expenses incurred	263,802	169,563	128,041
Payments [Abstract]
Current year	27,664	19,054	14,118
Prior years	74,403	74,006	67,653
Total payments	102,067	93,060	81,771
Net reserves for unpaid losses and loss adjustment expenses, end of period	552,283	390,266	313,763
Reinsurance recoverable for unpaid Claims losses, net, ending balance	83,730
Reinsurance recoverables on unpaid losses, end of period		69,792	55,389
Gross reserves for unpaid losses and loss adjustment expenses, end of year	636,013	460,058	$ 369,152
Cumulative Effect, Period of Adoption, Adjusted Balance
Reconciliation of consolidated beginning and ending reserves for unpaid losses and loss adjustment expenses [Roll Forward]
Net reserves for unpaid losses and loss adjustment expenses, beginning of period	$ 390,548
Payments [Abstract]
Net reserves for unpaid losses and loss adjustment expenses, end of period		$ 390,548

Reserves for unpaid losses an_4

Reserves for unpaid losses and loss adjustment expenses Liability for Unpaid Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense	$ (13,338)	$ (9,423)	$ (7,037)
Current year catastrophe losses	277,140	178,986	135,078
Catastrophe [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Current year catastrophe losses	23,200
Accident Year 2019 [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense	(10,500)
Accident Year 2018 [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense	$ (1,800)	(13,000)
Accident Year 2017 [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense		(1,600)	(6,800)
Accident Year 2016 [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense			(3,800)
Accident Years 2011 to 2015 [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense		$ 5,200	$ 3,600

Reserves for unpaid losses an_5

Reserves for unpaid losses and loss adjustment expenses Reserve Development (Details)	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)	Dec. 31, 2011USD ($)
Claims Development
Prior year losses and loss adjustment expense	$ (13,338,000)	$ (9,423,000)	$ (7,037,000)
Liability for claims and claim adjustment expense, net	504,248,000
Current year	277,140,000	178,986,000	135,078,000
Catastrophe [Member]
Claims Development
Current year	23,200,000
Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	59,955,000
All outstanding liabilities not separately presented, net of reinsurance	0
Liability for claims and claim adjustment expense, net	22,165,000
Incurred claims and claim adjustment expense, net	82,120,000
Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	69,478,000
All outstanding liabilities not separately presented, net of reinsurance	9,000
Liability for claims and claim adjustment expense, net	98,774,000
Incurred claims and claim adjustment expense, net	168,243,000
Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	249,945,000
All outstanding liabilities not separately presented, net of reinsurance	46,000
Liability for claims and claim adjustment expense, net	383,309,000
Incurred claims and claim adjustment expense, net	633,208,000
Accident Year 2011 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	3,104,000	3,104,000	3,065,000	$ 3,042,000	$ 3,042,000	$ 3,044,000	$ 2,116,000	$ 1,392,000	$ 1,037,000	$ 139,000
Incurred claims and claim adjustment expense, net	3,177,000	3,206,000	3,225,000	3,261,000	3,374,000	3,560,000	3,609,000	3,646,000	3,844,000	4,246,000
Total of IBNR liabilities plus expected development on reported claims	$ 73,000
Cumulative number of reported claims	76
Accident Year 2011 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 8,745,000	8,693,000	8,510,000	6,868,000	6,363,000	4,575,000	3,788,000	2,519,000	1,596,000	207,000
Incurred claims and claim adjustment expense, net	9,318,000	9,379,000	9,023,000	8,375,000	8,142,000	7,613,000	7,340,000	5,757,000	5,940,000	$ 5,839,000
Total of IBNR liabilities plus expected development on reported claims	$ 360,000
Cumulative number of reported claims	227
Accident Year 2012 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 1,946,000	1,946,000	1,946,000	1,882,000	1,090,000	1,024,000	877,000	475,000	153,000
Incurred claims and claim adjustment expense, net	2,136,000	2,207,000	2,314,000	2,477,000	2,845,000	3,102,000	4,205,000	5,749,000	7,913,000
Total of IBNR liabilities plus expected development on reported claims	$ 190,000
Cumulative number of reported claims	138
Accident Year 2012 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 21,408,000	20,707,000	19,383,000	16,474,000	14,382,000	11,238,000	7,850,000	4,441,000	757,000
Incurred claims and claim adjustment expense, net	23,197,000	23,223,000	22,401,000	22,001,000	20,579,000	20,401,000	18,803,000	17,436,000	$ 16,977,000
Total of IBNR liabilities plus expected development on reported claims	$ 1,288,000
Cumulative number of reported claims	586
Accident Year 2013 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 5,612,000	5,482,000	5,439,000	5,320,000	5,070,000	4,436,000	1,915,000	499,000
Incurred claims and claim adjustment expense, net	6,087,000	6,128,000	6,463,000	7,002,000	7,917,000	9,113,000	11,639,000	15,238,000
Total of IBNR liabilities plus expected development on reported claims	$ 465,000
Cumulative number of reported claims	228
Accident Year 2013 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 29,610,000	28,248,000	26,715,000	21,348,000	14,890,000	7,957,000	4,469,000	1,099,000
Incurred claims and claim adjustment expense, net	33,128,000	33,973,000	33,248,000	31,731,000	29,039,000	28,037,000	28,771,000	$ 30,616,000
Total of IBNR liabilities plus expected development on reported claims	$ 2,978,000
Cumulative number of reported claims	856
Accident Year 2014 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 9,491,000	9,415,000	8,290,000	6,385,000	5,039,000	1,865,000	435,000
Incurred claims and claim adjustment expense, net	10,620,000	10,988,000	10,948,000	11,217,000	11,748,000	14,289,000	18,847,000
Total of IBNR liabilities plus expected development on reported claims	$ 824,000
Cumulative number of reported claims	273
Accident Year 2014 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 34,338,000	31,026,000	23,771,000	17,576,000	8,489,000	3,081,000	698,000
Incurred claims and claim adjustment expense, net	42,434,000	41,859,000	39,313,000	36,678,000	38,049,000	40,668,000	$ 47,805,000
Total of IBNR liabilities plus expected development on reported claims	$ 5,843,000
Cumulative number of reported claims	1,196
Accident Year 2015 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 11,522,000	11,372,000	9,238,000	7,563,000	4,496,000	217,000
Incurred claims and claim adjustment expense, net	13,548,000	13,942,000	13,583,000	14,896,000	16,777,000	18,883,000
Total of IBNR liabilities plus expected development on reported claims	$ 1,378,000
Cumulative number of reported claims	258
Accident Year 2015 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 41,724,000	37,690,000	28,385,000	12,685,000	3,161,000	941,000
Incurred claims and claim adjustment expense, net	54,090,000	54,697,000	52,100,000	49,122,000	51,739,000	$ 59,717,000
Total of IBNR liabilities plus expected development on reported claims	$ 9,323,000
Cumulative number of reported claims	1,496
Accident Year 2016 [Member]
Claims Development
Prior year losses and loss adjustment expense			(3,800,000)
Accident Year 2016 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 3,270,000	3,265,000	3,265,000	3,257,000	1,867,000
Incurred claims and claim adjustment expense, net	3,270,000	3,278,000	3,301,000	3,392,000	4,177,000
Total of IBNR liabilities plus expected development on reported claims	$ 0
Cumulative number of reported claims	286
Accident Year 2016 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 11,381,000	9,839,000	6,907,000	3,015,000	1,158,000
Incurred claims and claim adjustment expense, net	13,583,000	14,322,000	14,675,000	14,693,000	19,170,000
Total of IBNR liabilities plus expected development on reported claims	$ 2,116,000
Cumulative number of reported claims	310
Accident Year 2016 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 34,437,000	28,924,000	17,225,000	6,015,000	1,099,000
Incurred claims and claim adjustment expense, net	57,401,000	55,534,000	53,549,000	55,680,000	$ 61,440,000
Total of IBNR liabilities plus expected development on reported claims	$ 13,928,000
Cumulative number of reported claims	1,434
Accident Year 2017 [Member]
Claims Development
Prior year losses and loss adjustment expense		(1,600,000)	(6,800,000)
Accident Year 2017 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 11,608,000	11,602,000	11,233,000	9,938,000
Incurred claims and claim adjustment expense, net	11,631,000	11,676,000	11,705,000	12,473,000
Total of IBNR liabilities plus expected development on reported claims	$ 19,000
Cumulative number of reported claims	1,041
Accident Year 2017 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 10,484,000	8,252,000	4,897,000	340,000
Incurred claims and claim adjustment expense, net	15,794,000	16,120,000	17,097,000	18,116,000
Total of IBNR liabilities plus expected development on reported claims	$ 3,703,000
Cumulative number of reported claims	369
Accident Year 2017 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 37,736,000	22,407,000	9,352,000	1,581,000
Incurred claims and claim adjustment expense, net	70,641,000	68,985,000	67,151,000	$ 71,126,000
Total of IBNR liabilities plus expected development on reported claims	$ 24,096,000
Cumulative number of reported claims	1,632
Accident Years 2011 to 2015 [Member]
Claims Development
Prior year losses and loss adjustment expense		5,200,000	3,600,000
Accident Year 2018 [Member]
Claims Development
Prior year losses and loss adjustment expense	$ (1,800,000)	(13,000,000)
Accident Year 2018 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	12,599,000	11,646,000	9,132,000
Incurred claims and claim adjustment expense, net	12,698,000	12,004,000	11,559,000
Total of IBNR liabilities plus expected development on reported claims	$ 88,000
Cumulative number of reported claims	649
Accident Year 2018 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 8,931,000	5,030,000	507,000
Incurred claims and claim adjustment expense, net	18,612,000	20,234,000	22,429,000
Total of IBNR liabilities plus expected development on reported claims	$ 7,275,000
Cumulative number of reported claims	458
Accident Year 2018 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 22,860,000	10,995,000	2,638,000
Incurred claims and claim adjustment expense, net	78,386,000	78,331,000	$ 86,157,000
Total of IBNR liabilities plus expected development on reported claims	$ 44,307,000
Cumulative number of reported claims	1,606
Accident Year 2019 [Member]
Claims Development
Prior year losses and loss adjustment expense	$ (10,500,000)
Accident Year 2019 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	12,581,000	9,852,000
Incurred claims and claim adjustment expense, net	13,909,000	14,914,000
Total of IBNR liabilities plus expected development on reported claims	$ 430,000
Cumulative number of reported claims	636
Accident Year 2019 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 6,005,000	2,487,000
Incurred claims and claim adjustment expense, net	29,056,000	34,693,000
Total of IBNR liabilities plus expected development on reported claims	$ 17,500,000
Cumulative number of reported claims	538
Accident Year 2019 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 16,687,000	3,944,000
Incurred claims and claim adjustment expense, net	109,994,000	$ 112,266,000
Total of IBNR liabilities plus expected development on reported claims	$ 81,322,000
Cumulative number of reported claims	1,644
Accident Year 2020 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 19,897,000
Incurred claims and claim adjustment expense, net	40,612,000
Total of IBNR liabilities plus expected development on reported claims	$ 7,139,000
Cumulative number of reported claims	2,189
Accident Year 2020 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 1,002,000
Incurred claims and claim adjustment expense, net	55,630,000
Total of IBNR liabilities plus expected development on reported claims	$ 48,966,000
Cumulative number of reported claims	738
Accident Year 2020 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 2,400,000
Incurred claims and claim adjustment expense, net	154,619,000
Total of IBNR liabilities plus expected development on reported claims	$ 146,945,000
Cumulative number of reported claims	1,076

Reserves for unpaid losses an_6

Reserves for unpaid losses and loss adjustment expenses Historical Claims Duration (Details)	Dec. 31, 2020Rate
Property [Member]
Historical Claims Duration [Line Items]
Historical Claims Duration, Year One	66.90%
Historical Claims Duration, Year Two	23.30%
Historical Claims Duration, Year Three	3.60%
Historical Claims Duration, Year Four	0.00%
Historical Claims Duration, Year Five	0.20%
Casualty - claims made [Member]
Historical Claims Duration [Line Items]
Historical Claims Duration, Year One	4.90%
Historical Claims Duration, Year Two	21.20%
Historical Claims Duration, Year Three	24.30%
Historical Claims Duration, Year Four	14.40%
Historical Claims Duration, Year Five	13.60%
Historical Claims Duration, Year Six	10.10%
Historical Claims Duration, Year Seven	1.10%
Historical Claims Duration, Year Eight	1.00%
Historical Claims Duration, Year Nine	0.60%
Historical Claims Duration, Year Ten	0.00%
Casualty - occurrence [Member]
Historical Claims Duration [Line Items]
Historical Claims Duration, Year One	2.50%
Historical Claims Duration, Year Two	10.30%
Historical Claims Duration, Year Three	14.80%
Historical Claims Duration, Year Four	20.20%
Historical Claims Duration, Year Five	13.80%
Historical Claims Duration, Year Six	13.80%
Historical Claims Duration, Year Seven	7.60%
Historical Claims Duration, Year Eight	9.10%
Historical Claims Duration, Year Nine	2.50%
Historical Claims Duration, Year Ten	0.60%

Reserves for unpaid losses an_7

Reserves for unpaid losses and loss adjustment expenses Reconciliation of Claims Development to Liability (Details) $ in Thousands	Dec. 31, 2020USD ($)
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for claims and claim adjustment expense, net	$ 504,248
Reinsurance recoverable for unpaid losses	83,730
Unallocated claim adjustment expenses	48,035
Property [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for claims and claim adjustment expense, net	22,165
Reinsurance recoverable for unpaid losses	10,800
Casualty - claims made [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for claims and claim adjustment expense, net	98,774
Reinsurance recoverable for unpaid losses	61,100
Casualty - occurrence [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for claims and claim adjustment expense, net	383,309
Reinsurance recoverable for unpaid losses	$ 11,830

Reinsurance, Effects of Reinsur

Reinsurance, Effects of Reinsurance on Premiums Written and Earned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Written [Abstract]
Direct	$ 552,814	$ 389,569	$ 275,538
Assumed	0	125	0
Ceded	(74,595)	(47,633)	(39,924)
Net written premiums	478,219	342,061	235,614
Earned [Abstract]
Direct	479,181	330,464	250,397
Assumed	21	104	0
Ceded	(66,448)	(47,587)	(37,709)
Net earned premiums	412,754	282,981	212,688
Ceded incurred losses and loss adjustment expenses	$ 42,000	$ 27,200	$ 25,500

Reinsurance Reinsurance Balance

Reinsurance Reinsurance Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reinsurance Disclosure [Abstract]
Reinsurance recoverables on paid losses, gross	$ 9,485	$ 2,782
Reinsurance recoverable for unpaid losses	83,730
Reinsurance recoverables on unpaid losses, gross		69,792	$ 55,389	$ 48,224
Reinsurance recoverables	93,215	72,574
Concentration Risk [Line Items]
Reinsurance recoverables	93,215	72,574
Ceded unearned premiums	24,265	16,118
Reinsurance Recoverable, Allowance for Credit Loss		$ 300
Credit Risk Reinsurer One [Member]
Reinsurance Disclosure [Abstract]
Reinsurance recoverables	26,300
Concentration Risk [Line Items]
Reinsurance recoverables	26,300
Ceded unearned premiums	6,100
Credit Risk Reinsurer Two [Member]
Reinsurance Disclosure [Abstract]
Reinsurance recoverables	19,700
Concentration Risk [Line Items]
Reinsurance recoverables	19,700
Ceded unearned premiums	4,000
Credit Risk Reinsurer Three [Member]
Reinsurance Disclosure [Abstract]
Reinsurance recoverables	11,900
Concentration Risk [Line Items]
Reinsurance recoverables	11,900
Ceded unearned premiums	2,700
Credit Risk Reinsurer Four [Member]
Reinsurance Disclosure [Abstract]
Reinsurance recoverables	8,600
Concentration Risk [Line Items]
Reinsurance recoverables	8,600
Ceded unearned premiums	2,400
Credit Risk Reinsurer Five [Member]
Reinsurance Disclosure [Abstract]
Reinsurance recoverables	6,500
Concentration Risk [Line Items]
Reinsurance recoverables	6,500
Ceded unearned premiums	$ 2,300
Prepaid reinsurance premiums ceded to five reinsurers as a percentage of total ceded unearned premium balance [Member] | Major Reinsurers [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	71.80%
Reinsurance recoverables on paid and unpaid losses from the Company’s five largest reinsurers as percent of total reinsurance recoverables [Member] | Major Reinsurers [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	78.40%

Stockholders' Equity Capital St

Stockholders' Equity Capital Stock (Details) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares issued	0	0
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	100,000,000	100,000,000
Preferred stock, outstanding (in shares)	0	0
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01

Stockholders' Equity, Public Of

Stockholders' Equity, Public Offering (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 07, 2020	Aug. 12, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stockholders' Equity Attributable to Parent [Abstract]
Stock issued, shares	310,500	741,750	311,000	742,000
Share price (in dollars per share)	$ 190	$ 93
Net proceeds from public offering, net of discounts, commissions and other offering costs	$ 56,700	$ 65,900	$ 56,698	$ 65,879	$ 0

Stockholders' Equity, Equity-ba

Stockholders' Equity, Equity-based Compensation, Options (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 27, 2016	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation		$ 3,600	$ 2,700	$ 1,600
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Intrinsic value of options exercised		$ 37,000	$ 11,900
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term of option granted	10 years
Award vesting period	4 years
Granted (in dollars per share)	$ 2.71
Assumptions used in estimating fair value of options granted [Abstract]
Risk-free rate of return		1.26%
Dividend yield		1.25%
Expected share price volatility		18.50%
Expected life		6 years 3 months 18 days
Options outstanding, number of awards [Roll Forward]
Options, beginning of the year (in shares)		614,345
Granted, shares		0
Forfeited (in shares)		(234)
Exercised (in shares)		(226,373)
Options, end of year (in shares)		387,738	614,345
Exercisable, shares		387,738
Options outstanding, weighted average exercise price [Abstract]
Options beginning of the year (in dollars per share)		$ 16
Granted	$ 16	0
Forfeited		16
Exercised		16
Options end of the year (in dollars per share)		16	$ 16
Exercisable		$ 16
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted average remaining contractual term		5 years 7 months 6 days
Exercisable, weighted average remaining contractual term		5 years 7 months 6 days
Outstanding, aggregate intrinsic value		$ 71,394
Exercisable, aggregate intrinsic value		$ 71,394
2016 Omnibus Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance	2,073,832
2016 Omnibus Incentive Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	1,036,916

Stockholders' Equity - Equity-b

Stockholders' Equity - Equity-based Compensation, Restricted Stock (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld for taxes	12,000	7,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld for taxes	11,966
Vested in period, fair value	$ 5.8	$ 2.1
Nonvested Restricted Stock, Number of Shares [Roll Forward]
Nonvested outstanding at the beginning of the period, shares		122,723
Granted, shares	42,694
Vested, shares	(41,010)
Forfeited, shares	(16,015)
Nonvested outstanding at the end of the period, shares	108,392
Nonvested Restricted Stock, Weighted Average Grant Date Fair Value [Abstract]
Nonvested outstanding at the beginning of the period	$ 67.01
Granted	147.45	$ 80.59	$ 52.99
Vested	63.86
Forfeited	83.79
Nonvested outstanding at the end of the period	$ 97.40	$ 67.01
Unrecognized stock-based compensation expense	$ 8.3
Compensation cost not yet recognized, period	2 years 9 months 18 days
Minimum [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period	1 year
Maximum [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period	4 years

Stockholders' Equity - Subseque

Stockholders' Equity - Subsequent Event (Details) - $ / shares	Feb. 11, 2021	Jan. 01, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Member] | Dividend Declared [Member]
Subsequent Event [Line Items]
Dividend declared date	Feb. 11, 2021
Dividends payable, per share	$ 0.11
Dividend payable date	Mar. 12, 2021
Dividend record date	Feb. 26, 2021
Restricted Stock [Member]
Subsequent Event [Line Items]
Grant date fair value			$ 147.45	$ 80.59	$ 52.99
Restricted Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Granted		3,200
Grant date fair value		$ 200.13
Award vesting period		1 year

Earnings per share (Details)

Earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of numerator and denominator of the basic and diluted earnings per share computations [Abstract]
Net income									$ 88,419	$ 63,316	$ 33,787
Basic earnings per share [Abstract]
Earnings per share - basic	$ 1.69	$ 0.66	$ 1.37	$ 0.23	$ 0.81	$ 0.60	$ 0.65	$ 0.88	$ 3.96	$ 2.94	$ 1.60
Diluted earnings per share [Abstract]
Earnings per share - diluted	$ 1.65	$ 0.65	$ 1.33	$ 0.22	$ 0.79	$ 0.58	$ 0.63	$ 0.86	$ 3.87	$ 2.86	$ 1.56
Basic weighted average shares outstanding [Abstract]
Weighted average shares outstanding - basic									22,319,000	21,528,000	21,090,000
Dilutive effect of shares issued under stock compensation arrangements [Abstract]
Dilutive effect of shares issued under stock compensation arrangements (in shares)									533,000	608,000	595,000
Diluted weighted average shares outstanding [Abstract]
Weighted average shares outstanding - diluted (in shares)									22,852,000	22,136,000	21,685,000
Antidilutive securities (in shares)									35,000	54,000	86,000
Stock options [Member]
Dilutive effect of shares issued under stock compensation arrangements [Abstract]
Dilutive effect of shares issued under stock compensation arrangements (in shares)									469,000	570,000	591,000
Restricted Stock [Member]
Dilutive effect of shares issued under stock compensation arrangements [Abstract]
Dilutive effect of shares issued under stock compensation arrangements (in shares)									64,000	38,000	4,000

Credit Agreement (Details)

Credit Agreement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Current borrowing capacity	$ 50,000
Accordion feature	$ 30,000
Maturity date	May 28, 2024
Interest rate description	Eurodollar loans bear an interest rate per annum equal to adjusted LIBOR for the applicable interest period plus a margin of 1.75%. ABR loans bear an interest rate per annum equal to the higher of the prime rate, the New York Federal Reserve Board Rate or the one-month adjusted LIBOR, plus the applicable margin of 0.75% to 1.75%, depending on which interest option was applicable for the particular ABR loan.
Credit facility draw down	$ 25,700
Credit facility	42,570	$ 16,744	$ 0
Debt issuance costs	$ 400
Weighted average interest rate	1.98%
Interest expense	$ 1,000
Interest capitalized	800
Interest paid	$ 800	$ 100

Employee benefit plan (Details)

Employee benefit plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Expenses related to employee benefit plan	$ 1.7	$ 1.3	$ 1

Other comprehensive income (l_3

Other comprehensive income (loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized gains (losses) arising during the period, before income taxes	$ 37,387	$ 19,190	$ (6,664)
Income taxes	(7,851)	(4,029)	1,399
Unrealized gains (losses) arising during the period, net of income tax	29,536	15,161	(5,265)
Less reclassification adjustment [Abstract]
Net realized investment gains	2,119	489	258
Income taxes	(445)	(102)	(54)
Reclassification adjustment included in net income	1,674	387	204
Other comprehensive income (loss)	$ 27,862	$ 14,774	$ (5,469)

Underwriting information (Detai

Underwriting information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2020USD ($)Rate	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Revenue from External Customer [Line Items]
Gross written premiums	$ 149,910	$ 144,777	$ 134,091	$ 124,036	$ 112,137	$ 97,984	$ 94,947	$ 84,626	$ 552,814	$ 389,694	$ 275,538
Number of operating segments									1
Construction [Member]
Revenue from External Customer [Line Items]
Gross written premiums									$ 87,206	71,035	50,879
Small Business [Member]
Revenue from External Customer [Line Items]
Gross written premiums									83,289	63,181	44,368
Excess Casualty [Member]
Revenue from External Customer [Line Items]
Gross written premiums									76,715	51,225	37,398
Commercial Property [Member]
Revenue from External Customer [Line Items]
Gross written premiums									51,789	29,115	9,166
Products Liability [Member]
Revenue from External Customer [Line Items]
Gross written premiums									38,306	26,333	20,049
Allied Health [Member]
Revenue from External Customer [Line Items]
Gross written premiums									37,562	23,962	16,815
Life Sciences [Member]
Revenue from External Customer [Line Items]
Gross written premiums									31,027	17,821	14,505
General Casualty [Member]
Revenue from External Customer [Line Items]
Gross written premiums									29,205	23,279	17,625
Professional Liability [Member]
Revenue from External Customer [Line Items]
Gross written premiums									27,051	20,029	16,717
Management Liability [Member]
Revenue from External Customer [Line Items]
Gross written premiums									24,061	14,820	8,161
Energy [Member]
Revenue from External Customer [Line Items]
Gross written premiums									16,985	15,371	15,586
Environmental [Member]
Revenue from External Customer [Line Items]
Gross written premiums									8,568	5,179	2,205
Health Care [Member]
Revenue from External Customer [Line Items]
Gross written premiums									7,666	5,963	5,725
Inland Marine [Member]
Revenue from External Customer [Line Items]
Gross written premiums									6,910	3,467	2,046
Public Entity [Member]
Revenue from External Customer [Line Items]
Gross written premiums									3,007	580	1,193
Commercial Insurance [Member]
Revenue from External Customer [Line Items]
Gross written premiums									1,757	1,674	1,096
Commercial [Member]
Revenue from External Customer [Line Items]
Gross written premiums									531,104	373,034	263,534
Personal Insurance [Member]
Revenue from External Customer [Line Items]
Gross written premiums									$ 21,710	$ 16,660	$ 12,004
Revenue Benchmark [Member]
Revenue from External Customer [Line Items]
Number of insurance brokers									3
Major Insurance Brokers, Group One [Member] | Revenue Benchmark [Member]
Revenue from External Customer [Line Items]
Gross written premiums									$ 72,100
Concentration risk, percentage | Rate									13.00%
Major Insurance Brokers, Group Two [Member] | Revenue Benchmark [Member]
Revenue from External Customer [Line Items]
Gross written premiums									$ 63,800
Concentration risk, percentage | Rate									11.50%
Major Insurance Brokers, Group Three [Member] | Revenue Benchmark [Member]
Revenue from External Customer [Line Items]
Gross written premiums									$ 56,500
Concentration risk, percentage | Rate									10.20%

Statutory financial informati_3

Statutory financial information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments [Abstract]
Statutory net income	$ 54,338	$ 40,917	$ 34,206
Statutory capital and surplus	$ 476,066	$ 348,811	$ 233,500
Percentage of policyholder surplus as of end of prior year used in determining maximum dividend distribution	10.00%
Maximum dividend distribution that can be paid without prior approval	$ 51,800

Unaudited Quarterly Financial D

Unaudited Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Gross written premiums	$ 149,910	$ 144,777	$ 134,091	$ 124,036	$ 112,137	$ 97,984	$ 94,947	$ 84,626	$ 552,814	$ 389,694	$ 275,538
Revenues	139,332	122,501	117,707	80,346	92,804	78,327	72,572	72,185	459,886	315,888	222,114
Net income	38,181	14,890	30,262	5,086	17,853	12,976	13,767	18,720	88,419	63,316	33,787
Comprehensive income	$ 41,704	$ 21,444	$ 57,270	$ (4,137)	$ 16,050	$ 16,218	$ 20,322	$ 25,500	$ 116,281	$ 78,090	$ 28,318
Basic earnings per share [Abstract]
Basic	$ 1.69	$ 0.66	$ 1.37	$ 0.23	$ 0.81	$ 0.60	$ 0.65	$ 0.88	$ 3.96	$ 2.94	$ 1.60
Diluted earnings per share [Abstract]
Diluted	$ 1.65	$ 0.65	$ 1.33	$ 0.22	$ 0.79	$ 0.58	$ 0.63	$ 0.86	$ 3.87	$ 2.86	$ 1.56

Schedule I-Summary of Investmen

Schedule I-Summary of Investments-Other than Related Parties (Details) $ in Thousands	Dec. 31, 2020USD ($)
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	$ 1,130,575
Fair Value	1,211,462
Amount	1,211,462
Fixed Maturities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	1,031,817
Fair Value	1,081,800
Amount	1,081,800
US States and Political Subdivisions Debt Securities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	216,181
Fair Value	230,906
Amount	230,906
Debt Security, Corporate, US [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	294,854
Fair Value	316,608
Amount	316,608
Asset-backed Securities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	236,813
Fair Value	240,661
Amount	240,661
Commercial mortgage-backed aecurities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	66,110
Fair Value	70,969
Amount	70,969
Residential Mortgage Backed Securities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	217,859
Fair Value	222,656
Amount	222,656
Equity Securities, Investment Summary [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	98,758
Fair Value	129,662
Amount	129,662
Exchange Traded Funds [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	68,032
Fair Value	98,050
Amount	98,050
Nonredeemable Preferred Stock [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	30,726
Fair Value	31,612
Amount	$ 31,612

Schedule II - Condensed Finan_3

Schedule II - Condensed Financial Information of Registrant, Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 77,093	$ 100,408	$ 75,089	$ 81,747
Deferred income tax asset, net	0	3,374
Income taxes receivable	1,200
Other assets	50,133	23,922
Total assets	1,546,896	1,090,550
Liabilities:
Accounts payable and accrued expenses	13,651	12,366
Income taxes payable		400
Credit facility	42,570	16,744	0
Other liabilities	118	977
Total liabilities	970,658	684,670
Stockholders' Equity [Abstract]
Common stock	228	222
Additional paid-in capital	291,315	229,229
Retained earnings	243,315	162,911
Accumulated other comprehensive income	41,380	13,518
Stockholders' equity	576,238	405,880	263,986	238,189
Total liabilities and stockholders' equity	1,546,896	1,090,550
Parent Company [Member]
Assets
Cash and cash equivalents	8,395	14,726	$ 10,016	$ 1,502
Due from subsidiaries	7,792	16,836
Investment in subsidiaries	600,931	391,071
Deferred income tax asset, net	587	519
Income taxes receivable	1,177	0
Other assets	290	208
Total assets	619,172	423,360
Liabilities:
Accounts payable and accrued expenses	302	260
Income taxes payable	0	434
Credit facility	42,570	16,744
Other liabilities	62	42
Total liabilities	42,934	17,480
Stockholders' Equity [Abstract]
Common stock	228	222
Additional paid-in capital	291,315	229,229
Retained earnings	243,315	162,911
Accumulated other comprehensive income	41,380	13,518
Stockholders' equity	576,238	405,880
Total liabilities and stockholders' equity	$ 619,172	$ 423,360

Schedule II - Condensed Finan_4

Schedule II - Condensed Financial Information of Registrant, Statements of Income and Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Revenues	$ 139,332	$ 122,501	$ 117,707	$ 80,346	$ 92,804	$ 78,327	$ 72,572	$ 72,185	$ 459,886	$ 315,888	$ 222,114
Expenses [Abstract]
Other expenses									1,375	57	168
Total expenses									359,473	239,837	181,634
Income tax benefit									11,994	12,735	6,693
Net income	38,181	14,890	30,262	5,086	17,853	12,976	13,767	18,720	88,419	63,316	33,787
Other Comprehensive Income (Loss) [Abstract]
Comprehensive income	$ 41,704	$ 21,444	$ 57,270	$ (4,137)	$ 16,050	$ 16,218	$ 20,322	$ 25,500	116,281	78,090	28,318
Parent Company [Member]
Revenues:
Revenues									5,709	4,502	3,215
Expenses [Abstract]
Other operating expenses									6,624	5,215	4,055
Other expenses									1,332	0	0
Total expenses									7,956	5,215	4,055
Loss before equity in net income of subsidiaries									(2,247)	(713)	(840)
Income tax benefit									(8,779)	(2,714)	(1,158)
Income before equity in net income of subsidiaries									6,532	2,001	318
Equity in net income of subsidiaries									81,887	61,315	33,469
Net income									88,419	63,316	33,787
Other Comprehensive Income (Loss) [Abstract]
Equity in other comprehensive earnings (losses) of subsidiaries									27,862	14,774	(5,469)
Comprehensive income									$ 116,281	$ 78,090	$ 28,318

Schedule II - Condensed Finan_5

Schedule II - Condensed Financial Information of Registrant, Statements of Cash Flows (Details) - USD ($) $ in Thousands	Aug. 07, 2020	Aug. 12, 2019	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net income			$ 38,181	$ 14,890	$ 30,262	$ 5,086	$ 17,853	$ 12,976	$ 13,767	$ 18,720	$ 88,419	$ 63,316	$ 33,787
Adjustments to reconcile net income to net cash used in operating activities:
Deferred tax (benefit) expense											616	(125)	(3,230)
Stock compensation expense											3,575	2,742	1,597
Dividends received from subsidiary											0	5,000	11,500
Net cash provided by operating activities											279,974	178,357	103,980
Net Cash Provided by (Used in) Investing Activities [Abstract]
Net cash provided by (used in) investing activities											(379,433)	(230,793)	(106,540)
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	$ 56,700	$ 65,900									56,698	65,879	0
Common stock issued, stock options exercised											3,622	2,750	1,808
Payroll taxes withheld and remitted on share-based payments											(1,803)	(617)	0
Dividends paid											(8,073)	(6,929)	(5,906)
Proceeds from credit facility											25,700	17,300	0
Debt issuance costs											0	(628)	0
Net cash provided by (used in) financing activities											76,144	77,755	(4,098)
Net change in cash and cash equivalents											(23,315)	25,319	(6,658)
Cash and cash equivalents at beginning of period						100,408				75,089	100,408	75,089	81,747
Cash and cash equivalents at end of period			77,093				100,408				77,093	100,408	75,089
Parent Company [Member]
Operating activities:
Net income											88,419	63,316	33,787
Adjustments to reconcile net income to net cash used in operating activities:
Deferred tax (benefit) expense											(68)	(150)	(170)
Stock compensation expense											3,575	2,742	1,597
Equity in undistributed earnings of subsidiaries											(81,887)	(61,315)	(33,469)
Changes in operating assets and liabilities											7,520	(14,247)	(633)
Dividends received from subsidiary											0	5,000	11,500
Net cash provided by operating activities											17,559	(4,654)	12,612
Net Cash Provided by (Used in) Investing Activities [Abstract]
Contribution to subsidiary											(100,034)	68,391	0
Net cash provided by (used in) investing activities											(100,034)	(68,391)	0
Financing activities:
Proceeds from issuance of common stock, net of issuance costs											56,698	65,879	0
Common stock issued, stock options exercised											3,622	2,750	1,808
Payroll taxes withheld and remitted on share-based payments											(1,803)	(617)	0
Dividends paid											(8,073)	(6,929)	(5,906)
Proceeds from credit facility											25,700	17,300	0
Debt issuance costs											0	(628)	0
Net cash provided by (used in) financing activities											76,144	77,755	(4,098)
Net change in cash and cash equivalents											(6,331)	4,710	8,514
Cash and cash equivalents at beginning of period						$ 14,726				$ 10,016	14,726	10,016	1,502
Cash and cash equivalents at end of period			$ 8,395				$ 14,726				$ 8,395	$ 14,726	$ 10,016

Schedule II - Condensed Finan_6

Schedule II - Condensed Financial Information of Registrant, Notes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Current borrowing capacity	$ 50,000
Accordion feature	$ 30,000
Maturity date	May 28, 2024
Interest rate description	Eurodollar loans bear an interest rate per annum equal to adjusted LIBOR for the applicable interest period plus a margin of 1.75%. ABR loans bear an interest rate per annum equal to the higher of the prime rate, the New York Federal Reserve Board Rate or the one-month adjusted LIBOR, plus the applicable margin of 0.75% to 1.75%, depending on which interest option was applicable for the particular ABR loan.
Credit facility	$ 42,570	$ 16,744	$ 0
Debt issuance costs	$ 400
Weighted average interest rate	1.98%
Interest expense	$ 1,000
Interest capitalized	800
Interest paid	800	100
Cash dividends paid to parent company by consolidated subsidiaries	$ 0	$ 5,000	$ 11,500

Schedule V - Valuation and Qu_2

Schedule V - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Reinsurance Recoverable, Allowance for Credit Loss		$ 300
Accounting Standards Update 2016-13 [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Adoption of ASU 2016-13	$ 400
Allowance for Premiums Receivable [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	2,705	2,615	$ 2,112
Balance at beginning of period, net of adoption of new accounting standard for credit losses				$ 2,345
Additions amounts charged to expense	1,240	835	663
Deductions amounts written off or disposals	(498)	(745)	(160)
Balance at end of period	3,087	2,705	2,615
Valuation Allowance for Deferred Tax Assets [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	1,592	780	690
Additions amounts charged to expense	1,899	812	90
Deductions amounts written off or disposals	0	0	0
Balance at end of period	3,491	1,592	$ 780
Allowance for Reinsurance Recoverable [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	282
Additions amounts charged to expense	0
Deductions amounts written off or disposals	0
Balance at end of period	$ 282	$ 282