AMERISAFE (AMSF) 10-K 26 Feb 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 16, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Trading Symbol	AMSF
Entity Registrant Name	AMERISAFE, INC.
Entity Central Index Key	0001018979
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Annual Report	true
Document Transition Report	false
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity File Number	001-12251
Entity Tax Identification Number	75-2069407
Entity Address, Address Line One	2301 Highway 190 West
Entity Address, City or Town	DeRidder
Entity Address, State or Province	LA
Entity Address, Postal Zip Code	70634
City Area Code	337
Local Phone Number	463-9052
Entity Common Stock, Shares Outstanding		19,331,059
Entity Public Float			$ 1,170.9
Entity Incorporation, State or Country Code	TX
Title of 12(b) Security	Common
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	true
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the Registrant’s Proxy Statement relating to the 2021 Annual Meeting of Shareholders are incorporated by reference in Items 10, 11, 12, 13 and 14 of Part III of this report.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Investments:
Fixed maturity securities—held-to-maturity, at amortized cost net of allowance for credit losses of $274 and $0 in 2020 and 2019, respectively, (fair value $621,654 and $621,343 in 2020 and 2019, respectively)	$ 585,130	$ 599,421
Fixed maturity securities—available-for-sale, at fair value (amortized cost $387,665, allowance for credit losses of $0 in 2020 and amortized cost $425,698, allowance for credit losses of $0 in 2019)	414,279	441,146
Equity securities, at fair value (cost $35,787 and $24,457 in 2020 and 2019, respectively)	43,437	27,903
Short-term investments	45,898	56,548
Total investments	1,088,744	1,125,018
Cash and cash equivalents	61,757	43,813
Amounts recoverable from reinsurers (net of allowance for credit losses of $452 and $0 in 2020 and 2019, respectively)	105,803	95,913
Premiums receivable (net of allowance for credit losses of $4,791 and $5,112 in 2020 and 2019, respectively)	156,760	157,953
Deferred income taxes	13,665	17,513
Accrued interest receivable	9,274	9,730
Property and equipment, net	6,182	6,331
Deferred policy acquisition costs	17,810	19,048
Other assets	10,860	17,587
Total assets	1,470,855	1,492,906
Liabilities:
Reserves for loss and loss adjustment expenses	760,561	772,887
Unearned premiums	129,260	140,873
Amounts held for others	43,402	37,937
Policyholder deposits	41,524	44,718
Insurance-related assessments	17,995	22,967
Federal income tax payable	417	3,220
Accounts payable and other liabilities	38,880	40,089
Total liabilities	1,032,039	1,062,691
Shareholders’ equity:
Common stock: voting—$0.01 par value authorized shares—50,000,000 in 2020 and 2019; 20,589,309 and 20,560,833 shares issued and 19,331,059 and 19,302,583 shares outstanding in 2020 and 2019, respectively	206	205
Additional paid-in capital	215,316	213,004
Treasury stock, at cost (1,258,250 shares in 2020 and 2019)	(22,370)	(22,370)
Accumulated earnings	224,645	227,165
Accumulated other comprehensive income, net	21,019	12,211
Total shareholders’ equity	438,816	430,215
Total liabilities and shareholders’ equity	$ 1,470,855	$ 1,492,906

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Fixed maturity securities, held-to-maturity, allowance for credit losses	$ 274,000	$ 0
Fixed maturity securities, fair value	621,654,000	621,343,000
Fixed maturity securities, available-for-sale, allowance for credit losses	0	0
Fixed maturity securities, amortized cost	387,665,000	425,698,000
Amounts recoverable from reinsurers, allowance for credit losses	452,000	0
Premiums receivable, allowance for credit losses	4,791,000	5,112,000	$ 5,390,000
Equity securities, cost	$ 35,787,000	$ 24,457,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	20,589,309	20,560,833
Common stock, shares outstanding	19,331,059	19,302,583
Treasury stock, shares	1,258,250	1,258,250

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues
Net premiums earned	$ 304,427	$ 332,888	$ 350,326
Net investment income	29,364	32,483	30,452
Net realized gains (losses) on investments	1,132	(80)	(1,536)
Net unrealized gains (losses) on equity securities	4,204	4,758	(2,088)
Fee and other income	350	321	599
Total revenues	339,477	370,370	377,753
Expenses
Loss and loss adjustment expenses incurred	157,226	176,342	204,891
Underwriting and certain other operating costs	20,834	22,221	28,981
Commissions	23,147	25,010	26,160
Salaries and benefits	27,925	27,120	25,992
Policyholder dividends	3,453	4,160	4,148
Provision for investment related credit loss benefit	(27)
Total expenses	232,558	254,853	290,172
Income before income taxes	106,919	115,517	87,581
Income tax expense	20,317	22,827	15,949
Net income	$ 86,602	$ 92,690	$ 71,632
Earnings per share
Basic	$ 4.49	$ 4.82	$ 3.73
Diluted	$ 4.47	$ 4.80	$ 3.71
Shares used in computing earnings per share
Basic	19,288,996	19,248,657	19,208,978
Diluted	19,363,809	19,329,238	19,293,082
Extraordinary cash dividends declared per common share	$ 3.50	$ 3.50	$ 3.50
Cash dividends declared per common share	$ 1.08	$ 1	$ 0.88

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 28,501	$ 23,353	$ 23,948	$ 10,800	$ 34,014	$ 21,386	$ 17,890	$ 19,400	$ 86,602	$ 92,690	$ 71,632
Other comprehensive income:
Unrealized gain (loss) on debt securities, net of tax									8,808	13,043	(4,243)
Comprehensive income	$ 29,608	$ 24,087	$ 29,431	$ 12,284	$ 33,610	$ 23,862	$ 23,068	$ 25,193	$ 95,410	$ 105,733	$ 67,389

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2017	$ 425,423	$ 204	$ 210,081	$ (22,370)	$ 233,896	$ 3,612
Beginning Balance (ASU 2018-02 [Member]) at Dec. 31, 2017					(414)	414
Beginning Balance (ASU 2016-01 [Member]) at Dec. 31, 2017					615	(615)
Beginning Balance, Shares at Dec. 31, 2017		20,504,165
Treasury Stock Beginning Balance, Shares at Dec. 31, 2017				(1,258,250)
Comprehensive income:
Net income	71,632				71,632
Other comprehensive income:
Change in unrealized gains loss, net of tax	(4,243)					(4,243)
Comprehensive income	67,389
Common stock issued upon exercise of options	67		67
Common stock issued upon exercise of options, Shares		15,000
Common stock issued	196	$ 1	195
Common stock issued, Shares		9,065
Share-based compensation	1,088		1,088
Dividends to shareholders	(84,401)				(84,401)
Ending Balance at Dec. 31, 2018	409,762	$ 205	211,431	$ (22,370)	221,328	(832)
Ending Balance (ASU 2016-02 [Member]) at Dec. 31, 2018	(1)				(1)
Ending Balance, Shares at Dec. 31, 2018		20,528,230
Treasury Stock Ending Balance, Shares at Dec. 31, 2018				(1,258,250)
Comprehensive income:
Net income	92,690				92,690
Other comprehensive income:
Change in unrealized gains loss, net of tax	13,043					13,043
Comprehensive income	105,733
Common stock issued upon exercise of options	20		20
Common stock issued upon exercise of options, Shares		5,000
Common stock issued	560		560
Common stock issued, Shares		27,603
Share-based compensation	993		993
Dividends to shareholders	(86,852)				(86,852)
Ending Balance at Dec. 31, 2019	430,215	$ 205	213,004	$ (22,370)	227,165	12,211
Ending Balance (ASU 2016-13 [Member]) at Dec. 31, 2019	$ (594)				(594)
Ending Balance, Shares at Dec. 31, 2019	19,302,583	20,560,833
Treasury Stock Ending Balance, Shares at Dec. 31, 2019	(1,258,250)			(1,258,250)
Comprehensive income:
Net income	$ 86,602				86,602
Other comprehensive income:
Change in unrealized gains loss, net of tax	8,808					8,808
Comprehensive income	95,410
Common stock issued	1,360	$ 1	1,359
Common stock issued, Shares		28,476
Share-based compensation	953		953
Dividends to shareholders	(88,528)				(88,528)
Ending Balance at Dec. 31, 2020	$ 438,816	$ 206	$ 215,316	$ (22,370)	$ 224,645	$ 21,019
Ending Balance, Shares at Dec. 31, 2020	19,331,059	20,589,309
Treasury Stock Ending Balance, Shares at Dec. 31, 2020	(1,258,250)			(1,258,250)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net income	$ 86,602	$ 92,690	$ 71,632
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	1,012	942	996
Net amortization of investments	8,177	8,659	10,787
Change in investment related allowance for credit losses	(27)
Deferred income taxes	1,657	872	(1,462)
Net realized (gains) losses on investments	(1,132)	80	1,536
Net unrealized (gains) losses on equity securities	(4,204)	(4,758)	2,088
Net realized losses on disposal of assets	58	3
Share-based compensation	3,296	2,351	2,065
Changes in operating assets and liabilities:
Premiums receivable, net	1,193	4,525	11,756
Accrued interest receivable	456	467	438
Deferred policy acquisition costs	1,238	686	517
Amounts held by others	7,856		(7,855)
Other assets	(1,230)	710	1,873
Reserves for loss and loss adjustment expenses	(12,326)	(25,522)	26,564
Unearned premiums	(11,613)	(8,423)	(7,974)
Reinsurance balances	(10,333)	16,093	(21,873)
Amounts held for others and policyholder deposits	2,271	(5,528)	2,911
Federal income taxes payable	(2,803)	(192)	5,173
Accounts payable and other liabilities	(6,750)	(4,831)	(904)
Net cash provided by operating activities	63,398	78,824	98,268
Investing activities
Purchases of investments held-to-maturity	(96,452)	(152,133)	(99,330)
Purchases of investments available-for-sale	(73,923)	(63,513)	(124,128)
Purchases of equity securities	(11,330)	(4,495)	(11,459)
Purchases of short-term investments	(139,242)	(125,763)	(133,355)
Proceeds from maturities of investments held-to-maturity	104,564	159,702	99,984
Proceeds from sales and maturities of investments available-for-sale	110,700	114,869	100,357
Proceeds from sales of equity securities			3
Proceeds from sales and maturities of short-term investments	149,975	84,039	139,865
Proceeds from redemptions of other investments			130
Purchases of property and equipment	(921)	(1,018)	(1,126)
Net cash provided by (used in) investing activities	43,371	11,688	(29,059)
Financing activities
Proceeds from stock option exercises		20	67
Finance lease purchases	(50)	(47)
Dividends to shareholders	(88,775)	(87,016)	(84,491)
Net cash used in financing activities	(88,825)	(87,043)	(84,424)
Change in cash and cash equivalents	17,944	3,469	(15,215)
Cash and cash equivalents at beginning of year	43,813	40,344	55,559
Cash and cash equivalents at end of year	61,757	43,813	40,344
Supplemental disclosure of cash flow information
Income taxes paid	$ 20,562	$ 20,850	$ 11,235

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. Summary of Significant Accounting Policies Organization AMERISAFE, Inc. is an insurance holding company incorporated in the state of Texas. The accompanying consolidated financial statements include the accounts of AMERISAFE and its subsidiaries: American Interstate Insurance Company (“AIIC”) and its insurance subsidiaries, Silver Oak Casualty, Inc. (“SOCI”) and American Interstate Insurance Company of Texas (“AIICTX”), Amerisafe Risk Services, Inc. (“RISK”) and Amerisafe General Agency, Inc. (“AGAI”). AIIC and SOCI are property and casualty insurance companies organized under the laws of the state of Nebraska. AIICTX is a property and casualty insurance company organized under the laws of the state of Texas. RISK, a wholly owned subsidiary of the Company, is a claims and safety service company currently servicing only affiliated insurance companies. AGAI, a wholly owned subsidiary of the Company, is a general agent for the Company. AGAI sells insurance, which is underwritten by AIIC, SOCI and AIICTX, as well as by nonaffiliated insurance carriers. The assets and operations of AGAI are not significant to that of the Company and its consolidated subsidiaries. The terms “AMERISAFE,” the “Company,” “we,” “us” or “our” refer to AMERISAFE, Inc. and its consolidated subsidiaries, as the context requires. The Company provides workers’ compensation insurance for small to mid-sized employers engaged in hazardous industries, principally construction, trucking, logging and lumber, manufacturing, agriculture, maritime, and oil and gas. Assets and revenues of AIIC and its subsidiaries represent at least 95% of comparable consolidated amounts of the Company for each of 2020, 2019 and 2018. Basis of Presentation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States, or GAAP. The preparation of financial statements in accordance with 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 financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Reclassifications Certain prior year amounts have been reclassified to conform with the current year presentation. Adopted Accounting Guidance In January 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. This guidance requires fair value measurement for equity investments (not including those that result in consolidation of the investee or use the equity method of accounting) and the recognition of changes in fair value to be presented as a component of net income. The guidance also revises the disclosure requirements related to fair value changes of liabilities presented in comprehensive income, eliminates disclosure related to the methods and assumptions underlying fair value for financial instruments measured at amortized cost, and simplifies impairment assessments for equity investments without readily determinable fair values. The adoption of this new guidance in the first quarter of 2018 resulted in an immaterial decrease in net income of $390 thousand or a $0.02 decrease to our diluted earnings per common share. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The new guidance requires a lessee to recognize a lease liability and a right of use asset for all leases extending beyond twelve months. This standard was effective for us beginning in the first quarter of 2019. We elected the new transition method under the transition guidance within the new standard. Therefore, prior comparative periods were not adjusted. We also elected the package of practical expedients, which among other things, allows us to carryforward the historical lease classification. We made an accounting policy election not to recognize lease assets and lease liabilities for short-term operating leases. Adoption of the new guidance resulted in the Company recognizing right-of-use assets of $0.4 million and lease liabilities of $0.3 million. The cumulative effect adjustment to the opening balance of retained earnings was minimal. Adoption of this new guidance did not have a material effect on the Company’s consolidated financial statements as the Company does not have any significant leases. O n January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses (“CECL”). The prior guidance delays the recognition of credit losses until a probable loss has occurred. The new guidance requires credit losses for securities measured at amortized cost to be determined using current expected credit loss estimates. These estimates are derived from historical, current and reasonable supporting forecasts, including prepayments and estimates, and are recorded through a valuation account. The same method is used for available-for-sale securities, but the valuation account is limited to the amount by which the fair value is below amortized cost. The Company implemented the new standard using the modified retrospective approach. Results for reporting periods beginning after January 1, 2020 are presented under the new guidance while prior period amounts continue to be reported in accordance with previously applicable GAAP. The Company recorded a net decrease to Retained Earnings of $594 thousand as of January 1, 2020, for the cumulative effect of adopting ASU 2016-13. The transition adjustment includes a $243 thousand impact to establish a credit loss allowance for held-to-maturity securities. The remaining $351 thousand of the transition adjustment was due to the creation of the reinsurance recoverable credit allowance. The Company believes that under the standard there is no current expected credit allowance necessary for U.S. Government Securities in its judgment as: 1) Treasury securities typically are the most highly rated securities among rating agencies; 2) Treasury securities have a long history of no credit losses; 3) Treasury securities are guaranteed by a sovereign entity (the U.S. Government) that can print its own money and whose currency (the U.S. dollar) is the reserve currency. The Company believes that under the standard there is no current expected credit allowance necessary for GNMA Securities in its judgment as: 1) GNMA securities typically are the most highly rated securities among rating agencies; 2) GNMA securities have a long history of no credit losses and payments are explicitly guaranteed by the United States; 3) Underlying mortgage loans for GNMA securities are insured by the Federal Housing Administration or guaranteed by the U.S. Department of Veteran Affairs; 4) the U.S. Government can print its own money to retire GNMA obligations. The Company believes that under the standard there is no current expected credit allowance necessary for FNMA or Freddie Mac (FHLMC) Securities in its judgment as: 1) These securities typically are among the most highly rated securities among rating agencies; 2) There is a long history of no credit losses; 3) Principal and interest payments are guaranteed by the issuing agency; 4) There is an explicit guarantee by the U.S. Government that can print its own money and whose currency (the U.S. dollar) is the reserve currency. The Company researched various options and methodologies and has chosen to use Moody’s default rates and recovery rates for our held-to-maturity fixed income securities based on the current credit rating of the security and the time period to the stated maturity date. This is a probability of default (PD) and loss given default (LGD) methodology. The credit rating used for held-to-maturity fixed income securities is the rating for each security as published by Moody’s, S&P, and Fitch to determine the probability of default. If there are two ratings, the lower rating is used. If there are three ratings, the median rating is used. If there is one rating, that rating is used. This methodology provides additional conservatism in determining the credit loss allowance needed. For corporate fixed income securities, the probability of default (given a rating) comes from Moody’s annual study of Corporate Bond defaults published each February. This study also contains the average recovery rates based on the historical defaults in the Moody’s study. We have chosen to use the 1983-2019 data as more reflective of the current historical pattern of defaults (the study goes back to 1920). The maximum maturity using the default rate is 20 years (any maturity greater than 20 years will use the 20-year rate). For municipal fixed income securities the probability of default (given a rating) comes from Moody’s annual study of Municipal Bond defaults published each July/August. This study also contains the average recovery rates based on the historical defaults in the Moody’s study. This study covers 1970-2019 data, which we believe is reflective of the current historical pattern of defaults. The maximum maturity using the default rate is 20 years (any maturity greater than 20 years will use the 20-year rate). The Company did not record a credit allowance for available-for-sale securities. The available-for-sale portfolio is composed of highly rated securities, which carry a low risk of default. The Company’s concentrations in municipal bonds have helped lower default risk, as the historical default rates and recovery rates for municipal bonds has been much better than corporate bonds rated at the same level. The Company creates a watch list of available-for-sale securities that are below book value at the end of each quarter. This watch list excludes US Treasury securities, GNMA Securities, and government agency securities (FNMA, etc.) as none of those securities will have an expected credit loss. The watch list will also exclude those securities that are trading at least at $95 or above (par value $ 100 ) as the Company believes any slight difference between $95 and par likely reflect interest rate changes and liquidity only and are not a sign of credit impairment or market expectations for any current expected credit loss. The list is reviewed by the Management Investment Committee to evaluate any security where the discounted cash flows expected no longer exceed the book value of the security. If the Company intends to sell the security (or more likely than not be required to sell the security before recovery of the loss) the Company will write down the security to fair value through earnings. If the Company intends to hold the security, the Company will establish a credit loss allowance for the security through earnings, and adjust the allowance each quarter through earnings, as the security changes in value. In determining the amount of the credit loss allowance, the Company will consider all of the following factors: 1. The extent to which the fair value is less than the amortized cost basis 2. Adverse conditions in the security, industry, or geography, including: a.) Changes in technology b.) Discontinuation of a segment of business that may affect future earnings c.) Changes in the quality of the credit enhancement, if any 3. Changes in the payment structure of the debt security 4. Failure of the issuer to make scheduled interest or principal payments 5. Any changes to the rating of the security by a rating agency The calculation of the credit loss allowance will not take into account the amount of time the security has been below book value or when the security might be expected to recover in value. The Company has researched various options and methodologies and has chosen to use Moody’s default rates and recovery rates for our unsecured reinsurance recoverables based on the current credit rating of the reinsurer and a time period of ten years. This is a probability of default (PD) and loss given default (LGD) methodology. The ten-year period is consistent with our current working layer reinsurance treaty where we have a three-year The credit rating used for reinsurance recoverables uses the average rating for each reinsurer as published by Moody’s, S&P, Fitch and A.M. Best to determine the probability of default. The median rating is used if there are three ratings. The probability of default (given a rating) comes from Moody’s annual study of Corporate Bond defaults published each February. This study also contains the average recovery rates based on the historical defaults in the Moody’s study. We have chosen to use the 1983-2019 data as more reflective of the current historical pattern of defaults (the study goes back to 1920). The Company does not hold any debt securities for which an other-than-temporary impairment has been recognized. Additionally, the Company does not hold any financial assets purchased with credit deterioration. The Company’s internal working group evaluated the existing allowance for doubtful accounts reserving methodology for premiums receivable and determined the calculation was consistent with the new credit loss guidance. There was no impact to the premiums receivable balance as a result of the adoption of the new standard. The Company has elected not to establish a credit allowance for investment interest receivable. The Company plans to continue use of the current policy for writing off investment related interest receivable balances over ninety days old. Prospective Accounting Guidance All other issued but not yet effective accounting and reporting standards as of December 31, 2020 are either not applicable to the Company or are not expected to have a material impact on the Company. Investments The Company has the ability and positive intent to hold certain investments until maturity. Therefore, fixed maturity securities classified as held-to-maturity are recorded at amortized cost net of the allowance for credit losses. Fixed maturity securities classified as available-for-sale are recorded at fair value. Temporary changes in the fair value of these securities are reported in shareholders’ equity as a component of other comprehensive income, net of deferred income taxes. Changes in the fair value of equity securities are recorded in net income. Investment income is recognized as it is earned. The discount or premium on fixed maturity securities is amortized using the “constant yield” method. Anticipated prepayments, where applicable, are considered when determining the amortization of premiums or discounts. Realized investment gains and losses are determined using the specific identification method. Cash and Cash Equivalents Cash equivalents include short-term money market funds with an original maturity of 90 days or less. Short-Term Investments Short-term investments include municipal securities and corporate bonds with an original maturity greater than 90 days but less than one year. Premiums Receivable Premiums receivable consist primarily of premium-related balances due from policyholders. The Company considers premiums receivable as past due based on the payment terms of the underlying policy. The balance is shown net of the allowance for credit losses. Receivables due from insureds are charged off when a determination has been made by management that a specific balance will not be collected. An estimate of amounts that are likely to be charged off is established as an allowance for credit losses as of the balance sheet date. The estimate is primarily comprised of specific balances that are considered probable to be charged off after all collection efforts have ceased, as well as historical trends and an analysis of the aging of the receivables. Property and Equipment The Company’s property and equipment, including certain costs incurred to develop or obtain software for internal use, are stated at cost less accumulated depreciation. Depreciation is calculated primarily by the straight-line method over the estimated useful lives of the respective assets, generally 39 years for buildings and three to seven years for all other fixed assets. Deferred Policy Acquisition Costs The direct costs of successfully acquiring and renewing business are capitalized to the extent recoverable and are amortized over the effective period of the related insurance policies in proportion to premium revenue earned. These capitalized costs consist mainly of sales commissions, premium taxes and other underwriting costs. The Company evaluates deferred policy acquisition costs for recoverability by comparing the unearned premiums to the estimated total expected claim costs and related expenses, offset by anticipated investment income. The Company would reduce the deferred costs if the unearned premiums were less than expected claims and expenses after considering investment income, and report any adjustments in amortization of deferred policy acquisition costs. There were no adjustments necessary in 2020, 2019 or 2018. Reserves for Loss and Loss Adjustment Expenses Reserves for loss and loss adjustment expenses represent the estimated ultimate cost of all reported and unreported losses incurred through December 31. The Company does not discount loss and loss adjustment expense reserves. In establishing our reserves for loss and loss adjustment expenses, we review the results of analyses using individual case-base valuations and statistical and actuarial methods that utilize historical loss data from our more than 35 years of underwriting workers’ compensation insurance. The actuarial analysis of our historical data provides the factors we use in estimating our loss reserves. These factors are primarily measures over time of the number of claims paid and reported, average paid and incurred claim amounts, claim closure rates and claim payment patterns. In evaluating the results of our analyses, management also uses substantial judgment in considering other factors that are not considered in these actuarial analyses, including changes in business mix, claims management, regulatory issues, medical trends, employment and wage patterns, insurance policy coverage interpretations, judicial determinations and other subjective factors. Due to the inherent uncertainty associated with these estimates, and the cost of incurred but unreported claims, our actual liabilities may vary significantly from our original estimates. Although considerable variability is inherent in these estimates, management believes that the reserves for loss and loss adjustment expenses are adequate. The estimates are continually reviewed and adjusted as necessary as experience develops or new information becomes known. Any such adjustments are included in income from current operations. Subrogation recoverables, as well as deductible recoverables from policyholders, are estimated using individual case-basis valuations and aggregate estimates. Deductibles that are recoverable from policyholders and other recoverables from state funds decrease the liability for loss and loss adjustment expenses. The Company funds its obligations under certain settled claims where the payment pattern and ultimate cost are fixed and determinable on an individual claim basis through the purchase of annuities. These annuities are purchased from unaffiliated carriers and name the claimant as payee. The cost of purchasing the annuity is recorded as paid loss and loss adjustment expenses. To the extent the annuity funds estimated future claims, reserves for loss and loss adjustment expense are reduced. Premium Revenue Premiums on workers’ compensation insurance are based on actual payroll costs or production during the policy term and are normally billed monthly in arrears or annually. However, the Company generally requires a deposit at the inception of a policy. Premium revenue is earned on a pro rata basis over periods covered by the policies. The reserve for unearned premiums on these policies is computed on a daily pro rata basis. The Company estimates the annual premiums to be paid by its policyholders when the Company issues the policies and records those amounts on the balance sheet as premiums receivable. The Company conducts premium audits on all of its voluntary business policyholders annually, upon the expiration of each policy, including when the policy is renewed. The purpose of these audits is to verify that policyholders have accurately reported their payroll expenses and employee job classifications, and therefore have paid the Company the premium required under the terms of the policies. The difference between the estimated premium and the ultimate premium is referred to as “earned but unbilled” premium, or EBUB premium. EBUB premium can be higher or lower than the estimated premium. EBUB premium is subject to significant variability and can either increase or decrease earned premium based upon several factors, including changes in premium growth, industry mix and economic conditions. Due to the timing of audits and other adjustments, ultimate premium earned is generally not determined for several months after the expiration of the policy. The Company estimates EBUB premiums on a quarterly basis using historical data and applying various assumptions based on the current market and economic conditions, and records an adjustment to premium, related losses, and expenses as warranted. Reinsurance Reinsurance premiums, losses and allocated loss adjustment expenses are accounted for on a basis consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Amounts recoverable from reinsurers include balances currently owed to the Company for losses and allocated loss adjustment expenses that have been paid to policyholders, amounts that are currently reserved for and will be recoverable once the related expense has been paid and experience-rated commissions recoverable upon commutation. Upon management’s determination that an amount due from a reinsurer is uncollectible due to the reinsurer’s insolvency or other matters, the amount is written off. Ceding commissions are earned from certain reinsurance companies and are intended to reimburse the Company for policy acquisition costs related to those premiums ceded to the reinsurers. Ceding commission income is recognized over the effective period of the related insurance policies in proportion to premium revenue earned and is reflected as a reduction in underwriting and certain other operating costs. Experience-rated commissions are earned from certain reinsurance companies based on the financial results of the applicable risks ceded to the reinsurers. These commission revenues on reinsurance contracts are recognized during the related reinsurance treaty period and are based on the same assumptions used for recording loss and allocated loss adjustment expenses. These commissions are reflected as a reduction in underwriting and certain other operating costs and are adjusted as necessary as experience develops or new information becomes known. Any such adjustments are included in income from current operations. Experience-rated commissions had no impact on underwriting and certain other operating costs in 2020 and 2019 and increased underwriting and certain other operating costs by $0.2 million in 2018. In December 2019, the Company commuted reinsurance agreements with Hannover Reinsurance (Ireland) Limited (“Hannover”) covering portions of accident years 2009 through 2011. The Company received an $8.5 million payment effectuated solely through offset against the balance of the funds withheld and recoverable from reinsurers accounts under the reinsurance agreements in exchange for releasing Hannover from their reinsurance obligations under the commuted agreements. Hannover remains obligated to the subsidiaries of the Company under other reinsurance agreements. There was no effect on the Company’s net income in the year ended December 31, 2019 as a result of the commutation. Fee and Other Income The Company recognizes income related to commissions earned by AGAI as the related services are performed. Advertising All advertising expenditures incurred by the Company are charged to expense in the period to which they relate and are included in underwriting and certain other operating costs in the consolidated statements of income. Total advertising expenses incurred were $0.2 million in 2020, $0.4 million in 2019, and $0.5 million in 2018. Income Taxes The Company accounts for income taxes using the liability method. The provision for income taxes has two components, amounts currently payable or receivable and deferred amounts. Deferred income tax assets and liabilities are recognized for the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred income tax assets and liabilities are measured using tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. The Company considers deferred tax assets to be recoverable if it is probable that the related tax losses can be offset by future taxable income. The Company includes reversal of existing temporary differences, tax planning strategies available and future operating income in this assessment. To the extent the deferred tax assets exceed the amount expected to be recovered in future years, the Company records a valuation allowance for the amount determined unrecoverable. Insurance-Related Assessments Insurance-related assessments are accrued in the period in which they have been incurred. The Company is subject to a variety of assessments related to insurance commerce, including those by state guaranty funds and workers’ compensation second-injury funds. State guaranty fund assessments are used by state insurance oversight agencies to cover losses of policyholders of insolvent or rehabilitated insurance companies and for the operating expenses of such agencies. Assessments based on premiums are generally paid one year after the calendar year in which the premium is written, while assessments based on losses are generally paid within one year of the calendar year in which the loss is paid. Policyholder Dividends The Company writes certain policies for which the policyholder may participate in favorable claims experience through a dividend. An estimated provision for workers’ compensation policyholders’ dividends is accrued as the related premiums are earned. Dividends do not become a fixed liability unless and until declared by the respective Boards of Directors of AMERISAFE’s insurance subsidiaries. The dividend to which a policyholder may be entitled is set forth in the policy and is related to the amount of losses sustained under the policy. Dividends are calculated after the policy expiration. The Company is able to estimate the policyholder dividend liability because the Company has information regarding the underlying loss experience of the policies written with dividend provisions and can estimate future dividend payments from the policy terms. Earnings Per Share The Company computes earnings per share (“EPS”) in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 260, Earnings Per Share. Basic EPS is calculated by dividing income available to common shareholders by the weighted average number of common shares outstanding during the period. The diluted EPS calculation includes potential common shares assumed issued under the treasury stock method, which reflects the potential dilution that would occur if any outstanding options or warrants were exercised or restricted stock becomes vested. Share-Based Compensation The Company recognizes the impact of its share-based compensation in accordance with FASB ASC Topic 718, Compensation-Stock Compensation.

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments Debt And Equity Securities [Abstract]
Investments	2. Investments Short-term investments held at December 31, 2020 include $30.7 million of U.S. Treasury securities and obligations of U.S. government agencies, $9.1 million of obligations of states and political subdivisions and $6.1 million of corporate bonds. Short-term investments held at December 31, 2019 include $54.6 million of U.S. Treasury securities and obligations of U.S. government agencies and $1.9 million of obligations of states and political subdivisions. The gross unrecognized gains and losses on, and the amortized cost, allowance for credit losses, carrying amount, and fair value of, those investments classified as held-to-maturity at December 31, 2020 are summarized as follows: Amortized Cost Allowance for Credit Losses Carrying Amount Gross Unrecognized Gains Gross Unrecognized Losses Fair Value (in thousands) States and political subdivisions $ 494,374 $ (42 ) $ 494,332 $ 32,489 $ — $ 526,821 Corporate bonds 69,981 (225 ) 69,756 3,144 — 72,900 U.S. agency-based mortgage-backed securities 7,261 — 7,261 645 — 7,906 U.S. Treasury securities and obligations of U.S. government agencies 13,626 — 13,626 239 — 13,865 Asset-backed securities 162 (7 ) 155 7 — 162 Totals $ 585,404 $ (274 ) $ 585,130 $ 36,524 $ — $ 621,654 The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as available-for-sale at December 31, 2020 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Allowance for Credit Losses (in thousands) States and political subdivisions $ 256,492 $ 20,050 $ — $ 276,542 $ — Corporate bonds 83,646 5,256 (3 ) 88,899 — U.S. agency-based mortgage-backed securities 18,654 400 (2 ) 19,052 — U.S. Treasury securities and obligations of U.S. government agencies 28,873 913 — 29,786 — Totals $ 387,665 $ 26,619 $ (5 ) $ 414,279 $ — The gross unrealized gains and losses on, and the cost of equity securities at December 31, 2020 are summarized as follows: Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Equity securities: Domestic common stock $ 35,787 $ 7,650 $ — $ 43,437 Total equity securities $ 35,787 $ 7,650 $ — $ 43,437 The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at December 31, 2019 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) States and political subdivisions $ 466,270 $ 19,570 $ (193 ) $ 485,647 Corporate bonds 109,241 1,684 — 110,925 U.S. agency-based mortgage-backed securities 10,967 544 — 11,511 U.S. Treasury securities and obligations of U.S. government agencies 12,723 330 (12 ) 13,041 Asset-backed securities 220 — (1 ) 219 Totals $ 599,421 $ 22,128 $ (206 ) $ 621,343 The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as available-for-sale at December 31, 2019 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) States and political subdivisions $ 225,895 $ 11,906 $ (26 ) $ 237,775 Corporate bonds 130,453 3,326 (1 ) 133,778 U.S. agency-based mortgage-backed securities 29,499 64 (96 ) 29,467 U.S. Treasury securities and obligations of U.S. government agencies 39,851 317 (42 ) 40,126 Totals $ 425,698 $ 15,613 $ (165 ) $ 441,146 The gross unrealized gains and losses on, and the cost of equity securities at December 31, 2019 are summarized as follows: Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Equity securities: Domestic common stock $ 24,457 $ 3,446 $ — $ 27,903 Total equity securities $ 24,457 $ 3,446 $ — $ 27,903 A summary of the carrying amounts and fair value of investments in fixed maturity securities classified as held-to-maturity by contractual maturity is as follows: December 31, 2020 December 31, 2019 Carrying Amount Fair Value Carrying Amount Fair Value (in thousands) Maturity: Within one year $ 54,316 $ 54,794 $ 49,967 $ 50,348 After one year through five years 195,706 204,289 198,025 202,109 After five years through ten years 107,347 113,643 110,460 113,877 After ten years 220,345 240,860 229,782 243,279 U.S. agency-based mortgage-backed securities 7,261 7,906 10,967 11,511 Asset-backed securities 155 162 220 219 Totals $ 585,130 $ 621,654 $ 599,421 $ 621,343 A summary of the amortized cost and fair value of investments in fixed maturity securities classified as available-for-sale by contractual maturity is as follows: December 31, 2020 December 31, 2019 Amortized Cost Fair Value Amortized Cost Fair Value (in thousands) Maturity: Within one year $ 69,177 $ 69,938 $ 27,160 $ 27,194 After one year through five years 80,593 85,829 144,142 146,469 After five years through ten years 53,835 57,829 47,175 49,419 After ten years 165,406 181,631 177,722 188,597 U.S. agency-based mortgage-backed securities 18,654 19,052 29,499 29,467 Totals $ 387,665 $ 414,279 $ 425,698 $ 441,146 Actual maturities may differ from contractual maturities because certain borrowers have the right to call or prepay certain obligations with or without call or prepayment penalties. At December 31, 2020, there were $19.9 million of held-to-maturity investments on deposit with regulatory agencies of states in which the Company does business. A summary of the Company’s realized gains and losses on sales, calls or redemptions of investments for 2020 , 2019 and 2018 is as follows: Fixed Maturity Securities Available-for-Sale Equity Securities Other Total (in thousands) Year ended December 31, 2020 Proceeds from sales $ 25,436 $ — $ 46,959 $ 72,395 Gross realized investment gains $ 711 $ — $ 306 $ 1,017 Gross realized investment losses (14 ) — (4 ) (18 ) Net realized investment gains 697 — 302 999 Other, including gains (losses) on calls and redemptions (43 ) — 176 133 Net realized gains on investments $ 654 $ — $ 478 $ 1,132 Year ended December 31, 2019 Proceeds from sales $ 33,113 $ — $ 21,977 $ 55,090 Gross realized investment gains $ 140 $ — $ 36 $ 176 Gross realized investment losses (68 ) — — (68 ) Net realized investment gains 72 — 36 108 Other, including gains (losses) on calls and redemptions (196 ) — 8 (188 ) Net realized gains (losses) on investments $ (124 ) $ — $ 44 $ (80 ) Year ended December 31, 2018 Proceeds from sales $ 15,025 $ 3 $ — $ 15,028 Gross realized investment gains $ 238 $ 1 $ — $ 239 Gross realized investment losses (1,354 ) — — (1,354 ) Net realized investment gains (losses) (1,116 ) 1 — (1,115 ) Other, including losses on calls and redemptions (144 ) — (277 ) (421 ) Net realized gains (losses) on investments $ (1,260 ) $ 1 $ (277 ) $ (1,536 ) Major categories of the Company’s net investment income are summarized as follows: Year Ended December 31, 2020 2019 2018 (in thousands) Gross investment income: Fixed maturity securities $ 28,414 $ 30,343 $ 28,762 Equity securities 1,006 628 448 Short-term investments and cash and cash equivalents 897 2,478 2,208 Total gross investment income 30,317 33,449 31,418 Investment expenses (953 ) (966 ) (966 ) Net investment income $ 29,364 $ 32,483 $ 30,452 The following table summarizes the fair value and gross unrealized losses on fixed maturity securities, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position: Less Than 12 Months 12 Months or Greater Total Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses (in thousands) December 31, 2020 Available-for-Sale Corporate bonds $ 2,515 $ 3 $ — $ — $ 2,515 $ 3 U.S. agency-based mortgage-backed securities 2,133 2 — — 2,133 2 Total available-for-sale securities $ 4,648 $ 5 $ — $ — $ 4,648 $ 5 December 31, 2019 Held-to-Maturity States and political subdivisions $ 21,074 $ 193 $ — $ — $ 21,074 $ 193 U.S. Treasury securities and obligations of U.S. government agencies — — 3,243 12 3,243 12 Asset-backed securities — — 68 1 68 1 Total held-to-maturity securities 21,074 193 3,311 13 24,385 206 Available-for-Sale States and political subdivisions $ 4,140 $ 26 $ — $ — $ 4,140 $ 26 Corporate bonds 6,426 1 — — 6,426 1 U.S. agency-based mortgage-backed securities 13,007 95 1,152 1 14,159 96 U.S. Treasury securities and obligations of U.S. government agencies — — 17,068 42 17,068 42 Total available-for-sale securities 23,573 122 18,220 43 41,793 165 Total $ 44,647 $ 315 $ 21,531 $ 56 $ 66,178 $ 371 At December 31, 2020, the Company held 2 individual fixed maturity securities that were in an unrealized loss position, of which none were in a continuous unrealized loss position for longer than 12 months. The following table illustrates the changes in the allowance for credit losses by major security type of the investments classified as held-to-maturity for the year ended December 31, 2020. States and Political Subdivisions Corporate Bonds U.S. Agency-Based Mortgage-Backed Securities U.S. Treasury Securities and Obligations of U.S. Government Agencies Asset-Backed Securities Totals (in thousands) Balance at January 1, 2020 $ 45 $ 245 $ — $ — $ 11 $ 301 Provision for credit loss benefit (3 ) (20 ) — — (4 ) (27 ) Balance at December 31, 2020 $ 42 $ 225 $ — $ — $ 7 $ 274 The Company has established an allowance for credit losses on 424 held-to-maturity securities totaling $0.3 million as of December 31, 2020. The majority of those securities were states and political subdivisions and corporate bonds at 393 and 28, respectively. The Company has no allowance for credit losses on investments classified as available-for-sale as of December 31, 2020. During 2019, the Company had no impairment losses recognized for other-than-temporary declines in the fair value of our investments. The credit rating used for held-to-maturity fixed income securities is the rating for each security as published by Moody’s, S&P, and Fitch to determine the probability of default. If there are two ratings, the lower rating is used. If there are three ratings, the median rating is used. If there is one rating, that rating is used. For corporate fixed income securities the probability of default (given a rating) comes from Moody’s annual study of corporate bond defaults published each February. The maximum maturity using the default rate is 20 years (any maturity greater than 20 years will use the 20-year rate). For municipal fixed income securities the probability of default (given a rating) comes from Moody’s annual study of municipal bond defaults published each July/August. The calculation of the credit loss allowance takes the amortized cost of the fixed income security and assumes default and recovery based on the average recovery rates from the Moody’s default studies. The amortized cost of the security, minus the amount recovered, is the estimated full amount the Company could lose in a default scenario. Then this amount is multiplied by the probability of default to determine the allowance for credit loss. The lower the security is rated, the higher likelihood of default, and therefore a higher allowance for credit loss. The longer to the maturity date of a security, the higher the default risk. The table below presents the amortized cost of held-to-maturity securities aggregated by credit quality indicator as of December 31, 2020. States and Political Subdivisions Corporate Bonds U.S. Agency-Based Mortgage-Backed Securities U.S. Treasury Securities and Obligations of U.S. Government Agencies Asset-Backed Securities Totals Amortized cost (in thousands) AAA/AA/A ratings $ 490,311 $ 29,890 $ 7,261 $ 13,626 $ 111 $ 541,199 Baa/BBB ratings 4,063 40,091 — — 18 44,172 B ratings — — — — 33 33 Total $ 494,374 $ 69,981 $ 7,261 $ 13,626 $ 162 $ 585,404

Premiums Receivable

Premiums Receivable	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Premiums Receivable	3. Premiums Receivable Premiums receivable consist primarily of premium-related balances due from policyholders. The balance is shown net of the allowance for credit losses. The components of premiums receivable are shown below: December 31, 2020 2019 (in thousands) Premiums receivable $ 161,551 $ 163,065 Allowance for credit losses (4,791 ) (5,112 ) Premiums receivable, net $ 156,760 $ 157,953 The following summarizes the activity in the allowance for credit losses: December 31, 2020 2019 (in thousands) Balance, beginning of year $ 5,112 $ 5,390 Provision for credit loss expense 1,278 723 Write-offs (1,599 ) (1,001 ) Balance, end of year $ 4,791 $ 5,112 Included in premiums receivable at December 31, 2020, 2019 and 2018 is the Company’s estimate for EBUB premium of $6.3 million, $8.5 million and $7.5 million, respectively.

Deferred Policy Acquisition Cos

Deferred Policy Acquisition Costs	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Deferred Policy Acquisition Costs	4. Deferred Policy Acquisition Costs Deferred policy acquisition costs represent those costs that are incremental and directly related to the successful acquisition of new or the renewal of existing insurance policies. We defer incremental costs that result directly from, and are essential to, the acquisition or renewal of an insurance policy. We also defer a portion of employee total compensation costs directly related to time spent performing specific acquisition or renewal activities. These costs are deferred and expensed over the life of the related policies. Major categories of the Company’s deferred policy acquisition costs are summarized as follows: December 31, 2020 2019 (in thousands) Agents’ commissions $ 13,244 $ 14,290 Premium taxes 2,806 2,960 Deferred underwriting expenses 1,760 1,798 Total deferred policy acquisition costs $ 17,810 $ 19,048 The following summarizes the activity in the deferred policy acquisition costs: Year Ended December 31, 2020 2019 2018 (in thousands) Balance, beginning of year $ 19,048 $ 19,734 $ 20,251 Policy acquisition costs deferred 40,345 43,872 45,252 Amortization expense during the year (41,583 ) (44,558 ) (45,769 ) Balance, end of year $ 17,810 $ 19,048 $ 19,734

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Property and Equipment	5. Property and Equipment Property and equipment consist of the following: December 31, 2020 2019 (in thousands) Land and office building $ 7,919 $ 7,819 Furniture and equipment 5,438 6,097 Software 7,916 7,366 Automobiles 74 74 Finance lease right-of-use assets 365 185 Total original cost 21,712 21,541 Accumulated depreciation and amortization (15,530 ) (15,210 ) Property and equipment, net $ 6,182 $ 6,331 Accumulated depreciation and amortization includes $0.2 million that is related to equipment held under finance leases at December 31, 2020 and 2019 and is included in the underwriting and certain other operating costs line item on the income statement. The lease liabilities related to these properties are included in accounts payable and other liabilities.

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Reinsurance	6. Reinsurance The Company cedes certain premiums and losses to various reinsurers under excess-of-loss treaties. These reinsurance arrangements provide for greater diversification of business, allow management to control exposure to potential losses arising from large risks, and provide additional capacity for growth. Ceded reinsurance contracts do not relieve the Company from its obligations to policyholders. The Company remains liable to its policyholders for the portion reinsured to the extent that any reinsurer does not meet the obligations assumed under the reinsurance agreements. To minimize its exposure to significant losses from reinsurer insolvencies, the Company evaluates the financial condition of its reinsurers and monitors concentrations of credit risk arising from similar geographic regions, activities, or economic characteristics of the reinsurers on a continual basis. The effect of reinsurance on premiums written and earned in 2020, 2019 and 2018 was as follows: 2020 Premiums 2019 Premiums 2018 Premiums Written Earned Written Earned Written Earned (in thousands) Gross $ 303,090 $ 314,703 $ 333,460 $ 341,883 $ 351,696 $ 359,670 Ceded (10,276 ) (10,276 ) (8,995 ) (8,995 ) (9,344 ) (9,344 ) Net premiums $ 292,814 $ 304,427 $ 324,465 $ 332,888 $ 342,352 $ 350,326 The amounts recoverable from reinsurers consist of the following: December 31, 2020 2019 (in thousands) Unpaid losses recoverable: Case basis $ 88,622 $ 82,252 Incurred but not reported 17,085 13,090 Paid losses recoverable 548 571 Allowance for credit losses (452 ) — Total $ 105,803 $ 95,913 Amounts recoverable from reinsurers consists of ceded case reserves, ceded incurred but not reported (“IBNR”) reserves, and paid losses recoverable. Ceded case and ceded IBNR reserves represent the portion of gross loss and loss adjustment expense liabilities that are recoverable under reinsurance agreements, but are not yet due from reinsurers. Paid losses recoverable are receivables currently due from reinsurers for ceded paid losses. The Company considers paid losses recoverable outstanding for more than 90 days to be past due. At December 31, 2020, paid losses recoverable past due were immaterial. The Company received reinsurance recoveries of $ 4.4 million in 2020 , $ 2.0 million in 2019 and $ 1.3 million in 2018 . The Company generally secures large reinsurance recoverable balances with various forms of collateral, including funds withheld accounts, irrevocable letters of credit and secured trusts. At December 31, 2020, reinsurance recoverables from reinsurers that exceeded 1.5% of statutory surplus of the Company’s insurance subsidiaries are shown below. Reinsurer A.M. Best Rating Amounts Recoverable as of December 31, 2020 (in thousands) Hannover Reinsurance (Ireland) Limited (1) A+ $ 56,753 Allianz Risk Transfer AG (Bermuda) A+ 12,050 Odyssey America Reinsurance Corporation A 8,688 Minnesota Workers' Compensation Reinsurance Association (1) NR 6,367 Other reinsurers 22,397 Total amounts recoverable from reinsurers 106,255 Allowance for credit losses (452 ) Total amounts recoverable from reinsurers net of allowance for credit losses 105,803 Funds withheld and letters of credit related to the above recoverables (71,986 ) Total unsecured amounts recoverable from reinsurers $ 33,817 (1) Current participant in our 2021 reinsurance program. The table below presents the change in the allowance for credit losses on amounts recoverable from reinsurers for the year ended December 31, 2020. Year Ended December 31, 2020 (in thousands) Balance, beginning of period $ 444 Provision for credit loss benefit 8 Balance, end of period $ 452

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	7. Income Taxes The Company’s deferred income tax assets and liabilities are as follows: December 31, 2020 2019 (in thousands) Deferred income tax assets: Discounting of net unpaid loss and loss adjustment expenses $ 19,297 $ 19,985 Unearned premiums 6,984 7,638 Accrued expenses and other 2,947 2,612 State income tax 2,212 2,484 Accrued policyholder dividends 2,020 2,330 Capital loss carryforward — 20 Accrued insurance-related assessments 1,963 2,672 Total deferred tax assets 35,423 37,741 Less: Valuation allowance (2,169 ) (2,025 ) Net deferred tax assets 33,254 35,716 Deferred income tax liabilities: Deferred policy acquisition costs (4,547 ) (4,838 ) Callable bond amortization — (2 ) Unrealized gain on securities available-for-sale (7,194 ) (3,970 ) Property and equipment and other (260 ) (271 ) Salvage and subrogation (516 ) (636 ) Loss reserves adjustment due to the Tax Act (7,072 ) (8,486 ) Total deferred income tax liabilities (19,589 ) (18,203 ) Net deferred income taxes $ 13,665 $ 17,513 The components of consolidated income tax expense (benefit) are as follows: Year Ended December 31, 2020 2019 2018 (in thousands) Current: Federal $ 17,760 $ 20,658 $ 16,407 State 900 1,297 1,004 18,660 21,955 17,411 Deferred: Federal 1,403 732 (1,389 ) State 254 140 (73 ) 1,657 872 (1,462 ) Total $ 20,317 $ 22,827 $ 15,949 As of December 31, 2020 and 2019, the Company had a valuation allowance against its deferred income tax benefits of $2.2 and $2.0 million, respectively. During 2018, there was no valuation allowance on the Company’s deferred income tax assets and liabilities. Income tax expense from operations is different from the amount computed by applying the U.S. federal income tax statutory rate of 21% to income before income taxes as follows: Year Ended December 31, 2020 2019 2018 (in thousands) Income tax computed at federal statutory tax rate $ 22,453 $ 24,258 $ 18,392 Tax-exempt interest, net (3,226 ) (2,999 ) (2,965 ) State income tax 1,080 1,178 720 Dividends received deduction (89 ) (59 ) (44 ) Other 99 449 (154 ) $ 20,317 $ 22,827 $ 15,949 In December 2018, the IRS released its guidance for determining the Tax Act transition adjustment related to the discounting of loss reserves. During the period ended December 31, 2018, the Company recorded an increase in its deferred tax assets and a corresponding increase in its deferred tax liabilities as a result of the transition adjustment, which had no impact on tax expense recognized in 2018. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was enacted in response to the COVID-19 pandemic. The bill intended to bolster the U.S. economy, among other things, and provide emergency assistance to qualifying businesses and individuals. The Company was able to take advantage of a provision in the Act delaying payment of certain payroll taxes until 2021 and 2022. The CARES Act had no material impact on the Company’s financial statements. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. There were no uncertain tax positions as of December 31, 2020, 2019 and 2018. Tax years 2017 through 2020 are subject to examination by the federal and state taxing authorities.

Line of Credit

Line of Credit	12 Months Ended
	Dec. 31, 2020
Text Block [Abstract]
Line of Credit	8. Line of Credit The Company has an agreement providing for a line of credit in the maximum amount of $20.0 million with Frost Bank. The agreement expires in December 2022

Loss and Loss Adjustment Expens

Loss and Loss Adjustment Expenses	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Loss and Loss Adjustment Expenses	9. Loss and Loss Adjustment Expenses The following development tables provide the incurred and paid losses and allocated loss adjustment expenses, net of reinsurance, for workers’ compensation and general liability for accident years 2011 through 2020. The incurred but not reported (“IBNR”) losses and claims frequency is included for each accident year presented. Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance As of For the Years Ended December 31, December 31, 2020 (Dollars in thousands) Total IBNR Plus Expected Cumulative Development Number of Accident Unaudited (1) on Reported Claims Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Claims Reported 2011 $ 196,384 $ 199,522 $ 199,163 $ 198,213 $ 195,262 $ 192,988 $ 191,126 $ 189,327 $ 188,226 $ 188,264 $ 5,198 6,044 2012 — 222,549 222,075 212,738 193,515 184,460 182,859 180,387 178,586 177,547 6,419 5,749 2013 — — 241,810 241,811 233,656 220,457 214,701 210,588 209,184 207,304 7,762 5,766 2014 — — — 268,846 268,846 249,097 235,058 226,933 218,386 212,417 5,468 5,839 2015 — — — — 262,573 262,573 252,514 235,471 220,965 211,758 6,717 5,516 2016 — — — — — 250,491 250,491 241,406 218,005 209,214 6,843 5,393 2017 — — — — — — 244,094 244,098 234,587 220,096 8,066 5,211 2018 — — — — — — — 250,487 250,487 235,641 16,057 5,467 2019 — — — — — — — — 241,344 241,344 16,609 5,199 2020 — — — — — — — — — 220,710 8,491 4,170 Total $ 2,124,295 $ 87,630 Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, (Dollars in thousands) Accident Unaudited (1) Claim Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Frequency (2) 2011 $ 53,329 $ 111,029 $ 140,831 $ 153,968 $ 161,639 $ 165,967 $ 167,757 $ 169,994 $ 170,785 $ 171,583 22.82 2012 — 50,579 107,467 133,658 149,161 154,553 157,207 159,807 161,014 162,588 18.73 2013 — — 51,396 119,507 150,304 165,994 172,479 177,724 180,614 182,465 16.55 2014 — — — 53,060 119,820 153,320 169,736 180,683 186,129 191,394 14.99 2015 — — — — 54,141 121,599 151,818 170,461 182,053 185,657 14.25 2016 — — — — — 52,238 115,713 143,016 156,861 166,887 14.23 2017 — — — — — — 56,951 122,552 151,427 166,448 14.68 2018 — — — — — — — 62,061 126,057 152,328 15.20 2019 — — — — — — — — 58,883 120,512 15.21 2020 — — — — — — — — — 50,113 13.25 Total 1,549,975 All outstanding liabilities before 2011, net of reinsurance 80,533 Liabilities for loss and loss adjustment expenses, net of reinsurance 654,854 (1) Data presented for these calendar years is required supplementary information, which is unaudited. (2) Frequency, as calculated above, refers to reported claims divided by gross premium earned. The average annual percentage payout of incurred losses by age, net of reinsurance, for workers’ compensation and general liability as of December 31, 2020 is summarized below. Since workers’ compensation has long payout periods, the table below shows less than 100% in the years disclosed. This is required supplementary information, which is unaudited. Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance (Unaudited) Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10 25.6% 30.2% 14.1% 7.6% 4.3% 2.1% 1.6% 0.9% 0.7% 0.4% The following table provides a reconciliation of the beginning and ending reserve balances, net of related amounts recoverable from reinsurers, for 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 (in thousands) Balance, beginning of period $ 772,887 $ 798,409 $ 771,845 Less amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses 95,343 107,216 84,889 Net balance, beginning of period 677,544 691,193 686,956 Add incurred related to: Current accident year 220,710 241,344 250,487 Prior accident years (63,484 ) (65,002 ) (45,596 ) Total incurred 157,226 176,342 204,891 Less paid related to: Current accident year 50,113 58,883 62,061 Prior accident years 129,803 131,108 138,593 Total paid 179,916 189,991 200,654 Net balance, end of period 654,854 677,544 691,193 Add amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses 105,707 95,343 107,216 Balance, end of period $ 760,561 $ 772,887 $ 798,409 The final resolution of the estimated loss reserve liability may be different from that anticipated at the reporting date because of the inherent uncertainty in loss reserve estimates, including, but not limited to, the future settlement environment. Consequently, actual paid losses in the future may result in a significantly different amount than currently reserved, favorable or unfavorable. The difference between currently estimated losses and losses estimated for a prior period at a prior valuation date is known as development. Development is unfavorable when the losses ultimately settle for more than they were reserved for or future estimates suggest that reserves should be increased on unresolved claims. Development is favorable when the losses ultimately settle for less than they were reserved for or future estimates suggest that reserves should be decreased on unresolved claims. Favorable or unfavorable development of loss reserves are reflected in our results of operations in the period the estimates are changed. The foregoing reconciliation reflects favorable development of the net reserves at December 31, 2020, 2019 and 2018. The favorable development reduced loss and loss adjustment expenses incurred by $63.5 million in 2020, driven primarily by accident years 2018 and 2017 of $14.8 million and $14.5 million, respectively. In 2019 and 2018, the Company recorded favorable development of $65.0 million and $45.6 million, respectively. The revisions to the Company’s reserves reflect new information gained by claims adjusters in the normal course of adjusting claims and is reflected in the financial statements when the information becomes available. It is typical for more serious claims to take several years or longer to settle and the Company continually revises estimates as more information about claimants’ medical conditions and potential disability becomes known and the claims get closer to being settled. Multiple factors can cause loss development both unfavorable and favorable. The favorable loss development we experienced across accident years was largely due to favorable case reserve development and continued favorable severity trends compared to those originally estimated. Reserves established for workers’ compensation insurance includes the exposure to occupational disease or accidents related to asbestos or environmental claims. The exposure to asbestos claims emanate from the direct sale of workers’ compensation insurance. These claims resulted from industry workers who were exposed to tremolite asbestos dust and electricians and carpenters who were exposed to products that contained asbestos. There has been no known exposure to asbestos claims arising from assumed business. The emergence of these claims is slow and highly unpredictable. The Company estimates full impact of the asbestos exposure by establishing full case basis reserves on all known losses. Reserves for losses incurred but not reported (IBNR) include a provision for development of reserves on reported losses. Reserves are established for loss adjustment expenses (LAE) associated with these case and IBNR loss reserves. The following table details our exposures to various asbestos related claims: Year Ended December 31, 2020 2019 2018 (in thousands) Reserves for loss and LAE at beginning of year $ 1,323 $ 1,555 $ 1,748 Incurred losses and LAE during the current year (936 ) (183 ) 108 Loss and LAE payments (69 ) (49 ) (301 ) Reserves for loss and LAE at end of year $ 318 $ 1,323 $ 1,555 The Company has historically written general liability coverages that are reported in other liability lines of business. These coverages may be associated with the property and casualty industry’s exposure to environmental claims. However, the Company has not been notified by any insured for which exposure exists due to these types of claims. Company management believes potential exposure to environmental claims to be remote. Therefore, the Company has no loss or loss adjustment expense reserves for such liabilities. The anticipated effect of inflation is implicitly considered when estimating liabilities for loss and loss adjustment expenses. In establishing our reserves for loss and loss adjustment expenses, we review the results of analyses using individual case-base valuations and statistical and actuarial methods that utilize historical loss data from our more than 35 years of underwriting workers’ compensation insurance. The actuarial analysis of our historical data provides some of the factors we use in estimating our loss reserves. These factors are primarily measures over time of the number of claims paid and reported, average paid and incurred claim amounts, claim closure rates and claim payment patterns. In evaluating the results of our analyses, management also uses substantial judgment in considering other factors that are not considered in these actuarial analyses, including changes in business mix, claims management, regulatory issues, medical trends, employment and wage patterns, insurance policy coverage interpretations, judicial determinations and other subjective factors. Due to the inherent uncertainty associated with these estimates, and the cost of incurred but unreported claims, our actual liabilities may vary significantly from our original estimates. These anticipated trends are monitored based on actual development and are modified if necessary.

Statutory Accounting and Regula

Statutory Accounting and Regulatory Requirements	12 Months Ended
	Dec. 31, 2018
Insurance [Abstract]
Statutory Accounting and Regulatory Requirements	10. Statutory Accounting and Regulatory Requirements The Company’s insurance subsidiaries file financial statements prepared in accordance with statutory accounting principles prescribed or permitted by the insurance regulatory authorities of the states in which the subsidiaries are domiciled. Statutory-basis shareholders’ capital and surplus at December 31, 2020, 2019 and 2018 of the directly owned insurance subsidiary, AIIC, and the combined statutory-basis net income and realized investment gains for all AMERISAFE’s insurance subsidiaries for the three years in the period ended December 31, 2020, were as follows: 2020 2019 2018 (in thousands) Capital and surplus $ 365,524 $ 359,952 $ 383,575 Net income 82,390 92,301 72,979 Net realized gains (losses) on investments 1,075 (80 ) (1,536 ) Property and casualty insurance companies are subject to certain risk-based capital requirements, or RBC requirements, specified by the National Association of Insurance Commissioners. Under these requirements, a target minimum amount of capital and surplus maintained by a property/casualty insurance company is determined based on the various risk factors related to it. At December 31, 2020, the capital and surplus of AIIC and its subsidiaries exceeded the minimum RBC requirements. Pursuant to regulatory requirements, AIIC cannot pay dividends to the Company in excess of the greater of 10% of statutory surplus, or statutory net income, excluding realized investment gains, for the preceding 12-month period, without the prior approval of the Nebraska Director of Insurance. However, for purposes of this dividend calculation, net income from the previous two calendar years may be carried forward to the extent that it has not already been paid out as dividends. AIIC paid $88.6 million in dividends to the Company in 2020, $115.9 million in 2019 and $65.4 million in 2018. Based upon the dividend limitation described above, AIIC could pay to the Company dividends of up to $83.4 million in 2021 without seeking regulatory approval.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Capital Stock	11. Capital Stock Common Stock The Company is authorized to issue 50,000,000 shares of common stock, par value $0.01 per share. At December 31, 2020, there were 20,589,309 shares of common stock issued and 19,331,059 shares outstanding. Preferred Stock The Company is authorized to issue 10,000,000 shares of preferred stock, par value $0.01 per share. At December 31, 2020, there were no shares of preferred stock outstanding.

Restricted Stock and Stock Opti

Restricted Stock and Stock Options	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Restricted Stock and Stock Options	12. Restricted Stock and Stock Options 2005 Incentive Plan The AMERISAFE 2005 Equity Incentive Plan (the “2005 Incentive Plan”) is administered by the Compensation Committee of the Board and was designed to provide incentive compensation to executive officers and other key management personnel. The 2005 Incentive Plan permitted awards in the form of incentive stock options, as defined in Section 422(b) of the Internal Revenue Code of 1986, non-qualified stock options, restricted shares of common stock and restricted stock units. In connection with the approval of the 2012 Equity and Incentive Compensation Plan by the Company’s shareholders, no further grants were made under the 2005 Incentive Plan. As of December 31, 2020, there are no outstanding options or restricted stock awards under the 2005 Incentive Plan. Stock options granted under the 2005 Incentive Plan were exercisable, subject to vesting requirements determined by the Compensation Committee, for periods of up to ten years from the date of grant. Stock options generally expire 90 days after the cessation of an optionee’s service as an employee. However, in the case of an optionee’s death or disability, the unexercised portion of a stock option remains exercisable for up to one year after the optionee’s death or disability. Stock options that were granted under the 2005 Incentive Plan are not transferable, except by will or the laws of descent and distribution. The Company used the Black-Scholes-Merton option pricing model to estimate the fair value of each option on the date of grant. The expected terms of options were developed by considering the Company’s historical attrition rate for those employees at the officer level, who were eligible to receive options. Further, the Company aggregated individual awards into homogenous groups based upon grant date. Expected volatility was estimated using daily historical volatility for six companies within the property and casualty insurance sector. The Company believes that historical volatility of this peer group was the best estimate of expected volatility of the market price of the Company’s common shares. The dividend yield was assumed to be zero as the Company did not pay cash dividends until 2013. The risk-free interest rate is the yield on the grant date of U.S. Treasury zero coupon securities with a maturity comparable to the expected term of the options. The following table summarizes information about the stock option activity under the 2005 Incentive Plan: Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Outstanding at January 1, 2018 20,000 5.21 2.1 Granted — — — Exercised (15,000 ) 4.46 0.9 Canceled, forfeited, or expired — — — Outstanding at December 31, 2018 5,000 3.95 1.9 Exercisable at December 31, 2018 5,000 3.95 1.9 Outstanding at January 1, 2019 5,000 3.95 1.9 Granted — — — Exercised (5,000 ) 3.95 0.9 Canceled, forfeited, or expired — — — Outstanding at December 31, 2019 — — — Exercisable at December 31, 2019 — — — Outstanding at January 1, 2020 — — — Granted — — — Exercised — — — Canceled, forfeited, or expired — — — Outstanding at December 31, 2020 — — — Exercisable at December 31, 2020 — — — 2020 2019 2018 (in thousands) Cash received from option exercises $ — $ 20 $ 67 Total intrinsic value of options exercised — 287 766 Aggregate intrinsic value of vested options outstanding — — 264 The Company recognized no compensation expense in 2020 and 2019 and $12,000 in 2018, related to awards made under the 2005 Incentive Plan. 2012 Equity and Incentive Compensation Plan In 2012, the Company’s shareholders approved the AMERISAFE 2012 Equity and Incentive Compensation Plan (the “2012 Incentive Plan”). The 2012 Incentive Plan is administered by the Compensation Committee of the Board and is designed to attract, retain and motivate non-employee directors, officers, key employees and consultants by providing incentives for superior performance. The 2012 Incentive Plan authorizes the grant of equity-based compensation in the form of option rights, appreciation rights, restricted shares, restricted stock units, cash incentive awards, performance shares and units, and other types of awards. A maximum of 500,000 shares of common stock may be issued or transferred upon the exercise of option rights or appreciation rights, as restricted shares and released from substantial risk of forfeiture, in payment of restricted stock units, in payment of performance shares or performance units that have been earned, as awards of shares of common stock, as other awards granted under the 2012 Incentive Plan, or in payment of dividend equivalents paid with respect to awards made under the plan subject to adjustment in the event of a merger, stock dividend, stock split or similar event, which may be original issue shares or treasury shares or a combination of the two. In 2020, 23,207 shares of common stock were granted under the 2012 Incentive Plan. In 2019, 9,391 shares of common stock and 13,322 shares of restricted stock were granted under the 2012 Incentive Plan, which will vest through 2024. At December 31, 2020, there were 297,227 shares of common stock available for future awards under the 2012 Incentive Plan. The following table summarizes information about the common and restricted stock activity under the 2012 Incentive Plan: Shares Weighted Average Grant Date Fair Value per Share Nonvested balance at January 1, 2018 60,879 45.71 Granted 3,304 59.16 Vested (24,608 ) 44.31 Forfeited — — Nonvested balance at December 31, 2018 39,575 48.93 Granted 22,713 61.08 Vested (29,760 ) 51.86 Forfeited — — Nonvested balance at December 31, 2019 32,528 54.02 Granted 23,207 58.62 Vested (40,421 ) 54.31 Forfeited — — Nonvested balance at December 31, 2020 15,314 60.23 The Company recognized compensation expense of $605,000, $676,000 and $726,000 in 2020, 2019 and 2018, respectively, related to share-based grants. The Company recognized compensation expense of $2,341,000, $1,359,000 and $976,000 in 2020, 2019 and 2018, respectively, related to long-term incentive awards under the 2012 Incentive Plan. The long-term incentive award is a liability award. Non-Employee Director Restricted Stock Plan The AMERISAFE Non-Employee Director Restricted Stock Plan (the “Restricted Stock Plan”) is administered by the Compensation Committee of the Board and provides for the automatic grant of restricted stock awards to non-employee directors of the Company. Awards to non-employee directors are generally subject to terms including non-transferability, immediate vesting upon death or total disability of a director, forfeiture of unvested shares upon termination of service by a director and acceleration of vesting upon a change of control of the Company. The maximum number of shares of common stock that may be issued pursuant to restricted stock awards under the Restricted Stock Plan is 150,000 shares, subject to the authority of the Board to adjust this amount in the event of a merger, consolidation, reorganization, stock split, combination of shares, recapitalization or similar transaction affecting the common stock. At December 31, 2020, there were 47,748 shares of common stock available for future awards under the Restricted Stock Plan. Under the Restricted Stock Plan, each non-employee director is automatically granted a restricted stock award for a number of shares equal to $50,000 divided by the closing price of the Company’s common stock on the date of the annual meeting of shareholders at which the non-employee director is elected or is continuing as a member of the Board. Each restricted stock award vests on the date of the next annual meeting of shareholders following the date of grant, subject to the continued service of the non-employee director. Under the terms of the Restricted Stock Plan, the Company’s Board of Directors may increase the dollar amount of the annual award to an amount up to $75,000 without further shareholder approval. As of December 31, 2020, there were 5,068 shares of restricted stock outstanding under the Non-Employee Director Restricted Stock Plan, all of which will vest on the date of the annual meeting of shareholders in 2021. The following table summarizes information about the restricted stock activity under the Non-Employee Director Restricted Stock Plan: Shares Weighted Average Grant Date Fair Value per Share Nonvested balance at January 1, 2018 6,454 54.20 Granted 5,761 60.75 Vested (6,454 ) 54.20 Forfeited — — Nonvested balance at December 31, 2018 5,761 60.75 Granted 4,890 61.34 Vested (5,761 ) 60.75 Forfeited — — Nonvested balance at December 31, 2019 4,890 61.34 Granted 5,269 68.88 Vested (5,091 ) 61.49 Forfeited — — Nonvested balance at December 31, 2020 5,068 69.03 The Company recognized compensation expense of $349,000 in 2020, $317,000 in 2019 and $351,000 in 2018 related to the Non-Employee Director Restricted Stock Plan.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	13. Earnings Per Share The Company computes earnings per share (“EPS”) in accordance with FASB Accounting Standards Codification (“ASC”) Topic 260, Earnings Per Share Basic EPS is calculated by dividing net income by the weighted average number of common shares outstanding during the period. The diluted EPS calculation includes potential common shares assumed issued under the treasury stock method, which reflects the potential dilution that would occur if any outstanding options were exercised or restricted stock becomes vested. The calculation of basic and diluted EPS for the years ended December 31, 2020, 2019 and 2018 are presented below. For the Year Ended December 31, 2020 2019 2018 (in thousands, except earnings per share amounts) Basic EPS: Net income – basic $ 86,602 $ 92,690 $ 71,632 Basic weighted average common shares 19,289 19,249 19,209 Basic earnings per share $ 4.49 $ 4.82 $ 3.73 Diluted EPS: Net income – diluted $ 86,602 $ 92,690 $ 71,632 Diluted weighted average common shares: Weighted average common shares 19,289 19,249 19,209 Restricted stock and stock options 75 80 84 Diluted weighted average common shares 19,364 19,329 19,293 Diluted earnings per common share $ 4.47 $ 4.80 $ 3.71 The table below sets forth the reconciliation of the weighted average shares used for the basic and diluted EPS calculation. Years Ended 2020 2019 2018 Basic weighted average common shares 19,288,996 19,248,657 19,208,978 Add: Other common shares eligible for common dividends: Restricted stock and stock options 74,813 80,581 84,104 Diluted weighted average common shares 19,363,809 19,329,238 19,293,082

Comprehensive Income and Accumu

Comprehensive Income and Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Comprehensive Income and Accumulated Other Comprehensive Income	14. Comprehensive income includes net income plus unrealized gains/losses on our available-for-sale investment securities, net of tax. The following table illustrates the changes in the balance of each component of accumulated other comprehensive income (loss) for each period presented in the financial statements. Year Ended December 31, 2020 2019 2018 (in thousands) Balance, beginning of period $ 12,211 $ (832 ) $ 3,612 Impact of adoption of ASU 2016-01 — — (615 ) Impact of adoption of ASU 2018-02 — — 414 Adjusted beginning balance 12,211 (832 ) 3,411 Other comprehensive income (loss) before reclassification 9,538 12,379 (4,551 ) Amounts reclassified from accumulated other comprehensive income (loss) (730 ) 664 308 Net current period other comprehensive income (loss) 8,808 13,043 (4,243 ) Balance, end of period $ 21,019 $ 12,211 $ (832 ) The sale or other-than-temporary impairment (“OTTI”) of an available-for-sale security results in amounts being reclassified from accumulated other comprehensive income to current period net income. The effects of reclassifications out of accumulated other comprehensive income by the respective line items of net income are presented in the following table. Component of Accumulated Other Comprehensive Income (Loss) Year Ended December 31, Affected line item in the statement of income 2020 2019 2018 (in thousands) Unrealized gains (losses) on available-for- sale securities $ 925 $ (841 ) $ (390 ) Net realized gains (losses) on investments 925 (841 ) (390 ) Income before income taxes (195 ) 177 82 Income tax expense $ 730 $ (664 ) $ (308 ) Net income Pre-Tax Amount Tax Expense (Benefit) Net-of-Tax Amount (in thousands) December 31, 2020 Unrealized gain on securities: Unrealized gain on available-for-sale securities $ 12,074 $ 2,536 $ 9,538 Reclassification adjustment for gains realized in net income (925 ) (195 ) (730 ) Net unrealized gain 11,149 2,341 8,808 Other comprehensive income $ 11,149 $ 2,341 $ 8,808 December 31, 2019 Unrealized gain on securities: Unrealized gain on available-for-sale securities $ 15,670 $ 3,291 $ 12,379 Reclassification adjustment for losses realized in net income 841 177 664 Net unrealized gain 16,511 3,468 13,043 Other comprehensive income $ 16,511 $ 3,468 $ 13,043 December 31, 2018 Unrealized loss on securities: Unrealized loss on available-for-sale securities $ (5,760 ) $ (1,209 ) $ (4,551 ) Reclassification adjustment for gains realized in net income 390 82 308 Net unrealized loss (5,370 ) (1,127 ) (4,243 ) Other comprehensive loss $ (5,370 ) $ (1,127 ) $ (4,243 )

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plan	15. Employee Benefit Plan The Company’s 401(k) benefit plan is available to all employees. The Company matches 50% of employee contributions up to 6% of compensation for participating employees, subject to certain limitations. Employees are fully vested in employer contributions to this plan after five years. Company contributions to this plan were $0.7 million in each of 2020, 2019 and 2018.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	16. Commitments and Contingencies The Company is a party to various legal actions arising principally from claims made under insurance policies and contracts. Those actions are considered by the Company in estimating reserves for loss and loss adjustment expenses. In the opinion of management, the ultimate disposition of these matters will not have a material adverse effect on the Company’s consolidated financial position or results of operations. The Company provides workers’ compensation insurance in several states that maintain second-injury funds. Incurred losses on qualifying claims that exceed certain amounts may be recovered from these state funds. There is no assurance that the applicable states will continue to provide funding under these programs. The Company manages risk on certain long-duration claims by settling these claims through the purchase of annuities from unaffiliated carriers. In the event these carriers are unable to meet their obligations under these contracts, the Company could be liable to the claimants. The following table summarizes the fair value of the annuities at December 31, 2020 , that the Company has purchased to satisfy its obligations. Life Insurance Company A.M. Best Rating Statement Value of Annuities Exceeding 1% of Statutory Surplus (in thousands) Pacific Life & Annuity Company A+ $ 16,489 American General Life Insurance Company A 14,462 Travelers Life and Annuity Insurance Company A 9,758 New York Life Insurance Company A++ 9,120 Metropolitan Life Insurance Company A+ 6,701 John Hancock Life Insurance Company A+ 6,536 United of Omaha Insurance Company A+ 5,141 Athene Annuity and Life Company A 4,363 Pacific Life Insurance Company A+ 4,010 Lincoln Life Assurance Company of Boston A+ 3,698 Other 18,997 $ 99,275 Substantially all of the annuities are issued or guaranteed by life insurance companies that have an A.M. Best Company rating of “A” (Excellent) or better. The Company has operating and finance leases for office space and equipment. Our leases have remaining lease terms of one month to 60 months The components of lease expense were as follows: Year Ended December 31, 2020 2019 (in thousands) Operating lease cost $ 160 $ 164 Finance lease cost: Amortization of right-of-use assets 6 62 Interest on lease liabilities 2 4 Total finance lease cost $ 8 $ 66 Supplemental cash flow information related to leases was as follows: Year Ended December 31, 2020 2019 (in thousands) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ (116 ) $ 430 Operating cash flows from finance leases 4 46 Financing cash flows from finance leases 50 47 Right-of-use assets obtained in the exchange for the lease obligations were as follows: December 31, 2020 2019 (in thousands) Operating leases $ 56 $ 369 Finance leases 180 — Supplemental balance sheet information related to leases was as follows: December 31, 2020 December 31, 2019 Balance Sheet Classification (in thousands) Operating leases: Operating lease right-of-use assets $ 314 $ 430 Other assets Operating lease liabilities $ 314 $ 430 Accounts payable and other liabilities Finance leases: Finance lease right-of-use assets $ 365 $ 185 Finance lease accumulated amortization right-of-use assets (185 ) (179 ) Property and equipment, net $ 180 $ 6 Property and equipment, net Finance lease liabilities $ 185 $ 54 Accounts payable and other liabilities December 31, 2020 2019 Weighted average remaining lease term: Operating leases 2.7 years 3.6 years Finance leases 4.9 years 1.1 years Weighted average discount rate: Operating leases 5.24 % 5.25 % Finance leases 3.30 % 5.21 % The following is a maturity analysis of the annual undiscounted cash flows of the operating and finance lease liabilities as of December 31, 2020: Operating Leases Finance Leases (in thousands) 2021 $ 136 $ 44 2022 120 39 2023 75 39 2024 6 39 2025 — 39 Total lease payments 337 200 Less imputed interest 23 15 Total $ 314 $ 185 Rental expense was $0.2 million in each of 2020, 2019 and 2018.

Concentration of Operations

Concentration of Operations	12 Months Ended
	Dec. 31, 2020
Concentration Of Operations [Abstract]
Concentration of Operations	17. Concentration of Operations The Company derives its premium revenues from its operations in the workers’ compensation insurance line of business. Net premiums earned during 2020, 2019 and 2018 for the top ten states in 2020 and all others are shown below: 2020 2019 2018 Dollars Percent Dollars Percent Dollars Percent (Dollars in thousands) Georgia $ 37,926 12.5 % $ 38,090 11.4 % $ 40,351 11.5 % Florida 34,617 11.4 % 39,936 12.0 % 39,672 11.3 % Pennsylvania 24,340 8.0 % 27,519 8.3 % 31,708 9.1 % Louisiana 22,668 7.4 % 24,782 7.4 % 25,810 7.4 % North Carolina 17,338 5.7 % 18,800 5.7 % 19,537 5.6 % Illinois 14,802 4.9 % 16,929 5.1 % 19,710 5.6 % Virginia 14,041 4.6 % 15,249 4.6 % 15,228 4.3 % Wisconsin 12,263 4.0 % 13,388 4.0 % 14,101 4.0 % South Carolina 11,270 3.7 % 13,020 3.9 % 13,924 4.0 % Minnesota 11,057 3.6 % 13,399 4.0 % 12,900 3.7 % All others 104,105 34.2 % 111,776 33.6 % 117,385 33.5 % Total net premiums earned $ 304,427 100.0 % $ 332,888 100.0 % $ 350,326 100.0 %

Fair Values of Financial Instru

Fair Values of Financial Instruments	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Values of Financial Instruments	18. Fair Values of Financial Instruments The Company determines fair value amounts for financial instruments using available third-party market information. When such information is not available, the Company determines the fair value amounts using appropriate valuation methodologies. Nonfinancial instruments such as real estate, property and equipment, deferred policy acquisition costs, deferred income taxes and loss and loss adjustment expense reserves are excluded from the fair value disclosure. Cash and Cash Equivalents —The carrying amounts reported in the accompanying consolidated balance sheets for these financial instruments approximate their fair values. Investments —The Company’s fixed maturity securities are priced by an independent pricing service. The prices provided by the independent pricing service are estimated based on observable market data in active markets utilizing pricing models and processes, which may include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, benchmark securities, bids, offers, sector groupings, matrix pricing and reference data. The Company reviews the prices provided by pricing services for reasonableness and compares them to prices provided by the Company’s custodian which uses different pricing services. Short Term Investments —The carrying amounts reported in the accompanying consolidated balance sheets for these financial instruments approximate their fair value. The following table summarizes the carrying or reported values and corresponding fair values for financial instruments: December 31, 2020 2019 Carrying Amount Fair Value Carrying Amount Fair Value (in thousands) Assets: Fixed maturity securities—held to maturity $ 585,130 $ 621,654 $ 599,421 $ 621,343 Fixed maturity securities—available-for-sale 414,279 414,279 441,146 441,146 Equity securities 43,437 43,437 27,903 27,903 Short-term investments 45,898 45,898 56,548 56,548 Cash and cash equivalents 61,757 61,757 43,813 43,813 The Company carries available-for-sale securities and equity securities at fair value in our consolidated financial statements and determines fair value measurements and disclosure in accordance with FASB ASC Topic 820, Fair Value Measurements and Disclosures. The Company determines the fair values of its financial instruments based on the fair value hierarchy established in ASC Topic 820, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard defines fair value, describes three levels of inputs that may be used to measure fair value, and expands disclosures about fair value measurements. Fair value is defined in ASC Topic 820 as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is the price to sell an asset or transfer a liability and, therefore, represents an exit price, not an entry price. Fair value is the exit price in the principal market (or, if lacking a principal market, the most advantageous market) in which the reporting entity would transact. Fair value is a market-based measurement, not an entity-specific measurement, and, as such, is determined based on the assumptions that market participants would use in pricing the asset or liability. The exit price objective of a fair value measurement applies regardless of the reporting entity’s intent and/or ability to sell the asset or transfer the liability at the measurement date. ASC Topic 820 requires the use of valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets and liabilities. The income approach uses valuation techniques to convert future amounts, such as cash flows or earnings, to a single present value amount on a discounted basis. The cost approach is based on the amount that currently would be required to replace the service capacity of an asset, also known as current replacement cost. Valuation techniques used to measure fair value are to be consistently applied. In ASC Topic 820, inputs refer broadly to the assumptions that market participants would use in pricing the asset or liability, including assumptions about risk, for example, the risk inherent in a particular valuation technique used to measure fair value (such as a pricing model) and/or the risk inherent in the inputs to the valuation technique. Inputs may be observable or unobservable: • Observable inputs are inputs that reflect the assumptions market participants would use in pricing the asset or liability developed based on market data obtained from sources independent of the reporting entity. • Unobservable inputs are inputs that reflect the reporting entity’s own assumptions about the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. Valuation techniques used to measure fair value are intended to maximize the use of observable inputs and minimize the use of unobservable inputs. ASC Topic 820 establishes a fair value hierarchy that prioritizes the use of inputs used in valuation techniques into the following three levels: • Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs 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, or inputs that are derived principally from or corroborated by observable market data. • Level 3 inputs are unobservable inputs for the asset or liability. Unobservable inputs are to be used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. In general, fair value is based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. The fair values of the Company’s investments are based upon prices provided by an independent pricing service. The Company has reviewed these prices for reasonableness and has not adjusted any prices received from the independent provider. Securities reported at fair value utilizing Level 1 inputs represent assets whose fair value is determined based upon observable unadjusted quoted market prices for identical assets in active markets. Level 2 securities represent assets whose fair value is determined using observable market information such as previous day trade prices, quotes from less active markets or quoted prices of securities with similar characteristics. There were no transfers between Level 1 and Level 2 during the year ended December 31, 2020 . Assets measured at fair value on a recurring basis as of December 31, 2020 and 2019 are as follows: December 31, 2020 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Financial instruments carried at fair value, classified as part of: Securities available-for-sale—fixed maturity: States and political subdivisions $ — $ 276,542 $ — $ 276,542 Corporate bonds — 88,899 — 88,899 U.S. agency-based mortgage-backed securities — 19,052 — 19,052 U.S. Treasury securities 29,786 — — 29,786 Total securities available-for-sale—fixed maturity 29,786 384,493 — 414,279 Equity securities: Domestic common stock 43,437 — — 43,437 Total $ 73,223 $ 384,493 $ — $ 457,716 December 31, 2019 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Financial instruments carried at fair value, classified as part of: Securities available-for-sale—fixed maturity: States and political subdivisions $ — $ 237,775 $ — $ 237,775 Corporate bonds — 133,778 — 133,778 U.S. agency-based mortgage-backed securities — 29,467 — 29,467 U.S. Treasury securities 40,126 — — 40,126 Total securities available-for-sale—fixed maturity 40,126 401,020 — 441,146 Equity securities: Domestic common stock 27,903 — — 27,903 Total $ 68,029 $ 401,020 $ — $ 469,049 Assets measured at amortized cost as of December 31, 2020 and 2019 are as follows: December 31, 2020 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Securities held-to-maturity—fixed maturity: States and political subdivisions $ — $ 526,821 $ — $ 526,821 Corporate bonds — 72,900 — 72,900 U.S. agency-based mortgage-backed securities — 7,906 — 7,906 U.S. Treasury securities 13,865 — — 13,865 Asset-backed securities — 162 — 162 Total held-to-maturity $ 13,865 $ 607,789 $ — $ 621,654 December 31, 2019 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Securities held-to-maturity—fixed maturity: States and political subdivisions $ — $ 485,647 $ — $ 485,647 Corporate bonds — 110,925 — 110,925 U.S. agency-based mortgage-backed securities — 11,511 — 11,511 U.S. Treasury securities 7,873 — — 7,873 Obligations of U.S. government agencies — 5,168 — 5,168 Asset-backed securities — 219 — 219 Total held-to-maturity $ 7,873 $ 613,470 $ — $ 621,343 At December 31, 2020 and 2019, the Company did not hold any securities measured at fair value on a nonrecurring basis due to impairment.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	19. Quarterly Financial Data (Unaudited) The following table represents unaudited quarterly financial data for the years ended December 31, 2020 and 2019. Three Months Ended March 31 June 30 September 30 December 31 (in thousands, except per share amounts) 2020 Net premiums earned $ 78,990 $ 75,964 $ 74,771 $ 74,702 Net investment income 7,749 7,324 7,063 7,228 Net realized gains (losses) on investments 992 163 309 (332 ) Net unrealized gains (losses) on equity securities (8,763 ) 5,570 844 6,553 Total revenues 79,169 89,082 83,005 88,221 Income before income taxes 13,241 29,391 28,669 35,618 Net income 10,800 23,948 23,353 28,501 Earnings per share: Basic $ 0.56 $ 1.24 $ 1.21 $ 1.48 Diluted $ 0.56 $ 1.24 $ 1.21 $ 1.47 Comprehensive income 12,284 29,431 24,087 29,608 Extraordinary cash dividends declared per common share $ — $ — $ — $ 3.50 Cash dividends declared per common share $ 0.27 $ 0.27 $ 0.27 $ 0.27 2019 Net premiums earned $ 84,948 $ 82,951 $ 82,712 $ 82,277 Net investment income 8,015 8,169 8,264 8,035 Net realized gains (losses) on investments 59 (82 ) (4 ) (53 ) Net unrealized gains on equity securities 2,158 642 365 1,593 Total revenues 95,190 91,753 91,488 91,939 Income before income taxes 23,809 22,169 26,613 42,926 Net income 19,400 17,890 21,386 34,014 Earnings per share: Basic $ 1.01 $ 0.93 $ 1.11 $ 1.77 Diluted $ 1.01 $ 0.93 $ 1.11 $ 1.76 Comprehensive income 25,193 23,068 23,862 33,610 Extraordinary cash dividends declared per common share $ — $ — $ — $ 3.50 Cash dividends declared per common share $ 0.25 $ 0.25 $ 0.25 $ 0.25

Capital Management

Capital Management	12 Months Ended
	Dec. 31, 2020
Text Block [Abstract]
Capital Management	20. Capital Management The Company’s Board of Directors initiated a share repurchase program in February 2010. In October 2016, the Board reauthorized this program with a limit of $25.0 million with no expiration date. There were no shares repurchased under this program in 2020. Since the beginning of this plan, the Company has repurchased a total of 1,258,250 shares for $22.4 million, or an average price of $17.78, including commissions. In 2013, the Company’s Board of Directors initiated a regular quarterly dividend. During 2020, the Company’s Board of Directors declared a quarterly dividend of $0.27 per share compared to $0.25 per share in 2019, and $0.22 per share in 2018. The Company declared extraordinary dividends totaling $3.50 per share in each of 2020, 2019 and 2018.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	21. Subsequent Events On February 23, 2021 the Company declared a regular quarterly cash dividend of $0.29 per share payable on March 26, 2021 to shareholders of record as of March 12, 2021. The Board considers the payment of a regular cash dividend each calendar quarter.

Schedule II. Condensed Financia

Schedule II. Condensed Financial Information of Registrant	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Schedule II. Condensed Financial Information of Registrant	Schedule II. Condensed Financial Information of Registrant AMERISAFE, INC. CONDENSED BALANCE SHEETS December 31, 2020 2019 (in thousands) Assets: Investments: Fixed maturity securities—held-to-maturity, at amortized cost net of allowance for credit losses of $0 in 2020 and 2019, (fair value $361 and $0, in 2020 and 2019, respectively) $ 361 $ — Fixed maturity securities—available-for-sale, at fair value (amortized cost $7,210 in 2020 and 2019) 7,259 7,216 Equity securities, at fair value (cost $10,007 in 2020 and 2019) 11,503 11,779 Short-term investments 9,676 17,967 Investment in subsidiaries 384,774 379,001 Total investments 413,573 415,963 Cash and cash equivalents 23,562 10,551 Notes receivable from subsidiaries 2,140 2,781 Property and equipment, net 1,605 1,720 Federal income tax recoverable 2,705 2,798 Other assets 1,420 804 Total assets $ 445,005 $ 434,617 Liabilities and shareholders’ equity Liabilities: Accounts payable and other liabilities 6,095 4,230 Deferred income taxes 94 172 Total liabilities 6,189 4,402 Shareholders' equity (net of Treasury stock of $22,370 at December 31, 2020 and 2019) 438,816 430,215 Total liabilities and shareholders' equity $ 445,005 $ 434,617 Schedule II. Condensed Financial Information of Registrant – (Continued) AMERISAFE, INC. CONDENSED STATEMENTS OF INCOME Year Ended December 31, 2020 2019 2018 (in thousands) Revenues Net investment income $ 944 $ 915 $ 1,089 Net unrealized gains (losses) on equity securities (276 ) 1,977 (948 ) Fee and other income 9,122 5,352 7,389 Total revenues 9,790 8,244 7,530 Expenses Other operating costs 9,122 8,244 7,530 Total expenses 9,122 8,244 7,530 Income before income taxes and equity in earnings of subsidiaries 668 — — Income tax expense (benefit) 259 376 (36 ) Gain (loss) before equity in earnings of subsidiaries 409 (376 ) 36 Equity in net income of subsidiaries 86,193 93,066 71,596 Net income $ 86,602 $ 92,690 $ 71,632 Schedule II. Condensed Financial Information of Registrant – (Continued) AMERISAFE, INC. CONDENSED STATEMENTS OF CASH FLOWS Year Ended December 31, 2020 2019 2018 (in thousands) Operating activities Net cash provided by operating activities $ 6,012 $ 2,333 $ 2,448 Investing activities Purchases of investments (10,982 ) (27,140 ) (47,825 ) Proceeds from sales of investments 18,970 1,987 54,600 Purchases of property and equipment (764 ) (995 ) (1,041 ) Dividends from subsidiary 88,600 115,900 65,400 Net cash provided by investing activities 95,824 89,752 71,134 Financing activities Proceeds from stock option exercises — 20 67 Finance lease purchases (50 ) (47 ) — Dividends to shareholders (88,775 ) (87,016 ) (84,491 ) Net cash used in financing activities (88,825 ) (87,043 ) (84,424 ) Change in cash and cash equivalents 13,011 5,042 (10,842 ) Cash and cash equivalents at beginning of year 10,551 5,509 16,351 Cash and cash equivalents at end of year $ 23,562 $ 10,551 $ 5,509

Schedule VI. Supplemental Infor

Schedule VI. Supplemental Information Concerning Property-Casualty Insurance Operations	12 Months Ended
	Dec. 31, 2020
Supplemental Information For Property Casualty Insurance Underwriters [Abstract]
Schedule VI. Supplemental Information Concerning Property-Casualty Insurance Operations	Schedule VI. Supplemental Information Concerning Property—Casualty Insurance Operations AMERISAFE, INC. AND SUBSIDIARIES Deferred Policy Acquisition Costs Reserves for Unpaid Loss and Loss Adjustment Expense Unearned Premium Net Premiums Earned Net Investment Income Loss and LAE Related to Current Period Loss and LAE Related to Prior Periods Amortization of Deferred Policy Acquisition Costs Paid Claims and Claim Adjustment Expenses Net Premiums Written (in thousands) 2020 $ 17,810 $ 760,561 $ 129,260 $ 304,427 $ 29,364 $ 220,710 $ (63,484 ) $ (41,583 ) $ 179,916 $ 292,814 2019 19,048 772,887 140,873 332,888 32,483 241,344 (65,002 ) (44,558 ) 189,991 324,465 2018 19,734 798,409 149,296 350,326 30,452 250,487 (45,596 ) (45,769 ) 200,654 342,352

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Organization	Organization AMERISAFE, Inc. is an insurance holding company incorporated in the state of Texas. The accompanying consolidated financial statements include the accounts of AMERISAFE and its subsidiaries: American Interstate Insurance Company (“AIIC”) and its insurance subsidiaries, Silver Oak Casualty, Inc. (“SOCI”) and American Interstate Insurance Company of Texas (“AIICTX”), Amerisafe Risk Services, Inc. (“RISK”) and Amerisafe General Agency, Inc. (“AGAI”). AIIC and SOCI are property and casualty insurance companies organized under the laws of the state of Nebraska. AIICTX is a property and casualty insurance company organized under the laws of the state of Texas. RISK, a wholly owned subsidiary of the Company, is a claims and safety service company currently servicing only affiliated insurance companies. AGAI, a wholly owned subsidiary of the Company, is a general agent for the Company. AGAI sells insurance, which is underwritten by AIIC, SOCI and AIICTX, as well as by nonaffiliated insurance carriers. The assets and operations of AGAI are not significant to that of the Company and its consolidated subsidiaries. The terms “AMERISAFE,” the “Company,” “we,” “us” or “our” refer to AMERISAFE, Inc. and its consolidated subsidiaries, as the context requires. The Company provides workers’ compensation insurance for small to mid-sized employers engaged in hazardous industries, principally construction, trucking, logging and lumber, manufacturing, agriculture, maritime, and oil and gas. Assets and revenues of AIIC and its subsidiaries represent at least 95% of comparable consolidated amounts of the Company for each of 2020, 2019 and 2018.
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States, or GAAP. The preparation of financial statements in accordance with 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 financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Reclassifications	Reclassifications Certain prior year amounts have been reclassified to conform with the current year presentation.
Adopted Accounting Guidance	Adopted Accounting Guidance In January 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. This guidance requires fair value measurement for equity investments (not including those that result in consolidation of the investee or use the equity method of accounting) and the recognition of changes in fair value to be presented as a component of net income. The guidance also revises the disclosure requirements related to fair value changes of liabilities presented in comprehensive income, eliminates disclosure related to the methods and assumptions underlying fair value for financial instruments measured at amortized cost, and simplifies impairment assessments for equity investments without readily determinable fair values. The adoption of this new guidance in the first quarter of 2018 resulted in an immaterial decrease in net income of $390 thousand or a $0.02 decrease to our diluted earnings per common share. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The new guidance requires a lessee to recognize a lease liability and a right of use asset for all leases extending beyond twelve months. This standard was effective for us beginning in the first quarter of 2019. We elected the new transition method under the transition guidance within the new standard. Therefore, prior comparative periods were not adjusted. We also elected the package of practical expedients, which among other things, allows us to carryforward the historical lease classification. We made an accounting policy election not to recognize lease assets and lease liabilities for short-term operating leases. Adoption of the new guidance resulted in the Company recognizing right-of-use assets of $0.4 million and lease liabilities of $0.3 million. The cumulative effect adjustment to the opening balance of retained earnings was minimal. Adoption of this new guidance did not have a material effect on the Company’s consolidated financial statements as the Company does not have any significant leases. O n January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses (“CECL”). The prior guidance delays the recognition of credit losses until a probable loss has occurred. The new guidance requires credit losses for securities measured at amortized cost to be determined using current expected credit loss estimates. These estimates are derived from historical, current and reasonable supporting forecasts, including prepayments and estimates, and are recorded through a valuation account. The same method is used for available-for-sale securities, but the valuation account is limited to the amount by which the fair value is below amortized cost. The Company implemented the new standard using the modified retrospective approach. Results for reporting periods beginning after January 1, 2020 are presented under the new guidance while prior period amounts continue to be reported in accordance with previously applicable GAAP. The Company recorded a net decrease to Retained Earnings of $594 thousand as of January 1, 2020, for the cumulative effect of adopting ASU 2016-13. The transition adjustment includes a $243 thousand impact to establish a credit loss allowance for held-to-maturity securities. The remaining $351 thousand of the transition adjustment was due to the creation of the reinsurance recoverable credit allowance. The Company believes that under the standard there is no current expected credit allowance necessary for U.S. Government Securities in its judgment as: 1) Treasury securities typically are the most highly rated securities among rating agencies; 2) Treasury securities have a long history of no credit losses; 3) Treasury securities are guaranteed by a sovereign entity (the U.S. Government) that can print its own money and whose currency (the U.S. dollar) is the reserve currency. The Company believes that under the standard there is no current expected credit allowance necessary for GNMA Securities in its judgment as: 1) GNMA securities typically are the most highly rated securities among rating agencies; 2) GNMA securities have a long history of no credit losses and payments are explicitly guaranteed by the United States; 3) Underlying mortgage loans for GNMA securities are insured by the Federal Housing Administration or guaranteed by the U.S. Department of Veteran Affairs; 4) the U.S. Government can print its own money to retire GNMA obligations. The Company believes that under the standard there is no current expected credit allowance necessary for FNMA or Freddie Mac (FHLMC) Securities in its judgment as: 1) These securities typically are among the most highly rated securities among rating agencies; 2) There is a long history of no credit losses; 3) Principal and interest payments are guaranteed by the issuing agency; 4) There is an explicit guarantee by the U.S. Government that can print its own money and whose currency (the U.S. dollar) is the reserve currency. The Company researched various options and methodologies and has chosen to use Moody’s default rates and recovery rates for our held-to-maturity fixed income securities based on the current credit rating of the security and the time period to the stated maturity date. This is a probability of default (PD) and loss given default (LGD) methodology. The credit rating used for held-to-maturity fixed income securities is the rating for each security as published by Moody’s, S&P, and Fitch to determine the probability of default. If there are two ratings, the lower rating is used. If there are three ratings, the median rating is used. If there is one rating, that rating is used. This methodology provides additional conservatism in determining the credit loss allowance needed. For corporate fixed income securities, the probability of default (given a rating) comes from Moody’s annual study of Corporate Bond defaults published each February. This study also contains the average recovery rates based on the historical defaults in the Moody’s study. We have chosen to use the 1983-2019 data as more reflective of the current historical pattern of defaults (the study goes back to 1920). The maximum maturity using the default rate is 20 years (any maturity greater than 20 years will use the 20-year rate). For municipal fixed income securities the probability of default (given a rating) comes from Moody’s annual study of Municipal Bond defaults published each July/August. This study also contains the average recovery rates based on the historical defaults in the Moody’s study. This study covers 1970-2019 data, which we believe is reflective of the current historical pattern of defaults. The maximum maturity using the default rate is 20 years (any maturity greater than 20 years will use the 20-year rate). The Company did not record a credit allowance for available-for-sale securities. The available-for-sale portfolio is composed of highly rated securities, which carry a low risk of default. The Company’s concentrations in municipal bonds have helped lower default risk, as the historical default rates and recovery rates for municipal bonds has been much better than corporate bonds rated at the same level. The Company creates a watch list of available-for-sale securities that are below book value at the end of each quarter. This watch list excludes US Treasury securities, GNMA Securities, and government agency securities (FNMA, etc.) as none of those securities will have an expected credit loss. The watch list will also exclude those securities that are trading at least at $95 or above (par value $ 100 ) as the Company believes any slight difference between $95 and par likely reflect interest rate changes and liquidity only and are not a sign of credit impairment or market expectations for any current expected credit loss. The list is reviewed by the Management Investment Committee to evaluate any security where the discounted cash flows expected no longer exceed the book value of the security. If the Company intends to sell the security (or more likely than not be required to sell the security before recovery of the loss) the Company will write down the security to fair value through earnings. If the Company intends to hold the security, the Company will establish a credit loss allowance for the security through earnings, and adjust the allowance each quarter through earnings, as the security changes in value. In determining the amount of the credit loss allowance, the Company will consider all of the following factors: 1. The extent to which the fair value is less than the amortized cost basis 2. Adverse conditions in the security, industry, or geography, including: a.) Changes in technology b.) Discontinuation of a segment of business that may affect future earnings c.) Changes in the quality of the credit enhancement, if any 3. Changes in the payment structure of the debt security 4. Failure of the issuer to make scheduled interest or principal payments 5. Any changes to the rating of the security by a rating agency The calculation of the credit loss allowance will not take into account the amount of time the security has been below book value or when the security might be expected to recover in value. The Company has researched various options and methodologies and has chosen to use Moody’s default rates and recovery rates for our unsecured reinsurance recoverables based on the current credit rating of the reinsurer and a time period of ten years. This is a probability of default (PD) and loss given default (LGD) methodology. The ten-year period is consistent with our current working layer reinsurance treaty where we have a three-year The credit rating used for reinsurance recoverables uses the average rating for each reinsurer as published by Moody’s, S&P, Fitch and A.M. Best to determine the probability of default. The median rating is used if there are three ratings. The probability of default (given a rating) comes from Moody’s annual study of Corporate Bond defaults published each February. This study also contains the average recovery rates based on the historical defaults in the Moody’s study. We have chosen to use the 1983-2019 data as more reflective of the current historical pattern of defaults (the study goes back to 1920). The Company does not hold any debt securities for which an other-than-temporary impairment has been recognized. Additionally, the Company does not hold any financial assets purchased with credit deterioration. The Company’s internal working group evaluated the existing allowance for doubtful accounts reserving methodology for premiums receivable and determined the calculation was consistent with the new credit loss guidance. There was no impact to the premiums receivable balance as a result of the adoption of the new standard. The Company has elected not to establish a credit allowance for investment interest receivable. The Company plans to continue use of the current policy for writing off investment related interest receivable balances over ninety days old.
Prospective Accounting Guidance	Prospective Accounting Guidance All other issued but not yet effective accounting and reporting standards as of December 31, 2020 are either not applicable to the Company or are not expected to have a material impact on the Company.
Investments	Investments The Company has the ability and positive intent to hold certain investments until maturity. Therefore, fixed maturity securities classified as held-to-maturity are recorded at amortized cost net of the allowance for credit losses. Fixed maturity securities classified as available-for-sale are recorded at fair value. Temporary changes in the fair value of these securities are reported in shareholders’ equity as a component of other comprehensive income, net of deferred income taxes. Changes in the fair value of equity securities are recorded in net income. Investment income is recognized as it is earned. The discount or premium on fixed maturity securities is amortized using the “constant yield” method. Anticipated prepayments, where applicable, are considered when determining the amortization of premiums or discounts. Realized investment gains and losses are determined using the specific identification method.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents include short-term money market funds with an original maturity of 90 days or less.
Short-Term Investments	Short-Term Investments Short-term investments include municipal securities and corporate bonds with an original maturity greater than 90 days but less than one year.
Premiums Receivable	Premiums Receivable Premiums receivable consist primarily of premium-related balances due from policyholders. The Company considers premiums receivable as past due based on the payment terms of the underlying policy. The balance is shown net of the allowance for credit losses. Receivables due from insureds are charged off when a determination has been made by management that a specific balance will not be collected. An estimate of amounts that are likely to be charged off is established as an allowance for credit losses as of the balance sheet date. The estimate is primarily comprised of specific balances that are considered probable to be charged off after all collection efforts have ceased, as well as historical trends and an analysis of the aging of the receivables.
Property and Equipment	Property and Equipment The Company’s property and equipment, including certain costs incurred to develop or obtain software for internal use, are stated at cost less accumulated depreciation. Depreciation is calculated primarily by the straight-line method over the estimated useful lives of the respective assets, generally 39 years for buildings and three to seven years for all other fixed assets.
Deferred Policy Acquisition Costs	Deferred Policy Acquisition Costs The direct costs of successfully acquiring and renewing business are capitalized to the extent recoverable and are amortized over the effective period of the related insurance policies in proportion to premium revenue earned. These capitalized costs consist mainly of sales commissions, premium taxes and other underwriting costs. The Company evaluates deferred policy acquisition costs for recoverability by comparing the unearned premiums to the estimated total expected claim costs and related expenses, offset by anticipated investment income. The Company would reduce the deferred costs if the unearned premiums were less than expected claims and expenses after considering investment income, and report any adjustments in amortization of deferred policy acquisition costs. There were no adjustments necessary in 2020, 2019 or 2018.
Reserves for Loss and Loss Adjustment Expenses	Reserves for Loss and Loss Adjustment Expenses Reserves for loss and loss adjustment expenses represent the estimated ultimate cost of all reported and unreported losses incurred through December 31. The Company does not discount loss and loss adjustment expense reserves. In establishing our reserves for loss and loss adjustment expenses, we review the results of analyses using individual case-base valuations and statistical and actuarial methods that utilize historical loss data from our more than 35 years of underwriting workers’ compensation insurance. The actuarial analysis of our historical data provides the factors we use in estimating our loss reserves. These factors are primarily measures over time of the number of claims paid and reported, average paid and incurred claim amounts, claim closure rates and claim payment patterns. In evaluating the results of our analyses, management also uses substantial judgment in considering other factors that are not considered in these actuarial analyses, including changes in business mix, claims management, regulatory issues, medical trends, employment and wage patterns, insurance policy coverage interpretations, judicial determinations and other subjective factors. Due to the inherent uncertainty associated with these estimates, and the cost of incurred but unreported claims, our actual liabilities may vary significantly from our original estimates. Although considerable variability is inherent in these estimates, management believes that the reserves for loss and loss adjustment expenses are adequate. The estimates are continually reviewed and adjusted as necessary as experience develops or new information becomes known. Any such adjustments are included in income from current operations. Subrogation recoverables, as well as deductible recoverables from policyholders, are estimated using individual case-basis valuations and aggregate estimates. Deductibles that are recoverable from policyholders and other recoverables from state funds decrease the liability for loss and loss adjustment expenses. The Company funds its obligations under certain settled claims where the payment pattern and ultimate cost are fixed and determinable on an individual claim basis through the purchase of annuities. These annuities are purchased from unaffiliated carriers and name the claimant as payee. The cost of purchasing the annuity is recorded as paid loss and loss adjustment expenses. To the extent the annuity funds estimated future claims, reserves for loss and loss adjustment expense are reduced.
Premium Revenue	Premium Revenue Premiums on workers’ compensation insurance are based on actual payroll costs or production during the policy term and are normally billed monthly in arrears or annually. However, the Company generally requires a deposit at the inception of a policy. Premium revenue is earned on a pro rata basis over periods covered by the policies. The reserve for unearned premiums on these policies is computed on a daily pro rata basis. The Company estimates the annual premiums to be paid by its policyholders when the Company issues the policies and records those amounts on the balance sheet as premiums receivable. The Company conducts premium audits on all of its voluntary business policyholders annually, upon the expiration of each policy, including when the policy is renewed. The purpose of these audits is to verify that policyholders have accurately reported their payroll expenses and employee job classifications, and therefore have paid the Company the premium required under the terms of the policies. The difference between the estimated premium and the ultimate premium is referred to as “earned but unbilled” premium, or EBUB premium. EBUB premium can be higher or lower than the estimated premium. EBUB premium is subject to significant variability and can either increase or decrease earned premium based upon several factors, including changes in premium growth, industry mix and economic conditions. Due to the timing of audits and other adjustments, ultimate premium earned is generally not determined for several months after the expiration of the policy. The Company estimates EBUB premiums on a quarterly basis using historical data and applying various assumptions based on the current market and economic conditions, and records an adjustment to premium, related losses, and expenses as warranted.
Reinsurance	Reinsurance Reinsurance premiums, losses and allocated loss adjustment expenses are accounted for on a basis consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Amounts recoverable from reinsurers include balances currently owed to the Company for losses and allocated loss adjustment expenses that have been paid to policyholders, amounts that are currently reserved for and will be recoverable once the related expense has been paid and experience-rated commissions recoverable upon commutation. Upon management’s determination that an amount due from a reinsurer is uncollectible due to the reinsurer’s insolvency or other matters, the amount is written off. Ceding commissions are earned from certain reinsurance companies and are intended to reimburse the Company for policy acquisition costs related to those premiums ceded to the reinsurers. Ceding commission income is recognized over the effective period of the related insurance policies in proportion to premium revenue earned and is reflected as a reduction in underwriting and certain other operating costs. Experience-rated commissions are earned from certain reinsurance companies based on the financial results of the applicable risks ceded to the reinsurers. These commission revenues on reinsurance contracts are recognized during the related reinsurance treaty period and are based on the same assumptions used for recording loss and allocated loss adjustment expenses. These commissions are reflected as a reduction in underwriting and certain other operating costs and are adjusted as necessary as experience develops or new information becomes known. Any such adjustments are included in income from current operations. Experience-rated commissions had no impact on underwriting and certain other operating costs in 2020 and 2019 and increased underwriting and certain other operating costs by $0.2 million in 2018. In December 2019, the Company commuted reinsurance agreements with Hannover Reinsurance (Ireland) Limited (“Hannover”) covering portions of accident years 2009 through 2011. The Company received an $8.5 million payment effectuated solely through offset against the balance of the funds withheld and recoverable from reinsurers accounts under the reinsurance agreements in exchange for releasing Hannover from their reinsurance obligations under the commuted agreements. Hannover remains obligated to the subsidiaries of the Company under other reinsurance agreements. There was no effect on the Company’s net income in the year ended December 31, 2019 as a result of the commutation.
Fee and Other Income	Fee and Other Income The Company recognizes income related to commissions earned by AGAI as the related services are performed.
Advertising	Advertising All advertising expenditures incurred by the Company are charged to expense in the period to which they relate and are included in underwriting and certain other operating costs in the consolidated statements of income. Total advertising expenses incurred were $0.2 million in 2020, $0.4 million in 2019, and $0.5 million in 2018.
Income Taxes	Income Taxes The Company accounts for income taxes using the liability method. The provision for income taxes has two components, amounts currently payable or receivable and deferred amounts. Deferred income tax assets and liabilities are recognized for the differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred income tax assets and liabilities are measured using tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. The Company considers deferred tax assets to be recoverable if it is probable that the related tax losses can be offset by future taxable income. The Company includes reversal of existing temporary differences, tax planning strategies available and future operating income in this assessment. To the extent the deferred tax assets exceed the amount expected to be recovered in future years, the Company records a valuation allowance for the amount determined unrecoverable.
Insurance-Related Assessments	Insurance-Related Assessments Insurance-related assessments are accrued in the period in which they have been incurred. The Company is subject to a variety of assessments related to insurance commerce, including those by state guaranty funds and workers’ compensation second-injury funds. State guaranty fund assessments are used by state insurance oversight agencies to cover losses of policyholders of insolvent or rehabilitated insurance companies and for the operating expenses of such agencies. Assessments based on premiums are generally paid one year after the calendar year in which the premium is written, while assessments based on losses are generally paid within one year of the calendar year in which the loss is paid.
Policyholder Dividends	Policyholder Dividends The Company writes certain policies for which the policyholder may participate in favorable claims experience through a dividend. An estimated provision for workers’ compensation policyholders’ dividends is accrued as the related premiums are earned. Dividends do not become a fixed liability unless and until declared by the respective Boards of Directors of AMERISAFE’s insurance subsidiaries. The dividend to which a policyholder may be entitled is set forth in the policy and is related to the amount of losses sustained under the policy. Dividends are calculated after the policy expiration. The Company is able to estimate the policyholder dividend liability because the Company has information regarding the underlying loss experience of the policies written with dividend provisions and can estimate future dividend payments from the policy terms.
Earnings Per Share	Earnings Per Share The Company computes earnings per share (“EPS”) in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 260, Earnings Per Share. Basic EPS is calculated by dividing income available to common shareholders by the weighted average number of common shares outstanding during the period. The diluted EPS calculation includes potential common shares assumed issued under the treasury stock method, which reflects the potential dilution that would occur if any outstanding options or warrants were exercised or restricted stock becomes vested.
Share-Based Compensation	Share-Based Compensation The Company recognizes the impact of its share-based compensation in accordance with FASB ASC Topic 718, Compensation-Stock Compensation.
Fair Values of Financial Instruments	The Company carries available-for-sale securities and equity securities at fair value in our consolidated financial statements and determines fair value measurements and disclosure in accordance with FASB ASC Topic 820, Fair Value Measurements and Disclosures. The Company determines the fair values of its financial instruments based on the fair value hierarchy established in ASC Topic 820, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard defines fair value, describes three levels of inputs that may be used to measure fair value, and expands disclosures about fair value measurements.

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Gross Unrealized Gains and Losses and Amortized Cost and Fair Value of Investments Classified as Held-to-maturity	The gross unrecognized gains and losses on, and the amortized cost, allowance for credit losses, carrying amount, and fair value of, those investments classified as held-to-maturity at December 31, 2020 are summarized as follows: Amortized Cost Allowance for Credit Losses Carrying Amount Gross Unrecognized Gains Gross Unrecognized Losses Fair Value (in thousands) States and political subdivisions $ 494,374 $ (42 ) $ 494,332 $ 32,489 $ — $ 526,821 Corporate bonds 69,981 (225 ) 69,756 3,144 — 72,900 U.S. agency-based mortgage-backed securities 7,261 — 7,261 645 — 7,906 U.S. Treasury securities and obligations of U.S. government agencies 13,626 — 13,626 239 — 13,865 Asset-backed securities 162 (7 ) 155 7 — 162 Totals $ 585,404 $ (274 ) $ 585,130 $ 36,524 $ — $ 621,654 The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at December 31, 2019 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) States and political subdivisions $ 466,270 $ 19,570 $ (193 ) $ 485,647 Corporate bonds 109,241 1,684 — 110,925 U.S. agency-based mortgage-backed securities 10,967 544 — 11,511 U.S. Treasury securities and obligations of U.S. government agencies 12,723 330 (12 ) 13,041 Asset-backed securities 220 — (1 ) 219 Totals $ 599,421 $ 22,128 $ (206 ) $ 621,343
Gross Unrealized Gains and Losses and Cost or Amortized Cost and Fair Value of Investments Classified as Available-for-sale	The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as available-for-sale at December 31, 2020 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Allowance for Credit Losses (in thousands) States and political subdivisions $ 256,492 $ 20,050 $ — $ 276,542 $ — Corporate bonds 83,646 5,256 (3 ) 88,899 — U.S. agency-based mortgage-backed securities 18,654 400 (2 ) 19,052 — U.S. Treasury securities and obligations of U.S. government agencies 28,873 913 — 29,786 — Totals $ 387,665 $ 26,619 $ (5 ) $ 414,279 $ — The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as available-for-sale at December 31, 2019 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) States and political subdivisions $ 225,895 $ 11,906 $ (26 ) $ 237,775 Corporate bonds 130,453 3,326 (1 ) 133,778 U.S. agency-based mortgage-backed securities 29,499 64 (96 ) 29,467 U.S. Treasury securities and obligations of U.S. government agencies 39,851 317 (42 ) 40,126 Totals $ 425,698 $ 15,613 $ (165 ) $ 441,146
Gross Unrealized Gains and Losses and Cost of Equity	The gross unrealized gains and losses on, and the cost of equity securities at December 31, 2020 are summarized as follows: Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Equity securities: Domestic common stock $ 35,787 $ 7,650 $ — $ 43,437 Total equity securities $ 35,787 $ 7,650 $ — $ 43,437 The gross unrealized gains and losses on, and the cost of equity securities at December 31, 2019 are summarized as follows: Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Equity securities: Domestic common stock $ 24,457 $ 3,446 $ — $ 27,903 Total equity securities $ 24,457 $ 3,446 $ — $ 27,903
A Summary of the Company's Realized Gains and Losses on Sales, Calls or Redemptions of Investments	A summary of the Company’s realized gains and losses on sales, calls or redemptions of investments for 2020 , 2019 and 2018 is as follows: Fixed Maturity Securities Available-for-Sale Equity Securities Other Total (in thousands) Year ended December 31, 2020 Proceeds from sales $ 25,436 $ — $ 46,959 $ 72,395 Gross realized investment gains $ 711 $ — $ 306 $ 1,017 Gross realized investment losses (14 ) — (4 ) (18 ) Net realized investment gains 697 — 302 999 Other, including gains (losses) on calls and redemptions (43 ) — 176 133 Net realized gains on investments $ 654 $ — $ 478 $ 1,132 Year ended December 31, 2019 Proceeds from sales $ 33,113 $ — $ 21,977 $ 55,090 Gross realized investment gains $ 140 $ — $ 36 $ 176 Gross realized investment losses (68 ) — — (68 ) Net realized investment gains 72 — 36 108 Other, including gains (losses) on calls and redemptions (196 ) — 8 (188 ) Net realized gains (losses) on investments $ (124 ) $ — $ 44 $ (80 ) Year ended December 31, 2018 Proceeds from sales $ 15,025 $ 3 $ — $ 15,028 Gross realized investment gains $ 238 $ 1 $ — $ 239 Gross realized investment losses (1,354 ) — — (1,354 ) Net realized investment gains (losses) (1,116 ) 1 — (1,115 ) Other, including losses on calls and redemptions (144 ) — (277 ) (421 ) Net realized gains (losses) on investments $ (1,260 ) $ 1 $ (277 ) $ (1,536 )
Major Categories of the Company's Net Investment Income	Major categories of the Company’s net investment income are summarized as follows: Year Ended December 31, 2020 2019 2018 (in thousands) Gross investment income: Fixed maturity securities $ 28,414 $ 30,343 $ 28,762 Equity securities 1,006 628 448 Short-term investments and cash and cash equivalents 897 2,478 2,208 Total gross investment income 30,317 33,449 31,418 Investment expenses (953 ) (966 ) (966 ) Net investment income $ 29,364 $ 32,483 $ 30,452
Investment Securities Continuous Unrealized Loss Position	The following table summarizes the fair value and gross unrealized losses on fixed maturity securities, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position: Less Than 12 Months 12 Months or Greater Total Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses (in thousands) December 31, 2020 Available-for-Sale Corporate bonds $ 2,515 $ 3 $ — $ — $ 2,515 $ 3 U.S. agency-based mortgage-backed securities 2,133 2 — — 2,133 2 Total available-for-sale securities $ 4,648 $ 5 $ — $ — $ 4,648 $ 5 December 31, 2019 Held-to-Maturity States and political subdivisions $ 21,074 $ 193 $ — $ — $ 21,074 $ 193 U.S. Treasury securities and obligations of U.S. government agencies — — 3,243 12 3,243 12 Asset-backed securities — — 68 1 68 1 Total held-to-maturity securities 21,074 193 3,311 13 24,385 206 Available-for-Sale States and political subdivisions $ 4,140 $ 26 $ — $ — $ 4,140 $ 26 Corporate bonds 6,426 1 — — 6,426 1 U.S. agency-based mortgage-backed securities 13,007 95 1,152 1 14,159 96 U.S. Treasury securities and obligations of U.S. government agencies — — 17,068 42 17,068 42 Total available-for-sale securities 23,573 122 18,220 43 41,793 165 Total $ 44,647 $ 315 $ 21,531 $ 56 $ 66,178 $ 371
Changes in Allowance for Credit Losses by Major Security Type of Investments Classified as Held-to-Maturity	The following table illustrates the changes in the allowance for credit losses by major security type of the investments classified as held-to-maturity for the year ended December 31, 2020. States and Political Subdivisions Corporate Bonds U.S. Agency-Based Mortgage-Backed Securities U.S. Treasury Securities and Obligations of U.S. Government Agencies Asset-Backed Securities Totals (in thousands) Balance at January 1, 2020 $ 45 $ 245 $ — $ — $ 11 $ 301 Provision for credit loss benefit (3 ) (20 ) — — (4 ) (27 ) Balance at December 31, 2020 $ 42 $ 225 $ — $ — $ 7 $ 274
Schedule of Amortized Cost Held-to-Maturity Securities Aggregated By Credit Quality Indicator	The table below presents the amortized cost of held-to-maturity securities aggregated by credit quality indicator as of December 31, 2020. States and Political Subdivisions Corporate Bonds U.S. Agency-Based Mortgage-Backed Securities U.S. Treasury Securities and Obligations of U.S. Government Agencies Asset-Backed Securities Totals Amortized cost (in thousands) AAA/AA/A ratings $ 490,311 $ 29,890 $ 7,261 $ 13,626 $ 111 $ 541,199 Baa/BBB ratings 4,063 40,091 — — 18 44,172 B ratings — — — — 33 33 Total $ 494,374 $ 69,981 $ 7,261 $ 13,626 $ 162 $ 585,404
Held-to-Maturity Securities [Member]
Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, by Contractual Maturity	A summary of the carrying amounts and fair value of investments in fixed maturity securities classified as held-to-maturity by contractual maturity is as follows: December 31, 2020 December 31, 2019 Carrying Amount Fair Value Carrying Amount Fair Value (in thousands) Maturity: Within one year $ 54,316 $ 54,794 $ 49,967 $ 50,348 After one year through five years 195,706 204,289 198,025 202,109 After five years through ten years 107,347 113,643 110,460 113,877 After ten years 220,345 240,860 229,782 243,279 U.S. agency-based mortgage-backed securities 7,261 7,906 10,967 11,511 Asset-backed securities 155 162 220 219 Totals $ 585,130 $ 621,654 $ 599,421 $ 621,343
Available-for-Sale Securities [Member]
Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, by Contractual Maturity	A summary of the amortized cost and fair value of investments in fixed maturity securities classified as available-for-sale by contractual maturity is as follows: December 31, 2020 December 31, 2019 Amortized Cost Fair Value Amortized Cost Fair Value (in thousands) Maturity: Within one year $ 69,177 $ 69,938 $ 27,160 $ 27,194 After one year through five years 80,593 85,829 144,142 146,469 After five years through ten years 53,835 57,829 47,175 49,419 After ten years 165,406 181,631 177,722 188,597 U.S. agency-based mortgage-backed securities 18,654 19,052 29,499 29,467 Totals $ 387,665 $ 414,279 $ 425,698 $ 441,146

Premiums Receivable (Tables)

Premiums Receivable (Tables)	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Components of Premiums Receivable	The components of premiums receivable are shown below: December 31, 2020 2019 (in thousands) Premiums receivable $ 161,551 $ 163,065 Allowance for credit losses (4,791 ) (5,112 ) Premiums receivable, net $ 156,760 $ 157,953
Summary of Activity in Allowance for Credit Losses	The following summarizes the activity in the allowance for credit losses: December 31, 2020 2019 (in thousands) Balance, beginning of year $ 5,112 $ 5,390 Provision for credit loss expense 1,278 723 Write-offs (1,599 ) (1,001 ) Balance, end of year $ 4,791 $ 5,112

Deferred Policy Acquisition C_2

Deferred Policy Acquisition Costs (Tables)	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Schedule of Major Categories of the Deferred Policy Acquisition Costs	Major categories of the Company’s deferred policy acquisition costs are summarized as follows: December 31, 2020 2019 (in thousands) Agents’ commissions $ 13,244 $ 14,290 Premium taxes 2,806 2,960 Deferred underwriting expenses 1,760 1,798 Total deferred policy acquisition costs $ 17,810 $ 19,048
Schedule of the Activity in the Deferred Policy Acquisition Costs	The following summarizes the activity in the deferred policy acquisition costs: Year Ended December 31, 2020 2019 2018 (in thousands) Balance, beginning of year $ 19,048 $ 19,734 $ 20,251 Policy acquisition costs deferred 40,345 43,872 45,252 Amortization expense during the year (41,583 ) (44,558 ) (45,769 ) Balance, end of year $ 17,810 $ 19,048 $ 19,734

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consist of the following: December 31, 2020 2019 (in thousands) Land and office building $ 7,919 $ 7,819 Furniture and equipment 5,438 6,097 Software 7,916 7,366 Automobiles 74 74 Finance lease right-of-use assets 365 185 Total original cost 21,712 21,541 Accumulated depreciation and amortization (15,530 ) (15,210 ) Property and equipment, net $ 6,182 $ 6,331

Reinsurance (Tables)

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Schedule of the Effect of Reinsurance on Premiums Written and Earned	The effect of reinsurance on premiums written and earned in 2020, 2019 and 2018 was as follows: 2020 Premiums 2019 Premiums 2018 Premiums Written Earned Written Earned Written Earned (in thousands) Gross $ 303,090 $ 314,703 $ 333,460 $ 341,883 $ 351,696 $ 359,670 Ceded (10,276 ) (10,276 ) (8,995 ) (8,995 ) (9,344 ) (9,344 ) Net premiums $ 292,814 $ 304,427 $ 324,465 $ 332,888 $ 342,352 $ 350,326
Schedule of the Amounts Recoverable from Reinsurers	The amounts recoverable from reinsurers consist of the following: December 31, 2020 2019 (in thousands) Unpaid losses recoverable: Case basis $ 88,622 $ 82,252 Incurred but not reported 17,085 13,090 Paid losses recoverable 548 571 Allowance for credit losses (452 ) — Total $ 105,803 $ 95,913
Schedule of Unsecured Reinsurance Recoverables from Reinsurers	Reinsurer A.M. Best Rating Amounts Recoverable as of December 31, 2020 (in thousands) Hannover Reinsurance (Ireland) Limited (1) A+ $ 56,753 Allianz Risk Transfer AG (Bermuda) A+ 12,050 Odyssey America Reinsurance Corporation A 8,688 Minnesota Workers' Compensation Reinsurance Association (1) NR 6,367 Other reinsurers 22,397 Total amounts recoverable from reinsurers 106,255 Allowance for credit losses (452 ) Total amounts recoverable from reinsurers net of allowance for credit losses 105,803 Funds withheld and letters of credit related to the above recoverables (71,986 ) Total unsecured amounts recoverable from reinsurers $ 33,817 (1) Current participant in our 2021 reinsurance program.
Change in Allowance for Credit Losses on Amounts Recoverable from Reinsurers	The table below presents the change in the allowance for credit losses on amounts recoverable from reinsurers for the year ended December 31, 2020. Year Ended December 31, 2020 (in thousands) Balance, beginning of period $ 444 Provision for credit loss benefit 8 Balance, end of period $ 452

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Company's Deferred Income Tax Assets and Liabilities	The Company’s deferred income tax assets and liabilities are as follows: December 31, 2020 2019 (in thousands) Deferred income tax assets: Discounting of net unpaid loss and loss adjustment expenses $ 19,297 $ 19,985 Unearned premiums 6,984 7,638 Accrued expenses and other 2,947 2,612 State income tax 2,212 2,484 Accrued policyholder dividends 2,020 2,330 Capital loss carryforward — 20 Accrued insurance-related assessments 1,963 2,672 Total deferred tax assets 35,423 37,741 Less: Valuation allowance (2,169 ) (2,025 ) Net deferred tax assets 33,254 35,716 Deferred income tax liabilities: Deferred policy acquisition costs (4,547 ) (4,838 ) Callable bond amortization — (2 ) Unrealized gain on securities available-for-sale (7,194 ) (3,970 ) Property and equipment and other (260 ) (271 ) Salvage and subrogation (516 ) (636 ) Loss reserves adjustment due to the Tax Act (7,072 ) (8,486 ) Total deferred income tax liabilities (19,589 ) (18,203 ) Net deferred income taxes $ 13,665 $ 17,513
Components of Consolidated Income Tax Expense (Benefit)	The components of consolidated income tax expense (benefit) are as follows: Year Ended December 31, 2020 2019 2018 (in thousands) Current: Federal $ 17,760 $ 20,658 $ 16,407 State 900 1,297 1,004 18,660 21,955 17,411 Deferred: Federal 1,403 732 (1,389 ) State 254 140 (73 ) 1,657 872 (1,462 ) Total $ 20,317 $ 22,827 $ 15,949
Income Tax Expense from Operations from the Amount Computed by Applying the U.S. Federal Income Tax Statutory Rate of 21% to Income Before Income Taxes	Income tax expense from operations is different from the amount computed by applying the U.S. federal income tax statutory rate of 21% to income before income taxes as follows: Year Ended December 31, 2020 2019 2018 (in thousands) Income tax computed at federal statutory tax rate $ 22,453 $ 24,258 $ 18,392 Tax-exempt interest, net (3,226 ) (2,999 ) (2,965 ) State income tax 1,080 1,178 720 Dividends received deduction (89 ) (59 ) (44 ) Other 99 449 (154 ) $ 20,317 $ 22,827 $ 15,949

Loss and Loss Adjustment Expe_2

Loss and Loss Adjustment Expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Summary of Development Tables of Incurred and Paid Losses and Allocated Loss Adjustment Expenses Net of Reinsurance	Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance As of For the Years Ended December 31, December 31, 2020 (Dollars in thousands) Total IBNR Plus Expected Cumulative Development Number of Accident Unaudited (1) on Reported Claims Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Claims Reported 2011 $ 196,384 $ 199,522 $ 199,163 $ 198,213 $ 195,262 $ 192,988 $ 191,126 $ 189,327 $ 188,226 $ 188,264 $ 5,198 6,044 2012 — 222,549 222,075 212,738 193,515 184,460 182,859 180,387 178,586 177,547 6,419 5,749 2013 — — 241,810 241,811 233,656 220,457 214,701 210,588 209,184 207,304 7,762 5,766 2014 — — — 268,846 268,846 249,097 235,058 226,933 218,386 212,417 5,468 5,839 2015 — — — — 262,573 262,573 252,514 235,471 220,965 211,758 6,717 5,516 2016 — — — — — 250,491 250,491 241,406 218,005 209,214 6,843 5,393 2017 — — — — — — 244,094 244,098 234,587 220,096 8,066 5,211 2018 — — — — — — — 250,487 250,487 235,641 16,057 5,467 2019 — — — — — — — — 241,344 241,344 16,609 5,199 2020 — — — — — — — — — 220,710 8,491 4,170 Total $ 2,124,295 $ 87,630 Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance For the Years Ended December 31, (Dollars in thousands) Accident Unaudited (1) Claim Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Frequency (2) 2011 $ 53,329 $ 111,029 $ 140,831 $ 153,968 $ 161,639 $ 165,967 $ 167,757 $ 169,994 $ 170,785 $ 171,583 22.82 2012 — 50,579 107,467 133,658 149,161 154,553 157,207 159,807 161,014 162,588 18.73 2013 — — 51,396 119,507 150,304 165,994 172,479 177,724 180,614 182,465 16.55 2014 — — — 53,060 119,820 153,320 169,736 180,683 186,129 191,394 14.99 2015 — — — — 54,141 121,599 151,818 170,461 182,053 185,657 14.25 2016 — — — — — 52,238 115,713 143,016 156,861 166,887 14.23 2017 — — — — — — 56,951 122,552 151,427 166,448 14.68 2018 — — — — — — — 62,061 126,057 152,328 15.20 2019 — — — — — — — — 58,883 120,512 15.21 2020 — — — — — — — — — 50,113 13.25 Total 1,549,975 All outstanding liabilities before 2011, net of reinsurance 80,533 Liabilities for loss and loss adjustment expenses, net of reinsurance 654,854 (1) Data presented for these calendar years is required supplementary information, which is unaudited. (2) Frequency, as calculated above, refers to reported claims divided by gross premium earned.
Summary of Average Annual Percentage Payout of Incurred Losses by Age Net of Reinsurance for Worker's Compensation and General Liability	The average annual percentage payout of incurred losses by age, net of reinsurance, for workers’ compensation and general liability as of December 31, 2020 is summarized below. Since workers’ compensation has long payout periods, the table below shows less than 100% in the years disclosed. This is required supplementary information, which is unaudited. Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance (Unaudited) Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10 25.6% 30.2% 14.1% 7.6% 4.3% 2.1% 1.6% 0.9% 0.7% 0.4%
Reconciliation of Beginning and Ending Reserve Balances, Net of Related Amounts Recoverable from Reinsurers	The following table provides a reconciliation of the beginning and ending reserve balances, net of related amounts recoverable from reinsurers, for 2020, 2019 and 2018: Year Ended December 31, 2020 2019 2018 (in thousands) Balance, beginning of period $ 772,887 $ 798,409 $ 771,845 Less amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses 95,343 107,216 84,889 Net balance, beginning of period 677,544 691,193 686,956 Add incurred related to: Current accident year 220,710 241,344 250,487 Prior accident years (63,484 ) (65,002 ) (45,596 ) Total incurred 157,226 176,342 204,891 Less paid related to: Current accident year 50,113 58,883 62,061 Prior accident years 129,803 131,108 138,593 Total paid 179,916 189,991 200,654 Net balance, end of period 654,854 677,544 691,193 Add amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses 105,707 95,343 107,216 Balance, end of period $ 760,561 $ 772,887 $ 798,409
Summary Exposures to Various Asbestos Related Claims	The following table details our exposures to various asbestos related claims: Year Ended December 31, 2020 2019 2018 (in thousands) Reserves for loss and LAE at beginning of year $ 1,323 $ 1,555 $ 1,748 Incurred losses and LAE during the current year (936 ) (183 ) 108 Loss and LAE payments (69 ) (49 ) (301 ) Reserves for loss and LAE at end of year $ 318 $ 1,323 $ 1,555

Statutory Accounting and Regu_2

Statutory Accounting and Regulatory Requirements (Tables)	12 Months Ended
	Dec. 31, 2018
Insurance [Abstract]
Insurance Subsidiaries	Statutory-basis shareholders’ capital and surplus at December 31, 2020, 2019 and 2018 of the directly owned insurance subsidiary, AIIC, and the combined statutory-basis net income and realized investment gains for all AMERISAFE’s insurance subsidiaries for the three years in the period ended December 31, 2020, were as follows: 2020 2019 2018 (in thousands) Capital and surplus $ 365,524 $ 359,952 $ 383,575 Net income 82,390 92,301 72,979 Net realized gains (losses) on investments 1,075 (80 ) (1,536 )

Restricted Stock and Stock Op_2

Restricted Stock and Stock Options (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Option Activity	The following table summarizes information about the stock option activity under the 2005 Incentive Plan: Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in years) Outstanding at January 1, 2018 20,000 5.21 2.1 Granted — — — Exercised (15,000 ) 4.46 0.9 Canceled, forfeited, or expired — — — Outstanding at December 31, 2018 5,000 3.95 1.9 Exercisable at December 31, 2018 5,000 3.95 1.9 Outstanding at January 1, 2019 5,000 3.95 1.9 Granted — — — Exercised (5,000 ) 3.95 0.9 Canceled, forfeited, or expired — — — Outstanding at December 31, 2019 — — — Exercisable at December 31, 2019 — — — Outstanding at January 1, 2020 — — — Granted — — — Exercised — — — Canceled, forfeited, or expired — — — Outstanding at December 31, 2020 — — — Exercisable at December 31, 2020 — — —
Weighted Average Grant Date Fair Values of Options Granted	2020 2019 2018 (in thousands) Cash received from option exercises $ — $ 20 $ 67 Total intrinsic value of options exercised — 287 766 Aggregate intrinsic value of vested options outstanding — — 264
Restricted Stock Activity	The following table summarizes information about the common and restricted stock activity under the 2012 Incentive Plan: Shares Weighted Average Grant Date Fair Value per Share Nonvested balance at January 1, 2018 60,879 45.71 Granted 3,304 59.16 Vested (24,608 ) 44.31 Forfeited — — Nonvested balance at December 31, 2018 39,575 48.93 Granted 22,713 61.08 Vested (29,760 ) 51.86 Forfeited — — Nonvested balance at December 31, 2019 32,528 54.02 Granted 23,207 58.62 Vested (40,421 ) 54.31 Forfeited — — Nonvested balance at December 31, 2020 15,314 60.23 The following table summarizes information about the restricted stock activity under the Non-Employee Director Restricted Stock Plan: Shares Weighted Average Grant Date Fair Value per Share Nonvested balance at January 1, 2018 6,454 54.20 Granted 5,761 60.75 Vested (6,454 ) 54.20 Forfeited — — Nonvested balance at December 31, 2018 5,761 60.75 Granted 4,890 61.34 Vested (5,761 ) 60.75 Forfeited — — Nonvested balance at December 31, 2019 4,890 61.34 Granted 5,269 68.88 Vested (5,091 ) 61.49 Forfeited — — Nonvested balance at December 31, 2020 5,068 69.03

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Calculation of Basic and Diluted Earnings Per Share	The calculation of basic and diluted EPS for the years ended December 31, 2020, 2019 and 2018 are presented below. For the Year Ended December 31, 2020 2019 2018 (in thousands, except earnings per share amounts) Basic EPS: Net income – basic $ 86,602 $ 92,690 $ 71,632 Basic weighted average common shares 19,289 19,249 19,209 Basic earnings per share $ 4.49 $ 4.82 $ 3.73 Diluted EPS: Net income – diluted $ 86,602 $ 92,690 $ 71,632 Diluted weighted average common shares: Weighted average common shares 19,289 19,249 19,209 Restricted stock and stock options 75 80 84 Diluted weighted average common shares 19,364 19,329 19,293 Diluted earnings per common share $ 4.47 $ 4.80 $ 3.71
Reconciliation of Weighted Average Shares used for Basic and Diluted Earnings Per Share Calculation	The table below sets forth the reconciliation of the weighted average shares used for the basic and diluted EPS calculation. Years Ended 2020 2019 2018 Basic weighted average common shares 19,288,996 19,248,657 19,208,978 Add: Other common shares eligible for common dividends: Restricted stock and stock options 74,813 80,581 84,104 Diluted weighted average common shares 19,363,809 19,329,238 19,293,082

Comprehensive Income and Accu_2

Comprehensive Income and Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Income (AOCI)	The following table illustrates the changes in the balance of each component of accumulated other comprehensive income (loss) for each period presented in the financial statements. Year Ended December 31, 2020 2019 2018 (in thousands) Balance, beginning of period $ 12,211 $ (832 ) $ 3,612 Impact of adoption of ASU 2016-01 — — (615 ) Impact of adoption of ASU 2018-02 — — 414 Adjusted beginning balance 12,211 (832 ) 3,411 Other comprehensive income (loss) before reclassification 9,538 12,379 (4,551 ) Amounts reclassified from accumulated other comprehensive income (loss) (730 ) 664 308 Net current period other comprehensive income (loss) 8,808 13,043 (4,243 ) Balance, end of period $ 21,019 $ 12,211 $ (832 )
Reclassification Out of Accumulated Other Comprehensive Income	The effects of reclassifications out of accumulated other comprehensive income by the respective line items of net income are presented in the following table. Component of Accumulated Other Comprehensive Income (Loss) Year Ended December 31, Affected line item in the statement of income 2020 2019 2018 (in thousands) Unrealized gains (losses) on available-for- sale securities $ 925 $ (841 ) $ (390 ) Net realized gains (losses) on investments 925 (841 ) (390 ) Income before income taxes (195 ) 177 82 Income tax expense $ 730 $ (664 ) $ (308 ) Net income
Other Comprehensive Income	Pre-Tax Amount Tax Expense (Benefit) Net-of-Tax Amount (in thousands) December 31, 2020 Unrealized gain on securities: Unrealized gain on available-for-sale securities $ 12,074 $ 2,536 $ 9,538 Reclassification adjustment for gains realized in net income (925 ) (195 ) (730 ) Net unrealized gain 11,149 2,341 8,808 Other comprehensive income $ 11,149 $ 2,341 $ 8,808 December 31, 2019 Unrealized gain on securities: Unrealized gain on available-for-sale securities $ 15,670 $ 3,291 $ 12,379 Reclassification adjustment for losses realized in net income 841 177 664 Net unrealized gain 16,511 3,468 13,043 Other comprehensive income $ 16,511 $ 3,468 $ 13,043 December 31, 2018 Unrealized loss on securities: Unrealized loss on available-for-sale securities $ (5,760 ) $ (1,209 ) $ (4,551 ) Reclassification adjustment for gains realized in net income 390 82 308 Net unrealized loss (5,370 ) (1,127 ) (4,243 ) Other comprehensive loss $ (5,370 ) $ (1,127 ) $ (4,243 )

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Fair Value of Annuities	The following table summarizes the fair value of the annuities at December 31, 2020 , that the Company has purchased to satisfy its obligations. Life Insurance Company A.M. Best Rating Statement Value of Annuities Exceeding 1% of Statutory Surplus (in thousands) Pacific Life & Annuity Company A+ $ 16,489 American General Life Insurance Company A 14,462 Travelers Life and Annuity Insurance Company A 9,758 New York Life Insurance Company A++ 9,120 Metropolitan Life Insurance Company A+ 6,701 John Hancock Life Insurance Company A+ 6,536 United of Omaha Insurance Company A+ 5,141 Athene Annuity and Life Company A 4,363 Pacific Life Insurance Company A+ 4,010 Lincoln Life Assurance Company of Boston A+ 3,698 Other 18,997 $ 99,275
Components of Lease Expense	The components of lease expense were as follows: Year Ended December 31, 2020 2019 (in thousands) Operating lease cost $ 160 $ 164 Finance lease cost: Amortization of right-of-use assets 6 62 Interest on lease liabilities 2 4 Total finance lease cost $ 8 $ 66
Schedule of Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases was as follows: Year Ended December 31, 2020 2019 (in thousands) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ (116 ) $ 430 Operating cash flows from finance leases 4 46 Financing cash flows from finance leases 50 47
Schedule of Right-of-use Assets Obtained in Exchange for Lease Obligations	Right-of-use assets obtained in the exchange for the lease obligations were as follows: December 31, 2020 2019 (in thousands) Operating leases $ 56 $ 369 Finance leases 180 —
Schedule of Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases was as follows: December 31, 2020 December 31, 2019 Balance Sheet Classification (in thousands) Operating leases: Operating lease right-of-use assets $ 314 $ 430 Other assets Operating lease liabilities $ 314 $ 430 Accounts payable and other liabilities Finance leases: Finance lease right-of-use assets $ 365 $ 185 Finance lease accumulated amortization right-of-use assets (185 ) (179 ) Property and equipment, net $ 180 $ 6 Property and equipment, net Finance lease liabilities $ 185 $ 54 Accounts payable and other liabilities
Schedule of Weighted Average Remaining Lease Term and Discount Rate	December 31, 2020 2019 Weighted average remaining lease term: Operating leases 2.7 years 3.6 years Finance leases 4.9 years 1.1 years Weighted average discount rate: Operating leases 5.24 % 5.25 % Finance leases 3.30 % 5.21 %
Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating and Finance Lease Liabilities	The following is a maturity analysis of the annual undiscounted cash flows of the operating and finance lease liabilities as of December 31, 2020: Operating Leases Finance Leases (in thousands) 2021 $ 136 $ 44 2022 120 39 2023 75 39 2024 6 39 2025 — 39 Total lease payments 337 200 Less imputed interest 23 15 Total $ 314 $ 185

Concentration of Operations (Ta

Concentration of Operations (Tables)	12 Months Ended
	Dec. 31, 2020
Concentration Of Operations [Abstract]
Net Premiums Earned for the Top Ten States	Net premiums earned during 2020, 2019 and 2018 for the top ten states in 2020 and all others are shown below: 2020 2019 2018 Dollars Percent Dollars Percent Dollars Percent (Dollars in thousands) Georgia $ 37,926 12.5 % $ 38,090 11.4 % $ 40,351 11.5 % Florida 34,617 11.4 % 39,936 12.0 % 39,672 11.3 % Pennsylvania 24,340 8.0 % 27,519 8.3 % 31,708 9.1 % Louisiana 22,668 7.4 % 24,782 7.4 % 25,810 7.4 % North Carolina 17,338 5.7 % 18,800 5.7 % 19,537 5.6 % Illinois 14,802 4.9 % 16,929 5.1 % 19,710 5.6 % Virginia 14,041 4.6 % 15,249 4.6 % 15,228 4.3 % Wisconsin 12,263 4.0 % 13,388 4.0 % 14,101 4.0 % South Carolina 11,270 3.7 % 13,020 3.9 % 13,924 4.0 % Minnesota 11,057 3.6 % 13,399 4.0 % 12,900 3.7 % All others 104,105 34.2 % 111,776 33.6 % 117,385 33.5 % Total net premiums earned $ 304,427 100.0 % $ 332,888 100.0 % $ 350,326 100.0 %

Fair Values of Financial Inst_2

Fair Values of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Summary of Carrying or Reported Values and Corresponding Fair Values for Financial Instruments	The following table summarizes the carrying or reported values and corresponding fair values for financial instruments: December 31, 2020 2019 Carrying Amount Fair Value Carrying Amount Fair Value (in thousands) Assets: Fixed maturity securities—held to maturity $ 585,130 $ 621,654 $ 599,421 $ 621,343 Fixed maturity securities—available-for-sale 414,279 414,279 441,146 441,146 Equity securities 43,437 43,437 27,903 27,903 Short-term investments 45,898 45,898 56,548 56,548 Cash and cash equivalents 61,757 61,757 43,813 43,813
Schedule of Assets Measured at Fair Value on Recurring Basis	Assets measured at fair value on a recurring basis as of December 31, 2020 and 2019 are as follows: December 31, 2020 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Financial instruments carried at fair value, classified as part of: Securities available-for-sale—fixed maturity: States and political subdivisions $ — $ 276,542 $ — $ 276,542 Corporate bonds — 88,899 — 88,899 U.S. agency-based mortgage-backed securities — 19,052 — 19,052 U.S. Treasury securities 29,786 — — 29,786 Total securities available-for-sale—fixed maturity 29,786 384,493 — 414,279 Equity securities: Domestic common stock 43,437 — — 43,437 Total $ 73,223 $ 384,493 $ — $ 457,716 December 31, 2019 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Financial instruments carried at fair value, classified as part of: Securities available-for-sale—fixed maturity: States and political subdivisions $ — $ 237,775 $ — $ 237,775 Corporate bonds — 133,778 — 133,778 U.S. agency-based mortgage-backed securities — 29,467 — 29,467 U.S. Treasury securities 40,126 — — 40,126 Total securities available-for-sale—fixed maturity 40,126 401,020 — 441,146 Equity securities: Domestic common stock 27,903 — — 27,903 Total $ 68,029 $ 401,020 $ — $ 469,049
Schedule of Assets Measured at Amortized Cost	Assets measured at amortized cost as of December 31, 2020 and 2019 are as follows: December 31, 2020 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Securities held-to-maturity—fixed maturity: States and political subdivisions $ — $ 526,821 $ — $ 526,821 Corporate bonds — 72,900 — 72,900 U.S. agency-based mortgage-backed securities — 7,906 — 7,906 U.S. Treasury securities 13,865 — — 13,865 Asset-backed securities — 162 — 162 Total held-to-maturity $ 13,865 $ 607,789 $ — $ 621,654 December 31, 2019 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Securities held-to-maturity—fixed maturity: States and political subdivisions $ — $ 485,647 $ — $ 485,647 Corporate bonds — 110,925 — 110,925 U.S. agency-based mortgage-backed securities — 11,511 — 11,511 U.S. Treasury securities 7,873 — — 7,873 Obligations of U.S. government agencies — 5,168 — 5,168 Asset-backed securities — 219 — 219 Total held-to-maturity $ 7,873 $ 613,470 $ — $ 621,343

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Unaudited Quarterly Financial Data	The following table represents unaudited quarterly financial data for the years ended December 31, 2020 and 2019. Three Months Ended March 31 June 30 September 30 December 31 (in thousands, except per share amounts) 2020 Net premiums earned $ 78,990 $ 75,964 $ 74,771 $ 74,702 Net investment income 7,749 7,324 7,063 7,228 Net realized gains (losses) on investments 992 163 309 (332 ) Net unrealized gains (losses) on equity securities (8,763 ) 5,570 844 6,553 Total revenues 79,169 89,082 83,005 88,221 Income before income taxes 13,241 29,391 28,669 35,618 Net income 10,800 23,948 23,353 28,501 Earnings per share: Basic $ 0.56 $ 1.24 $ 1.21 $ 1.48 Diluted $ 0.56 $ 1.24 $ 1.21 $ 1.47 Comprehensive income 12,284 29,431 24,087 29,608 Extraordinary cash dividends declared per common share $ — $ — $ — $ 3.50 Cash dividends declared per common share $ 0.27 $ 0.27 $ 0.27 $ 0.27 2019 Net premiums earned $ 84,948 $ 82,951 $ 82,712 $ 82,277 Net investment income 8,015 8,169 8,264 8,035 Net realized gains (losses) on investments 59 (82 ) (4 ) (53 ) Net unrealized gains on equity securities 2,158 642 365 1,593 Total revenues 95,190 91,753 91,488 91,939 Income before income taxes 23,809 22,169 26,613 42,926 Net income 19,400 17,890 21,386 34,014 Earnings per share: Basic $ 1.01 $ 0.93 $ 1.11 $ 1.77 Diluted $ 1.01 $ 0.93 $ 1.11 $ 1.76 Comprehensive income 25,193 23,068 23,862 33,610 Extraordinary cash dividends declared per common share $ — $ — $ — $ 3.50 Cash dividends declared per common share $ 0.25 $ 0.25 $ 0.25 $ 0.25

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)

3 Months Ended

12 Months Ended

Dec. 31, 2020

Sep. 30, 2020

Jun. 30, 2020

Mar. 31, 2020

Dec. 31, 2019

Sep. 30, 2019

Jun. 30, 2019

Mar. 31, 2019

Mar. 31, 2018

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

Jan. 01, 2020

Jan. 01, 2019

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Percentage of comparable consolidated amounts

95.00%

95.00%

95.00%

Decrease in net income

$ 86,602,000

$ 92,690,000

$ 71,632,000

Decrease to diluted earnings per common share

$ 1.47

$ 1.21

$ 1.24

$ 0.56

$ 1.76

$ 1.11

$ 0.93

$ 1.01

$ 4.47

$ 4.80

$ 3.71

Right-of-use assets

$ 314,000

$ 430,000

$ 314,000

$ 430,000

Operating lease liabilities

314,000

430,000

314,000

430,000

Net decrease to retained earnings, cumulative effect

(224,645,000)

(227,165,000)

(224,645,000)

(227,165,000)

Credit allowance for held-to-maturity fixed income securities

274,000

0

274,000

0

Credit allowance for reinsurance recoverables

452,000

0

452,000

0

Available-for-sale securities, credit allowance

$ 0

0

$ 0

0

Trading securities, par value per share

$ 100

Reinsurance recoverables, current credit rating period

10 years

Reinsurance treaty term to be commuted by end of current credit rating period

3 years

Other-than-temporary impairment loss, debt securities, portion recognized in earnings

$ 0

Financial assets purchased with credit deterioration, financing receivable

0

Financial assets purchased with credit deterioration, held-to-maturity debt securities

0

Financial assets purchased with credit deterioration, available-for-sale debt securities

$ 0

Threshold period for writing off balances receivable

90 days

90 days

Original maturity of cash equivalent

90 days

Minimum period of underwriting workers’ compensation insurance from which historical loss data utilize

35 years

Experience rated commission and other operating costs

$ 0

200,000

$ 200,000

Commutation payment adjusted through offset against balance of funds withheld and recoverable from reinsurers accounts

$ 8,500,000

8,500,000

Advertising expense

$ 200,000

$ 400,000

$ 400,000

Assessment Related premium Payment period

1 year

Assessment Related loss Payment period

1 year

Buildings [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Estimated useful life of assets

39 years

Maximum [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Short-term investments maturity period

1 year

Maximum [Member] | Other Fixed Assets [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Estimated useful life of assets

7 years

Minimum [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Trading price of securities excluded from watch list

$ 95

Short-term investments maturity period

90 days

Minimum [Member] | Other Fixed Assets [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Estimated useful life of assets

3 years

Corporate Fixed Income Securities [Member] | Maximum [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Investments maturity period using default rate

20 years

Municipal Fixed Income Securities [Member] | Maximum [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Investments maturity period using default rate

20 years

ASU 2016-02 [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Right-of-use assets

$ 400,000

Operating lease liabilities

$ 300,000

ASU 2016-13 [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Credit allowance for held-to-maturity fixed income securities

$ 243,000

Credit allowance for reinsurance recoverables

351,000

ASU 2016-13 [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Net decrease to retained earnings, cumulative effect

$ 594,000

ASU 2016-01 [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Decrease in net income

$ 390,000

ASU 2016-01 [Member] | Common Shares [Member]

New Accounting Pronouncements Or Change In Accounting Principle [Line Items]

Decrease to diluted earnings per common share

$ 0.02

Investments - Additional Inform

Investments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)Security	Dec. 31, 2019USD ($)
Marketable Securities [Line Items]
Individual fixed maturity held in unrealized loss position | Security	2
Individual fixed maturity held in unrealized loss position longer than 12 months | Security	12
Number of fixed maturity securities, allowance for credit loss | Security	424
Fixed maturity securities, allowance for credit loss	$ 274,000	$ 0
Impairment losses recognized		0
Held-to-Maturity Securities [Member]
Marketable Securities [Line Items]
Investments on deposit with regulatory agencies	19,900,000
Corporate Bonds [Member]
Marketable Securities [Line Items]
Short-term investments	6,100,000
Fixed maturity securities, allowance for credit loss	$ 225,000
Number of majority securities | Security	393
States and Political Subdivisions [Member]
Marketable Securities [Line Items]
Short-term investments	$ 9,100,000	1,900,000
Fixed maturity securities, allowance for credit loss	$ 42,000
Number of majority securities | Security	28
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Marketable Securities [Line Items]
Short-term investments	$ 30,700,000	$ 54,600,000
Corporate Fixed Income Securities [Member] | Maximum [Member]
Marketable Securities [Line Items]
Investments maturity period using default rate	20 years

Investments - Gross Unrealized

Investments - Gross Unrealized Gains and Losses and Amortized Cost and Fair Value of Investments Classified as Held-to-Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity, Amortized Cost, Totals	$ 585,404	$ 599,421
Held-to-Maturity, Allowance for Credit Losses	(274)	0
Held-to-Maturity, Carrying Amount	585,130	599,421
Held-to-Maturity, Gross Unrecognized Gains	36,524	22,128
Held-to-Maturity, Gross Unrecognized Losses		(206)
Held-to-Maturity, Fair Value	621,654	621,343
States and Political Subdivisions [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity, Amortized Cost, Totals	494,374	466,270
Held-to-Maturity, Allowance for Credit Losses	(42)
Held-to-Maturity, Carrying Amount	494,332
Held-to-Maturity, Gross Unrecognized Gains	32,489	19,570
Held-to-Maturity, Gross Unrecognized Losses		(193)
Held-to-Maturity, Fair Value	526,821	485,647
Corporate Bonds [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity, Amortized Cost, Totals	69,981	109,241
Held-to-Maturity, Allowance for Credit Losses	(225)
Held-to-Maturity, Carrying Amount	69,756
Held-to-Maturity, Gross Unrecognized Gains	3,144	1,684
Held-to-Maturity, Fair Value	72,900	110,925
U.S. Agency-Based Mortgage-Backed Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity, Amortized Cost, Totals	7,261	10,967
Held-to-Maturity, Carrying Amount	7,261
Held-to-Maturity, Gross Unrecognized Gains	645	544
Held-to-Maturity, Fair Value	7,906	11,511
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity, Amortized Cost, Totals	13,626	12,723
Held-to-Maturity, Carrying Amount	13,626
Held-to-Maturity, Gross Unrecognized Gains	239	330
Held-to-Maturity, Gross Unrecognized Losses		(12)
Held-to-Maturity, Fair Value	13,865	13,041
Asset-Backed Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity, Amortized Cost, Totals	162	220
Held-to-Maturity, Allowance for Credit Losses	(7)
Held-to-Maturity, Carrying Amount	155
Held-to-Maturity, Gross Unrecognized Gains	7
Held-to-Maturity, Gross Unrecognized Losses		(1)
Held-to-Maturity, Fair Value	$ 162	$ 219

Investments - Gross Unrealize_2

Investments - Gross Unrealized Gains and Losses and Cost or Amortized Cost and Fair Value of Investments Classified as Available-for-Sale (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	$ 387,665,000	$ 425,698,000
Available-for-sale, Gross Unrealized Gains	26,619,000	15,613,000
Available-for-sale, Gross Unrealized Losses	(5,000)	(165,000)
Available-for-sale, Fair Value	414,279,000	441,146,000
Available-for-sale, Allowance for Credit Losses	0	0
States and Political Subdivisions [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	256,492,000	225,895,000
Available-for-sale, Gross Unrealized Gains	20,050,000	11,906,000
Available-for-sale, Gross Unrealized Losses		(26,000)
Available-for-sale, Fair Value	276,542,000	237,775,000
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	83,646,000	130,453,000
Available-for-sale, Gross Unrealized Gains	5,256,000	3,326,000
Available-for-sale, Gross Unrealized Losses	(3,000)	(1,000)
Available-for-sale, Fair Value	88,899,000	133,778,000
U.S. Agency-Based Mortgage-Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	18,654,000	29,499,000
Available-for-sale, Gross Unrealized Gains	400,000	64,000
Available-for-sale, Gross Unrealized Losses	(2,000)	(96,000)
Available-for-sale, Fair Value	19,052,000	29,467,000
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale, Amortized Cost	28,873,000	39,851,000
Available-for-sale, Gross Unrealized Gains	913,000	317,000
Available-for-sale, Gross Unrealized Losses		(42,000)
Available-for-sale, Fair Value	$ 29,786,000	$ 40,126,000

Investments - Gross Unrealize_3

Investments - Gross Unrealized Gains and Losses and Cost of Equity (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Equity securities, Cost	$ 35,787	$ 24,457
Equity securities, Gross Unrealized Gains	7,650	3,446
Equity securities, Fair Value	43,437	27,903
Domestic Common Stock [Member]
Schedule Of Trading Securities And Other Trading Assets [Line Items]
Equity securities, Cost	35,787	24,457
Equity securities, Gross Unrealized Gains	7,650	3,446
Equity securities, Fair Value	$ 43,437	$ 27,903

Investments - Summary of Carryi

Investments - Summary of Carrying Amounts and Fair Value of Investments in Fixed Maturity Securities, Classified as Held-to-Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Held To Maturity Securities [Line Items]
Within one year, Carrying Amount	$ 54,316	$ 49,967
After one year through five years, Carrying Amount	195,706	198,025
After five years through ten years, Carrying Amount	107,347	110,460
After ten years, Carrying Amount	220,345	229,782
Held-to-maturity, Carrying Amount, Totals	585,130	599,421
Within one year, Fair Value	54,794	50,348
After one year through five years, Fair Value	204,289	202,109
After five years through ten years, Fair Value	113,643	113,877
After ten years, Fair Value	240,860	243,279
Held-to-maturity, Fair Value, Totals	621,654	621,343
U.S. Agency-Based Mortgage-Backed Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Without single maturity, Carrying Amount	7,261	10,967
Held-to-maturity, Carrying Amount, Totals	7,261
Without single maturity, Fair Value	7,906	11,511
Held-to-maturity, Fair Value, Totals	7,906	11,511
Asset-Backed Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Without single maturity, Carrying Amount	155	220
Held-to-maturity, Carrying Amount, Totals	155
Without single maturity, Fair Value	162	219
Held-to-maturity, Fair Value, Totals	$ 162	$ 219

Investments - Summary of Amorti

Investments - Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, Classified as Available-for-Sale (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Within one year, Amortized Cost	$ 69,177	$ 27,160
After one year through five years, Amortized Cost	80,593	144,142
After five years through ten years, Amortized Cost	53,835	47,175
After ten years, Amortized Cost	165,406	177,722
Available-for-sale, Amortized Cost	387,665	425,698
Within one year, Fair Value	69,938	27,194
After one year through five years, Fair Value	85,829	146,469
After five years through ten years, Fair Value	57,829	49,419
After ten years, Fair Value	181,631	188,597
Available-for-sale, Fair Value	414,279	441,146
U.S. Agency-Based Mortgage-Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Without single maturity date, Amortized Cost	18,654	29,499
Available-for-sale, Amortized Cost	18,654	29,499
Without single maturity date, Fair value	19,052	29,467
Available-for-sale, Fair Value	$ 19,052	$ 29,467

Investments - A Summary of the

Investments - A Summary of the Company's Realized Gains and Losses on Sales, Calls or Redemptions of Investments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Marketable Securities [Line Items]
Proceeds from sales									$ 72,395	$ 55,090	$ 15,028
Gross realized investment gains									1,017	176	239
Gross realized investment (losses)									(18)	(68)	(1,354)
Net realized investment gains (losses)									999	108	(1,115)
Other, including gains (losses) on calls and redemptions									133	(188)	(421)
Net realized gains (losses) on investments	$ (332)	$ 309	$ 163	$ 992	$ (53)	$ (4)	$ (82)	$ 59	1,132	(80)	(1,536)
Fixed Maturity Securities Available for Sale [Member]
Marketable Securities [Line Items]
Proceeds from sales									25,436	33,113	15,025
Gross realized investment gains									711	140	238
Gross realized investment (losses)									(14)	(68)	(1,354)
Net realized investment gains (losses)									697	72	(1,116)
Other, including gains (losses) on calls and redemptions									(43)	(196)	(144)
Net realized gains (losses) on investments									654	(124)	(1,260)
Equity Securities [Member]
Marketable Securities [Line Items]
Proceeds from sales											3
Gross realized investment gains											1
Net realized investment gains (losses)											1
Net realized gains (losses) on investments											1
Other [Member]
Marketable Securities [Line Items]
Proceeds from sales									46,959	21,977
Gross realized investment gains									306	36
Gross realized investment (losses)									(4)
Net realized investment gains (losses)									302	36
Other, including gains (losses) on calls and redemptions									176	8	(277)
Net realized gains (losses) on investments									$ 478	$ 44	$ (277)

Investments - Major Categories

Investments - Major Categories of the Company's Net Investment Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total gross investment income									$ 30,317	$ 33,449	$ 31,418
Investment expenses									(953)	(966)	(966)
Net investment income	$ 7,228	$ 7,063	$ 7,324	$ 7,749	$ 8,035	$ 8,264	$ 8,169	$ 8,015	29,364	32,483	30,452
Fixed Maturity Securities Available for Sale [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total gross investment income									28,414	30,343	28,762
Equity Securities [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total gross investment income									1,006	628	448
Short-term Investments [Member]
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total gross investment income									$ 897	$ 2,478	$ 2,208

Investments - Investment Securi

Investments - Investment Securities Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Marketable Securities [Line Items]
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, Less Than 12 Months		$ 21,074
Held-to-Maturity, Gross Unrealized Losses, Less Than 12 Months		193
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, 12 Months or Greater		3,311
Held-to-Maturity, Gross Unrealized Losses, 12 Months or Greater		13
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, Total		24,385
Held-to-Maturity, Gross Unrealized Losses, Total		206
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	$ 4,648	23,573
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	5	122
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater		18,220
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater		43
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	4,648	41,793
Available-for Sale, Gross Unrealized Losses, Total	5	165
Fair Value of Investments with Unrealized Losses, Less Than 12 months		44,647
Gross Unrealized Loss, Less Than 12 Months		315
Fair Value of Investments with Unrealized Losses, 12 Months or Greater		21,531
Gross Unrealized Losses, 12 Months or Greater		56
Fair Value of Investments with Unrealized Losses, Total		66,178
Gross Unrealized Losses, Total		371
Corporate Bonds [Member]
Marketable Securities [Line Items]
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	2,515	6,426
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	3	1
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	2,515	6,426
Available-for Sale, Gross Unrealized Losses, Total	3	1
U.S. Agency-Based Mortgage-Backed Securities [Member]
Marketable Securities [Line Items]
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	2,133	13,007
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	2	95
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater		1,152
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater		1
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	2,133	14,159
Available-for Sale, Gross Unrealized Losses, Total	$ 2	96
States and Political Subdivisions [Member]
Marketable Securities [Line Items]
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, Less Than 12 Months		21,074
Held-to-Maturity, Gross Unrealized Losses, Less Than 12 Months		193
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, Total		21,074
Held-to-Maturity, Gross Unrealized Losses, Total		193
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months		4,140
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months		26
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total		4,140
Available-for Sale, Gross Unrealized Losses, Total		26
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Marketable Securities [Line Items]
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, 12 Months or Greater		3,243
Held-to-Maturity, Gross Unrealized Losses, 12 Months or Greater		12
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, Total		3,243
Held-to-Maturity, Gross Unrealized Losses, Total		12
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater		17,068
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater		42
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total		17,068
Available-for Sale, Gross Unrealized Losses, Total		42
Asset-Backed Securities [Member]
Marketable Securities [Line Items]
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, 12 Months or Greater		68
Held-to-Maturity, Gross Unrealized Losses, 12 Months or Greater		1
Held-to-Maturity, Fair Value of Investments with Unrealized Losses, Total		68
Held-to-Maturity, Gross Unrealized Losses, Total		$ 1

Investments - Changes in Allowa

Investments - Changes in Allowance for Credit Losses by Major Security Type of Investments Classified as Held-to-Maturity (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Balance	$ 301
Provision for credit loss benefit	(27)
Balance	274
Amortized cost	585,404
AAA/AA/A Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	541,199
Baa/BBB Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	44,172
B Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	33
States and Political Subdivisions [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Balance	45
Provision for credit loss benefit	(3)
Balance	42
Amortized cost	494,374
States and Political Subdivisions [Member] | AAA/AA/A Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	490,311
States and Political Subdivisions [Member] | Baa/BBB Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	4,063
Corporate Bonds [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Balance	245
Provision for credit loss benefit	(20)
Balance	225
Amortized cost	69,981
Corporate Bonds [Member] | AAA/AA/A Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	29,890
Corporate Bonds [Member] | Baa/BBB Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	40,091
U.S. Agency-Based Mortgage-Backed Securities [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	7,261
U.S. Agency-Based Mortgage-Backed Securities [Member] | AAA/AA/A Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	7,261
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	13,626
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member] | AAA/AA/A Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	13,626
Asset-Backed Securities [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Balance	11
Provision for credit loss benefit	(4)
Balance	7
Amortized cost	162
Asset-Backed Securities [Member] | AAA/AA/A Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	111
Asset-Backed Securities [Member] | Baa/BBB Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	18
Asset-Backed Securities [Member] | B Ratings [Member]
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]
Amortized cost	$ 33

Premiums Receivable - Component

Premiums Receivable - Components of Premiums Receivable (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Premiums Receivable, Net [Abstract]
Premiums receivable	$ 161,551	$ 163,065
Allowance for credit losses	(4,791)	(5,112)	$ (5,390)
Premiums receivable, net	$ 156,760	$ 157,953

Premiums Receivable - Summary o

Premiums Receivable - Summary of Activity in Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Premiums Receivable, Allowance for Doubtful Accounts [Roll Forward]
Balance, beginning of year	$ 5,112	$ 5,390
Provision for credit loss expense	1,278	723
Write-offs	(1,599)	(1,001)
Balance, end of year	$ 4,791	$ 5,112

Premiums Receivable - Additiona

Premiums Receivable - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Premiums Receivable, Net [Abstract]
Earned but Unbilled	$ 6.3	$ 8.5	$ 7.5

Deferred Policy Acquisition C_3

Deferred Policy Acquisition Costs - Schedule of Major Categories of the Deferred Policy Acquisition Costs (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred Charges Insurers [Abstract]
Agents’ commissions	$ 13,244	$ 14,290
Premium taxes	2,806	2,960
Deferred underwriting expenses	1,760	1,798
Total deferred policy acquisition costs	$ 17,810	$ 19,048	$ 19,734	$ 20,251

Deferred Policy Acquisition C_4

Deferred Policy Acquisition Costs - Schedule of Activity in the Deferred Policy Acquisition Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	$ 19,048	$ 19,734	$ 20,251
Policy acquisition costs deferred	40,345	43,872	45,252
Amortization expense during the year	(41,583)	(44,558)	(45,769)
Balance, end of year	$ 17,810	$ 19,048	$ 19,734

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 21,712	$ 21,541
Accumulated depreciation and amortization	(15,530)	(15,210)
Property and equipment, net	6,182	6,331
Land and Office Building [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	7,919	7,819
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	5,438	6,097
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	7,916	7,366
Automobiles [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	74	74
Finance Lease Right-of-use Assets [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 365	$ 185

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Accumulated depreciation	$ 0.2	$ 0.2

Reinsurance - Schedule of the E

Reinsurance - Schedule of the Effect of Reinsurance on Premiums Written and Earned (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Premiums Written and Earned [Abstract]
Gross Written									$ 303,090	$ 333,460	$ 351,696
Ceded Written									(10,276)	(8,995)	(9,344)
Net premiums Written									292,814	324,465	342,352
Gross Earned									314,703	341,883	359,670
Ceded Earned									(10,276)	(8,995)	(9,344)
Net premiums Earned	$ 74,702	$ 74,771	$ 75,964	$ 78,990	$ 82,277	$ 82,712	$ 82,951	$ 84,948	$ 304,427	$ 332,888	$ 350,326

Reinsurance - Schedule of the A

Reinsurance - Schedule of the Amounts Recoverable from Reinsurers (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Unpaid losses recoverable:
Case basis	$ 88,622	$ 82,252
Incurred but not reported	17,085	13,090
Paid losses recoverable	548	571
Allowance for credit losses	(452)	0
Total reinsurance recoverables	$ 105,803	$ 95,913

Reinsurance - Additional Inform

Reinsurance - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Insurance [Abstract]
Paid losses recoverable outstanding due date	90 days
Received reinsurance recoveries	$ 4.4	$ 2	$ 1.3
Unsecured reinsurance recoverable by reinsurer reporting threshold	1.50%

Reinsurance - Schedule of Unsec

Reinsurance - Schedule of Unsecured Reinsurance Recoverables from Reinsurers (Detail) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Ceded Credit Risk [Line Items]
Total reinsurance recoverables		$ 105,803	$ 95,913
Allowance for credit losses		(452)	$ 0
Funds withheld and letters of credit related to the above recoverables		(71,986)
Total unsecured amounts recoverable from reinsurers		33,817
Reinsurance Recoverable [Member] | Reinsurer Concentration Risk
Ceded Credit Risk [Line Items]
Total reinsurance recoverables		105,803
Total amounts recoverable from reinsurers		106,255
Allowance for credit losses		(452)
Reinsurance Recoverable [Member] | Reinsurer Concentration Risk | Hannover Reinsurance (Ireland) Limited [Member] | A.M. Best Rating, A+ [Member]
Ceded Credit Risk [Line Items]
Total reinsurance recoverables	[1]	56,753
Reinsurance Recoverable [Member] | Reinsurer Concentration Risk | Allianz Risk Transfer AG (Bermuda) [Member] | A.M. Best Rating, A+ [Member]
Ceded Credit Risk [Line Items]
Total reinsurance recoverables		12,050
Reinsurance Recoverable [Member] | Reinsurer Concentration Risk | Odyssey America Reinsurance Corporation [Member] | A.M. Best Rating, A [Member]
Ceded Credit Risk [Line Items]
Total reinsurance recoverables		8,688
Reinsurance Recoverable [Member] | Reinsurer Concentration Risk | Minnesota Workers' Compensation Reinsurance Association [Member]
Ceded Credit Risk [Line Items]
Total reinsurance recoverables	[1]	6,367
Reinsurance Recoverable [Member] | Reinsurer Concentration Risk | Other Reinsurers [Member]
Ceded Credit Risk [Line Items]
Total reinsurance recoverables		$ 22,397
[1]	Current participant in our 2021 reinsurance program.

Reinsurance - Change in Allowan

Reinsurance - Change in Allowance for Credit Losses on Amounts Recoverable from Reinsurers (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Insurance [Abstract]
Balance, beginning of period	$ 444
Provision for credit loss benefit	8
Balance, end of period	$ 452

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Company's Deferred Income Tax Assets and Liabilities (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred income tax assets:
Discounting of net unpaid loss and loss adjustment expenses	$ 19,297,000	$ 19,985,000
Unearned premiums	6,984,000	7,638,000
Accrued expenses and other	2,947,000	2,612,000
State income tax	2,212,000	2,484,000
Accrued policyholder dividends	2,020,000	2,330,000
Capital loss carryforward		20,000
Accrued insurance-related assessments	1,963,000	2,672,000
Total deferred tax assets	35,423,000	37,741,000
Less: Valuation allowance	(2,169,000)	(2,025,000)	$ 0
Net deferred tax assets	33,254,000	35,716,000
Deferred income tax liabilities:
Deferred policy acquisition costs	(4,547,000)	(4,838,000)
Callable bond amortization		(2,000)
Unrealized gain on securities available-for-sale	(7,194,000)	(3,970,000)
Property and equipment and other	(260,000)	(271,000)
Salvage and subrogation	(516,000)	(636,000)
Loss reserves adjustment due to the Tax Act	(7,072,000)	(8,486,000)
Total deferred income tax liabilities	(19,589,000)	(18,203,000)
Net deferred income taxes	$ 13,665,000	$ 17,513,000

Income Taxes - Components of Co

Income Taxes - Components of Consolidated Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 17,760	$ 20,658	$ 16,407
State	900	1,297	1,004
Total Current	18,660	21,955	17,411
Deferred:
Federal	1,403	732	(1,389)
State	254	140	(73)
Total Deferred	1,657	872	(1,462)
Income tax expense, Total	$ 20,317	$ 22,827	$ 15,949

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Valuation allowance	$ 2,169,000	$ 2,025,000	$ 0
U.S. federal income tax statutory rate	21.00%	21.00%	21.00%
Uncertain tax positions recognized	$ 0	$ 0	$ 0

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense from Operations from the Amount Computed by Applying the U.S. Federal Income Tax Statutory Rate of 21% to Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income tax computed at federal statutory tax rate	$ 22,453	$ 24,258	$ 18,392
Tax-exempt interest, net	(3,226)	(2,999)	(2,965)
State income tax	1,080	1,178	720
Dividends received deduction	(89)	(59)	(44)
Other	99	449	(154)
Income tax expense, Total	$ 20,317	$ 22,827	$ 15,949

Line of Credit - Additional Inf

Line of Credit - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Maximum amount of line of credit	$ 20,000,000
Line of credit facility expiration date	Dec. 31, 2022
Outstanding borrowings or letters of credit	$ 0	$ 0
Line of Credit Facility Expired December 2022 [Member]
Line of Credit Facility [Line Items]
Payment on unused portion of the loan	0.25%
Total fee	$ 50,000

Loss and Loss Adjustment Expe_3

Loss and Loss Adjustment Expenses - Development Tables of Incurred and Paid Losses and Allocated Loss Adjustment Expenses Net of Reinsurance (Detail) $ in Thousands		12 Months Ended
		Dec. 31, 2020USD ($)Claim	Dec. 31, 2019USD ($)		Dec. 31, 2018USD ($)		Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)		Dec. 31, 2014USD ($)		Dec. 31, 2013USD ($)		Dec. 31, 2012USD ($)		Dec. 31, 2011USD ($)
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 2,124,295
Total IBNR Plus Expected Development on Reported Claims		87,630
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	1,549,975
All outstanding liabilities before 2011, net of reinsurance		80,533
Liabilities for loss and loss adjustment expenses, net of reinsurance		654,854
Accident Year 2011 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		188,264	$ 188,226	[1]	$ 189,327	[1]	$ 191,126	[1]	$ 192,988	[1]	$ 195,262	[1]	$ 198,213	[1]	$ 199,163	[1]	$ 199,522	[1]	$ 196,384	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 5,198
Cumulative Number of Claims Reported | Claim		6,044
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 171,583	170,785		169,994		167,757		165,967		161,639		153,968		140,831		111,029		$ 53,329
Claim Frequency	[2]	22.82%
Accident Year 2012 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 177,547	178,586	[1]	180,387	[1]	182,859	[1]	184,460	[1]	193,515	[1]	212,738	[1]	222,075	[1]	222,549	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 6,419
Cumulative Number of Claims Reported | Claim		5,749
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 162,588	161,014		159,807		157,207		154,553		149,161		133,658		107,467		$ 50,579
Claim Frequency	[2]	18.73%
Accident Year 2013 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 207,304	209,184	[1]	210,588	[1]	214,701	[1]	220,457	[1]	233,656	[1]	241,811	[1]	241,810	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 7,762
Cumulative Number of Claims Reported | Claim		5,766
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 182,465	180,614		177,724		172,479		165,994		150,304		119,507		$ 51,396
Claim Frequency	[2]	16.55%
Accident Year 2014 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 212,417	218,386	[1]	226,933	[1]	235,058	[1]	249,097	[1]	268,846	[1]	268,846	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 5,468
Cumulative Number of Claims Reported | Claim		5,839
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 191,394	186,129		180,683		169,736		153,320		119,820		$ 53,060
Claim Frequency	[2]	14.99%
Accident Year 2015 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 211,758	220,965	[1]	235,471	[1]	252,514	[1]	262,573	[1]	262,573	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 6,717
Cumulative Number of Claims Reported | Claim		5,516
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 185,657	182,053		170,461		151,818		121,599		$ 54,141
Claim Frequency	[2]	14.25%
Accident Year 2016 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 209,214	218,005	[1]	241,406	[1]	250,491	[1]	250,491	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 6,843
Cumulative Number of Claims Reported | Claim		5,393
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 166,887	156,861		143,016		115,713		$ 52,238
Claim Frequency	[2]	14.23%
Accident Year 2017 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 220,096	234,587	[1]	244,098	[1]	244,094	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 8,066
Cumulative Number of Claims Reported | Claim		5,211
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 166,448	151,427		122,552		$ 56,951
Claim Frequency	[2]	14.68%
Accident Year 2018 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 235,641	250,487	[1]	250,487	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 16,057
Cumulative Number of Claims Reported | Claim		5,467
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 152,328	126,057		$ 62,061
Claim Frequency	[2]	15.20%
Accident Year 2019 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 241,344	241,344	[1]
Total IBNR Plus Expected Development on Reported Claims		$ 16,609
Cumulative Number of Claims Reported | Claim		5,199
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 120,512	$ 58,883
Claim Frequency	[2]	15.21%
Accident Year 2020 [Member]
Claims Development [Line Items]
Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance		$ 220,710
Total IBNR Plus Expected Development on Reported Claims		$ 8,491
Cumulative Number of Claims Reported | Claim		4,170
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	[1]	$ 50,113
Claim Frequency	[2]	13.25%
[1]	Data presented for these calendar years is required supplementary information, which is unaudited
[2]	Frequency, as calculated above, refers to reported claims divided by gross premium earned

Loss and Loss Adjustment Expe_4

Loss and Loss Adjustment Expenses - Summary of Average Annual Percentage Payout Of Incurred Losses By Age Net of Reinsurance For Worker's Compensation and general Liability (Unaudited) (Detail)	Dec. 31, 2020
Shortduration Insurance Contracts Liability For Unpaid Claims And Allocated Claim Adjustment Expense Net [Abstract]
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 1	25.60%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 2	30.20%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 3	14.10%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 4	7.60%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 5	4.30%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 6	2.10%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 7	1.60%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 8	0.90%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 9	0.70%
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance, Year 10	0.40%

Loss and Loss Adjustment Expe_5

Loss and Loss Adjustment Expenses - Reconciliation of Beginning and Ending Reserve Balances, Net of Related Amounts Recoverable from Reinsurers (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Roll Forward In Liability For Unpaid Claims And Claims Adjustment Expense [Abstract]
Balance, beginning of period	$ 772,887	$ 798,409	$ 771,845
Less amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses	95,343	107,216	84,889
Net balance, beginning of period	677,544	691,193	686,956
Add incurred related to:
Current accident year	220,710	241,344	250,487
Prior accident years	(63,484)	(65,002)	(45,596)
Total incurred	157,226	176,342	204,891
Less paid related to:
Current accident year	50,113	58,883	62,061
Prior accident years	129,803	131,108	138,593
Total paid	179,916	189,991	200,654
Net balance, end of period	654,854	677,544	691,193
Add amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses	105,707	95,343	107,216
Balance, end of period	$ 760,561	$ 772,887	$ 798,409

Loss and Loss Adjustment Expe_6

Loss and Loss Adjustment Expenses - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unpaid Losses And Loss Expenses [Line Items]
Loss and LAE Related to Prior Periods	$ 63,484	$ 65,002	$ 45,596
Minimum period of underwriting workers’ compensation insurance from which historical loss data utilize	35 years
Accident Year 2017 [Member]
Unpaid Losses And Loss Expenses [Line Items]
Loss and LAE Related to Prior Periods	$ 14,500
Accident Year 2018 [Member]
Unpaid Losses And Loss Expenses [Line Items]
Loss and LAE Related to Prior Periods	$ 14,800

Loss and Loss Adjustment Expe_7

Loss and Loss Adjustment Expenses - Summary Exposures to Various Asbestos Related Claims (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Asbestos Claims [Line Items]
Balance, beginning of period	$ 772,887	$ 798,409	$ 771,845
Incurred losses and LAE during the current year	157,226	176,342	204,891
Loss and LAE payments	(50,113)	(58,883)	(62,061)
Balance, end of period	760,561	772,887	798,409
Asbestos Issue [Member]
Asbestos Claims [Line Items]
Balance, beginning of period	1,323	1,555	1,748
Incurred losses and LAE during the current year	(936)	(183)	108
Loss and LAE payments	(69)	(49)	(301)
Balance, end of period	$ 318	$ 1,323	$ 1,555

Statutory Accounting and Regu_3

Statutory Accounting and Regulatory Requirements - Insurance Subsidiaries (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Insurance [Abstract]
Capital and surplus	$ 365,524	$ 359,952	$ 383,575
Net income	82,390	92,301	72,979
Net realized gains (losses) on investments	$ 1,075	$ (80)	$ (1,536)

Statutory Accounting and Regu_4

Statutory Accounting and Regulatory Requirements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Insurance [Abstract]
Dividends to the Company	10.00%
Dividends paid	$ 88.6	$ 115.9	$ 65.4
Dividends permissible to pay without seeking regulatory approval	$ 83.4

Capital Stock - Additional Info

Capital Stock - Additional Information (Detail) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Equity [Abstract]
Common stock, shares authorized	50,000,000	50,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares issued	20,589,309	20,560,833
Common stock, shares outstanding	19,331,059	19,302,583
Preferred stock, shares authorized	10,000,000
Preferred stock, par value	$ 0.01
Preferred stock, shares outstanding	0

Restricted Stock and Stock Op_3

Restricted Stock and Stock Options - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)Companyshares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)shares	Dec. 31, 2013USD ($)
2005 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Duration for Stock option grants exercisable	10 years
Expiration of stock option	90 days
Unexercised portion of stock option remains exercisable	1 year
Number of companies used for the estimation of expected volatility | Company	6
Dividend yield assumed	0.00%
Cash dividends paid | $					$ 0
Compensation expense | $	$ 0	$ 0	$ 12,000
2005 Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	0
2012 Equity and Incentive Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under incentive plan	500,000
Common stock granted	23,207	9,391
Common stock available for future awards		297,227
2012 Equity and Incentive Compensation Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock granted			13,322
2012 Equity and Incentive Compensation Plan [Member] | Share Based Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $	$ 605,000		$ 676,000	$ 726,000
2012 Equity and Incentive Compensation Plan [Member] | Long-Term Incentive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $	$ 2,341,000		$ 1,359,000	$ 976,000
Non-Employee Director Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding	5,068	4,890	5,761	6,454
Compensation expense | $	$ 349,000	$ 317,000	$ 351,000
Shares authorized under incentive plan	150,000
Common stock granted	5,269	4,890	5,761
Common stock available for future awards	47,748
Restricted stock award for a number of shares | $	$ 50,000
Non-Employee Director Restricted Stock Plan [Member] | Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in annual restricted stock award | $	$ 75,000

Restricted Stock and Stock Op_4

Restricted Stock and Stock Options - Stock Option Activity (Detail) - 2005 Incentive Plan [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding, Beginning balance	0	5,000	20,000
Shares, Granted	0	0	0
Shares, Exercised	0	(5,000)	(15,000)
Shares Canceled, forfeited, or expired	0	0	0
Shares outstanding, Ending balance	0	0	5,000	20,000
Shares exercisable, Ending balance	0	0	5,000
Weighted- Average Exercise Price, Beginning balance	$ 0	$ 3.95	$ 5.21
Weighted- Average Exercise Price, Granted	0	0	0
Weighted- Average Exercise Price, Exercised	0	3.95	4.46
Weighted- Average Exercise Price, Canceled, forfeited, or expired	0	0	0
Weighted- Average Exercise Price, Ending balance	0	0	3.95	$ 5.21
Weighted- Average Exercise Price, Exercisable Ending balance	$ 0	$ 0	$ 3.95
Weighted- Average Remaining Contractual Life (in years)			1 year 10 months 24 days	2 years 1 month 6 days
Weighted- Average Remaining Contractual Life (in years), Exercised		10 months 24 days	10 months 24 days
Weighted- Average Remaining Contractual Life (in years), Exercisable			1 year 10 months 24 days

Restricted Stock and Stock Op_5

Restricted Stock and Stock Options - Weighted Average Grant Date Fair Values of Options Granted (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Cash received from option exercises	$ 20	$ 67
Total intrinsic value of options exercised	$ 287	766
Aggregate intrinsic value of vested options outstanding		$ 264

Restricted Stock and Stock Op_6

Restricted Stock and Stock Options - Restricted Stock Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
2012 Incentive Plan [Member] | Common and Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Nonvested outstanding, Beginning balance	32,528	39,575	60,879
Shares, Granted	23,207	22,713	3,304
Shares, Vested	(40,421)	(29,760)	(24,608)
Shares, Nonvested outstanding, Ending balance	15,314	32,528	39,575
Weighted-Average Grant-Date Fair Value per Share, Beginning balance	$ 54.02	$ 48.93	$ 45.71
Weighted-Average Grant-Date Fair Value per Share, Granted	58.62	61.08	59.16
Weighted-Average Grant-Date Fair Value per Share, Vested	54.31	51.86	44.31
Weighted-Average Grant-Date Fair Value per Share, Ending balance	$ 60.23	$ 54.02	$ 48.93
Non-Employee Director Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Nonvested outstanding, Beginning balance	4,890	5,761	6,454
Shares, Granted	5,269	4,890	5,761
Shares, Vested	(5,091)	(5,761)	(6,454)
Shares, Nonvested outstanding, Ending balance	5,068	4,890	5,761
Weighted-Average Grant-Date Fair Value per Share, Beginning balance	$ 61.34	$ 60.75	$ 54.20
Weighted-Average Grant-Date Fair Value per Share, Granted	68.88	61.34	60.75
Weighted-Average Grant-Date Fair Value per Share, Vested	61.49	60.75	54.20
Weighted-Average Grant-Date Fair Value per Share, Ending balance	$ 69.03	$ 61.34	$ 60.75

Earnings Per Share - Calculatio

Earnings Per Share - Calculation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share Basic [Abstract]
Net income – basic	$ 28,501	$ 23,353	$ 23,948	$ 10,800	$ 34,014	$ 21,386	$ 17,890	$ 19,400	$ 86,602	$ 92,690	$ 71,632
Basic weighted average common shares									19,288,996	19,248,657	19,208,978
Basic earnings per share	$ 1.48	$ 1.21	$ 1.24	$ 0.56	$ 1.77	$ 1.11	$ 0.93	$ 1.01	$ 4.49	$ 4.82	$ 3.73
Net income – diluted									$ 86,602	$ 92,690	$ 71,632
Weighted average common shares									19,288,996	19,248,657	19,208,978
Restricted stock and stock options									75,000	80,000	84,000
Diluted weighted average common shares									19,363,809	19,329,238	19,293,082
Decrease to diluted earnings per common share	$ 1.47	$ 1.21	$ 1.24	$ 0.56	$ 1.76	$ 1.11	$ 0.93	$ 1.01	$ 4.47	$ 4.80	$ 3.71

Earnings Per Share - Reconcilia

Earnings Per Share - Reconciliation of Weighted Average Shares used for Basic and Diluted Earnings Per Share Calculation (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Basic weighted average common shares	19,288,996	19,248,657	19,208,978
Add: Other common shares eligible for common dividends:
Restricted stock and stock options	74,813	80,581	84,104
Diluted weighted average common shares	19,363,809	19,329,238	19,293,082

Comprehensive Income and Accu_3

Comprehensive Income and Accumulated Other Comprehensive Income - Schedule of Changes in Accumulated Other Comprehensive Income (AOCI) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 430,215	$ 409,762	$ 425,423
Net current period other comprehensive income (loss)	8,808	13,043	(4,243)
Ending Balance	438,816	430,215	409,762
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	12,211	(832)	3,612
Other comprehensive income (loss) before reclassification	9,538	12,379	(4,551)
Amounts reclassified from accumulated other comprehensive income (loss)	(730)	664	308
Net current period other comprehensive income (loss)	8,808	13,043	(4,243)
Ending Balance	21,019	12,211	(832)
Accumulated Other Comprehensive Income (Loss) [Member] | ASU 2016-01 [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(615)
Accumulated Other Comprehensive Income (Loss) [Member] | ASU 2018-02 [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			414
Accumulated Other Comprehensive Income (Loss) [Member] | ASU 2016-01 [Member] | ASU 2016-01 [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(615)
Accumulated Other Comprehensive Income (Loss) [Member] | ASU 2016-01 [Member] | ASU 2018-02 [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			414
Accumulated Other Comprehensive Income (Loss) [Member] | Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Adjusted beginning balance	$ 12,211	$ (832)	$ 3,411

Comprehensive Income and Accu_4

Comprehensive Income and Accumulated Other Comprehensive Income - Reclassification Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments	$ (332)	$ 309	$ 163	$ 992	$ (53)	$ (4)	$ (82)	$ 59	$ 1,132	$ (80)	$ (1,536)
Income before income taxes	35,618	28,669	29,391	13,241	42,926	26,613	22,169	23,809	106,919	115,517	87,581
Income tax expense									(20,317)	(22,827)	(15,949)
Net income	$ 28,501	$ 23,353	$ 23,948	$ 10,800	$ 34,014	$ 21,386	$ 17,890	$ 19,400	86,602	92,690	71,632
Unrealized Gains (losses) on Available-for-Sale Securities [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net realized gains (losses) on investments									925	(841)	(390)
Income before income taxes									925	(841)	(390)
Income tax expense									(195)	177	82
Net income									$ 730	$ (664)	$ (308)

Comprehensive Income and Accu_5

Comprehensive Income and Accumulated Other Comprehensive Income - Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Unrealized gain (loss) on available-for-sale securities, Pre-Tax Amount	$ 12,074	$ 15,670	$ (5,760)
Reclassification adjustment for gains (losses) realized in net income, Pre-Tax Amount	(925)	841	390
Net unrealized gain loss, Pre-Tax Amount	11,149	16,511	(5,370)
Other comprehensive income (loss), Pre-Tax Amount	11,149	16,511	(5,370)
Unrealized gain loss on available-for-sale securities, Tax Expense (Benefit)	2,536	3,291	(1,209)
Reclassification adjustment for gains (losses) realized in net income, Tax Expense (Benefit)	(195)	177	82
Net unrealized gain loss, Tax Expense (Benefit)	2,341	3,468	(1,127)
Other comprehensive income (loss), Tax Expense (Benefit)	2,341	3,468	(1,127)
Unrealized gain (loss) on available-for-sale securities, Net-of-Tax Amount	9,538	12,379	(4,551)
Reclassification adjustment for gains (losses) realized in net income, Net-of-Tax Amount	(730)	664	308
Net unrealized gain loss, Net-of-Tax Amount	8,808	13,043	(4,243)
Other comprehensive income (loss), Net-of-Tax Amount	$ 8,808	$ 13,043	$ (4,243)

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan name	401(k) benefit plan
Defined Contribution Plan, Plan Name [Extensible List]	amsf:KBenefitPlanMember
Matches employee compensation for participating employees	50.00%
Fully vested in employer contributions	5 years
Defined contribution this plan	$ 0.7	$ 0.7	$ 0.7
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Matches employee compensation for participating employees	6.00%

Commitments and Contingencies -

Commitments and Contingencies - Fair Value of Annuities (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	$ 99,275
Pacific Life and Annuity Company [Member] | A.M. Best Rating, A+ [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	16,489
American General Life Insurance Company [Member] | A.M. Best Rating, A [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	14,462
New York Life Insurance Company [Member] | A.M. Best Rating, A++ [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	9,120
Travelers Life and Annuity Insurance Company [Member] | A.M. Best Rating, A [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	9,758
Metropolitan Life Insurance Company [Member] | A.M. Best Rating, A+ [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	6,701
John Hancock Life Insurance Company [Member] | A.M. Best Rating, A+ [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	6,536
Athene Annuity and Life Company [Member] | A.M. Best Rating, A [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	4,363
United of Omaha Life Insurance Company [Member] | A.M. Best Rating, A+ [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	5,141
Lincoln Life Assurance Company of Boston [Member] | A.M. Best Rating, A [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	3,698
Pacific Life Insurance Company [Member] | A.M. Best Rating, A+ [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	4,010
Other [Member]
Commitments And Contingencies [Line Items]
Statement value of annuities exceeding 1% of statutory surplus	$ 18,997

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Commitments And Contingencies [Line Items]
Operating lease, existence of option to extend	true
Finance lease, existence of option to extend	true
Rent expense	$ 0.2	$ 0.2	$ 0.2
Minimum [Member]
Commitments And Contingencies [Line Items]
Operating lease, remaining lease term	1 month
Finance lease, remaining lease term	1 month
Maximum [Member]
Commitments And Contingencies [Line Items]
Operating lease, remaining lease term	60 months
Finance lease, remaining lease term	60 months
Operating lease, options to extend lease term	5 years
Finance lease, options to extend lease term	5 years

Commitments and Contingencies_3

Commitments and Contingencies - Components of Lease Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Operating lease cost	$ 160	$ 164
Finance lease cost:
Amortization of right-of-use assets	6	62
Interest on lease liabilities	2	4
Total finance lease cost	$ 8	$ 66

Commitments and Contingencies_4

Commitments and Contingencies - Schedule of Supplemental Cash Flow Information Related to Leases (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ (116)	$ 430
Operating cash flows from finance leases	4	46
Financing cash flows from finance leases	$ 50	$ 47

Commitments and Contingencies_5

Commitments and Contingencies - Schedule of Right-of-use Assets Obtained in Exchange for Lease Obligations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Operating leases	$ 56	$ 369
Finance leases	$ 180

Commitments and Contingencies_6

Commitments and Contingencies - Schedule of Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Operating lease right-of-use assets	$ 314	$ 430
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets	us-gaap:OtherAssets
Operating lease liabilities	$ 314	$ 430
Operating Lease, Liability, Statement of Financial Position [Extensible List]	amsf:AccountsPayableAndOtherLiabilities	amsf:AccountsPayableAndOtherLiabilities
Finance lease right-of-use assets	$ 365	$ 185
Finance lease accumulated amortization right-of-use assets	(185)	(179)
Property and equipment, net	$ 180	$ 6
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Finance lease liabilities	$ 185	$ 54
Finance Lease, Liability, Statement of Financial Position [Extensible List]	amsf:AccountsPayableAndOtherLiabilities	amsf:AccountsPayableAndOtherLiabilities

Commitments and Contingencies_7

Commitments and Contingencies - Schedule of Weighted Average Remaining Lease Term and Discount Rate (Detail)	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Operating leases, Weighted average remaining lease term:	2 years 8 months 12 days	3 years 7 months 6 days
Finance leases, Weighted average remaining lease term:	4 years 10 months 24 days	1 year 1 month 6 days
Operating leases, Weighted average discount rate:	5.24%	5.25%
Finance leases, Weighted average discount rate:	3.30%	5.21%

Commitments and Contingencies_8

Commitments and Contingencies - Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating and Finance Lease Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Operating Leases, 2021	$ 136
Operating Leases, 2022	120
Operating Leases, 2023	75
Operating Leases, 2024	6
Operating Leases, 2025
Total lease payments	337
Operating Leases, Less imputed interest	23
Operating Leases, Total	314	$ 430
Finance Leases, 2021	44
Finance Leases, 2022	39
Finance Leases, 2023	39
Finance Leases, 2024	39
Finance Leases, 2025	39
Total lease payments	200
Finance Leases, Less imputed interest	15
Finance Leases, Total	$ 185	$ 54

Concentration of Operations - N

Concentration of Operations - Net Premiums Earned for the Top Ten States (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned	$ 74,702	$ 74,771	$ 75,964	$ 78,990	$ 82,277	$ 82,712	$ 82,951	$ 84,948	$ 304,427	$ 332,888	$ 350,326
Premium earned percentage									100.00%	100.00%	100.00%
Florida [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 34,617	$ 39,936	$ 39,672
Premium earned percentage									11.40%	12.00%	11.30%
Georgia [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 37,926	$ 38,090	$ 40,351
Premium earned percentage									12.50%	11.40%	11.50%
Pennsylvania [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 24,340	$ 27,519	$ 31,708
Premium earned percentage									8.00%	8.30%	9.10%
Louisiana [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 22,668	$ 24,782	$ 25,810
Premium earned percentage									7.40%	7.40%	7.40%
North Carolina [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 17,338	$ 18,800	$ 19,537
Premium earned percentage									5.70%	5.70%	5.60%
Illinois [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 14,802	$ 16,929	$ 19,710
Premium earned percentage									4.90%	5.10%	5.60%
Virginia [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 14,041	$ 15,249	$ 15,228
Premium earned percentage									4.60%	4.60%	4.30%
Minnesota [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 11,057	$ 13,399	$ 12,900
Premium earned percentage									3.60%	4.00%	3.70%
Wisconsin [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 12,263	$ 13,388	$ 14,101
Premium earned percentage									4.00%	4.00%	4.00%
South Carolina [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 11,270	$ 13,020	$ 13,924
Premium earned percentage									3.70%	3.90%	4.00%
All Others [Member]
Schedule Of Premiums Earned Net By Segment [Line Items]
Net premiums earned									$ 104,105	$ 111,776	$ 117,385
Premium earned percentage									34.20%	33.60%	33.50%

Fair Values of Financial Inst_3

Fair Values of Financial Instruments - Summary of Carrying or Reported Values and Corresponding Fair Values for Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturity securities—held to maturity	$ 621,654	$ 621,343
Fixed maturity securities—available-for-sale	414,279	441,146
Equity securities	43,437	27,903
Short-term investments	45,898	56,548
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturity securities—held to maturity	585,130	599,421
Fixed maturity securities—available-for-sale	414,279	441,146
Equity securities	43,437	27,903
Short-term investments	45,898	56,548
Cash and cash equivalents	61,757	43,813
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturity securities—held to maturity	621,654	621,343
Fixed maturity securities—available-for-sale	414,279	441,146
Equity securities	43,437	27,903
Short-term investments	45,898	56,548
Cash and cash equivalents	$ 61,757	$ 43,813

Fair Values of Financial Inst_4

Fair Values of Financial Instruments - Schedule of Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	$ 414,279	$ 441,146
Equity securities, Fair Value	43,437	27,903
Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	414,279	441,146
Total	457,716	469,049
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	29,786	40,126
Total	73,223	68,029
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	384,493	401,020
Total	384,493	401,020
Fair Value, Measurements, Recurring [Member] | States and Political Subdivisions [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	276,542	237,775
Fair Value, Measurements, Recurring [Member] | States and Political Subdivisions [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	276,542	237,775
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	88,899	133,778
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	88,899	133,778
Fair Value, Measurements, Recurring [Member] | U.S. Agency-Based Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	19,052	29,467
Fair Value, Measurements, Recurring [Member] | U.S. Agency-Based Mortgage-Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	19,052	29,467
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	29,786	40,126
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale—fixed maturity, Fair Value	29,786	40,126
Fair Value, Measurements, Recurring [Member] | Common Stock [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities, Fair Value	43,437	27,903
Fair Value, Measurements, Recurring [Member] | Common Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities, Fair Value	$ 43,437	$ 27,903

Fair Values of Financial Inst_5

Fair Values of Financial Instruments - Schedule of Assets Measured at Amortized Cost (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	$ 621,654	$ 621,343
States and Political Subdivisions [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	526,821	485,647
Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	72,900	110,925
U.S. Agency-Based Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	7,906	11,511
U.S. Treasury Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	13,865	7,873
Asset-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	162	219
Obligations of U.S. Government Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value		5,168
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	13,865	7,873
Fair Value, Inputs, Level 1 [Member] | U.S. Treasury Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	13,865	7,873
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	607,789	613,470
Fair Value, Inputs, Level 2 [Member] | States and Political Subdivisions [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	526,821	485,647
Fair Value, Inputs, Level 2 [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	72,900	110,925
Fair Value, Inputs, Level 2 [Member] | U.S. Agency-Based Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	7,906	11,511
Fair Value, Inputs, Level 2 [Member] | Asset-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	$ 162	219
Fair Value, Inputs, Level 2 [Member] | Obligations of U.S. Government Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value		$ 5,168

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) - Unaudited Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Net premiums earned	$ 74,702	$ 74,771	$ 75,964	$ 78,990	$ 82,277	$ 82,712	$ 82,951	$ 84,948	$ 304,427	$ 332,888	$ 350,326
Net investment income	7,228	7,063	7,324	7,749	8,035	8,264	8,169	8,015	29,364	32,483	30,452
Net realized gains (losses) on investments	(332)	309	163	992	(53)	(4)	(82)	59	1,132	(80)	(1,536)
Net unrealized gains (losses) on equity securities	6,553	844	5,570	(8,763)	1,593	365	642	2,158	4,204	4,758	(2,088)
Total revenues	88,221	83,005	89,082	79,169	91,939	91,488	91,753	95,190	339,477	370,370	377,753
Income before income taxes	35,618	28,669	29,391	13,241	42,926	26,613	22,169	23,809	106,919	115,517	87,581
Net income	$ 28,501	$ 23,353	$ 23,948	$ 10,800	$ 34,014	$ 21,386	$ 17,890	$ 19,400	$ 86,602	$ 92,690	$ 71,632
Earnings per share:
Basic	$ 1.48	$ 1.21	$ 1.24	$ 0.56	$ 1.77	$ 1.11	$ 0.93	$ 1.01	$ 4.49	$ 4.82	$ 3.73
Diluted	$ 1.47	$ 1.21	$ 1.24	$ 0.56	$ 1.76	$ 1.11	$ 0.93	$ 1.01	$ 4.47	$ 4.80	$ 3.71
Comprehensive income	$ 29,608	$ 24,087	$ 29,431	$ 12,284	$ 33,610	$ 23,862	$ 23,068	$ 25,193	$ 95,410	$ 105,733	$ 67,389
Extraordinary cash dividends declared per common share	$ 3.50				$ 3.50				$ 3.50	$ 3.50	$ 3.50
Cash dividends declared per common share	$ 0.27	$ 0.27	$ 0.27	$ 0.27	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 1.08	$ 1	$ 0.88

Capital Management - Additional

Capital Management - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 31, 2016
Equity [Abstract]
Share repurchase program, new limit amount						$ 25,000,000
Shares repurchased under the program			0
Shares repurchased	1,258,250	1,258,250	1,258,250	1,258,250
Shares repurchased, value	$ 22,370,000	$ 22,370,000	$ 22,370,000	$ 22,370,000
Shares repurchased, average price			$ 17.78
Quarterly dividend per share	$ 0.27	$ 0.25	0.27	$ 0.25	$ 0.22
Extraordinary dividends declared per share	$ 3.50	$ 3.50	$ 3.50	$ 3.50	$ 3.50

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - $ / shares	Feb. 23, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Cash dividend per share		$ 0.27	$ 0.25	$ 0.22
Subsequent Event [Member] | Dividend Declared [Member]
Subsequent Event [Line Items]
Cash dividend per share	$ 0.29
Date of payment for dividend	Mar. 26, 2021
Date of record for dividend payment	Mar. 12, 2021

Schedule II. Condensed Financ_2

Schedule II. Condensed Financial Information of Registrant - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Fixed maturity securities—held-to-maturity, at amortized cost net of allowance for credit losses of $0 in 2020 and 2019, (fair value $361 and $0, in 2020 and 2019, respectively)	$ 585,130	$ 599,421
Fixed maturity securities—available-for-sale, at fair value (amortized cost $7,210 in 2020 and 2019)	414,279	441,146
Equity securities, at fair value (cost $10,007 in 2020 and 2019)	43,437	27,903
Short-term investments	45,898	56,548
Total investments	1,088,744	1,125,018
Cash and cash equivalents	61,757	43,813
Property and equipment, net	6,182	6,331
Other assets	10,860	17,587
Total assets	1,470,855	1,492,906
Liabilities:
Accounts payable and other liabilities	38,880	40,089
Total liabilities	1,032,039	1,062,691
Shareholders' equity (net of Treasury stock of $22,370 at December 31, 2020 and 2019)	438,816	430,215	$ 409,762	$ 425,423
Total liabilities and shareholders’ equity	1,470,855	1,492,906
Parent Company [Member]
Assets
Fixed maturity securities—held-to-maturity, at amortized cost net of allowance for credit losses of $0 in 2020 and 2019, (fair value $361 and $0, in 2020 and 2019, respectively)	361
Fixed maturity securities—available-for-sale, at fair value (amortized cost $7,210 in 2020 and 2019)	7,259	7,216
Equity securities, at fair value (cost $10,007 in 2020 and 2019)	11,503	11,779
Short-term investments	9,676	17,967
Investment in subsidiaries	384,774	379,001
Total investments	413,573	415,963
Cash and cash equivalents	23,562	10,551
Notes receivable from subsidiaries	2,140	2,781
Property and equipment, net	1,605	1,720
Federal income tax recoverable	2,705	2,798
Other assets	1,420	804
Total assets	445,005	434,617
Liabilities:
Accounts payable and other liabilities	6,095	4,230
Deferred income taxes	94	172
Total liabilities	6,189	4,402
Shareholders' equity (net of Treasury stock of $22,370 at December 31, 2020 and 2019)	438,816	430,215
Total liabilities and shareholders’ equity	$ 445,005	$ 434,617

Schedule II. Condensed Financ_3

Schedule II. Condensed Financial Information of Registrant - Condensed Balance Sheets (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Condensed Balance Sheet Statements, Captions [Line Items]
Fixed maturity securities, held-to-maturity, allowance for credit losses	$ 274	$ 0
Fixed maturity securities, fair value	621,654	621,343
Fixed maturity securities, amortized cost	387,665	425,698
Equity securities, cost	35,787	24,457
Net of Treasury stock	22,370	22,370
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Fixed maturity securities, held-to-maturity, allowance for credit losses	0	0
Fixed maturity securities, fair value	361	0
Fixed maturity securities, amortized cost	7,210	7,210
Equity securities, cost	10,007	10,007
Net of Treasury stock	$ 22,370	$ 22,370

Schedule II. Condensed Financ_4

Schedule II. Condensed Financial Information of Registrant - Condensed Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues
Net investment income	$ 7,228	$ 7,063	$ 7,324	$ 7,749	$ 8,035	$ 8,264	$ 8,169	$ 8,015	$ 29,364	$ 32,483	$ 30,452
Net unrealized gains (losses) on equity securities	6,553	844	5,570	(8,763)	1,593	365	642	2,158	4,204	4,758	(2,088)
Fee and other income									350	321	599
Total revenues	88,221	83,005	89,082	79,169	91,939	91,488	91,753	95,190	339,477	370,370	377,753
Expenses
Total expenses									232,558	254,853	290,172
Income tax expense (benefit)									20,317	22,827	15,949
Net income	$ 28,501	$ 23,353	$ 23,948	$ 10,800	$ 34,014	$ 21,386	$ 17,890	$ 19,400	86,602	92,690	71,632
Parent Company [Member]
Revenues
Net investment income									944	915	1,089
Net unrealized gains (losses) on equity securities									(276)	1,977	(948)
Fee and other income									9,122	5,352	7,389
Total revenues									9,790	8,244	7,530
Expenses
Other operating costs									9,122	8,244	7,530
Total expenses									9,122	8,244	7,530
Income before income taxes and equity in earnings of subsidiaries									668
Income tax expense (benefit)									259	376	(36)
Gain (loss) before equity in earnings of subsidiaries									409	(376)	36
Equity in net income of subsidiaries									86,193	93,066	71,596
Net income									$ 86,602	$ 92,690	$ 71,632

Schedule II. Condensed Financ_5

Schedule II. Condensed Financial Information of Registrant - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net cash provided by operating activities	$ 63,398	$ 78,824	$ 98,268
Investing activities
Purchases of property and equipment	(921)	(1,018)	(1,126)
Net cash provided by (used in) investing activities	43,371	11,688	(29,059)
Financing activities
Proceeds from stock option exercises		20	67
Finance lease purchases	(50)	(47)
Dividends to shareholders	(88,775)	(87,016)	(84,491)
Net cash used in financing activities	(88,825)	(87,043)	(84,424)
Change in cash and cash equivalents	17,944	3,469	(15,215)
Cash and cash equivalents at beginning of year	43,813	40,344	55,559
Cash and cash equivalents at end of year	61,757	43,813	40,344
Parent Company [Member]
Operating activities
Net cash provided by operating activities	6,012	2,333	2,448
Investing activities
Purchases of investments	(10,982)	(27,140)	(47,825)
Proceeds from sales of investments	18,970	1,987	54,600
Purchases of property and equipment	(764)	(995)	(1,041)
Dividends from subsidiary	88,600	115,900	65,400
Net cash provided by (used in) investing activities	95,824	89,752	71,134
Financing activities
Proceeds from stock option exercises		20	67
Finance lease purchases	(50)	(47)
Dividends to shareholders	(88,775)	(87,016)	(84,491)
Net cash used in financing activities	(88,825)	(87,043)	(84,424)
Change in cash and cash equivalents	13,011	5,042	(10,842)
Cash and cash equivalents at beginning of year	10,551	5,509	16,351
Cash and cash equivalents at end of year	$ 23,562	$ 10,551	$ 5,509

Schedule VI. Supplemental Inf_2

Schedule VI. Supplemental Information Concerning Property-Casualty Insurance Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Supplemental Information For Property Casualty Insurance Underwriters [Abstract]
Deferred Policy Acquisition Costs	$ 17,810	$ 19,048	$ 19,734
Reserves for Unpaid Loss and Loss Adjustment Expense	760,561	772,887	798,409
Unearned Premium	129,260	140,873	149,296
Net Premiums Earned	304,427	332,888	350,326
Net Investment Income	29,364	32,483	30,452
Loss and LAE Related to Current Period	220,710	241,344	250,487
Loss and LAE Related to Prior Periods	(63,484)	(65,002)	(45,596)
Amortization of Deferred Policy Acquisition Costs	(41,583)	(44,558)	(45,769)
Paid Claims and Claim Adjustment Expenses	179,916	189,991	200,654
Net Premiums Written	$ 292,814	$ 324,465	$ 342,352