Kinsale Capital (KNSL) 10-K 2 Mar 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 20, 2020	Jun. 30, 2019
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	2221 Edward Holland Drive
Entity Address, Address Line Two	Suite 600
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, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		22,227,323
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Public Float			$ 1,836,524,103
Security Exchange Name	NASDAQ
Entity Tax Identification Number	98-0664337

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Investments:
Fixed-maturity securities available-for-sale, at fair value (amortized cost: $714,817 in 2019; $514,237 in 2018)	$ 729,532	$ 510,251
Equity securities, at fair value (cost: $64,245 in 2019; $56,051 in 2018)	78,294	57,711
Total investments	807,826	567,962
Cash and cash equivalents	100,408	75,089
Investment income due and accrued	4,743	3,783
Premiums receivable, net	34,483	24,253
Reinsurance recoverables	72,574	56,788
Ceded unearned premiums	16,118	16,072
Deferred policy acquisition costs, net of ceding commissions	23,564	14,801
Intangible assets	3,538	3,538
Deferred income tax asset, net	3,374	7,176
Other assets	23,922	3,601
Total assets	1,090,550	773,063
Liabilities:
Reserves for unpaid losses and loss adjustment expenses	460,058	369,152
Unearned premiums	187,374	128,250
Payable to reinsurers	7,151	4,565
Accounts payable and accrued expenses	12,366	7,090
Credit facility	16,744	0
Other liabilities	977	20
Total liabilities	684,670	509,077
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value, 400,000,000 shares authorized, 22,205,665 shares issued and outstanding as of December 31, 2019; 21,241,504 shares issued and outstanding as of December 31, 2018	222	212
Additional paid-in capital	229,229	158,485
Retained earnings	162,911	106,545
Accumulated other comprehensive income (loss)	13,518	(1,256)
Stockholders' equity	405,880	263,986
Total liabilities and stockholders' equity	$ 1,090,550	$ 773,063

Consolidated Balance Sheets - (

Consolidated Balance Sheets - (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Investments:
Fixed maturity securities available-for-sale, amortized cost	$ 714,817	$ 514,237
Equity securities - cost	$ 64,245	$ 56,051
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)	22,205,665	21,241,504
Common stock, shares outstanding (in shares)	22,205,665	21,241,504

Consolidated Statements of Inco

Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Gross written premiums	$ 389,694	$ 275,538	$ 223,191
Ceded written premiums	(47,633)	(39,924)	(33,719)
Net written premiums	342,061	235,614	189,472
Change in unearned premiums	(59,080)	(22,926)	(13,419)
Net earned premiums	282,981	212,688	176,053
Net investment income	20,133	15,688	10,569
Change in fair value of equity securities	12,389	(6,555)	0
Net realized investment gains	359	281	151
Other income	26	12	3
Total revenues	315,888	222,114	186,776
Expenses:
Losses and loss adjustment expenses	169,563	128,041	103,680
Underwriting, acquisition and insurance expenses	70,217	53,425	44,146
Other expenses	57	168	429
Total expenses	239,837	181,634	148,255
Income before income taxes	76,051	40,480	38,521
Income tax expense (benefit)	12,735	6,693	13,620
Net income	63,316	33,787	24,901
Other comprehensive income (loss):
Change in unrealized gains (losses) on available-for-sale investments, net of taxes of $3,927 in 2019, $(1,453) in 2018, and $3,047 in 2017	14,774	(5,469)	6,384
Total comprehensive income	$ 78,090	$ 28,318	$ 31,285
Earnings per share:
Basic	$ 2.94	$ 1.60	$ 1.19
Diluted	$ 2.86	$ 1.56	$ 1.16
Weighted-average common shares outstanding:
Basic	21,528	21,090	20,992
Diluted	22,136	21,685	21,498

Consolidated Statements of In_2

Consolidated Statements of Income and Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other comprehensive income (loss):
Change in unrealized gains (losses), taxes	$ 3,927	$ (1,453)	$ 3,047

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]	Accumulated Other Comprehensive Income [Member]
Balance, shares at Dec. 31, 2016	20,969,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, shares	67,000
Balance, shares at Dec. 31, 2017	21,036,000
Balance at Dec. 31, 2016	$ 210,214	$ 210	$ 153,353	$ 53,640	$ 3,011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	1,077	0	1,077
Stock-based compensation expense	652		652
Dividends declared	(5,039)			(5,039)
Other comprehensive income (loss), net of income tax	6,384				6,384
Net income	24,901			24,901
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				79,992	2,905
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment - unrealized gains on equity securities, net of tax | Accounting Standards Update 2016-01 [Member]	$ 0			6,490	(6,490)
Stock-based compensation, shares	206,000
Balance, shares at Dec. 31, 2018	21,241,504
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification of tax effect of TCJA | Accounting Standards Update 2018-02 [Member]	$ 0			(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]
Common stock issuance, net of transaction 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

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net income	$ 63,316	$ 33,787	$ 24,901
Adjustments to reconcile net income to net cash provided by operating activities:
Change in fair value of equity securities	(12,389)	6,555	0
Net investment gains	(359)	(281)	(151)
Deferred tax (benefit) expense	(125)	(3,230)	1,065
Depreciation and amortization	682	631	515
Stock compensation expense	2,742	1,597	652
Change in operating assets and liabilities:
Investment income due and accrued	(960)	(706)	(784)
Premiums receivable, net	(10,230)	(4,466)	(2,803)
Reserves for unpaid loss and loss adjustment expenses	90,906	53,435	50,916
Unearned premiums	59,124	25,140	13,766
Reinsurance balances, net	(13,246)	(8,070)	28,081
Funds held for reinsurers	0	0	(36,497)
Increase (Decrease) in Deferred Policy Acquisition Costs	(8,763)	(3,026)	(1,625)
Income taxes payable	1,221	18	(922)
Accounts payable and accrued expenses	2,972	464	(2,299)
Other	3,466	2,132	2,583
Net cash provided by (used in) operating activities	178,357	103,980	77,398
Investing Activities:
Purchase of property and equipment	(19,622)	(1,273)	(179)
Purchases - fixed-maturity securities	(306,203)	(194,989)	(111,580)
Purchases - equity securities		(12,656)	(31,608)
Purchases - equity securities, available for sale	(29,887)
Sales - fixed-maturity securities	35,526	10,427	12,040
Sales - equity securities	21,459
Sales - equity securities, available for sale		2,429	0
Maturities and calls - fixed-maturity securities	67,934	89,522	88,895
Net cash provided by (used in) investing activities	(230,793)	(106,540)	(42,432)
Financing activities:
Proceeds from Issuance of Common Stock	65,879	0	0
Proceeds from credit facility	17,300	0	0
Debt issuance costs	(628)	0	0
Payroll taxes withheld and remitted on share-based payments	(617)	0	0
Common stock issued, stock options exercised	2,750	1,808	1,077
Dividends paid	(6,929)	(5,906)	(5,039)
Payments on capital lease	0	0	(9)
Net cash provided by (used in) financing activities	77,755	(4,098)	(3,971)
Net change in cash and cash equivalents	25,319	(6,658)	30,995
Cash and cash equivalents at beginning of period	75,089	81,747	50,752
Cash and cash equivalents at end of period	$ 100,408	$ 75,089	$ 81,747

Description of business

Description of business	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of business	Description of business Kinsale 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. 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, 2019
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 other-than-temporary declines in fair value. 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, 2019 or December 31, 2018 . 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 comprehensive income and stockholders’ equity, net of deferred income taxes. Equity securities are reported at fair value. Prior to the adoption of new accounting guidance effective January 1, 2018, equity securities were classified as available-for-sale and, similar to fixed-maturity securities, unrealized gains and losses were recorded as a separate component of comprehensive income and stockholders’ equity, net of deferred income taxes. In accordance with new accounting guidance, the available-for-sale classification was eliminated for equity securities and changes in unrealized gains and losses in fair value of these investments are recognized in net income. The Company regularly evaluates its available-for-sale securities using both quantitative and qualitative criteria to determine impairment losses for other-than-temporary declines in the fair value of the investments. See Note 2 for further discussion of other-than-temporary impairments ("OTTI"). Interest on fixed-maturity securities is credited to earnings as it accrues. Premiums and discounts are amortized or accreted over the lives of the related fixed maturities, or to the earliest call date. 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 $2.7 million and $2.6 million at December 31, 2019 and 2018 , 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 7 to 10 years for furniture and equipment, 3 to 7 years for electronic data processing hardware and software, and from 2 to 6 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, 2019 2018 (in thousands) Equipment $ 2,353 $ 1,950 Software 2,356 1,031 Furniture and fixtures 1,025 1,019 Leasehold improvements 984 983 Construction in progress - corporate headquarters 19,789 318 26,507 5,301 Accumulated depreciation (3,873 ) (3,191 ) Total property and equipment, net $ 22,634 $ 2,110 In January 2019, the Company purchased land for $2.5 million in Henrico County, Virginia for the development of its new corporate headquarters and is currently targeting a third quarter 2020 completion date. The project is estimated to cost approximately $50 million to $55 million , which will be funded through a combination of existing cash flows from operations and draw down on the credit facility. See Note 11 for further discussion. 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 2019, 2018, or 2017. In addition, as of December 31, 2019 , 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, 2019 and 2018 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 manager 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 investments are included in the amounts disclosed as Level 2. For those bonds where significant inputs are unobservable, Level 3 inputs, the Company's investment manager obtains valuations from pricing vendors using the market approach and income approach valuation techniques. For equity securities, the Company’s investment manager 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 ASU 2016-02, Leases (Topic 842) In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)" to improve the financial reporting of leasing transactions. Under this ASU, lessees will recognize a right-of-use ("ROU") asset and corresponding liability on the balance sheet for all leases, except for leases covering a period of 12 months or less. The lessee’s income statement treatment for leases will vary depending on the nature and classification of the lease. Effective January 1, 2019, the Company adopted this ASU and recorded a ROU asset and corresponding lease liability of approximately $0.9 million . The ROU and operating lease liability are included in "other assets" and "other liabilities," respectively, in the accompanying consolidated balance sheet. The Company elected the package of practical expedients permitted under the adoption of the new standard, which allowed the Company to account for existing leases under their current classification, as well as omit any new costs classified as initial direct costs, under the new standard. This election kept the existing agreements as operating leases. The Company also elected the practical expedient allowing an accounting policy election by class of underlying asset, to account for separate lease and nonlease components as a single lease component. In addition, the Company has implemented the necessary internal controls relating to the adoption of the standard. ASU 2017-08, Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued ASU 2017-08, "Premium Amortization on Purchased Callable Debt Securities," which shortens the amortization period of the premium for certain callable debt securities, from the contractual maturity date to the earliest call date. Effective January 1, 2019, the Company adopted ASU 2017-08 using a modified retrospective approach. The adoption of ASU 2017-08 did not have a material impact on the Company's financial statements. Prospective accounting pronouncements ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) On June 16, 2016, the FASB issued ASU 2016-13, "Financial Instruments – Credit Losses (Topic 326)" to provide more useful information about the expected credit losses on financial instruments. Current GAAP delays the recognition of credit losses until it is probable a loss has been incurred. The update will require 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 debt securities will also be recorded through an allowance for credit losses. However, the amendments would 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 current 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 an additional ASUs on Topic 326 that do not change the core principle of the guidance in ASU 2016-13 but clarify or certain aspects of it. This ASU and the additional ASUs on Topic 326 are effective for annual and interim reporting periods beginning after December 15, 2019. Upon adoption, the update will be applied using the modified-retrospective approach, by which a cumulative-effect adjustment will be made to retained earnings as of the beginning of the first reporting period presented. The adoption of this ASU is not expected to have a material impact on the Company's 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. This guidance is effective for reporting periods beginning after December 15, 2019. The adoption of the guidance is not expected to have a material effect on the Company’s 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, 2019
Investments [Abstract]
Investments	Investments Available-for-sale investments The following tables summarize the Company’s available-for-sale investments: December 31, 2019 Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding 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 Commercial mortgage and asset-backed securities 195,750 2,930 (710 ) 197,970 Residential mortgage-backed securities 172,358 1,819 (388 ) 173,789 Total available-for-sale investments $ 714,817 $ 17,029 $ (2,314 ) $ 729,532 December 31, 2018 Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Estimated Fair Value (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 610 $ 2 $ (1 ) $ 611 Obligations of states, municipalities and political subdivisions 153,884 2,010 (1,294 ) 154,600 Corporate and other securities 97,889 264 (1,401 ) 96,752 Commercial mortgage and asset-backed securities 151,137 252 (1,522 ) 149,867 Residential mortgage-backed securities 110,717 354 (2,650 ) 108,421 Total available-for-sale investments $ 514,237 $ 2,882 $ (6,868 ) $ 510,251 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 declines in the securities’ fair value are deemed to be an other-than-temporary impairment ("OTTI"). The Company considers a number of factors in completing its OTTI review, including the length of time and 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 an OTTI, but rather a temporary decline in fair value. 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 considered to be other-than-temporary 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, resulting in a new cost basis for the security. If the decline in fair value of a fixed-maturity security below its amortized cost is considered to be other-than-temporary based upon other considerations, 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 OTTI, which is recognized in net income, resulting in a new cost basis for the security. Any remaining decline in fair value represents the noncredit portion of the OTTI, which is recognized in other comprehensive income The following tables summarize gross unrealized losses and fair value for available-for-sale securities by length of time that the securities have continuously been in an unrealized loss position: 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: U.S. Treasury securities and obligations of U.S. government agencies $ — $ — $ — $ — $ — $ — 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 ) Commercial mortgage and asset-backed securities 37,723 (303 ) 46,623 (407 ) 84,346 (710 ) Residential mortgage-backed securities 36,986 (148 ) 24,815 (240 ) 61,801 (388 ) Total available-for-sale investments $ 126,115 $ (1,663 ) $ 73,201 $ (651 ) $ 199,316 $ (2,314 ) At December 31, 2019 , the Company held 137 fixed-maturity securities with a total estimated fair value of $199.3 million and gross unrealized losses of $2.3 million . Of those securities, 51 were in a continuous unrealized loss position for greater than one year. Unrealized losses were caused by interest rate changes or other market factors and were not credit specific issues. At December 31, 2019 , 89% 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 other-than-temporary impairments from fixed-maturity securities with unrealized losses for the year ended December 31, 2019 . December 31, 2018 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: U.S. Treasury securities and obligations of U.S. government agencies $ — $ — $ 499 $ (1 ) $ 499 $ (1 ) Obligations of states, municipalities and political subdivisions 42,718 (440 ) 34,326 (854 ) 77,044 (1,294 ) Corporate and other securities 62,045 (890 ) 12,092 (511 ) 74,137 (1,401 ) Commercial mortgage and asset-backed securities 93,247 (1,017 ) 25,746 (505 ) 118,993 (1,522 ) Residential mortgage-backed securities 24,571 (155 ) 55,638 (2,495 ) 80,209 (2,650 ) Total available-for-sale investments $ 222,581 $ (2,502 ) $ 128,301 $ (4,366 ) $ 350,882 $ (6,868 ) At December 31, 2018 , the Company held 317 fixed-maturity securities with a total estimated fair value of $350.9 million and gross unrealized losses of $6.9 million . Of these securities, 158 were in a continuous unrealized loss position for greater than one year. Unrealized losses were caused by interest rate changes or other market factors and were not credit specific issues. At December 31, 2018 , 86.4% 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 other-than-temporary impairments from the fixed-maturity or equity securities with unrealized losses at December 31, 2018 . 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, 2019 are summarized, by contractual maturity, as follows: Amortized Estimated Cost Fair Value (in thousands) Due in one year or less $ 9,940 $ 9,990 Due after one year through five years 115,480 118,611 Due after five years through ten years 79,235 82,314 Due after ten years 142,054 146,858 Commercial mortgage and asset-backed securities 195,750 197,970 Residential mortgage-backed securities 172,358 173,789 Total fixed maturities $ 714,817 $ 729,532 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, 2019 2018 2017 (in thousands) Interest: Taxable bonds $ 14,853 $ 9,474 $ 6,233 Municipal bonds (tax exempt) 3,692 4,298 3,619 Cash equivalents and short-term investments 842 1,017 678 Dividends on equity securities 2,136 2,014 1,041 Gross investment income 21,523 16,803 11,571 Investment expenses (1,390 ) (1,115 ) (1,002 ) Net investment income $ 20,133 $ 15,688 $ 10,569 Realized investment gains and losses The following table presents realized investment gains and losses: Year Ended December 31, 2019 2018 2017 (in thousands) Fixed-maturity securities: Realized gains $ 567 $ 263 $ 220 Realized losses (79 ) (17 ) (69 ) Net realized gains from fixed-maturity securities 488 246 151 Equity securities: Realized gains 556 57 — Realized losses (688 ) (22 ) — Net realized gains (losses) from equity securities (132 ) 35 — Short-term securities - realized gain 3 — — Net realized investment gains $ 359 $ 281 $ 151 Change in net unrealized gains (losses) on investments The change in net unrealized gains for fixed-maturity securities was $18.7 million for the year ended December 31, 2019 . The change in net unrealized losses for fixed-maturity securities was $6.9 million for the year ended December 31, 2018 . The change in net unrealized gains for fixed-maturity securities was $5.2 million for the year ended December 31, 2017 . For the year ended December 31, 2017 , the change in net unrealized gains for equity securities was $4.2 million . Insurance – statutory deposits The Company had invested assets with a carrying value of $6.9 million and $6.9 million on deposit with state regulatory authorities at December 31, 2019 and 2018 , respectively.

Fair value measurements

Fair value measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements Fair 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 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 manager from nationally recognized third-party pricing services, where available. For securities where the Company is unable to obtain fair values from a pricing service or broker, fair values are estimated using information obtained from the Company's investment manager. Management performs several procedures to ascertain the reasonableness of investment values included in the consolidated financial statements at December 31, 2019 and 2018, including 1) obtaining and reviewing internal control reports from the Company's investment manager that assess fair values from third party pricing services, 2) discussing with the Company's investment manager 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 manager 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, 2019 and 2018 , by level within the fair value hierarchy. 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 Commercial mortgage and asset-backed securities — 197,970 — 197,970 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 December 31, 2018 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 611 $ — $ — $ 611 Obligations of states, municipalities and political subdivisions — 154,600 — 154,600 Corporate and other securities — 96,752 — 96,752 Commercial mortgage and asset-backed securities — 149,867 — 149,867 Residential mortgage-backed securities — 108,421 — 108,421 Total fixed maturities 611 509,640 — 510,251 Equity securities: Exchange traded funds 38,987 — — 38,987 Nonredeemable preferred stock — 18,724 — 18,724 Total equity securities 38,987 18,724 — 57,711 Total $ 39,598 $ 528,364 $ — $ 567,962 There were no transfers into or out of Level 1 and Level 2 during the years ended December 31, 2019 or 2018 . There were no assets or liabilities measured at fair value on a nonrecurring basis as of December 31, 2019 or 2018 . The carrying value of cash equivalents approximates its fair value at December 31, 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, 2019. See Note 11 for further information regarding the Credit Facility.

Deferred policy acquisition cos

Deferred policy acquisition costs	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 2017 (in thousands) Balance, beginning of year $ 14,801 $ 11,775 $ 10,150 Policy acquisition costs deferred: Direct commissions 56,841 40,546 32,927 Ceding commissions (12,373 ) (11,239 ) (9,984 ) Other underwriting and policy acquisition costs 3,727 3,141 2,827 Policy acquisition costs deferred 48,195 32,448 25,770 Amortization of net policy acquisition costs (39,432 ) (29,422 ) (24,145 ) Balance, end of year $ 23,564 $ 14,801 $ 11,775 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, 2019
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, 2019 2018 2017 (in thousands) Underwriting, acquisition and insurance expenses incurred: Direct commissions $ 48,382 $ 36,885 $ 31,001 Ceding commissions (12,347 ) (10,448 ) (9,799 ) Other operating expenses 34,182 26,988 22,944 Total $ 70,217 $ 53,425 $ 44,146 Other operating expenses within underwriting, acquisition and insurance expenses included salaries, employee benefits and bonus expense of $27.8 million , $19.7 million and $17.7 million , for the years ended December 31, 2019 , 2018 and 2017 , respectively.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2019
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, 2016 . Income tax expense includes the following components for the years ending December 31, 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 (in thousands) Current federal income tax expense $ 12,860 $ 9,923 $ 12,555 Deferred federal income tax (benefit) expense (125 ) (3,230 ) 1,065 Income tax expense $ 12,735 $ 6,693 $ 13,620 The Company paid $11.6 million , $9.9 million and $13.5 million in federal income taxes during the years ended December 31, 2019 , 2018 and 2017 , respectively. Current income taxes payable was $0.4 million at December 31, 2019 , and included in "other liabilities" in the accompanying consolidated balance sheets. Current income taxes receivable was $0.8 million at December 31, 2018, and included in "other assets" in the accompanying consolidated balance sheets. On December 22, 2017, the President of the United States signed into law the Tax Cuts and Jobs Act of 2017 (the "TCJA"). The legislation significantly changed U.S. tax law by, among other things, lowering corporate income tax rates from 35% to 21% , effective January 1, 2018. U.S. GAAP requires companies to recognize the effect of tax law changes in the period of enactment. Accordingly, the Company remeasured its deferred tax assets and liabilities using enacted tax rates applicable in the years in which the temporary differences were expected to be recovered or paid, which resulted in a $1.9 million increase in income tax expense and a corresponding decrease in net deferred tax assets as of the enactment date. In addition, the TCJA modified the manner in which property and casualty insurance loss reserves were computed for federal income tax purposes. In computing its taxable income, the Company records a deduction for unpaid losses and loss adjustment expenses, which is discounted using interest rates and loss payment patterns prescribed by the U.S. Treasury. The TCJA changed the prescribed interest rates, which are now based on corporate bond yield curves, and extended the applicable time periods for the loss payment pattern period for long-tailed lines of business. The changes were effective for tax years beginning after 2017 with a transition rule that spread the adjustments related to pre-effective-date losses and loss adjustment expenses over the next eight years beginning in 2018. The prevailing federal income tax rate was 21% in 2019 and 2018 and 35% in 2017. 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, 2019 2018 2017 (in thousands) Income tax expense at federal income tax rate $ 15,971 $ 8,501 $ 13,482 Stock options exercised (2,411 ) (918 ) (471 ) Tax-exempt investment income (577 ) (672 ) (1,064 ) Effect of tax rate change — — 1,915 Other (248 ) (218 ) (242 ) Total $ 12,735 $ 6,693 $ 13,620 The significant components of the net deferred tax asset are summarized as follows: December 31, 2019 2018 (in thousands) Deferred tax assets: Unpaid losses and loss adjustment expenses $ 8,199 $ 6,854 Unearned premiums 7,193 4,711 Organizational costs 162 196 Stock compensation 765 557 State operating loss carryforwards 1,497 708 Allowance for doubtful accounts 570 551 Unrealized losses on fixed-maturity securities — 837 Other 256 196 Deferred tax assets before allowance 18,642 14,610 Less: valuation allowance (1,592 ) (780 ) Total deferred tax assets 17,050 13,830 Deferred tax liabilities: Unrealized gains on fixed-maturity securities 3,090 — Unrealized gains on equity securities 2,995 374 Deferred policy acquisition costs, net of ceding commissions 4,949 3,108 Intangible assets 743 743 Transition adjustment for loss reserve discount 1,537 2,060 Other 362 369 Total deferred tax liabilities 13,676 6,654 Net deferred tax asset $ 3,374 $ 7,176 At December 31, 2019 and 2018 , the Company had state net operating loss carryforwards ("NOLS") of $31.6 million and $19.5 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, 2019 and 2018 , 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, 2019 and 2018 , 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 uncertain tax positions in 2019 or 2018. Management is not aware of any events that would give rise to any uncertain tax positions. The Company recognized its entire uncertain tax position of $1.0 million in 2017 due to lapse of the statute of limitations. The recognition of the uncertain tax position had no impact on the effective tax rate as it resulted in a decrease of current taxes and an offsetting increase to deferred taxes.

Reserves for unpaid losses and

Reserves for unpaid losses and loss adjustment expenses	12 Months Ended
	Dec. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract]
Reserves for unpaid losses and loss adjustment expenses	Reserves for unpaid losses and loss adjustment expenses The 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, 2019 2018 2017 (in thousands) Net reserves for unpaid losses and loss adjustment expenses, beginning of year $ 313,763 $ 267,493 $ 194,602 Commutation of MLQS — — 27,929 Adjusted net reserves for losses and loss adjustment expenses 313,763 267,493 222,531 Incurred losses and loss adjustment expenses: Current year 178,986 135,078 114,960 Prior year (9,423 ) (7,037 ) (11,280 ) Total net losses and loss adjustment expenses incurred 169,563 128,041 103,680 Payments: Current year 19,054 14,118 13,792 Prior year 74,006 67,653 44,926 Total payments 93,060 81,771 58,718 Net reserves for unpaid losses and loss adjustment expenses, end of year 390,266 313,763 267,493 Reinsurance recoverable on unpaid losses 69,792 55,389 48,224 Gross reserves for unpaid losses and loss adjustment expenses, end of year $ 460,058 $ 369,152 $ 315,717 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 accident year 2017. 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. During the year ended December 31, 2017, our net incurred losses for accident years 2016 and prior developed favorably by $11.3 million . This favorable development included $9.4 million for the 2016 accident year and $6.0 million of favorable development for accident years 2015 and 2014. The 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 $4.1 million for the 2011 through 2013 accident years. The unfavorable development was primarily attributable to the other liability occurrence line of business. Prior to 2017, the Company participated in a multi-line quota share treaty ("MLQS") that transferred a portion of its risk related to certain lines of business to reinsurers that received a portion of the direct written premiums on that business. Effective January 1, 2017, the Company commuted the remaining outstanding MLQS covering the period January 1, 2015 to December 31, 2015, which reduced reinsurance recoverables on unpaid losses by approximately $27.9 million . The commutation did not have any effect on the Company's results of operations or cash flows for the applicable period. Incurred and Paid Claims Development The following is information about incurred and paid claims development as of December 31, 2019, net of reinsurance, as well as cumulative claim frequency and the total of IBNR liabilities plus expected development on reported claims included within the net incurred claims amounts. The development and claims duration tables below exclude commuted MLQS contracts, which would distort development patterns related to those transactions. Cumulative number of reported claims is reported on a per claim basis. The information about incurred and paid claims development for the years ended December 31, 2010 to December 31, 2018, is presented as unaudited supplementary information. Property Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2019 Accident Year 2015 2016 2017 2018 2019 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims ($ in thousands) 2015 $ 1,394 $ 880 $ 857 $ 872 $ 869 $ — 63 2016 4,177 3,392 3,301 3,278 14 286 2017 12,473 11,705 11,676 65 1,038 2018 11,559 12,004 236 643 2019 14,914 2,384 598 Total $ 42,741 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 ($ in thousands) 2015 $ 584 $ 706 $ 832 $ 865 $ 869 2016 1,867 3,257 3,265 3,265 2017 9,938 11,233 11,602 2018 9,132 11,646 2019 9,852 Total 37,234 All outstanding liabilities before 2015, net of reinsurance — Liabilities for claims and claim adjustment expenses, net of reinsurance $ 5,507 Historical Claims Duration The following is supplementary information about average historical claims duration as of December 31, 2019: Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance (Unaudited) Years 1 2 3 4 5 Property 70.3 % 22.1 % 5.9 % 1.9 % 0.4 % Casualty - Claims Made Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2019 Accident Year 2010 2011 2012 2013 2014 Unaudited 2015 2016 2017 Unaudited 2018 Unaudited 2019 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims ($ in thousands) 2010 $ 778 $ 805 $ 679 $ 737 $ 946 $ 916 $ 894 $ 883 $ 876 $ 872 $ 13 14 2011 4,246 3,844 3,646 3,609 3,560 3,374 3,261 3,225 3,206 102 76 2012 7,913 5,749 4,205 3,102 2,845 2,477 2,314 2,207 261 138 2013 15,238 11,639 9,113 7,917 7,002 6,463 6,128 629 228 2014 18,847 14,289 11,748 11,217 10,948 10,988 1,239 273 2015 18,883 16,777 14,896 13,583 13,942 2,024 257 2016 19,170 14,694 14,675 14,322 3,248 309 2017 18,116 17,096 16,121 5,024 366 2018 22,429 20,235 10,949 448 2019 34,693 27,450 504 Total $ 122,714 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2010 2011 2012 2013 2014 2015 2016 2017 Unaudited 2018 Unaudited 2019 ($ in thousands) 2010 $ — $ 79 $ 368 $ 393 $ 862 $ 859 $ 859 $ 859 $ 859 $ 859 2011 139 1,037 1,392 2,116 3,044 3,042 3,042 3,065 3,104 2012 153 475 877 1,024 1,090 1,882 1,946 1,946 2013 499 1,915 4,436 5,070 5,320 5,439 5,482 2014 435 1,865 5,039 6,384 8,290 9,415 2015 217 4,496 7,562 9,238 11,371 2016 1,158 3,015 6,907 9,839 2017 340 4,897 8,252 2018 507 5,030 2019 2,487 Total 57,785 Liabilities for claims and claim adjustment expenses, net of reinsurance $ 64,929 Casualty - Occurrence Incurred Claims and Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, As of December 31, 2019 Accident Year 2010 2011 2012 2013 2014 Unaudited 2015 2016 2017 Unaudited 2018 Unaudited 2019 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims ($ in thousands) 2010 $ 843 $ 771 $ 531 $ 460 $ 458 $ 404 $ 406 $ 429 402 $ 406 $ 59 49 2011 5,839 5,940 5,757 7,340 7,613 8,142 8,375 9,023 9,379 471 226 2012 16,977 17,436 18,803 20,401 20,579 22,001 22,401 23,223 1,716 581 2013 30,616 28,771 28,037 29,039 31,731 33,248 33,973 4,016 840 2014 47,805 40,668 38,049 36,678 39,313 41,859 7,980 1,158 2015 59,717 51,739 49,122 52,100 54,697 13,117 1,322 2016 61,440 55,680 53,549 55,534 19,588 1,318 2017 71,126 67,151 68,985 33,798 1,373 2018 86,157 78,331 56,169 1,297 2019 112,266 99,970 951 Total $ 478,653 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2010 2011 2012 2013 2014 Unaudited 2015 2016 2017 Unaudited 2018 Unaudited 2019 ($ in thousands) 2010 $ 4 $ 37 $ 59 $ 113 $ 263 $ 261 $ 273 $ 313 346 347 2011 207 1,596 2,519 3,788 4,575 6,363 6,868 8,510 8,693 2012 757 4,441 7,850 11,238 14,382 16,474 19,383 20,707 2013 1,099 4,469 7,957 14,890 21,348 26,715 28,248 2014 698 3,081 8,489 17,576 23,771 31,026 2015 941 3,161 12,685 28,385 37,690 2016 1,099 6,015 17,225 28,924 2017 1,581 9,352 22,407 2018 2,638 10,995 2019 3,944 Total 192,981 Liabilities for claims and claim adjustment expenses, net of reinsurance $ 285,672 Historical Claims Duration The following is supplementary information about average historical claims duration as of December 31, 2019: 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 4.5 % 20.2 % 25.3 % 12.5 % 20.4 % 9.5 % 0.9 % 0.2 % 0.6 % — % Casualty - occurrence 2.4 % 9.9 % 13.7 % 19.0 % 18.3 % 12.1 % 6.3 % 11.1 % 5.1 % — % 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 claims and claim adjustment expenses in the consolidated statement of financial position is as follows: (in thousands) December 31, 2019 Net outstanding liabilities Property $ 5,507 Casualty - claims made 64,929 Casualty - occurrence 285,672 Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance 356,108 Reinsurance recoverable on unpaid claims Property 3,119 Casualty - claims made 9,852 Casualty - occurrence 56,821 Total reinsurance recoverable on unpaid claims 69,792 Unallocated claims adjustment expenses 34,158 Gross liability for unpaid claims and claim adjustment expense $ 460,058

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 2017 (in thousands) Written: Direct $ 389,569 $ 275,538 $ 223,191 Assumed 125 — — Ceded (47,633 ) (39,924 ) (33,719 ) Net written $ 342,061 $ 235,614 $ 189,472 Earned: Direct $ 330,464 $ 250,397 $ 209,426 Assumed 104 — — Ceded (47,587 ) (37,709 ) (33,373 ) Net earned $ 282,981 $ 212,688 $ 176,053 Incurred losses and loss adjustment expenses were net of reinsurance recoverables (ceded incurred losses and loss adjustment expenses) of $27.2 million , $25.5 million and $12.2 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. Reinsurance balances Credit risk exists with reinsurance ceded to the extent that any reinsurer is unable to meet the obligations assumed under the reinsurance agreements. Reinsurance recoverables for unpaid losses were $69.8 million and $55.4 million , at December 31, 2019 and 2018 , respectively. Reinsurance recoverables for paid losses were $2.8 million and $1.4 million at December 31, 2019 and 2018 , respectively. Ceded unearned premiums related to reinsurance were $16.1 million and $16.1 million , at December 31, 2019 and 2018 , respectively. 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. The Company has not recorded an allowance for doubtful accounts related to its reinsurance balances at December 31, 2019 and 2018 and believes this to be appropriate after consideration of all currently available information; however, the deterioration in the credit quality of existing reinsurers or disputes over reinsurance agreements could result in future charges. At December 31, 2019 , the net reinsurance receivable, defined as the sum of paid and unpaid reinsurance recoverables and ceded unearned premiums less reinsurance payables, from five reinsurers represented 88.8% of the total balance.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
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, 2019 or December 31, 2018. Public Offering On August 12, 2019, the Company completed an underwritten public offering of 741,750 shares of its common stock at a price of $93.00 per share, which included 96,750 shares sold to the underwriters pursuant to the underwriter’s option to purchase additional shares. After underwriter discounts and commissions and offering expenses, the Company received net proceeds from the offering of approximately $65.9 million . Dividend Declaration On February 14, 2019 , the Company’s Board of Directors declared a cash dividend of $0.08 per share of common stock. This dividend was paid on March 14, 2019 to all stockholders of record on February 28, 2019 . On May 23, 2019 , the Company’s Board of Directors declared a cash dividend of $0.08 per share of common stock. This dividend was paid on June 13, 2019 to all stockholders of record on June 3, 2019 . On August 15, 2019 , the Company’s Board of Directors declared a cash dividend of $0.08 per share of common stock. This dividend was paid on September 12, 2019 to all stockholders of record on August 29, 2019 . On November 13, 2019 , the Company’s Board of Directors declared a cash dividend of $0.08 per share of common stock. This dividend was paid on December 12, 2019 to all stockholders of record on November 29, 2019 . On February 13, 2020 , the Company’s Board of Directors declared a cash dividend of $0.09 per share of common stock. This dividend is payable on March 12, 2020 to all stockholders of record on February 28, 2020 . 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 $2.7 million , $1.6 million and $0.7 million for the years ended December 31, 2019, 2018 and 2017, 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 vest 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 under the employee share option plan as of December 31, 2019 , 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, 2018 804,303 $ 16.00 Granted — — Forfeited (18,068 ) 16.00 Exercised (171,890 ) 16.00 Outstanding at December 31, 2019 614,345 $ 16.00 6.6 $ 52,625 Exercisable at December 31, 2019 393,614 $ 16.00 6.6 $ 33,717 The total intrinsic value of options exercised was $11.9 million during the year ended December 31, 2019 and $4.7 million during the year ended December 31, 2018 . As of December 31, 2019 , the Company had $0.3 million of unrecognized share-based compensation expense expected to be charged to earnings over a weighted-average period of 0.6 years. Restricted Stock Awards During 2019, 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 one year to four years corresponding to the anniversary date of the grants. The fair value of restricted stock awards was determined based on the closing trading price of the Company’s shares on the grant date or, if no shares were traded on the grant date, the last preceding date for which there was a sale of shares. Except for restrictions placed on the transferability of restricted stock, holders of unvested restricted stock have full stockholder’s rights, including voting rights and the right to receive cash dividends. Unvested shares of restricted stock awards and accrued dividends, if any, are forfeited upon the termination of service to or employment with the Company. A summary of all restricted stock activity under the equity compensation plans for the year ended is as follows: December 31, 2019 Number of Shares Weighted Average Grant Date Fair Value per Share Nonvested outstanding at the beginning of the period 92,465 $ 52.98 Granted 62,015 $ 80.59 Vested (27,628 ) $ 51.53 Forfeited (4,129 ) $ 60.58 Nonvested outstanding at the end of the period 122,723 $ 67.01 Employees have the option to surrender shares to pay for withholding tax obligations resulting from any vesting of restricted stock awards. During the year ended December 31, 2019 , restricted shares withheld for taxes in connection with the vesting of restricted stock awards totaled 7,365 . The weighted average grant-date fair value of the Company's restricted stock awards granted during the years ended December 31, 2019 and 2018 was $80.59 and $52.99 , respectively. There were no restricted stock awards granted during the year ended December 31, 2017. The fair value of restricted stock awards that vested during the year ended December 31, 2019 was $2.1 million .There were no restricted stock awards that vested during the years ended December 31, 2018 or 2017. As of December 31, 2019 , the Company had $6.5 million of total unrecognized stock-based compensation expense expected to be charged to earnings over a weighted-average period of 3.0 years. Subsequent Event The Board of Directors granted 4,428 shares of restricted stock on January 1, 2020 under the 2016 Incentive Plan to the Company’s non-employee directors. The restricted stock had a fair value on the date of grant of $101.66 per share and will vest on a straight-line basis over a one year period.

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 2017 (in thousands, except per share data) Net income $ 63,316 $ 33,787 $ 24,901 Weighted average common shares outstanding - basic 21,528 21,090 20,992 Dilutive effect of shares issued under stock compensation arrangements: Stock options 570 591 506 Restricted stock awards 38 4 — Total dilutive effect of shares issued under stock compensation arrangements 608 595 506 Weighted average common shares outstanding - diluted 22,136 21,685 21,498 Earnings per common share: Basic $ 2.94 $ 1.60 $ 1.19 Diluted $ 2.86 $ 1.56 $ 1.16 There were approximately 54 thousand and approximately 86 thousand anti-dilutive stock awards for the years ended December 31, 2019 and 2018, respectively. There were no anti-dilutive stock awards for the year ended December 31, 2017.

Credit Agreement

Credit Agreement	12 Months Ended
	Dec. 31, 2019
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 will be used to fund construction of the Company’s new headquarters and 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. As of December 31, 2019, there was $17.3 million outstanding under the Credit Facility, net of debt issuance cost of $0.6 million , with a weighted average interest rate of 3.75% . Total interest expense under the Credit Facility was $0.2 million for the year ended December 31, 2019 and was capitalized as part of the real estate project under construction. See Note 1 for further details. Interest paid was $0.1 million for the year ending December 31, 2019. There were no credit agreements outstanding at December 31, 2018 or December 31, 2017. 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, 2019, the Company was in compliance with all of its financial covenants under the Credit Facility.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Contingencies arise in the normal conduct of the Company’s operations and are not expected to have a material effect on the Company’s financial condition or results of operations. However, adverse outcomes are possible and could negatively affect the Company’s financial condition and results of operations.

Employee benefit plan

Employee benefit plan	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Employee benefit plan	Employee benefit plan The 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 $1.3 million , $1.0 million and $1.0 million in 2019 , 2018 and 2017 , respectively.

Other comprehensive income (los

Other comprehensive income (loss)	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 2017 (in thousands) Unrealized gains (losses) arising during the period, before income taxes: Fixed-maturity securities $ 19,190 $ (6,664 ) $ 5,371 Equity securities (1) — — 4,192 Total unrealized gains (losses) arising during the period, before income taxes 19,190 (6,664 ) 9,563 Income taxes (4,029 ) 1,399 (3,094 ) Unrealized gains (losses) arising during the period, net of income taxes 15,161 (5,265 ) 6,469 Less reclassification adjustment: Net realized investment gains on available-for-sale investments 489 258 132 Income taxes (102 ) (54 ) (47 ) Reclassification adjustment included in net income 387 204 85 Other comprehensive income (loss) $ 14,774 $ (5,469 ) $ 6,384 (1) Adoption of ASU 2016-01, "Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities," which was effective January 1, 2018, eliminated the available-for-sale classification for equity investments and required changes in the fair value of equity securities to be recognized in net income. 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, 2019
Segment Reporting [Abstract]
Underwriting information	Underwriting information The 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, 2019 2018 2017 (in thousands) Commercial: Construction $ 71,035 $ 50,879 $ 48,587 Small business 63,181 44,368 34,896 Excess casualty 51,225 37,398 30,260 Commercial property 29,115 9,166 5,609 Product liability 26,333 20,049 14,288 Allied health 23,962 16,815 10,645 General casualty 23,279 17,625 15,865 Professional liability 20,029 16,717 12,956 Life sciences 17,821 14,505 12,408 Energy 15,371 15,586 13,544 Management liability 14,820 8,161 4,123 Health care 5,963 5,725 6,235 Environmental 5,179 2,205 2,046 Inland marine 3,467 2,046 967 Commercial insurance 1,674 1,096 816 Public entity 580 1,193 1,265 Total commercial 373,034 263,534 214,510 Personal: Personal insurance 16,660 12,004 8,681 Total personal 16,660 12,004 8,681 Total $ 389,694 $ 275,538 $ 223,191 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 above. Coverage is written over our 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. During 2019, certain business previously underwritten by the Energy and Environmental divisions is now underwritten by this division and prior year amounts have been reclassified to conform to the current year's presentation. Commercial property underwrites catastrophe-exposed risks including 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. 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 we cover include accountants, architects and engineers, financial planners, insurance agents, lawyers, realtors, and certain other professions. 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. 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 and product manufacturers. As previously discussed, during 2019, certain business previously underwritten by this division is now underwritten by the Excess Casualty division and prior year amounts have been reclassified to conform to the current year's presentation. Management liability underwrites directors and officers liability, employment practices liability and fiduciary liability coverage on a variety of commercial and government risks. Health care underwrites medical professional liability for physicians, surgeons, dentists, chiropractors and podiatrists. Policies cover both individuals and small practice groups. 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. As previously discussed, during 2019, certain business previously underwritten by this division is now underwritten by the Excess Casualty division and prior year amounts have been reclassified to conform to the current year's presentation. Inland marine underwrites a variety of inland marine coverages including builders risk, contractors' equipment, transportation risks and mobile equipment. Commercial insurance underwrites commercial general liability on small accounts, through our wholly-owned broker, Aspera. Public entity underwrites law enforcement professional liability and school board liability. Personal insurance writes homeowners coverage on manufactured homes with a catastrophe exposure due to coastal location. The Company does business with two unaffiliated insurance brokers that generated $47.2 million and $41.1 million of gross written premiums for the year ended December 31, 2019, representing 12.1% and 10.5% of gross written premiums, respectively. No other broker generated 10.0% or more of the gross written premiums for the year ended December 31, 2019.

Statutory financial information

Statutory financial information	12 Months Ended
	Dec. 31, 2019
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 GAAP. In converting from statutory accounting principles to 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, 2019 , 2018 , and 2017 and for the years then ended are summarized as follows: Year ended December 31, 2019 2018 2017 (in thousands) Statutory net income $ 40,917 $ 34,206 $ 23,841 Statutory capital and surplus 348,811 233,500 213,833 Kinsale Insurance is subject to risk-based capital ("RBC") requirements. RBC is a method developed by the 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, 2019 and 2018 , actual statutory capital and surplus for Kinsale Insurance substantially exceeded the regulatory requirements. Dividend payments to Kinsale from Kinsale Insurance are restricted by state insurance laws as to the amount that may be paid without prior approval of the regulatory authorities of Arkansas. The maximum dividend distribution is limited by Arkansas law to the greater of 10% of policyholder surplus as of December 31 of the previous year or statutory net income, not including realized capital gains, for the previous calendar year. Dividend payments are further limited to that part of available policyholder surplus which is derived from net profits on its business. The maximum dividend distribution that can be paid by Kinsale Insurance during 2020 without prior approval is $40.7 million .

Unaudited Selected Quarterly Fi

Unaudited Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2019
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: 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 2018 Quarter ​(in thousands, except per share data) First Second Third Fourth Gross written premiums $ 63,847 $ 69,981 $ 69,546 $ 72,164 Total revenues 50,126 54,947 60,137 56,904 Net income 7,287 10,112 11,940 4,448 Comprehensive income 2,431 9,096 9,987 6,804 Earnings per share - basic $ 0.35 $ 0.48 $ 0.57 $ 0.21 Earnings per share - diluted $ 0.34 $ 0.47 $ 0.55 $ 0.20 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.

Schedule I-Summary of Investmen

Schedule I-Summary of Investments-Other than Related Parties [Disclosure]	12 Months Ended
	Dec. 31, 2019
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 Amortized Cost Fair Value Amount at which shown on Balance Sheet (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 110 $ 112 $ 112 Obligations of states, municipalities and political subdivisions 166,312 172,893 172,893 Corporate and other securities 180,287 184,768 184,768 Commercial mortgage and asset-backed securities 195,750 197,970 197,970 Residential mortgage-backed securities 172,358 173,789 173,789 Total fixed maturities 714,817 729,532 729,532 Equity securities: Common stock-exchange traded funds 40,842 54,463 54,463 Nonredeemable preferred stock 23,403 23,831 23,831 Total equity securities 64,245 78,294 78,294 Total investments $ 779,062 $ 807,826 $ 807,826

Schedule II - Condensed Financi

Schedule II - Condensed Financial Information of Registrant	12 Months Ended
	Dec. 31, 2019
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 December 31, 2019 2018 (in thousands) Assets Cash and cash equivalents $ 14,726 $ 10,016 Due from subsidiaries 16,836 1,001 Investment in subsidiaries 391,071 251,591 Deferred tax assets 519 369 Income taxes recoverable — 787 Other assets 208 549 Total assets $ 423,360 $ 264,313 Liabilities and Stockholders' Equity Liabilities: Accounts payable and accrued expenses $ 260 $ 308 Income taxes payable 434 — Credit facility 16,744 — Other liabilities 42 19 Total liabilities 17,480 327 Stockholders’ equity: Common stock 222 212 Additional paid-in capital 229,229 158,485 Retained earnings 162,911 106,545 Accumulated other comprehensive income (loss) 13,518 (1,256 ) Stockholders’ equity 405,880 263,986 Total liabilities and stockholders’ equity $ 423,360 $ 264,313 See accompanying notes. 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 Years Ended December 31, 2019 2018 2017 (in thousands) Revenues: Management fees from subsidiaries $ 4,502 $ 3,215 $ 2,037 Total revenues 4,502 3,215 2,037 Expenses: Other operating expenses 2,473 2,457 2,526 Other expenses 2,742 1,598 652 Total expenses 5,215 4,055 3,178 Loss before income taxes (713 ) (840 ) (1,141 ) Income tax benefit (2,714 ) (1,158 ) (739 ) Income (loss) before equity in net income of subsidiaries 2,001 318 (402 ) Equity in net income of subsidiaries 61,315 33,469 25,303 Net income 63,316 33,787 24,901 Other comprehensive income (loss): Equity in other comprehensive earnings (losses) of subsidiaries 14,774 (5,469 ) 6,384 Total comprehensive income $ 78,090 $ 28,318 $ 31,285 See accompanying notes. 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 Years Ended December 31, 2019 2018 2017 (in thousands) Operating activities Net income $ 63,316 $ 33,787 $ 24,901 Adjustments to reconcile net income to net cash used in operating activities: Deferred tax (benefit) expense (150 ) (170 ) 429 Stock compensation expense 2,742 1,597 652 Equity in undistributed earnings of subsidiaries (61,315 ) (33,469 ) (25,303 ) Changes in operating assets and liabilities (14,247 ) (633 ) (1,583 ) Dividends received from subsidiary 5,000 11,500 4,500 Net cash (used in) provided by operating activities (4,654 ) 12,612 3,596 Investing activities Contributions to subsidiary (68,391 ) — — Net cash used in investing activities (68,391 ) — — Financing activities Common stock issued, net of transaction costs 65,879 — — Common stock issued, stock options exercised 2,750 1,808 1,077 Payroll taxes withheld and remitted on share-based payments (617 ) — — Dividends paid (6,929 ) (5,906 ) (5,039 ) Proceeds from credit facility 17,300 — — Debt issuance costs (628 ) — — Net cash provided by (used in) financing activities 77,755 (4,098 ) (3,962 ) Net change in cash and cash equivalents 4,710 8,514 (366 ) Cash and cash equivalents at beginning of year 10,016 1,502 1,868 Cash and cash equivalents at end of year $ 14,726 $ 10,016 $ 1,502 See accompanying notes. See accompanying Report of Independent Registered Public Accounting Firm. KINSALE CAPITAL GROUP, INC. Condensed Financial Information of Registrant Notes to Condensed Financial Information 1. Accounting policies Organization Kinsale Capital Group, Inc., 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 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 will be used to fund construction of the Company’s new headquarters and 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. As of December 31, 2019, there was $17.3 million outstanding under the Credit Facility, net of debt issuance cost of $0.6 million , with a weighted average interest rate of 3.75% . Total interest expense under the Credit Facility was $0.2 million for the year ended December 31, 2019 and was capitalized as part of the real estate project under construction. See Note 1 for further details. Interest paid was $0.1 million for the year ending December 31, 2019. There were no credit agreements outstanding at December 31, 2018 or December 31, 2017. 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, 2019, 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, $11.5 million for the year ended December 31, 2018, and $4.5 million for the year ended December 31, 2017.

Schedule V - Valuation and Qual

Schedule V - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2019
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 Amounts Charged to Expense Amounts Written Off or Disposals Balance at End of Period 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 Year Ended December 31, 2017: Allowance for premiums receivable 1,977 488 353 2,112 Valuation allowance for deferred tax assets 623 67 — 690

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Principles of consolidation	Principles of consolidation
Use of estimates	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 other-than-temporary declines in fair value.
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, 2019 or December 31, 2018 .
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 comprehensive income and stockholders’ equity, net of deferred income taxes. Equity securities are reported at fair value. Prior to the adoption of new accounting guidance effective January 1, 2018, equity securities were classified as available-for-sale and, similar to fixed-maturity securities, unrealized gains and losses were recorded as a separate component of comprehensive income and stockholders’ equity, net of deferred income taxes. In accordance with new accounting guidance, the available-for-sale classification was eliminated for equity securities and changes in unrealized gains and losses in fair value of these investments are recognized in net income. The Company regularly evaluates its available-for-sale securities using both quantitative and qualitative criteria to determine impairment losses for other-than-temporary declines in the fair value of the investments. See Note 2 for further discussion of other-than-temporary impairments ("OTTI"). Interest on fixed-maturity securities is credited to earnings as it accrues. Premiums and discounts are amortized or accreted over the lives of the related fixed maturities, or to the earliest call date. 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 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 $2.7 million and $2.6 million at December 31, 2019 and 2018 , 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 7 to 10 years for furniture and equipment, 3 to 7 years for electronic data processing hardware and software, and from 2 to 6 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, 2019 2018 (in thousands) Equipment $ 2,353 $ 1,950 Software 2,356 1,031 Furniture and fixtures 1,025 1,019 Leasehold improvements 984 983 Construction in progress - corporate headquarters 19,789 318 26,507 5,301 Accumulated depreciation (3,873 ) (3,191 ) Total property and equipment, net $ 22,634 $ 2,110 In January 2019, the Company purchased land for $2.5 million in Henrico County, Virginia for the development of its new corporate headquarters and is currently targeting a third quarter 2020 completion date. The project is estimated to cost approximately $50 million to $55 million , which will be funded through a combination of existing cash flows from operations and draw down on the credit facility. See Note 11 for further discussion.
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 2019, 2018, or 2017. In addition, as of December 31, 2019 , 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 Company believes that the reserves for unpaid losses and loss adjustment expenses at December 31, 2019 and 2018 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	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 manager 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 investments are included in the amounts disclosed as Level 2. For those bonds where significant inputs are unobservable, Level 3 inputs, the Company's investment manager obtains valuations from pricing vendors using the market approach and income approach valuation techniques. For equity securities, the Company’s investment manager 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 ASU 2016-02, Leases (Topic 842) In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)" to improve the financial reporting of leasing transactions. Under this ASU, lessees will recognize a right-of-use ("ROU") asset and corresponding liability on the balance sheet for all leases, except for leases covering a period of 12 months or less. The lessee’s income statement treatment for leases will vary depending on the nature and classification of the lease. Effective January 1, 2019, the Company adopted this ASU and recorded a ROU asset and corresponding lease liability of approximately $0.9 million . The ROU and operating lease liability are included in "other assets" and "other liabilities," respectively, in the accompanying consolidated balance sheet. The Company elected the package of practical expedients permitted under the adoption of the new standard, which allowed the Company to account for existing leases under their current classification, as well as omit any new costs classified as initial direct costs, under the new standard. This election kept the existing agreements as operating leases. The Company also elected the practical expedient allowing an accounting policy election by class of underlying asset, to account for separate lease and nonlease components as a single lease component. In addition, the Company has implemented the necessary internal controls relating to the adoption of the standard. ASU 2017-08, Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued ASU 2017-08, "Premium Amortization on Purchased Callable Debt Securities," which shortens the amortization period of the premium for certain callable debt securities, from the contractual maturity date to the earliest call date. Effective January 1, 2019, the Company adopted ASU 2017-08 using a modified retrospective approach. The adoption of ASU 2017-08 did not have a material impact on the Company's financial statements.
Prospective accounting pronouncements	Prospective accounting pronouncements ASU 2016-13, Financial Instruments – Credit Losses (Topic 326) On June 16, 2016, the FASB issued ASU 2016-13, "Financial Instruments – Credit Losses (Topic 326)" to provide more useful information about the expected credit losses on financial instruments. Current GAAP delays the recognition of credit losses until it is probable a loss has been incurred. The update will require 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 debt securities will also be recorded through an allowance for credit losses. However, the amendments would 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 current 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 an additional ASUs on Topic 326 that do not change the core principle of the guidance in ASU 2016-13 but clarify or certain aspects of it. This ASU and the additional ASUs on Topic 326 are effective for annual and interim reporting periods beginning after December 15, 2019. Upon adoption, the update will be applied using the modified-retrospective approach, by which a cumulative-effect adjustment will be made to retained earnings as of the beginning of the first reporting period presented. The adoption of this ASU is not expected to have a material impact on the Company's 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. This guidance is effective for reporting periods beginning after December 15, 2019. The adoption of the guidance is not expected to have a material effect on the Company’s 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, 2019
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, 2019 2018 (in thousands) Equipment $ 2,353 $ 1,950 Software 2,356 1,031 Furniture and fixtures 1,025 1,019 Leasehold improvements 984 983 Construction in progress - corporate headquarters 19,789 318 26,507 5,301 Accumulated depreciation (3,873 ) (3,191 ) Total property and equipment, net $ 22,634 $ 2,110

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2019
Investments [Abstract]
Available-for-sale Investments	The following tables summarize the Company’s available-for-sale investments: December 31, 2019 Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding 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 Commercial mortgage and asset-backed securities 195,750 2,930 (710 ) 197,970 Residential mortgage-backed securities 172,358 1,819 (388 ) 173,789 Total available-for-sale investments $ 714,817 $ 17,029 $ (2,314 ) $ 729,532 December 31, 2018 Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Estimated Fair Value (in thousands) Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 610 $ 2 $ (1 ) $ 611 Obligations of states, municipalities and political subdivisions 153,884 2,010 (1,294 ) 154,600 Corporate and other securities 97,889 264 (1,401 ) 96,752 Commercial mortgage and asset-backed securities 151,137 252 (1,522 ) 149,867 Residential mortgage-backed securities 110,717 354 (2,650 ) 108,421 Total available-for-sale investments $ 514,237 $ 2,882 $ (6,868 ) $ 510,251
Available-for-sale Securities in a Unrealized Loss Position	December 31, 2018 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: U.S. Treasury securities and obligations of U.S. government agencies $ — $ — $ 499 $ (1 ) $ 499 $ (1 ) Obligations of states, municipalities and political subdivisions 42,718 (440 ) 34,326 (854 ) 77,044 (1,294 ) Corporate and other securities 62,045 (890 ) 12,092 (511 ) 74,137 (1,401 ) Commercial mortgage and asset-backed securities 93,247 (1,017 ) 25,746 (505 ) 118,993 (1,522 ) Residential mortgage-backed securities 24,571 (155 ) 55,638 (2,495 ) 80,209 (2,650 ) Total available-for-sale investments $ 222,581 $ (2,502 ) $ 128,301 $ (4,366 ) $ 350,882 $ (6,868 ) The following tables summarize gross unrealized losses and fair value for available-for-sale securities by length of time that the securities have continuously been in an unrealized loss position: 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: U.S. Treasury securities and obligations of U.S. government agencies $ — $ — $ — $ — $ — $ — 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 ) Commercial mortgage and asset-backed securities 37,723 (303 ) 46,623 (407 ) 84,346 (710 ) Residential mortgage-backed securities 36,986 (148 ) 24,815 (240 ) 61,801 (388 ) Total available-for-sale 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, 2019 are summarized, by contractual maturity, as follows: Amortized Estimated Cost Fair Value (in thousands) Due in one year or less $ 9,940 $ 9,990 Due after one year through five years 115,480 118,611 Due after five years through ten years 79,235 82,314 Due after ten years 142,054 146,858 Commercial mortgage and asset-backed securities 195,750 197,970 Residential mortgage-backed securities 172,358 173,789 Total fixed maturities $ 714,817 $ 729,532
Net Investment Income	The following table presents the components of net investment income: Year Ended December 31, 2019 2018 2017 (in thousands) Interest: Taxable bonds $ 14,853 $ 9,474 $ 6,233 Municipal bonds (tax exempt) 3,692 4,298 3,619 Cash equivalents and short-term investments 842 1,017 678 Dividends on equity securities 2,136 2,014 1,041 Gross investment income 21,523 16,803 11,571 Investment expenses (1,390 ) (1,115 ) (1,002 ) Net investment income $ 20,133 $ 15,688 $ 10,569
Schedule of Realized Gain (Loss)	The following table presents realized investment gains and losses: Year Ended December 31, 2019 2018 2017 (in thousands) Fixed-maturity securities: Realized gains $ 567 $ 263 $ 220 Realized losses (79 ) (17 ) (69 ) Net realized gains from fixed-maturity securities 488 246 151 Equity securities: Realized gains 556 57 — Realized losses (688 ) (22 ) — Net realized gains (losses) from equity securities (132 ) 35 — Short-term securities - realized gain 3 — — Net realized investment gains $ 359 $ 281 $ 151

Fair value measurements (Tables

Fair value measurements (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 and 2018 , by level within the fair value hierarchy. 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 Commercial mortgage and asset-backed securities — 197,970 — 197,970 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 December 31, 2018 Level 1 Level 2 Level 3 Total (in thousands) Assets Fixed maturities: U.S. Treasury securities and obligations of U.S. government agencies $ 611 $ — $ — $ 611 Obligations of states, municipalities and political subdivisions — 154,600 — 154,600 Corporate and other securities — 96,752 — 96,752 Commercial mortgage and asset-backed securities — 149,867 — 149,867 Residential mortgage-backed securities — 108,421 — 108,421 Total fixed maturities 611 509,640 — 510,251 Equity securities: Exchange traded funds 38,987 — — 38,987 Nonredeemable preferred stock — 18,724 — 18,724 Total equity securities 38,987 18,724 — 57,711 Total $ 39,598 $ 528,364 $ — $ 567,962

Deferred policy acquisition c_2

Deferred policy acquisition costs (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 2017 (in thousands) Balance, beginning of year $ 14,801 $ 11,775 $ 10,150 Policy acquisition costs deferred: Direct commissions 56,841 40,546 32,927 Ceding commissions (12,373 ) (11,239 ) (9,984 ) Other underwriting and policy acquisition costs 3,727 3,141 2,827 Policy acquisition costs deferred 48,195 32,448 25,770 Amortization of net policy acquisition costs (39,432 ) (29,422 ) (24,145 ) Balance, end of year $ 23,564 $ 14,801 $ 11,775

Underwriting, acquisition and_2

Underwriting, acquisition and insurance expenses (Tables)	12 Months Ended
	Dec. 31, 2019
Underwriting, Acquisition and Insurance Expenses [Abstract]
Underwriting, Acquisition and Insurance Expenses	Underwriting, acquisition and insurance expenses consist of the following: Year Ended December 31, 2019 2018 2017 (in thousands) Underwriting, acquisition and insurance expenses incurred: Direct commissions $ 48,382 $ 36,885 $ 31,001 Ceding commissions (12,347 ) (10,448 ) (9,799 ) Other operating expenses 34,182 26,988 22,944 Total $ 70,217 $ 53,425 $ 44,146

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Components of Income Tax Expense (Benefit)	Income tax expense includes the following components for the years ending December 31, 2019 , 2018 and 2017 : Year Ended December 31, 2019 2018 2017 (in thousands) Current federal income tax expense $ 12,860 $ 9,923 $ 12,555 Deferred federal income tax (benefit) expense (125 ) (3,230 ) 1,065 Income tax expense $ 12,735 $ 6,693 $ 13,620
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, 2019 2018 2017 (in thousands) Income tax expense at federal income tax rate $ 15,971 $ 8,501 $ 13,482 Stock options exercised (2,411 ) (918 ) (471 ) Tax-exempt investment income (577 ) (672 ) (1,064 ) Effect of tax rate change — — 1,915 Other (248 ) (218 ) (242 ) Total $ 12,735 $ 6,693 $ 13,620
Deferred Tax Assets and Liabilities	The significant components of the net deferred tax asset are summarized as follows: December 31, 2019 2018 (in thousands) Deferred tax assets: Unpaid losses and loss adjustment expenses $ 8,199 $ 6,854 Unearned premiums 7,193 4,711 Organizational costs 162 196 Stock compensation 765 557 State operating loss carryforwards 1,497 708 Allowance for doubtful accounts 570 551 Unrealized losses on fixed-maturity securities — 837 Other 256 196 Deferred tax assets before allowance 18,642 14,610 Less: valuation allowance (1,592 ) (780 ) Total deferred tax assets 17,050 13,830 Deferred tax liabilities: Unrealized gains on fixed-maturity securities 3,090 — Unrealized gains on equity securities 2,995 374 Deferred policy acquisition costs, net of ceding commissions 4,949 3,108 Intangible assets 743 743 Transition adjustment for loss reserve discount 1,537 2,060 Other 362 369 Total deferred tax liabilities 13,676 6,654 Net deferred tax asset $ 3,374 $ 7,176

Reserves for unpaid losses an_2

Reserves for unpaid losses and loss adjustment expenses (Tables)	12 Months Ended
	Dec. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract]
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, 2019 2018 2017 (in thousands) Net reserves for unpaid losses and loss adjustment expenses, beginning of year $ 313,763 $ 267,493 $ 194,602 Commutation of MLQS — — 27,929 Adjusted net reserves for losses and loss adjustment expenses 313,763 267,493 222,531 Incurred losses and loss adjustment expenses: Current year 178,986 135,078 114,960 Prior year (9,423 ) (7,037 ) (11,280 ) Total net losses and loss adjustment expenses incurred 169,563 128,041 103,680 Payments: Current year 19,054 14,118 13,792 Prior year 74,006 67,653 44,926 Total payments 93,060 81,771 58,718 Net reserves for unpaid losses and loss adjustment expenses, end of year 390,266 313,763 267,493 Reinsurance recoverable on unpaid losses 69,792 55,389 48,224 Gross reserves for unpaid losses and loss adjustment expenses, end of year $ 460,058 $ 369,152 $ 315,717

Reserves for unpaid losses an_3

Reserves for unpaid losses and loss adjustment expenses Reserve Development (Tables)	12 Months Ended
	Dec. 31, 2019
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 claims and claim adjustment expenses in the consolidated statement of financial position is as follows: (in thousands) December 31, 2019 Net outstanding liabilities Property $ 5,507 Casualty - claims made 64,929 Casualty - occurrence 285,672 Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance 356,108 Reinsurance recoverable on unpaid claims Property 3,119 Casualty - claims made 9,852 Casualty - occurrence 56,821 Total reinsurance recoverable on unpaid claims 69,792 Unallocated claims adjustment expenses 34,158 Gross liability for unpaid claims and claim adjustment expense $ 460,058
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, 2019 Accident Year 2015 2016 2017 2018 2019 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims ($ in thousands) 2015 $ 1,394 $ 880 $ 857 $ 872 $ 869 $ — 63 2016 4,177 3,392 3,301 3,278 14 286 2017 12,473 11,705 11,676 65 1,038 2018 11,559 12,004 236 643 2019 14,914 2,384 598 Total $ 42,741 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2015 2016 2017 2018 2019 ($ in thousands) 2015 $ 584 $ 706 $ 832 $ 865 $ 869 2016 1,867 3,257 3,265 3,265 2017 9,938 11,233 11,602 2018 9,132 11,646 2019 9,852 Total 37,234 All outstanding liabilities before 2015, net of reinsurance — Liabilities for claims and claim adjustment expenses, net of reinsurance $ 5,507
Short-duration Insurance Contracts, Schedule of Historical Claims Duration	The following is supplementary information about average historical claims duration as of December 31, 2019: Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance (Unaudited) Years 1 2 3 4 5 Property 70.3 % 22.1 % 5.9 % 1.9 % 0.4 %
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, 2019 Accident Year 2010 2011 2012 2013 2014 Unaudited 2015 2016 2017 Unaudited 2018 Unaudited 2019 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims ($ in thousands) 2010 $ 778 $ 805 $ 679 $ 737 $ 946 $ 916 $ 894 $ 883 $ 876 $ 872 $ 13 14 2011 4,246 3,844 3,646 3,609 3,560 3,374 3,261 3,225 3,206 102 76 2012 7,913 5,749 4,205 3,102 2,845 2,477 2,314 2,207 261 138 2013 15,238 11,639 9,113 7,917 7,002 6,463 6,128 629 228 2014 18,847 14,289 11,748 11,217 10,948 10,988 1,239 273 2015 18,883 16,777 14,896 13,583 13,942 2,024 257 2016 19,170 14,694 14,675 14,322 3,248 309 2017 18,116 17,096 16,121 5,024 366 2018 22,429 20,235 10,949 448 2019 34,693 27,450 504 Total $ 122,714 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2010 2011 2012 2013 2014 2015 2016 2017 Unaudited 2018 Unaudited 2019 ($ in thousands) 2010 $ — $ 79 $ 368 $ 393 $ 862 $ 859 $ 859 $ 859 $ 859 $ 859 2011 139 1,037 1,392 2,116 3,044 3,042 3,042 3,065 3,104 2012 153 475 877 1,024 1,090 1,882 1,946 1,946 2013 499 1,915 4,436 5,070 5,320 5,439 5,482 2014 435 1,865 5,039 6,384 8,290 9,415 2015 217 4,496 7,562 9,238 11,371 2016 1,158 3,015 6,907 9,839 2017 340 4,897 8,252 2018 507 5,030 2019 2,487 Total 57,785 Liabilities for claims and claim adjustment expenses, net of reinsurance $ 64,929
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, 2019 Accident Year 2010 2011 2012 2013 2014 Unaudited 2015 2016 2017 Unaudited 2018 Unaudited 2019 Total of IBNR Liabilities Plus Expected Development on Reported Claims Cumulative Number of Reported Claims ($ in thousands) 2010 $ 843 $ 771 $ 531 $ 460 $ 458 $ 404 $ 406 $ 429 402 $ 406 $ 59 49 2011 5,839 5,940 5,757 7,340 7,613 8,142 8,375 9,023 9,379 471 226 2012 16,977 17,436 18,803 20,401 20,579 22,001 22,401 23,223 1,716 581 2013 30,616 28,771 28,037 29,039 31,731 33,248 33,973 4,016 840 2014 47,805 40,668 38,049 36,678 39,313 41,859 7,980 1,158 2015 59,717 51,739 49,122 52,100 54,697 13,117 1,322 2016 61,440 55,680 53,549 55,534 19,588 1,318 2017 71,126 67,151 68,985 33,798 1,373 2018 86,157 78,331 56,169 1,297 2019 112,266 99,970 951 Total $ 478,653 Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, Accident Year 2010 2011 2012 2013 2014 Unaudited 2015 2016 2017 Unaudited 2018 Unaudited 2019 ($ in thousands) 2010 $ 4 $ 37 $ 59 $ 113 $ 263 $ 261 $ 273 $ 313 346 347 2011 207 1,596 2,519 3,788 4,575 6,363 6,868 8,510 8,693 2012 757 4,441 7,850 11,238 14,382 16,474 19,383 20,707 2013 1,099 4,469 7,957 14,890 21,348 26,715 28,248 2014 698 3,081 8,489 17,576 23,771 31,026 2015 941 3,161 12,685 28,385 37,690 2016 1,099 6,015 17,225 28,924 2017 1,581 9,352 22,407 2018 2,638 10,995 2019 3,944 Total 192,981 Liabilities for claims and claim adjustment expenses, net of reinsurance $ 285,672
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, 2019: 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 4.5 % 20.2 % 25.3 % 12.5 % 20.4 % 9.5 % 0.9 % 0.2 % 0.6 % — % Casualty - occurrence 2.4 % 9.9 % 13.7 % 19.0 % 18.3 % 12.1 % 6.3 % 11.1 % 5.1 % — %

Reinsurance (Tables)

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 2017 (in thousands) Written: Direct $ 389,569 $ 275,538 $ 223,191 Assumed 125 — — Ceded (47,633 ) (39,924 ) (33,719 ) Net written $ 342,061 $ 235,614 $ 189,472 Earned: Direct $ 330,464 $ 250,397 $ 209,426 Assumed 104 — — Ceded (47,587 ) (37,709 ) (33,373 ) Net earned $ 282,981 $ 212,688 $ 176,053

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2019
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 under the employee share option plan as of December 31, 2019 , 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, 2018 804,303 $ 16.00 Granted — — Forfeited (18,068 ) 16.00 Exercised (171,890 ) 16.00 Outstanding at December 31, 2019 614,345 $ 16.00 6.6 $ 52,625 Exercisable at December 31, 2019 393,614 $ 16.00 6.6 $ 33,717
Nonvested Restricted Stock Shares Activity	A summary of all restricted stock activity under the equity compensation plans for the year ended is as follows: December 31, 2019 Number of Shares Weighted Average Grant Date Fair Value per Share Nonvested outstanding at the beginning of the period 92,465 $ 52.98 Granted 62,015 $ 80.59 Vested (27,628 ) $ 51.53 Forfeited (4,129 ) $ 60.58 Nonvested outstanding at the end of the period 122,723 $ 67.01

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 2017 (in thousands, except per share data) Net income $ 63,316 $ 33,787 $ 24,901 Weighted average common shares outstanding - basic 21,528 21,090 20,992 Dilutive effect of shares issued under stock compensation arrangements: Stock options 570 591 506 Restricted stock awards 38 4 — Total dilutive effect of shares issued under stock compensation arrangements 608 595 506 Weighted average common shares outstanding - diluted 22,136 21,685 21,498 Earnings per common share: Basic $ 2.94 $ 1.60 $ 1.19 Diluted $ 2.86 $ 1.56 $ 1.16

Other comprehensive income (l_2

Other comprehensive income (loss) (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 2018 2017 (in thousands) Unrealized gains (losses) arising during the period, before income taxes: Fixed-maturity securities $ 19,190 $ (6,664 ) $ 5,371 Equity securities (1) — — 4,192 Total unrealized gains (losses) arising during the period, before income taxes 19,190 (6,664 ) 9,563 Income taxes (4,029 ) 1,399 (3,094 ) Unrealized gains (losses) arising during the period, net of income taxes 15,161 (5,265 ) 6,469 Less reclassification adjustment: Net realized investment gains on available-for-sale investments 489 258 132 Income taxes (102 ) (54 ) (47 ) Reclassification adjustment included in net income 387 204 85 Other comprehensive income (loss) $ 14,774 $ (5,469 ) $ 6,384

Underwriting information (Table

Underwriting information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Gross Written Premiums by Underwriting Division	Gross written premiums by underwriting division are presented below: Year Ended December 31, 2019 2018 2017 (in thousands) Commercial: Construction $ 71,035 $ 50,879 $ 48,587 Small business 63,181 44,368 34,896 Excess casualty 51,225 37,398 30,260 Commercial property 29,115 9,166 5,609 Product liability 26,333 20,049 14,288 Allied health 23,962 16,815 10,645 General casualty 23,279 17,625 15,865 Professional liability 20,029 16,717 12,956 Life sciences 17,821 14,505 12,408 Energy 15,371 15,586 13,544 Management liability 14,820 8,161 4,123 Health care 5,963 5,725 6,235 Environmental 5,179 2,205 2,046 Inland marine 3,467 2,046 967 Commercial insurance 1,674 1,096 816 Public entity 580 1,193 1,265 Total commercial 373,034 263,534 214,510 Personal: Personal insurance 16,660 12,004 8,681 Total personal 16,660 12,004 8,681 Total $ 389,694 $ 275,538 $ 223,191

Statutory financial informati_2

Statutory financial information (Tables)	12 Months Ended
	Dec. 31, 2019
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, 2019 , 2018 , and 2017 and for the years then ended are summarized as follows: Year ended December 31, 2019 2018 2017 (in thousands) Statutory net income $ 40,917 $ 34,206 $ 23,841 Statutory capital and surplus 348,811 233,500 213,833

Unaudited Seleted Quarterly Fin

Unaudited Seleted Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Table Text Block]	The following is a summary of the unaudited quarterly results of operations: 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 2018 Quarter ​(in thousands, except per share data) First Second Third Fourth Gross written premiums $ 63,847 $ 69,981 $ 69,546 $ 72,164 Total revenues 50,126 54,947 60,137 56,904 Net income 7,287 10,112 11,940 4,448 Comprehensive income 2,431 9,096 9,987 6,804 Earnings per share - basic $ 0.35 $ 0.48 $ 0.57 $ 0.21 Earnings per share - diluted $ 0.34 $ 0.47 $ 0.55 $ 0.20

Schedule II - Condensed Finan_2

Schedule II - Condensed Financial Information of Registrant, Balance Sheets (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheet	December 31, 2019 2018 (in thousands) Assets Cash and cash equivalents $ 14,726 $ 10,016 Due from subsidiaries 16,836 1,001 Investment in subsidiaries 391,071 251,591 Deferred tax assets 519 369 Income taxes recoverable — 787 Other assets 208 549 Total assets $ 423,360 $ 264,313 Liabilities and Stockholders' Equity Liabilities: Accounts payable and accrued expenses $ 260 $ 308 Income taxes payable 434 — Credit facility 16,744 — Other liabilities 42 19 Total liabilities 17,480 327 Stockholders’ equity: Common stock 222 212 Additional paid-in capital 229,229 158,485 Retained earnings 162,911 106,545 Accumulated other comprehensive income (loss) 13,518 (1,256 ) Stockholders’ equity 405,880 263,986 Total liabilities and stockholders’ equity $ 423,360 $ 264,313

Schedule II - Condensed Finan_3

Schedule II - Condensed Financial Information of Registrant, Statements of Income and Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
Condensed Income Statement	Years Ended December 31, 2019 2018 2017 (in thousands) Revenues: Management fees from subsidiaries $ 4,502 $ 3,215 $ 2,037 Total revenues 4,502 3,215 2,037 Expenses: Other operating expenses 2,473 2,457 2,526 Other expenses 2,742 1,598 652 Total expenses 5,215 4,055 3,178 Loss before income taxes (713 ) (840 ) (1,141 ) Income tax benefit (2,714 ) (1,158 ) (739 ) Income (loss) before equity in net income of subsidiaries 2,001 318 (402 ) Equity in net income of subsidiaries 61,315 33,469 25,303 Net income 63,316 33,787 24,901 Other comprehensive income (loss): Equity in other comprehensive earnings (losses) of subsidiaries 14,774 (5,469 ) 6,384 Total comprehensive income $ 78,090 $ 28,318 $ 31,285

Schedule II - Condensed Finan_4

Schedule II - Condensed Financial Information of Registrant, Statements of Cash Flows (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
Condensed Cash Flow Statement	Years Ended December 31, 2019 2018 2017 (in thousands) Operating activities Net income $ 63,316 $ 33,787 $ 24,901 Adjustments to reconcile net income to net cash used in operating activities: Deferred tax (benefit) expense (150 ) (170 ) 429 Stock compensation expense 2,742 1,597 652 Equity in undistributed earnings of subsidiaries (61,315 ) (33,469 ) (25,303 ) Changes in operating assets and liabilities (14,247 ) (633 ) (1,583 ) Dividends received from subsidiary 5,000 11,500 4,500 Net cash (used in) provided by operating activities (4,654 ) 12,612 3,596 Investing activities Contributions to subsidiary (68,391 ) — — Net cash used in investing activities (68,391 ) — — Financing activities Common stock issued, net of transaction costs 65,879 — — Common stock issued, stock options exercised 2,750 1,808 1,077 Payroll taxes withheld and remitted on share-based payments (617 ) — — Dividends paid (6,929 ) (5,906 ) (5,039 ) Proceeds from credit facility 17,300 — — Debt issuance costs (628 ) — — Net cash provided by (used in) financing activities 77,755 (4,098 ) (3,962 ) Net change in cash and cash equivalents 4,710 8,514 (366 ) Cash and cash equivalents at beginning of year 10,016 1,502 1,868 Cash and cash equivalents at end of year $ 14,726 $ 10,016 $ 1,502

Description of business - (Deta

Description of business - (Details)	Dec. 31, 2019
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 Millions	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Allowance for doubtful accounts	$ 2.7	$ 2.6

Summary of significant accoun_4

Summary of significant accounting policies Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 26,507	$ 5,301
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(3,873)	(3,191)
Property, Plant and Equipment, Net	22,634	2,110
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	2,353	1,950
Software Development [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	2,356	1,031
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 1,025	1,019
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
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	$ 984	983
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	6 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 19,789	$ 318
Construction in Progress [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	50,000
Construction in Progress [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	55,000
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 2,500

Intangible assets and other inf

Intangible assets and other information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Indefinite-lived Intangible Assets [Line Items]
Short-term Investments	$ 0	$ 0
Excess and surplus lines insurance authorization [Member]
Indefinite-lived Intangible Assets [Line Items]
Impairment of intangible assets	$ 0	$ 0	$ 0

Recent accounting pronouncement

Recent accounting pronouncements (Details) $ in Thousands	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, liability	$ 900
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use asset	$ 900

Investments, Available-for-sale

Investments, Available-for-sale Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 714,817	$ 514,237
Gross Unrealized Holding Gains	17,029	2,882
Gross Unrealized Holding Losses	2,314	6,868
Estimated Fair Value	729,532	510,251
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	110	610
Gross Unrealized Holding Gains	2	2
Gross Unrealized Holding Losses	0	1
Estimated Fair Value	112	611
Obligations of States, Municipalities and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	166,312	153,884
Gross Unrealized Holding Gains	7,542	2,010
Gross Unrealized Holding Losses	961	1,294
Estimated Fair Value	172,893	154,600
Corporate and Other Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	180,287	97,889
Gross Unrealized Holding Gains	4,736	264
Gross Unrealized Holding Losses	255	1,401
Estimated Fair Value	184,768	96,752
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	195,750	151,137
Gross Unrealized Holding Gains	2,930	252
Gross Unrealized Holding Losses	710	1,522
Estimated Fair Value	197,970	149,867
Residential Mortgage-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	172,358	110,717
Gross Unrealized Holding Gains	1,819	354
Gross Unrealized Holding Losses	388	2,650
Estimated Fair Value	$ 173,789	$ 108,421

Investments, Available-for-sa_2

Investments, Available-for-sale Securities in a Loss Position (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)Rate	Dec. 31, 2018USD ($)Rate
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	$ 126,115	$ 222,581
Less than 12 months, gross unrealized holding losses	1,663	2,502
12 Months or Longer, Estimated Fair Value	73,201	128,301
12 Months or Longer, Gross Unrealized Holding Losses	651	4,366
Total Estimated Fair Value	199,316	350,882
Total Gross Unrealized Holding Losses	$ (2,314)	$ (6,868)
Number of available-for-sale securities in unrealized loss positions	137	317
Number of available-for-sale securities in unrealized loss positions, greater than one year	51	158
Fixed Maturities [Member]
Debt Securities, Available-for-sale [Line Items]
Percentage of securities rated A- or better | Rate	89.00%	86.40%
Other-than-temporary impairment losses	$ 0	$ 0
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	0	0
Less than 12 months, gross unrealized holding losses	0	0
12 Months or Longer, Estimated Fair Value	0	499
12 Months or Longer, Gross Unrealized Holding Losses	0	1
Total Estimated Fair Value	0	499
Total Gross Unrealized Holding Losses	0	(1)
Obligations of States, Municipalities and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	28,997	42,718
Less than 12 months, gross unrealized holding losses	961	440
12 Months or Longer, Estimated Fair Value	254	34,326
12 Months or Longer, Gross Unrealized Holding Losses	0	854
Total Estimated Fair Value	29,251	77,044
Total Gross Unrealized Holding Losses	(961)	(1,294)
Corporate and Other Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	22,409	62,045
Less than 12 months, gross unrealized holding losses	251	890
12 Months or Longer, Estimated Fair Value	1,509	12,092
12 Months or Longer, Gross Unrealized Holding Losses	4	511
Total Estimated Fair Value	23,918	74,137
Total Gross Unrealized Holding Losses	(255)	(1,401)
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	37,723	93,247
Less than 12 months, gross unrealized holding losses	303	1,017
12 Months or Longer, Estimated Fair Value	46,623	25,746
12 Months or Longer, Gross Unrealized Holding Losses	407	505
Total Estimated Fair Value	84,346	118,993
Total Gross Unrealized Holding Losses	(710)	(1,522)
Residential Mortgage-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Estimated Fair Value	36,986	24,571
Less than 12 months, gross unrealized holding losses	148	155
12 Months or Longer, Estimated Fair Value	24,815	55,638
12 Months or Longer, Gross Unrealized Holding Losses	240	2,495
Total Estimated Fair Value	61,801	80,209
Total Gross Unrealized Holding Losses	$ (388)	$ (2,650)

Investments, Contractual Maturi

Investments, Contractual Maturities of Available-for-sale Fixed Maturity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amortized Cost [Abstract]
Due in one year or less, Amortized Cost	$ 9,940
Due after one year through five years, Amortized Cost	115,480
Due after five years through ten years, Amortized Cost	79,235
Due after ten years, Amortized Cost	142,054
Total fixed maturities, Amortized Cost	714,817	$ 514,237
Estimated Fair Value [Abstract]
Due in one year or less, Estimated Fair Value	9,990
Due after one year through five years, Estimated Fair Value	118,611
Due after five years through ten years, Estimated Fair Value	82,314
Due after ten years, Estimated Fair Value	146,858
Estimated Fair Value	729,532	510,251
Asset-backed Securities [Member]
Amortized Cost [Abstract]
Without single maturity date, Amortized Cost	195,750
Total fixed maturities, Amortized Cost	195,750	151,137
Estimated Fair Value [Abstract]
Without single maturity date, Estimated Fair Value	197,970
Estimated Fair Value	197,970	149,867
Residential Mortgage-backed Securities [Member]
Amortized Cost [Abstract]
Without single maturity date, Amortized Cost	172,358
Total fixed maturities, Amortized Cost	172,358	110,717
Estimated Fair Value [Abstract]
Without single maturity date, Estimated Fair Value	173,789
Estimated Fair Value	$ 173,789	$ 108,421

Investments, Net Investment Inc

Investments, Net Investment Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest [Abstract]
Taxable bonds	$ 14,853	$ 9,474	$ 6,233
Municipal bonds (tax exempt)	3,692	4,298	3,619
Cash equivalents and short-term investments	842	1,017	678
Dividends on equity securities	2,136	2,014	1,041
Gross investment income	21,523	16,803	11,571
Investment expenses	(1,390)	(1,115)	(1,002)
Net investment income	$ 20,133	$ 15,688	$ 10,569

Investments Realized Investment

Investments Realized Investment Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fixed-maturity securities - realized gains (losses) [Abstract]
Realized gains	$ 567	$ 263	$ 220
Realized losses	(79)	(17)	(69)
Net realized gains from fixed-maturity securities	488	246	151
Equity securities - realized gains (losses) [Abstract]
Realized gains	556	57
Realized gains, available for sale			0
Realized losses	(688)	(22)
Realized losses, available for sale			0
Net realized gains (losses) from equity securities	(132)	35
Net realized gains (losses), available for sale			0
Short-term securities - realized gain	3	0	0
Net realized investment gains	$ 359	$ 281	$ 151

Investments, Unrealized Gain (L

Investments, Unrealized Gain (Losses) on Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Change in unrealized gains (losses), fixed-maturity securities	$ 18.7	$ (6.9)	$ 5.2
Change in unrealized gains, equity securities			$ 4.2

Investments Investment Deposits

Investments Investment Deposits and Payables (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
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, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 807,826	$ 567,962
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	54,575	39,598
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	753,251	528,364
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	729,532	510,251
Fixed Maturities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	112	611
Fixed Maturities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	729,420	509,640
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	611
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	611
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	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	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	172,893	154,600
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	172,893	154,600
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	184,768	96,752
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	184,768	96,752
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	197,970	149,867
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	197,970	149,867
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
Residential Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value - available for sale	173,789	108,421
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	173,789	108,421
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	78,294	57,711
Equity Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	54,463	38,987
Equity Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	23,831	18,724
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	54,463	38,987
Exchange Traded Fund [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	54,463	38,987
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	23,831	18,724
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	23,831	18,724
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) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from Level 1 to Level 2	$ 0	$ 0
Transfers from Level 2 to Level 1	0	0
Fair Value, Nonrecurring [Member]
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, 2019	Dec. 31, 2018	Dec. 31, 2017
Movement analysis of deferred policy acquisition costs [Roll Forward]
Balance, beginning of period	$ 14,801	$ 11,775	$ 10,150
Policy acquisition costs deferred:
Direct commissions deferred	56,841	40,546	32,927
Ceding commissions deferred	(12,373)	(11,239)	(9,984)
Other underwriting and policy acquisition costs deferred	3,727	3,141	2,827
Policy acquisition costs deferred	48,195	32,448	25,770
Amortization of net policy acquisition costs	(39,432)	(29,422)	(24,145)
Balance, end of period	$ 23,564	$ 14,801	$ 11,775

Underwriting, acquisition and_3

Underwriting, acquisition and insurance expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Underwriting, Acquisition and Insurance Expenses [Abstract]
Direct commissions	$ 48,382	$ 36,885	$ 31,001
Ceding commissions	(12,347)	(10,448)	(9,799)
Other expenses	34,182	26,988	22,944
Total	70,217	53,425	44,146
Salaries, employee benefits and bonus expense	$ 27,800	$ 19,700	$ 17,700

Income taxes (Details)

Income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of income tax expense
Current federal income tax expense	$ 12,860	$ 9,923	$ 12,555
Deferred federal income tax benefit	(125)	(3,230)	1,065
Income tax expense (benefit)	12,735	6,693	13,620
Federal income taxes paid	11,600	9,900	$ 13,500
Income tax payable	$ 400
Income taxes receivable		$ 800
Statutory income tax rate, percent	21.00%	21.00%	35.00%
Effective income tax rate reconciliation, amount [Abstract]
Income tax expense at federal income tax	$ 15,971	$ 8,501	$ 13,482
Stock options exercised	(2,411)	(918)	471
Tax-exempt investment income	(577)	(672)	(1,064)
Effect of tax rate change	0	0	1,915
Other	(248)	(218)	(242)
Income tax expense (benefit)	12,735	6,693	13,620
Unrecognized tax positions	$ 0	$ 0
Decrease in unrecognized tax positions			$ 1,000

Income taxes - Deferred Tax Ass

Income taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets [Abstract]
Unpaid losses and loss adjustment expenses	$ 8,199	$ 6,854
Unearned premiums	7,193	4,711
Organizational costs	162	196
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	765	557
State operating loss carryforwards	1,497	708
Allowance for doubtful accounts	570	551
Unrealized losses on fixed-maturity securities	0	837
Other	256	196
Deferred tax assets before allowance	18,642	14,610
Less: valuation allowance	(1,592)	(780)
Total deferred tax assets	17,050	13,830
Deferred tax liabilities [Abstract]
Unrealized gains on fixed-maturity securities	3,090	0
deferred tax liabilities, unrealized gains on equity securities	2,995	374
Deferred policy acquisition costs, net of ceding commissions	4,949	3,108
Intangible assets	743	743
Transition adjustment for loss discounting	1,537	2,060
Other	362	369
Total deferred tax liabilities	13,676	6,654
Net deferred tax assets	3,374	7,176
State Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 31,600	$ 19,500

Reserves for unpaid losses an_4

Reserves for unpaid losses and loss adjustment expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	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]
Net reserves for unpaid losses and loss adjustment expenses, beginning of period	$ 313,763	$ 267,493	$ 194,602
Commutation of 2015 MLQS	0	0	27,929
Adjusted net reserves for losses and loss adjustment expenses, beginning of year	313,763	267,493	222,531
Incurred losses and loss adjustment expenses [Abstract]
Current year	178,986	135,078	114,960
Prior year losses and loss adjustment expense	(9,423)	(7,037)	(11,280)
Total net losses and loss adjustment expenses incurred	169,563	128,041	103,680
Payments [Abstract]
Current year	19,054	14,118	13,792
Prior years	74,006	67,653	44,926
Total payments	93,060	81,771	58,718
Net reserves for unpaid losses and loss adjustment expenses, end of period	390,266	313,763	267,493
Reinsurance recoverable for unpaid losses	69,792	55,389	48,224
Gross reserves for unpaid losses and loss adjustment expenses, end of period	$ 460,058	$ 369,152	$ 315,717

Reserves for unpaid losses an_5

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, 2019	Dec. 31, 2018	Dec. 31, 2017
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense	$ (9,423)	$ (7,037)	$ (11,280)
Commutation of 2015 MLQS	0	0	27,929
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	(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)	(9,400)
us-gaap_ShortdurationInsuranceContractsAccidentYear2015and2014 [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense			(6,000)
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
Accident Years 2011 to 2013 [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Prior year losses and loss adjustment expense			$ 4,100

Reserves for unpaid losses an_6

Reserves for unpaid losses and loss adjustment expenses Reserve Development (Details)	12 Months Ended
	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 ($)	Dec. 31, 2010USD ($)
Claims Development
Prior year losses and loss adjustment expense	$ (9,423,000)	$ (7,037,000)	$ (11,280,000)
Liability for claims and claim adjustment expense, net	356,108,000
Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	37,234,000
All outstanding liabilities before 2015, net of reinsurance	0
Liability for claims and claim adjustment expense, net	5,507,000
Incurred claims and claim adjustment expense, net	42,741,000
Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	57,785,000
Liability for claims and claim adjustment expense, net	64,929,000
Incurred claims and claim adjustment expense, net	122,714,000
Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	192,981,000
Liability for claims and claim adjustment expense, net	285,672,000
Incurred claims and claim adjustment expense, net	478,653,000
Accident Year 2010 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	859,000	859,000	859,000	$ 859,000	$ 859,000	$ 862,000	$ 393,000	$ 368,000	$ 79,000	$ 0
Incurred claims and claim adjustment expense, net	872,000	876,000	883,000	894,000	916,000	946,000	737,000	679,000	805,000	778,000
Total of IBNR liabilities plus expected development on reported claims	$ 13,000
Cumulative number of reported claims	14
Accident Year 2010 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 347,000	346,000	313,000	273,000	261,000	263,000	113,000	59,000	37,000	4,000
Incurred claims and claim adjustment expense, net	406,000	402,000	429,000	406,000	404,000	458,000	460,000	531,000	771,000	$ 843,000
Total of IBNR liabilities plus expected development on reported claims	$ 59,000
Cumulative number of reported claims	49
Accident Year 2011 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 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	3,206,000	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	$ 102,000
Cumulative number of reported claims	76
Accident Year 2011 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 8,693,000	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	9,379,000	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	$ 471,000
Cumulative number of reported claims	226
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	1,882,000	1,090,000	1,024,000	877,000	475,000	153,000
Incurred claims and claim adjustment expense, net	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	$ 261,000
Cumulative number of reported claims	138
Accident Year 2012 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 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	23,223,000	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	$ 1,716,000
Cumulative number of reported claims	581
Accident Year 2013 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 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	6,128,000	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	$ 629,000
Cumulative number of reported claims	228
Accident Year 2013 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 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	33,973,000	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	$ 4,016,000
Cumulative number of reported claims	840
Accident Year 2014 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 9,415,000	8,290,000	6,384,000	5,039,000	1,865,000	435,000
Incurred claims and claim adjustment expense, net	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	$ 1,239,000
Cumulative number of reported claims	273
Accident Year 2014 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 31,026,000	23,771,000	17,576,000	8,489,000	3,081,000	698,000
Incurred claims and claim adjustment expense, net	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	$ 7,980,000
Cumulative number of reported claims	1,158
Accident Year 2015 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 869,000	865,000	832,000	706,000	584,000
Incurred claims and claim adjustment expense, net	869,000	872,000	857,000	880,000	1,394,000
Total of IBNR liabilities plus expected development on reported claims	$ 0
Cumulative number of reported claims	63
Accident Year 2015 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 11,371,000	9,238,000	7,562,000	4,496,000	217,000
Incurred claims and claim adjustment expense, net	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	$ 2,024,000
Cumulative number of reported claims	257
Accident Year 2015 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 37,690,000	28,385,000	12,685,000	3,161,000	941,000
Incurred claims and claim adjustment expense, net	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	$ 13,117,000
Cumulative number of reported claims	1,322
Accident Year 2016 [Member]
Claims Development
Prior year losses and loss adjustment expense		(3,800,000)	(9,400,000)
Accident Year 2016 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 3,265,000	3,265,000	3,257,000	1,867,000
Incurred claims and claim adjustment expense, net	3,278,000	3,301,000	3,392,000	4,177,000
Total of IBNR liabilities plus expected development on reported claims	$ 14,000
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	$ 9,839,000	6,907,000	3,015,000	1,158,000
Incurred claims and claim adjustment expense, net	14,322,000	14,675,000	14,694,000	19,170,000
Total of IBNR liabilities plus expected development on reported claims	$ 3,248,000
Cumulative number of reported claims	309
Accident Year 2016 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 28,924,000	17,225,000	6,015,000	1,099,000
Incurred claims and claim adjustment expense, net	55,534,000	53,549,000	55,680,000	$ 61,440,000
Total of IBNR liabilities plus expected development on reported claims	$ 19,588,000
Cumulative number of reported claims	1,318
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	11,602,000	11,233,000	9,938,000
Incurred claims and claim adjustment expense, net	11,676,000	11,705,000	12,473,000
Total of IBNR liabilities plus expected development on reported claims	$ 65,000
Cumulative number of reported claims	1,038
Accident Year 2017 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 8,252,000	4,897,000	340,000
Incurred claims and claim adjustment expense, net	16,121,000	17,096,000	18,116,000
Total of IBNR liabilities plus expected development on reported claims	$ 5,024,000
Cumulative number of reported claims	366
Accident Year 2017 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 22,407,000	9,352,000	1,581,000
Incurred claims and claim adjustment expense, net	68,985,000	67,151,000	$ 71,126,000
Total of IBNR liabilities plus expected development on reported claims	$ 33,798,000
Cumulative number of reported claims	1,373
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	(13,000,000)
Accident Year 2018 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	11,646,000	9,132,000
Incurred claims and claim adjustment expense, net	12,004,000	11,559,000
Total of IBNR liabilities plus expected development on reported claims	$ 236,000
Cumulative number of reported claims	643
Accident Year 2018 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 5,030,000	507,000
Incurred claims and claim adjustment expense, net	20,235,000	22,429,000
Total of IBNR liabilities plus expected development on reported claims	$ 10,949,000
Cumulative number of reported claims	448
Accident Year 2018 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 10,995,000	2,638,000
Incurred claims and claim adjustment expense, net	78,331,000	$ 86,157,000
Total of IBNR liabilities plus expected development on reported claims	$ 56,169,000
Cumulative number of reported claims	1,297
Accident Year 2019 [Member] | Property [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 9,852,000
Incurred claims and claim adjustment expense, net	14,914,000
Total of IBNR liabilities plus expected development on reported claims	$ 2,384,000
Cumulative number of reported claims	598
Accident Year 2019 [Member] | Casualty - claims made [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 2,487,000
Incurred claims and claim adjustment expense, net	34,693,000
Total of IBNR liabilities plus expected development on reported claims	$ 27,450,000
Cumulative number of reported claims	504
Accident Year 2019 [Member] | Casualty - occurrence [Member]
Claims Development
Cumulative paid claims and allocated claim adjustment expense, net	$ 3,944,000
Incurred claims and claim adjustment expense, net	112,266,000
Total of IBNR liabilities plus expected development on reported claims	$ 99,970,000
Cumulative number of reported claims	951

Reserves for unpaid losses an_7

Reserves for unpaid losses and loss adjustment expenses Historical Claims Duration (Details)	Dec. 31, 2019Rate
Property [Member]
Historical Claims Duration [Line Items]
Historical Claims Duration, Year One	70.30%
Historical Claims Duration, Year Two	22.10%
Historical Claims Duration, Year Three	5.90%
Historical Claims Duration, Year Four	1.90%
Historical Claims Duration, Year Five	0.40%
Casualty - claims made [Member]
Historical Claims Duration [Line Items]
Historical Claims Duration, Year One	4.50%
Historical Claims Duration, Year Two	20.20%
Historical Claims Duration, Year Three	25.30%
Historical Claims Duration, Year Four	12.50%
Historical Claims Duration, Year Five	20.40%
Historical Claims Duration, Year Six	9.50%
Historical Claims Duration, Year Seven	0.90%
Historical Claims Duration, Year Eight	0.20%
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	2.40%
Historical Claims Duration, Year Two	9.90%
Historical Claims Duration, Year Three	13.70%
Historical Claims Duration, Year Four	19.00%
Historical Claims Duration, Year Five	18.30%
Historical Claims Duration, Year Six	12.10%
Historical Claims Duration, Year Seven	6.30%
Historical Claims Duration, Year Eight	11.10%
Historical Claims Duration, Year Nine	5.10%
Historical Claims Duration, Year Ten	0.00%

Reserves for unpaid losses an_8

Reserves for unpaid losses and loss adjustment expenses Reconciliation of Claims Development to Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for claims and claim adjustment expense, net	$ 356,108
Reinsurance recoverable for unpaid losses	69,792	$ 55,389	$ 48,224
Unallocated claim adjustment expenses	34,158
Reserves for unpaid losses and loss adjustment expenses	460,058	$ 369,152	$ 315,717
Property [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for claims and claim adjustment expense, net	5,507
Reinsurance recoverable for unpaid losses	3,119
Casualty - claims made [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for claims and claim adjustment expense, net	64,929
Reinsurance recoverable for unpaid losses	9,852
Casualty - occurrence [Member]
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Liability for claims and claim adjustment expense, net	285,672
Reinsurance recoverable for unpaid losses	$ 56,821

Reinsurance, Effects of Reinsur

Reinsurance, Effects of Reinsurance on Premiums Written and Earned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Written [Abstract]
Direct	$ 389,569	$ 275,538	$ 223,191
Assumed	125	0	0
Ceded	(47,633)	(39,924)	(33,719)
Net written premiums	342,061	235,614	189,472
Earned [Abstract]
Direct	330,464	250,397	209,426
Assumed	104	0	0
Ceded	(47,587)	(37,709)	(33,373)
Net earned premiums	282,981	212,688	176,053
Ceded incurred losses and loss adjustment expenses	$ 27,200	$ 25,500	$ 12,200

Reinsurance Reinsurance Balance

Reinsurance Reinsurance Balances (Details)	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Concentration Risk [Line Items]
Reinsurance recoverable for unpaid losses	$ 69,792,000	$ 55,389,000	$ 48,224,000
Reinsurance recoverable for paid losses	2,800,000	1,400,000
Reinsurance Recoverable, Allowance for Credit Loss	0	0
Ceded unearned premiums	$ 16,118,000	$ 16,072,000
Reinsurance Receivable, Net [Member] | Major Reinsurers [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	88.80%
Number of Major Reinsurers	5

Stockholders' Equity Capital St

Stockholders' Equity Capital Stock (Details) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
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
Preferred stock, outstanding (in shares)	0	0
Preferred stock, par value (in dollars per share)	$ 0.01

Stockholders' Equity, Public Of

Stockholders' Equity, Public Offering (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 12, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Stock issued, shares	741,750	742,000
Share price (in dollars per share)	$ 93
Net proceeds from public offering, net of discounts, commissions and other offering costs	$ 65,900	$ 65,879	$ 0	$ 0
Over-Allotment Option [Member]
Class of Stock [Line Items]
Stock issued, shares	96,750

Stockholders' Equity, Dividend

Stockholders' Equity, Dividend Declaration (Details) - $ / shares	Feb. 13, 2020	Nov. 13, 2019	Aug. 15, 2019	May 23, 2019	Feb. 14, 2019
Dividend Declared [Member]
Dividends Payable [Line Items]
Dividend declared date		Nov. 13, 2019	Aug. 15, 2019	May 23, 2019	Feb. 14, 2019
Cash dividend paid (in dollars per share)		$ 0.08	$ 0.08	$ 0.08	$ 0.08
Dividend record date		Nov. 29, 2019	Aug. 29, 2019	Jun. 3, 2019	Feb. 28, 2019
Dividend Declared [Member] | Subsequent Event [Member]
Dividends Payable [Line Items]
Dividend declared date	Feb. 13, 2020
Cash dividend paid (in dollars per share)	$ 0.09
Dividend record date	Feb. 28, 2020
Dividend Paid [Member]
Dividends Payable [Line Items]
Dividend payable date		Dec. 12, 2019	Sep. 12, 2019	Jun. 13, 2019	Mar. 14, 2019
Dividend Paid [Member] | Subsequent Event [Member]
Dividends Payable [Line Items]
Dividend payable date	Mar. 12, 2020

Stockholders' Equity, Equity-ba

Stockholders' Equity, Equity-based Compensation, Options (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 27, 2016	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation		$ 2,700	$ 1,600	$ 700
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Intrinsic value of options exercised		$ 11,900	$ 4,700
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)		804,303
Granted, shares		0
Forfeited (in shares)		(18,068)
Exercised (in shares)		(171,890)
Options, end of year (in shares)		614,345	804,303
Exercisable, shares		393,614
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		6 years 7 months 6 days
Exercisable, weighted average remaining contractual term		6 years 7 months 6 days
Outstanding, aggregate intrinsic value		$ 52,625
Exercisable, aggregate intrinsic value		33,717
Unrecognized stock-based compensation expense		$ 300
Compensation cost not yet recognized, period		7 months 6 days
2016 Omnibus Incentive Plan [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance	2,073,832
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, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld for taxes	7,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld for taxes	7,365
Vested in period, fair value	$ 2.1
Nonvested Restricted Stock, Number of Shares [Roll Forward]
Nonvested outstanding at the beginning of the period, shares		92,465
Granted, shares	62,015		0
Vested, shares	(27,628)	0	0
Forfeited, shares	(4,129)
Nonvested outstanding at the end of the period, shares		122,723
Nonvested Restricted Stock, Weighted Average Grant Date Fair Value [Abstract]
Nonvested outstanding at the beginning of the period	$ 52.98
Granted	80.59	$ 52.99
Vested	51.53
Forfeited	60.58
Nonvested outstanding at the end of the period	$ 67.01	$ 52.98
Unrecognized stock-based compensation expense	$ 6.5
Compensation cost not yet recognized, period	3 years
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	Jan. 01, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Member]
Subsequent Event [Line Items]
Weighted average grant date fair value	$ 101.66
Restricted Stock [Member]
Subsequent Event [Line Items]
Weighted average grant date fair value		$ 80.59	$ 52.99
Restricted Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Award vesting period	1 year
Restricted Stock [Member] | 2016 Omnibus Incentive Plan [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Granted	4,428

Earnings per share (Details)

Earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of numerator and denominator of the basic and diluted earnings per share computations [Abstract]
Net income									$ 63,316	$ 33,787	$ 24,901
Basic earnings per share [Abstract]
Earnings per share - basic	$ 0.81	$ 0.60	$ 0.65	$ 0.88	$ 0.21	$ 0.57	$ 0.48	$ 0.35	$ 2.94	$ 1.60	$ 1.19
Diluted earnings per share [Abstract]
Earnings per share - diluted	$ 0.79	$ 0.58	$ 0.63	$ 0.86	$ 0.20	$ 0.55	$ 0.47	$ 0.34	$ 2.86	$ 1.56	$ 1.16
Basic weighted average shares outstanding [Abstract]
Weighted average shares outstanding - basic									21,528,000	21,090,000	20,992,000
Dilutive effect of shares issued under stock compensation arrangements [Abstract]
Dilutive effect of shares issued under stock compensation arrangements (in shares)									608,000	595,000	506,000
Diluted weighted average shares outstanding [Abstract]
Weighted average shares outstanding - diluted (in shares)									22,136,000	21,685,000	21,498,000
Antidilutive securities (in shares)									54,000		0
Stock options [Member]
Dilutive effect of shares issued under stock compensation arrangements [Abstract]
Dilutive effect of shares issued under stock compensation arrangements (in shares)									570,000	591,000	506,000
Restricted Stock [Member]
Dilutive effect of shares issued under stock compensation arrangements [Abstract]
Dilutive effect of shares issued under stock compensation arrangements (in shares)									38,000	4,000	0

Credit Agreement (Details)

Credit Agreement (Details)	12 Months Ended
	Dec. 31, 2019USD ($)Rate
Debt Disclosure [Abstract]
Current Borrowing Capacity	$ 50,000,000
Accordion Feature	$ 30,000,000
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	$ 17,300,000
Debt Issuance Costs	$ 600,000
Weighted Average Interest Rate | Rate	3.75%
Interest Expense	$ 200,000
Interest paid	$ 100,000

Employee benefit plan (Details)

Employee benefit plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Expenses related to employee benefit plan	$ 1.3	$ 1	$ 1

Other comprehensive income (l_3

Other comprehensive income (loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) arising during the period, before income taxes	$ 19,190	$ (6,664)	$ 9,563
Income taxes	(4,029)	1,399	(3,094)
Unrealized gains (losses) arising during the period, net of income tax	15,161	(5,265)	6,469
Less reclassification adjustment [Abstract]
Net realized investment gains (losses)	489	258	132
Income taxes	(102)	(54)	(47)
Reclassification adjustment included in net income	387	204	85
Other comprehensive income (loss)	14,774	(5,469)	6,384
Fixed Maturities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) arising during the period, before income taxes	19,190	(6,664)	5,371
Equity Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized gains (losses) arising during the period, before income taxes	$ 0	$ 0	$ 4,192

Underwriting information (Detai

Underwriting information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)Rate	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Revenue from External Customer [Line Items]
Gross written premiums	$ 112,137	$ 97,984	$ 94,947	$ 84,626	$ 72,164	$ 69,546	$ 69,981	$ 63,847	$ 389,694	$ 275,538	$ 223,191
Number of operating segments									1
Construction [Member]
Revenue from External Customer [Line Items]
Gross written premiums									$ 71,035	50,879	48,587
Small Business [Member]
Revenue from External Customer [Line Items]
Gross written premiums									63,181	44,368	34,896
Energy [Member]
Revenue from External Customer [Line Items]
Gross written premiums									15,371	15,586	13,544
Excess Casualty [Member]
Revenue from External Customer [Line Items]
Gross written premiums									51,225	37,398	30,260
General Casualty [Member]
Revenue from External Customer [Line Items]
Gross written premiums									23,279	17,625	15,865
Products Liability [Member]
Revenue from External Customer [Line Items]
Gross written premiums									26,333	20,049	14,288
Professional Liability [Member]
Revenue from External Customer [Line Items]
Gross written premiums									20,029	16,717	12,956
Life Sciences [Member]
Revenue from External Customer [Line Items]
Gross written premiums									17,821	14,505	12,408
Allied Health [Member]
Revenue from External Customer [Line Items]
Gross written premiums									23,962	16,815	10,645
Health Care [Member]
Revenue from External Customer [Line Items]
Gross written premiums									5,963	5,725	6,235
Commercial Property [Member]
Revenue from External Customer [Line Items]
Gross written premiums									29,115	9,166	5,609
Management Liability [Member]
Revenue from External Customer [Line Items]
Gross written premiums									14,820	8,161	4,123
Environmental [Member]
Revenue from External Customer [Line Items]
Gross written premiums									5,179	2,205	2,046
Public Entity [Member]
Revenue from External Customer [Line Items]
Gross written premiums									580	1,193	1,265
Inland Marine [Member]
Revenue from External Customer [Line Items]
Gross written premiums									3,467	2,046	967
Commercial Insurance [Member]
Revenue from External Customer [Line Items]
Gross written premiums									1,674	1,096	816
Commercial [Member]
Revenue from External Customer [Line Items]
Gross written premiums									373,034	263,534	214,510
Personal Insurance [Member]
Revenue from External Customer [Line Items]
Gross written premiums									16,660	12,004	8,681
Personal [Member]
Revenue from External Customer [Line Items]
Gross written premiums									16,660	$ 12,004	$ 8,681
Revenue Benchmark [Member]
Revenue from External Customer [Line Items]
Number of insurance brokers										2
Major Insurance Brokers, Group One [Member] | Revenue Benchmark [Member]
Revenue from External Customer [Line Items]
Gross written premiums									$ 47,200
Concentration Risk, Percentage | Rate									12.10%
Major Insurance Brokers, Group Two [Member] | Revenue Benchmark [Member]
Revenue from External Customer [Line Items]
Gross written premiums									$ 41,100
Concentration Risk, Percentage | Rate									10.50%

Statutory financial informati_3

Statutory financial information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments [Abstract]
Statutory net income	$ 40,917	$ 34,206	$ 23,841
Statutory capital and surplus	$ 348,811	$ 233,500	$ 213,833
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	$ 40,700

Unaudited Quarterly Financial D

Unaudited Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Gross written premiums	$ 112,137	$ 97,984	$ 94,947	$ 84,626	$ 72,164	$ 69,546	$ 69,981	$ 63,847	$ 389,694	$ 275,538	$ 223,191
Revenues	92,804	78,327	72,572	72,185	56,904	60,137	54,947	50,126	315,888	222,114	186,776
Net income	17,853	12,976	13,767	18,720	4,448	11,940	10,112	7,287	63,316	33,787	24,901
Comprehensive income	$ 16,050	$ 16,218	$ 20,322	$ 25,500	$ 6,804	$ 9,987	$ 9,096	$ 2,431	$ 78,090	$ 28,318	$ 31,285
Earnings Per Share, Basic [Abstract]
Basic	$ 0.81	$ 0.60	$ 0.65	$ 0.88	$ 0.21	$ 0.57	$ 0.48	$ 0.35	$ 2.94	$ 1.60	$ 1.19
Diluted earnings per share [Abstract]
Diluted	$ 0.79	$ 0.58	$ 0.63	$ 0.86	$ 0.20	$ 0.55	$ 0.47	$ 0.34	$ 2.86	$ 1.56	$ 1.16

Schedule I-Summary of Investm_2

Schedule I-Summary of Investments-Other than Related Parties (Details) $ in Thousands	Dec. 31, 2019USD ($)
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	$ 779,062
Fair Value	807,826
Amount	807,826
Fixed Maturities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	714,817
Fair Value	729,532
Amount	729,532
US Treasury and Government [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	110
Fair Value	112
Amount	112
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	166,312
Fair Value	172,893
Amount	172,893
Debt Security, Corporate, US [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	180,287
Fair Value	184,768
Amount	184,768
Asset-backed Securities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	195,750
Fair Value	197,970
Amount	197,970
Residential Mortgage Backed Securities [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	172,358
Fair Value	173,789
Amount	173,789
Equity Securities, Investment Summary [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	64,245
Fair Value	78,294
Amount	78,294
Nonredeemable Preferred Stock [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	23,403
Fair Value	23,831
Amount	23,831
Exchange Traded Funds [Member]
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items]
Cost	40,842
Fair Value	54,463
Amount	$ 54,463

Schedule II - Condensed Finan_5

Schedule II - Condensed Financial Information of Registrant, Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 100,408	$ 75,089	$ 81,747	$ 50,752
Deferred income tax asset, net	3,374	7,176
Income taxes receivable		800
Other assets	23,922	3,601
Total assets	1,090,550	773,063
Liabilities:
Accounts payable and accrued expenses	12,366	7,090
Income taxes payable	400
Other liabilities	977	20
Total liabilities	684,670	509,077
Stockholders' Equity [Abstract]
Common stock	222	212
Additional paid-in capital	229,229	158,485
Retained earnings	162,911	106,545
Accumulated other comprehensive income (loss)	13,518	(1,256)
Stockholders' equity	405,880	263,986	238,189	210,214
Total liabilities and stockholders' equity	1,090,550	773,063
Parent Company [Member]
Assets
Cash and cash equivalents	14,726	10,016	$ 1,502	$ 1,868
Due from subsidiaries	16,836	1,001
Investment in subsidiaries	391,071	251,591
Deferred income tax asset, net	519	369
Income taxes receivable	0	787
Other assets	208	549
Total assets	423,360	264,313
Liabilities:
Accounts payable and accrued expenses	260	308
Income taxes payable	434	0
Credit facility	16,744	0
Other liabilities	42	19
Total liabilities	17,480	327
Stockholders' Equity [Abstract]
Common stock	222	212
Additional paid-in capital	229,229	158,485
Retained earnings	162,911	106,545
Accumulated other comprehensive income (loss)	13,518	(1,256)
Stockholders' equity	405,880	263,986
Total liabilities and stockholders' equity	$ 423,360	$ 264,313

Schedule II - Condensed Finan_6

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, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Revenues	$ 92,804	$ 78,327	$ 72,572	$ 72,185	$ 56,904	$ 60,137	$ 54,947	$ 50,126	$ 315,888	$ 222,114	$ 186,776
Expenses [Abstract]
Other expenses									57	168	429
Total expenses									239,837	181,634	148,255
Income tax benefit									12,735	6,693	13,620
Net income	17,853	12,976	13,767	18,720	4,448	11,940	10,112	7,287	63,316	33,787	24,901
Other Comprehensive Income (Loss) [Abstract]
Total comprehensive income	$ 16,050	$ 16,218	$ 20,322	$ 25,500	$ 6,804	$ 9,987	$ 9,096	$ 2,431	78,090	28,318	31,285
Parent Company [Member]
Revenues:
Revenues									4,502	3,215	2,037
Expenses [Abstract]
Other operating expenses									2,473	2,457	2,526
Other expenses									2,742	1,598	652
Total expenses									5,215	4,055	3,178
Loss before equity in net income of subsidiaries									(713)	(840)	(1,141)
Income tax benefit									(2,714)	(1,158)	(739)
Loss before equity in net income of subsidiaries									2,001	318	(402)
Equity in net income of subsidiaries									61,315	33,469	25,303
Net income									63,316	33,787	24,901
Other Comprehensive Income (Loss) [Abstract]
Equity in other comprehensive earnings (losses) of subsidiaries									14,774	(5,469)	6,384
Total comprehensive income									$ 78,090	$ 28,318	$ 31,285

Schedule II - Condensed Finan_7

Schedule II - Condensed Financial Information of Registrant, Statements of Cash Flows (Details) - USD ($) $ in Thousands	Aug. 12, 2019	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net income		$ 17,853	$ 12,976	$ 13,767	$ 18,720	$ 4,448	$ 11,940	$ 10,112	$ 7,287	$ 63,316	$ 33,787	$ 24,901
Adjustments to reconcile net income to net cash used in operating activities:
Deferred tax (benefit) expense										(125)	(3,230)	1,065
Stock compensation expense										2,742	1,597	652
Dividends received from subsidiary										5,000	11,500	4,500
Net cash provided by (used in) operating activities										178,357	103,980	77,398
Net Cash Provided by (Used in) Investing Activities [Abstract]
Net cash provided by (used in) investing activities										(230,793)	(106,540)	(42,432)
Financing activities:
Proceeds from Issuance of Common Stock	$ 65,900									65,879	0	0
Common stock issued, stock options exercised										2,750	1,808	1,077
Payroll taxes withheld and remitted on share-based payments										(617)	0	0
Dividends paid										(6,929)	(5,906)	(5,039)
Proceeds from credit facility										17,300	0	0
Debt issuance costs										(628)	0	0
Net cash provided by (used in) financing activities										77,755	(4,098)	(3,971)
Net change in cash and cash equivalents										25,319	(6,658)	30,995
Cash and cash equivalents at beginning of period					75,089				81,747	75,089	81,747	50,752
Cash and cash equivalents at end of period		100,408				75,089				100,408	75,089	81,747
Parent Company [Member]
Operating activities:
Net income										63,316	33,787	24,901
Adjustments to reconcile net income to net cash used in operating activities:
Deferred tax (benefit) expense										(150)	(170)	429
Stock compensation expense										2,742	1,597	652
Equity in undistributed earnings of subsidiaries										(61,315)	(33,469)	(25,303)
Changes in operating assets and liabilities										(14,247)	(633)	(1,583)
Dividends received from subsidiary										5,000	11,500	4,500
Net cash provided by (used in) operating activities										(4,654)	12,612	3,596
Net Cash Provided by (Used in) Investing Activities [Abstract]
Contribution to subsidiary										(68,391)	0	0
Net cash provided by (used in) investing activities										(68,391)	0	0
Financing activities:
Proceeds from Issuance of Common Stock										65,879	0	0
Common stock issued, stock options exercised										2,750	1,808	1,077
Payroll taxes withheld and remitted on share-based payments										(617)	0	0
Dividends paid										(6,929)	(5,906)	(5,039)
Proceeds from credit facility										17,300	0	0
Debt issuance costs										(628)
Net cash provided by (used in) financing activities										77,755	(4,098)	(3,962)
Net change in cash and cash equivalents										4,710	8,514	(366)
Cash and cash equivalents at beginning of period					$ 10,016				$ 1,502	10,016	1,502	1,868
Cash and cash equivalents at end of period		$ 14,726				$ 10,016				$ 14,726	$ 10,016	$ 1,502

Schedule II - Condensed Finan_8

Schedule II - Condensed Financial Information of Registrant, Notes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
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	$ 16,744	$ 0
Debt Issuance Costs	$ 600
Weighted Average Interest Rate	3.75%
Interest Expense	$ 200
Interest paid	100
Cash dividends paid to parent company by consolidated subsidiaries	$ 5,000	$ 11,500	$ 4,500

Schedule V - Valuation and Qu_2

Schedule V - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for Premiums Receivable [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 2,615	$ 2,112	$ 1,977
Additions amounts charged to expense	835	663	488
Deductions amounts written off or disposals	(745)	(160)	(353)
Balance at end of period	2,705	2,615	2,112
Valuation Allowance for Deferred Tax Assets [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	780	690	623
Additions amounts charged to expense	812	90	67
Deductions amounts written off or disposals	0	0	0
Balance at end of period	$ 1,592	$ 780	$ 690