Donegal (DGICA) 10-Q 5 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 31, 2021
Document Information [Line Items]
Document Type	10-Q
Entity Interactive Data Current	Yes
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Document Quarterly Report	true
Document Transition Report	false
Entity Registrant Name	Donegal Group Inc.
Entity Central Index Key	0000800457
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Address, State or Province	PA
Entity Address, Address Line One	1195 River Road, P.O. Box 302
Entity Address, City or Town	Marietta
Entity Address, Postal Zip Code	17547
Entity File Number	0-15341
Entity Tax Identification Number	23-2424711
City Area Code	717
Local Phone Number	426-1931
Entity Incorporation, State or Country Code	DE
Class A Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		25,752,572
Title of 12(b) Security	Common Stock
Trading Symbol	DGICA
Security Exchange Name	NASDAQ
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		5,576,775
Title of 12(b) Security	Common Stock
Trading Symbol	DGICB
Security Exchange Name	NASDAQ

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Fixed maturities
Held to maturity, at amortized cost	$ 661,080,363	$ 586,609,439
Available for sale, at fair value	520,490,593	555,136,017
Equity securities, at fair value	71,182,988	58,556,173
Short-term investments, at cost, which approximates fair value	4,693,721	20,900,155
Total investments	1,257,447,665	1,221,201,784
Cash	68,904,458	103,094,236
Accrued investment income	9,107,677	7,936,879
Premiums receivable	181,544,695	169,596,332
Reinsurance receivable	456,650,868	408,908,850
Deferred policy acquisition costs	70,396,767	59,156,958
Deferred tax asset, net	5,939,053	5,683,113
Prepaid reinsurance premiums	184,354,144	169,418,333
Property and equipment, net	3,299,347	4,390,377
Accounts receivable - securities	66,781	67,676
Federal income taxes recoverable	6,356,968	3,089,369
Goodwill	5,625,354	5,625,354
Other intangible assets	958,010	958,010
Other	1,363,087	1,393,053
Total assets	2,252,014,874	2,160,520,324
Liabilities
Losses and loss expenses	1,050,163,161	962,007,437
Unearned premiums	598,632,054	537,189,598
Accrued expenses	10,346,512	29,115,198
Reinsurance balances payable	3,943,544	3,233,523
Borrowings under lines of credit	35,000,000	85,000,000
Cash dividends declared to stockholders	0	4,436,301
Subordinated debentures	0	5,000,000
Accounts payable - securities	2,067,911	0
Due to affiliate	6,313,813	10,293,495
Other	7,414,463	6,470,652
Total liabilities	1,713,881,458	1,642,746,204
Stockholders' Equity
Preferred stock
Additional paid-in capital	303,844,499	289,149,567
Accumulated other comprehensive income	6,825,161	11,130,612
Retained earnings	268,346,629	258,387,288
Treasury stock, at cost	(41,226,357)	(41,226,357)
Total stockholders' equity	538,133,416	517,774,120
Total liabilities and stockholders' equity	2,252,014,874	2,160,520,324
Class A Common Stock [Member]
Stockholders' Equity
Common stock value	286,992	276,518
Total stockholders' equity	286,992	276,518
Class B Common Stock [Member]
Stockholders' Equity
Common stock value	56,492	56,492
Total stockholders' equity	$ 56,492	$ 56,492

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Class A Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	28,699,165	27,651,774
Common stock, shares outstanding	25,696,577	24,649,186
Class B Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	5,649,240	5,649,240
Common stock, shares outstanding	5,576,775	5,576,775

Consolidated Statements of (Los

Consolidated Statements of (Loss) Income - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues:
Net premiums earned	$ 196,234,626	$ 184,925,733	$ 575,974,891	$ 556,552,279
Investment income, net of investment expenses	7,763,562	7,403,251	22,926,320	21,951,679
Net investment (losses) gains	(1,570,476)	3,268,459	5,139,609	(940,488)
Lease income	107,977	107,907	323,782	326,379
Installment payment fees	570,492	806,916	1,857,420	2,433,395
Total revenues	203,106,181	196,512,266	606,222,022	580,323,244
Expenses:
Net losses and loss expenses	148,142,237	120,881,041	381,318,636	343,476,586
Amortization of deferred policy acquisition costs	31,778,000	29,605,000	95,060,000	89,176,000
Other underwriting expenses	30,101,717	29,480,706	100,113,444	95,645,601
Policyholder dividends	1,287,147	1,811,019	4,210,667	5,336,677
Interest	209,547	219,039	739,163	871,461
Other expenses, net	217,209	183,877	962,278	994,115
Total expenses	211,735,857	182,180,682	582,404,188	535,500,440
(Loss) income before income tax (benefit) expense	(8,629,676)	14,331,584	23,817,834	44,822,804
Income tax (benefit) expense	(1,917,698)	2,494,586	3,835,928	6,575,907
Net (loss) income	$ (6,711,978)	$ 11,836,998	$ 19,981,906	$ 38,246,897
Class A Common Stock [Member]
(Loss) earnings per common share:
common stock - basic	$ (0.22)	$ 0.41	$ 0.66	$ 1.34
common stock - diluted	(0.22)	0.41	0.66	1.33
common stock - basic and diluted	(0.22)	0.41
Class B Common Stock [Member]
(Loss) earnings per common share:
common stock - basic	(0.20)	0.37	0.59	1.21
common stock - diluted	(0.20)	0.37	0.59	1.21
common stock - basic and diluted	$ (0.20)	$ 0.37	$ 0.59	$ 1.21

Consolidated Statements of (L_2

Consolidated Statements of (Loss) Income (Parenthetical) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net investment (losses) gains	$ (1,570,476)	$ 3,268,459	$ 5,139,609	$ (940,488)
Income tax (benefit) expense	(1,917,698)	2,494,586	3,835,928	6,575,907
Reclassification out of Accumulated Other Comprehensive Income [Member]
Net investment (losses) gains	26,163	134,795	476,188	571,123
Income tax (benefit) expense	$ 5,494	$ 28,307	$ 99,999	$ 119,936

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (6,711,978)	$ 11,836,998	$ 19,981,906	$ 38,246,897
Unrealized (loss) gain on securities:
Unrealized holding (loss) gain during the period, net of income tax (benefit) expense	(1,627,641)	109,480	(3,929,262)	10,317,234
Reclassification adjustment for gains included in net income, net of income tax expense	(20,669)	(106,488)	(376,189)	(451,187)
Other comprehensive (loss) income	(1,648,310)	2,992	(4,305,451)	9,866,047
Comprehensive (loss) income	$ (8,360,288)	$ 11,839,990	$ 15,676,455	$ 48,112,944

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Unrealized holding (loss) gain during the period, net of income tax (benefit) expense	$ 432,664	$ 29,102	$ (1,046,983)	$ 2,742,556
Income tax expense (benefit) on reclassification adjustment for losses (gains)	$ 5,494	$ 28,307	$ 99,999	$ 119,936

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($)	Total	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Class A Common Stock [Member]	Class B Common Stock [Member]
Beginning balance at Dec. 31, 2019	$ 451,015,519	$ 268,151,601	$ 504,170	$ 223,267,573	$ (41,226,357)	$ 262,040	$ 56,492
Beginning balance, shares at Dec. 31, 2019						26,203,935	5,649,240
Issuance of common stock (stock compensation plans)	376,828	376,539				$ 289
Issuance of common stock (stock compensation plans), shares						28,924
Share-based compensation	1,242,986	1,242,315				$ 671
Share-based compensation, Shares						67,087
Net (loss) income	3,731,121			3,731,121
Cash dividends declared	(5,363)			(5,363)
Grant of stock options		118,525		(118,525)
Other comprehensive (loss) income	3,199,840		3,199,840
Ending balance at Mar. 31, 2020	459,560,931	269,888,980	3,704,010	226,874,806	(41,226,357)	$ 263,000	$ 56,492
Ending balance, shares at Mar. 31, 2020						26,299,946	5,649,240
Beginning balance at Dec. 31, 2019	451,015,519	268,151,601	504,170	223,267,573	(41,226,357)	$ 262,040	$ 56,492
Beginning balance, shares at Dec. 31, 2019						26,203,935	5,649,240
Net (loss) income	38,246,897
Other comprehensive (loss) income	9,866,047
Ending balance at Sep. 30, 2020	504,068,676	281,917,193	10,370,217	252,679,717	(41,226,357)	$ 271,414	$ 56,492
Ending balance, shares at Sep. 30, 2020						27,141,361	5,649,240
Beginning balance at Mar. 31, 2020	459,560,931	269,888,980	3,704,010	226,874,806	(41,226,357)	$ 263,000	$ 56,492
Beginning balance, shares at Mar. 31, 2020						26,299,946	5,649,240
Issuance of common stock (stock compensation plans)	720,548	720,018				$ 530
Issuance of common stock (stock compensation plans), shares						52,964
Share-based compensation	2,491,744	2,490,136				$ 1,608
Share-based compensation, Shares						160,869
Net (loss) income	22,678,778			22,678,778
Cash dividends declared	(4,255,882)			(4,255,882)
Grant of stock options		76,354		(76,354)
Other comprehensive (loss) income	6,663,215		6,663,215
Ending balance at Jun. 30, 2020	487,859,334	273,175,488	10,367,225	245,221,348	(41,226,357)	$ 265,138	$ 56,492
Ending balance, shares at Jun. 30, 2020						26,513,779	5,649,240
Issuance of common stock (stock compensation plans)	273,915	273,689				$ 226
Issuance of common stock (stock compensation plans), shares						22,662
Share-based compensation	8,364,438	8,358,388				$ 6,050
Share-based compensation, Shares						604,920
Net (loss) income	11,836,998			11,836,998
Cash dividends declared	(4,269,001)			(4,269,001)
Grant of stock options		109,628		(109,628)
Other comprehensive (loss) income	2,992		2,992
Ending balance at Sep. 30, 2020	504,068,676	281,917,193	10,370,217	252,679,717	(41,226,357)	$ 271,414	$ 56,492
Ending balance, shares at Sep. 30, 2020						27,141,361	5,649,240
Beginning balance at Dec. 31, 2020	517,774,120	289,149,567	11,130,612	258,387,288	(41,226,357)	$ 276,518	$ 56,492
Beginning balance, shares at Dec. 31, 2020						27,651,774	5,649,240
Issuance of common stock (stock compensation plans)	419,788	419,454				$ 334
Issuance of common stock (stock compensation plans), shares						33,336
Share-based compensation	4,722,849	4,719,388				$ 3,461
Share-based compensation, Shares						346,124
Net (loss) income	10,529,848			10,529,848
Cash dividends declared	(5,000)			(5,000)
Grant of stock options		109,184		(109,184)
Other comprehensive (loss) income	(4,207,115)		(4,207,115)
Ending balance at Mar. 31, 2021	529,234,490	294,397,593	6,923,497	268,802,952	(41,226,357)	$ 280,313	$ 56,492
Ending balance, shares at Mar. 31, 2021						28,031,234	5,649,240
Beginning balance at Dec. 31, 2020	517,774,120	289,149,567	11,130,612	258,387,288	(41,226,357)	$ 276,518	$ 56,492
Beginning balance, shares at Dec. 31, 2020						27,651,774	5,649,240
Net (loss) income	19,981,906
Other comprehensive (loss) income	(4,305,451)
Ending balance at Sep. 30, 2021	538,133,416	303,844,499	6,825,161	268,346,629	(41,226,357)	$ 286,992	$ 56,492
Ending balance, shares at Sep. 30, 2021						28,699,165	5,649,240
Beginning balance at Mar. 31, 2021	529,234,490	294,397,593	6,923,497	268,802,952	(41,226,357)	$ 280,313	$ 56,492
Beginning balance, shares at Mar. 31, 2021						28,031,234	5,649,240
Issuance of common stock (stock compensation plans)	730,501	730,005				$ 496
Issuance of common stock (stock compensation plans), shares						49,613
Share-based compensation	7,318,421	7,313,031				$ 5,390
Share-based compensation, Shares						539,019
Net (loss) income	16,164,036			16,164,036
Cash dividends declared	(4,840,629)			(4,840,629)
Grant of stock options		69,995		(69,995)
Other comprehensive (loss) income	1,549,974		1,549,974
Ending balance at Jun. 30, 2021	550,156,793	302,510,624	8,473,471	280,056,364	(41,226,357)	$ 286,199	$ 56,492
Ending balance, shares at Jun. 30, 2021						28,619,866	5,649,240
Issuance of common stock (stock compensation plans)	292,548	292,302				$ 246
Issuance of common stock (stock compensation plans), shares						24,619
Share-based compensation	946,551	946,004				$ 547
Share-based compensation, Shares						54,680
Net (loss) income	(6,711,978)			(6,711,978)
Cash dividends declared	(4,902,188)			(4,902,188)
Grant of stock options		95,569		(95,569)
Other comprehensive (loss) income	(1,648,310)		(1,648,310)
Ending balance at Sep. 30, 2021	$ 538,133,416	$ 303,844,499	$ 6,825,161	$ 268,346,629	$ (41,226,357)	$ 286,992	$ 56,492
Ending balance, shares at Sep. 30, 2021						28,699,165	5,649,240

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities:
Net income	$ 19,981,906	$ 38,246,897
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash items	4,492,720	5,115,850
Net investment (gains) losses	(5,139,609)	940,488
Changes in assets and liabilities:
Losses and loss expenses	88,155,724	72,256,493
Unearned premiums	61,442,456	48,083,628
Premiums receivable	(11,948,363)	(11,941,733)
Deferred acquisition costs	(11,239,809)	(2,269,695)
Deferred income taxes	900,430	(619,312)
Reinsurance receivable	(47,742,018)	(36,843,000)
Prepaid reinsurance premiums	(14,935,811)	(31,916,191)
Accrued investment income	(1,170,798)	(1,557,230)
Due to affiliate	(3,979,682)	(3,613,903)
Reinsurance balances payable	710,021	260,626
Current income taxes	(3,267,599)	(4,490,180)
Accrued expenses	(18,768,686)	(3,869,386)
Other, net	973,775	678,760
Net adjustments	38,482,751	30,215,215
Net cash provided by operating activities	58,464,657	68,462,112
Cash Flows from Investing Activities:
Purchases of fixed maturities, held to maturity	(106,290,824)	(110,914,229)
Purchases of fixed maturities, available for sale	(118,899,756)	(143,743,351)
Purchases of equity securities, available for sale	(25,354,790)	(6,964,092)
Maturity of fixed maturities:
Held to maturity	31,914,527	39,629,000
Available for sale	140,908,191	120,857,543
Sales of fixed maturities, available for sale	6,281,963	22,172,930
Sales of equity securities, available for sale	17,391,396	5,985,211
Net sales (purchases) of property and equipment	934,297	(73,706)
Net sales (purchases) of short-term investments	16,206,434	(6,655,716)
Net cash used in investing activities	(36,908,562)	(79,706,410)
Cash Flows from Financing Activities:
Cash dividends paid	(14,184,118)	(12,605,480)
Issuance of common stock	13,438,245	12,407,700
Payments on subordinated debentures	5,000,000
Borrowing under lines of credit		50,000,000
Payments on lines of credit	(50,000,000)
Net cash (used in) provided by financing activities	(55,745,873)	49,802,220
Net (decrease) increase in cash	(34,189,778)	38,557,922
Cash at beginning of period	103,094,236	49,318,930
Cash at end of period	68,904,458	87,876,852
Cash paid during period - Interest	993,769	928,474
Net cash paid during period - Taxes	$ 6,200,000	$ 10,800,000

Organization

Organization	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1 - Organization Donegal Mutual Insurance Company (“Donegal Mutual”) organized us as an insurance holding company on August 26, 1986. Our insurance subsidiaries, Atlantic States Insurance Company (“Atlantic States”), Southern Insurance Company of Virginia (“Southern”), the Peninsula Insurance Group (“Peninsula”), which consists of Peninsula Indemnity Company and The Peninsula Insurance Company, and Michigan Insurance Company (“MICO”), and our affiliates write personal and commercial lines of property and casualty coverages exclusively through independent insurance agents in certain Mid-Atlantic, We have three segments: our investment function, our commercial lines of insurance and our personal lines of i n At September 30, 2021, Donegal Mutual held approximately 41 84 70 Atlantic States, our largest subsidiary, participates in a proportional reinsurance agreement, or pooling agreement, with Donegal Mutual. Under the pooling agreement, Donegal Mutual and Atlantic States contribute substantially all of their respective premiums, losses and loss expenses to the underwriting pool, and the underwriting pool, acting through Donegal Mutual, then allocates 80% of the pooled business to Atlantic States. Thus, Donegal Mutual and Atlantic States share the underwriting results of the pooled business in proportion to their respective participation in the underwriting pool. In addition, Donegal Mutual has a 100% quota-share reinsurance agreement with Southern Mutual Insurance Company, or Southern Mutual. Donegal Mutual places its assumed business from Southern Mutual into the underwriting pool. Donegal Mutual completed the merger of Mountain States Mutual Casualty Company, or Mountain States, with and into Donegal Mutual effective May 25, 2017. Donegal Mutual was the surviving company in the merger, and Mountain States’ insurance subsidiaries, Mountain States Indemnity Company and Mountain States Commercial Insurance Company (collectively, the “Mountain States insurance subsidiaries”), became insurance subsidiaries of Donegal Mutual upon completion of the merger. Upon completion of the merger, Donegal Mutual assumed all of the policy obligations of Mountain States and began to market its products together with the Mountain States insurance subsidiaries as the Mountain States Insurance Group in four Southwestern states. Donegal Mutual also entered into a 100% quota-share reinsurance agreement with the Mountain States insurance subsidiaries on the merger date. Beginning with policies effective in 2021, Donegal Mutual began to place the business of the Mountain States Insurance Group into the underwriting pool. As a result, our consolidated financial results through December 31, 2020 excluded the results of the Mountain States Insurance Group operations in those Southwestern states. The same executive management and underwriting personnel administer products, classes of business underwritten, pricing practices and underwriting standards of Donegal Mutual and our insurance subsidiaries. In addition, as the Donegal Insurance Group, Donegal Mutual and our insurance subsidiaries share a combined business plan to achieve market penetration and underwriting profitability objectives. The products our insurance subsidiaries and Donegal Mutual market are generally complementary, thereby allowing the Donegal Insurance Group to offer a broader range of products to a given market and to expand the Donegal Insurance Group’s ability to service an entire personal lines or commercial lines account. Distinctions within the products of Donegal Mutual and our insurance subsidiaries generally relate to specific risk profiles targeted within similar classes of business, such as preferred tier versus standard tier products, but we do not allocate all of the standard risk gradients to one company. Therefore, the underwriting profitability of the business the individual companies write directly will vary. However, the underwriting pool homogenizes the risk characteristics of all business that Donegal Mutual and Atlantic States write directly. The business Atlantic States derives from the underwriting pool represents a significant percentage of our total consolidated revenues.

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	2 - Basis of Presentation Our financial information for the interim periods included in this Form 10-Q 10-Q We recommend you read the interim financial statements we include in this Form 10-Q 10-K

Earnings (Loss) Per Share

Earnings (Loss) Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	3 - Earnings (Loss) Per Share We have two classes of common stock, which we refer to as our Class A common stock and our Class B common stock. Our certificate of incorporation provides that whenever our board of directors declares a dividend on our Class B common stock, our board of directors shall simultaneously declare a dividend on our Class A common stock that is payable to the holders of our Class A common stock at the same time and as of the same record date at a rate that is at least 10% greater than the rate at which our board of directors declared a dividend on our Class B common stock. Accordingly, we use the two-class method to compute our earnings (loss) per common share. The two-class method is an earnings allocation formula that determines earnings (loss) per share separately for each class of common stock based on dividends we have declared and an allocation of our remaining undistributed earnings (loss) using a participation percentage that reflects the dividend rights of each class. The table below presents for the periods indicated a reconciliation of the numerators and denominators we used to compute basic and diluted net income (loss) per share for our Class A common stock and our Class B common stock: Three Months Ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except per share data) Basic (loss) earnings per share: Numerator: Allocation of net (loss) income $ (5,592 ) $ (1,120 ) $ 9,768 $ 2,069 Denominator: Weighted-average shares outstanding 25,676 5,577 23,767 5,577 Basic (loss) earnings per share $ (0.22 ) $ (0.20 ) $ 0.41 $ 0.37 Diluted (loss) earnings per share: Numerator: Allocation of net (loss) income $ (5,592 ) $ (1,120 ) $ 9,768 $ 2,069 Denominator: Number of shares used in basic computation 25,676 5,577 23,767 5,577 Weighted-average shares effect of dilutive securities: Director and employee stock options — — 170 — Number of shares used in diluted computation 25,676 5,577 23,937 5,577 Diluted (loss) earnings per share $ (0.22 ) $ (0.20 ) $ 0.41 $ 0.37 Nine Months Ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except per share data) Basic earnings per share: Numerator: Allocation of net income $ 16,682 $ 3,300 $ 31,495 $ 6,752 Denominator: Weighted-average shares outstanding 25,265 5,577 23,494 5,577 Basic earnings per share $ 0.66 $ 0.59 $ 1.34 $ 1.21 Diluted earnings per share: Numerator: Allocation of net income $ 16,682 $ 3,300 $ 31,495 $ 6,752 Denominator: Number of shares used in basic computation 25,265 5,577 23,494 5,577 Weighted-average shares effect of dilutive sec u Director and employee stock options 179 — 185 — Number of shares used in diluted computation 25,444 5,577 23,679 5,577 Diluted earnings per share $ 0.66 $ 0.59 $ 1.33 $ 1.21 We did not include outstanding options to purchase the following number of shares of Class A common stock in our computation of diluted earnings (loss) per share because the exercise price of the options exceeded the average market price of our Class A common stock during the applicable periods. Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Number of options to purchase Class A shares excluded — 6,180,592 4,839,910 6,180,592 We did not include any effect of dilutive securities in the computation of diluted earnings (loss) per share for the three months ended September 30, 2021 because we sustained a net loss for this period.

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2021
Insurance [Abstract]
Reinsurance	4 - Reinsurance Atlantic States and Donegal Mutual have participated in a pooling agreement since 1986 under which they pool their direct premiums written, and Atlantic States and Donegal Mutual then share the underwriting results of the pool in accordance with the terms of the pooling agreement. Atlantic States has an 80% share of the results of the pool, and Donegal Mutual has a 20% share of the results of the pool. Donegal Mutual began placing the business of the Mountain States Insurance Group into the pool beginning with policies effective in 2021. Our insurance subsidiaries and Donegal Mutual have a combined third-party reinsurance program. The coverage and parameters of the program are common to all of our insurance subsidiaries and Donegal Mutual. Our insurance subsidiaries and Donegal Mutual use several different reinsurers. They require their reinsurers to maintain an A.M. Best rating of A- A- • excess of loss reinsurance, under which the losses of Donegal Mutual and our insurance subsidiaries are automatically reinsured, through a series of contracts, over a set retention of $2.0 million; and • catastrophe reinsurance, under which Donegal Mutual and our insurance subsidiaries recover, through a series of reinsurance agreements, 100% of an accumulation of many losses resulting from a single event, including natural disasters, over a set retention of $15.0 million up to aggregate losses of $185.0 million per occurrence. In addition to the pooling agreement and third-party reinsurance, our insurance subsidiaries have a catastrophe reinsurance agreement with Donegal Mutual, under which each of our insurance subsidiaries recovers 100% of an accumulation of multiple losses resulting from a single event, including natural disasters, over a set retention of $2.0 million up to aggregate losses of $13.0 million per occurrence. The agreement also provides additional coverage for an accumulation of losses from a single event including a combination of our insurance subsidiaries over a combined retention of $5.0 million. Our insurance subsidiaries and Donegal Mutual also purchase facultative reinsurance to cover certain exposures, including property exposures that exceeded the limits provided by their respective treaty reinsurance.

Investments

Investments	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Investments	5 - Investments The amortized cost and estimated fair values of our fixed maturities at September 30, 2021 were as follows: Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Held to Maturity U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 93,686 $ 2,455 $ 829 $ 95,312 Obligations of states and political subdivisions 355,461 17,087 1,449 371,099 Corporate securities 194,188 13,496 644 207,040 Mortgage-backed securities 17,745 911 — 18,656 Totals $ 661,080 $ 33,949 $ 2,922 $ 692,107 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Available for Sale U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 27,500 $ 206 $ 277 $ 27,429 Obligations of states and political subdivisions 57,221 2,048 67 59,202 Corporate securities 203,519 8,588 365 211,742 Mortgage-backed securities 218,273 4,590 745 222,118 Totals $ 506,513 $ 15,432 $ 1,454 $ 520,491 At September 30, 2021, our holdings of obligations of states and political subdivisions included general obligation bonds with an aggregate fair value of $275.4 million and an amortized cost of $264.2 million. Our holdings at September 30, 2021 also included special revenue bonds with an aggregate fair value of $154.9 million and an amortized cost of $148.5 million. With respect to both categories of those bonds at September 30, 2021, we held no securities of any issuer that comprised more than 10% of our holdings of either bond category. Education bonds and water and sewer utility bonds represented 47% and 35%, respectively, of our total investments in special revenue bonds based on the carrying values of these investments at September 30, 2021. Many of the issuers of the special revenue bonds we held at September 30, 2021 have the authority to impose ad valorem taxes. In that respect, many of the special revenue bonds we held at September 30, 2021 are similar to general obligation bonds. The amortized cost and estimated fair values of our fixed maturities at December 31, 2020 were as follows: Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Held to Maturity U.S. $ 77,435 $ 3,984 $ 223 $ 81,196 Obligations of states and political subdivisions 312,319 23,212 143 335,388 Corporate securities 173,270 18,172 206 191,236 Mortgage-backed securities 23,585 1,236 — 24,821 Totals $ 586,609 $ 46,604 $ 572 $ 632,641 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Available for Sale U.S. $ 47,512 $ 424 $ 121 $ 47,815 Obligations of states and political subdivisions 66,287 2,690 12 68,965 Corporate securities 202,396 10,496 184 212,708 Mortgage-backed securities 218,763 6,902 17 225,648 Totals $ 534,958 $ 20,512 $ 334 $ 555,136 At December 31, 2020, our holdings of obligations of states and political subdivisions included general obligation bonds with an aggregate fair value of $263.6 million and an amortized cost of $247.5 million. Our holdings also included special revenue bonds with an aggregate fair value of $140.8 million and an amortized cost of $131.1 million. With respect to both categories of bonds, we held no securities of any issuer that comprised more than 10% of that category at December 31, 2020. Education bonds and water and sewer utility bonds represented 44% and 39%, respectively, of our total investments in special revenue bonds based on their carrying values at December 31, 2020. Many of the issuers of the special revenue bonds we held at December 31, 2020 have the authority to impose ad valorem taxes. In that respect, many of the special revenue bonds we held are similar to general obligation bonds. We made reclassifications from available for sale to held to maturity of certain fixed maturities at fair value on November 30, 2013. We segregated within accumulated other comprehensive income the net unrealized losses of $15.1 million arising prior to the November 30, 2013 reclassifications. We are amortizing this balance over the remaining life of the related securities as an adjustment to yield in a manner consistent with the accretion of discount on the same fixed maturities. We recorded amortization of $ 738,815 (loss) 5.3 We show below the amortized cost and estimated fair value of our fixed maturities at September 30, 2021 by contractual maturity. Expected maturities may differ from contractual maturities because issuers of the securities may have the right to call or pre p . Amortized Cost Estimated Fair (in thousands) Held to maturity Due in one year or less $ 36,112 $ 36,838 Due after one year through five years 82,968 87,988 Due after five years through ten years 232,949 244,151 Due after ten years 291,306 304,474 Mortgage-backed securities 17,745 18,656 Total held to maturity $ 661,080 $ 692,107 Available for sale Due in one year or less $ 22,414 $ 22,809 Due after one year through five years 120,648 126,744 Due after five years through ten years 113,678 116,556 Due after ten years 31,500 32,264 Mortgage-backed securities 218,273 222,118 Total available for sale $ 506,513 $ 520,491 The cost and estimated fair values of our equity securities at September 30, 2021 were as follows: Cost Gross Gains Gross Losses Estimated Fair (in thousands) Equity securities $ 50,864 $ 20,576 $ 257 $ 71,183 The cost and estimated fair values of our equity securities at December 31, 2020 were as follows: Cost Gross Gains Gross Losses Estimated Fair (in thousands) Equity securities $ 42,410 $ 17,103 $ 957 $ 58,556 Gross investment gains and losses before applicable income taxes for the three months and nine months ended September 30, 2021 and 2020 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Gross investment gains: Fixed maturities $ 86 $ 159 $ 610 $ 811 Equity securities — 3,131 5,287 5,617 86 3,290 5,897 6,428 Gross investment losses: Fixed maturities 82 22 156 240 Equity securities 1,574 — 601 7,128 1,656 22 757 7,368 Net investment (losses) gains $ (1,570 ) $ 3,268 $ 5,140 $ (940 ) We recognized $ 4.7 248,146 We held fixed maturities with unrealized losses representing declines that we considered temporary at September 30, 2021 as follows: Less Than 12 Months More Than 12 Months Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 36,355 $ 566 $ 17,458 $ 540 Obligations of states and political subdivisions 77,320 1,327 6,532 189 Corporate securities 56,319 726 3,217 283 Mortgage-backed securities 75,372 742 133 3 Totals $ 245,366 $ 3,361 $ 27,340 $ 1,015 We held fixed maturities with unrealized losses representing declines that we considered temporary at December 31, 2020 as follows: Less Than 12 Months More Than 12 Months Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 29,144 $ 345 $ — $ — Obligations of states and political subdivisions 9,362 154 — — Corporate securities 26,143 115 8,230 276 Mortgage-backed securities 3,091 15 236 1 Totals $ 67,740 $ 629 $ 8,466 $ 277 We make estimates concerning the valuation of our investments and the recognition of other-than-temporary declines in the value of our investments. For equity securities, we measure investments at fair value, and we recognize changes in fair value in our results of operations. With respect to a debt security that is in an unrealized loss position, we first assess if we intend to sell the debt security. If we determine we intend to sell the debt security, we recognize the impairment loss in our results of operations. If we do not intend to sell the debt security, we determine whether it is more likely than not that we will be required to sell the debt security prior to recovery. If we determine it is more likely than not that we will be required to sell the debt security prior to recovery, we recognize the impairment loss in our results of operations. If we determine it is more likely than not that we will not be required to sell the debt security prior to recovery, we then evaluate whether a credit loss has occurred with respect to that security. We determine whether a credit loss has occurred by comparing the amortized cost of the debt security to the present value of the cash flows we expect to collect. If we expect a cash flow shortfall, we consider that a credit loss has occurred. If we determine that a credit loss has occurred, we consider the impairment to be other than temporary. We then recognize the amount of the impairment loss related to the credit loss in our results of operations, and we recognize the remaining portion of the impairme n 139 debt securities that were in an unrealized loss position at September 30, 2021. Based upon our analysis of general market cond i We amortize premiums and discounts on debt securities over the life of the security as an adjustment to yield using the effective interest method. We compute realized investment gains and losses using the specific identification method. We amortize premiums and discounts on mortgage-backed debt securities using anticipated prepayments.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Segment Information	6 - Segment Information We evaluate the performance of our personal lines and commercial lines segments based upon the underwriting results of our insurance subsidiaries using statutory accounting principles (“SAP”) that various state insurance departments prescribe or permit. Our management uses SAP to measure the performance of our insurance subsidiaries instead of United States generally accepted accounting principles (“GAAP”). SAP financial measures are considered non-GAAP financial measures under applicable SEC rules because they include or exclude certain items that the most comparable GAAP financial measures do not ordinarily include or exclude. Financial data by segment for the three and nine months ended September 30, 2021 and 2020 is as follows: Three Months Ended September 30, 2021 2020 (in thousands) Revenues: Premiums earned: Commercial lines $ 119,709 $ 103,436 Personal lines 76,526 81,490 GAAP premiums earned 196,235 184,926 Net investment income 7,764 7,403 Investment (losses) (1,570 ) 3,268 Other 677 915 Total revenues $ 203,106 $ 196,512 (Loss) income (benefit) Underwriting (loss) Commercial lines $ (10,962 ) $ (1,703 ) Personal lines (4,976 ) 6,427 SAP underwriting (loss) (15,938 ) 4,724 GAAP adjustments 864 (1,576 ) GAAP underwriting (loss) (15,074 ) 3,148 Net investment income 7,764 7,403 Investment (losses) (1,570 ) 3,268 Other 250 513 (Loss) income (benefit) $ (8,630 ) $ 14,332 Nine Months Ended September 30, 2021 2020 (in thousands) Revenues: Premiums earned: Commercial lines $ 344,234 $ 307,080 Personal lines 231,741 249,472 GAAP premiums earned 575,975 556,552 Net investment income 22,926 21,952 Investment gains (losses) 5,140 (940 ) Other 2,181 2,759 Total revenues $ 606,222 $ 580,323 Income before income tax expense: Underwriting (loss) income: Commercial lines $ (17,437 ) $ 2,203 Personal lines 608 19,528 SAP underwriting (loss) income (16,829 ) 21,731 GAAP adjustments 12,101 1,186 GAAP underwriting (loss) (4,728 ) 22,917 Net investment income 22,926 21,952 Investment gains (losses) 5,140 (940 ) Other 480 894 Income before income tax expense $ 23,818 $ 44,823

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Borrowings	7 - Borrowings Lines of Credit In August 2020, we entered into a credit agreement with Manufacturers and Traders Trust Company (“M&T”) that related to a $20.0 million unsecured demand line of credit. The line of credit has no expiration date, no annual fees and no covenants. At September 30, 2021, we had no outstanding borrowings from M&T and had the ability to borrow up to $20.0 million at interest rates equal to the then-current LIBOR rate plus 2.00%. Atlantic States is a member of the FHLB of Pittsburgh. Through its membership, Atlantic States h a COVID-19 FHLB of Pittsburgh stock purchased and owned $ 1,575,600 Collateral pledged, at par (carrying value $41,831,206) 41,155,784 Borrowing capacity currently available 5,504,094 S ubordinated Debentures In September 2021, upon receipt of approval from the Michigan Department of Insurance and Financial Services, MIC O repaid in full the $5.0 million surplus note held previously by Donegal Mutual, along with accrued interest of $178,082.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2021
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	8 - Share–Based Compensation We measure all share-based payments to employees, including grants of stock options, and use a fair-value-based method for the recording of related compensation expense in our results of operations. In determining the expense we record for stock options granted to directors and employees of our subsidiaries and affiliates, we estimate the fair value of each option award on the date of grant using the Black-Scholes option pricing model. The significant assumptions we utilize in applying the Black-Scholes option pricing model are the risk-free interest rate, the expected term, the dividend yield and the expected volatility. We recorded compensation expense related to our stock compensation plans of $ We received cash from option exercises under all stock compensation plans during the three months ended September 30, 2021 and 2020 of $ 764,956 12.2 16,655 437,790

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	9 - Fair Value Measurements We account for financial assets using a framework that establishes a hierarchy that ranks the quality and reliability of the inputs, or assumptions, we use in the determination of fair value, and we classify financial assets and liabilities carried at fair value in one of the following three categories: Level 1 – quoted prices in active markets for identical assets and liabilities; Level 2 – directly or indirectly observable inputs other than Level 1 quoted prices; and Level 3 – unobservable inputs not corroborated by market data. For investments that have quoted market prices in active markets, we use the quoted market price as fair value and include these investments in Level 1 of the fair value hierarchy. We classify publicly-traded equity securities as Level 1. When quoted market prices in active markets are not available, we base fair values on quoted market prices of comparable instruments or price estimates we obtain from independent pricing services and include these investments in Level 2 of the fair value hierarchy. We classify our fixed maturity investments as Level 2. Our fixed maturity investments consist of U.S. Treasury securities and obligations of U.S. government corporations and agencies, obligations of states and political subdivisions, corporate securities and mortgage-backed securities. We present our investments in available-for-sale recognized independent pricing services to estimate fair values or obtain market quotations for substantially all of our fixed maturity and equity investments. These pricing services utilize market quotations for fixed maturity and equity securities that have quoted prices in active markets. For fixed maturity securities that generally do not trade on a daily basis, the pricing services prepare estimates of fair value measurements based predominantly on observable market inputs. The pricing services do not use broker quotes in determining the fair values of our investments. Our investment personnel review the estimates of fair value the pricing services provide to verify that the estimates we obtain from the pricing services are representative of fair values based upon our investment personnel’s general knowledge of the market, their research findings related to unusual fluctuations in value and their comparison of such values to execution prices for similar securities. Our investment personnel regularly monitor the market, current trading ranges for similar securities and the pricing of specific investments. Our investment personnel review all pricing estimates that we receive from the pricing services against their expectations with respect to pricing based on fair market curves, security ratings, interest rates, security types and recent trading activity. Our investment personnel periodically review documentation with respect to the pricing services’ pricing methodology that they obtain to determine if the primary pricing sources, market inputs and pricing frequency for various security types are reasonable. At September 30, 2021, we received two estimates per security from the pricing services, and we priced substantially all of our Level 1 and Level 2 investments using those prices. In our review of the estimates the pricing services provided at September 30, 2021, we did not identify any material discrepancies, and we did not make any adjustments to the estimates the pricing services provided. We present our cash and short-term investments at estimated fair value. We classify these items as Level 1. The carrying values we report in our balance sheet for premium receivables and reinsurance receivables and payables for premiums and paid losses and loss expenses approximate their fair values. The carrying amounts we report in our balance sheets for our subordinated debentures and borrowings under lines of credit approximate their fair values. We classify these items as Level 3. We evaluate our assets and liabilities to determine the appropriate level at which to classify them for each reporting period. The following table presents our fair value measurements for our investments in available-for-sale fi x , : Fair Value Measurements Using Fair Value Quoted Prices in Significant Other Significant (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 27,429 $ — $ 27,429 $ — Obligations of states and political subdivisions 59,202 — 59,202 — Corporate securities 211,742 — 211,742 — Mortgage-backed securities 222,118 — 222,118 — Equity securities 71,183 68,893 2,290 — Total investments in the fair value hierarchy $ 591,674 $ 68,893 $ 522,781 $ — The following table presents our fair value measurements for our investments in a v Fair Value Measurements Using Fair Value Quoted Prices in Significant Other Significant (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 47,815 $ — $ 47,815 $ — Obligations of states and political subdivisions 68,965 — 68,965 — Corporate securities 212,708 — 212,708 — Mortgage-backed securities 225,648 — 225,648 — Equity securities 58,556 54,152 4,404 — Totals $ 613,692 $ 54,152 $ 559,540 $ —

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	10 - Income Taxes At September 30, 2021 and December 31, 2020, respectively, we had no material unrecognized tax benefits or accrued interest and penalties. Tax years 2016 through 2020 remained open for examination at September 30, 2021. We provide a valuation allowance when we believe it is more likely than not that we will not realize some portion of our tax assets. We established a valuation allowance of $ 7.9 28.1 On March 27, 2020, the Coronavirus Aid, Relief and Security Act (the “CARES Act”) was signed into law. The CARES Act amended net operating loss provisions in effect prior to its enactment. The CARES Act allows for the carryback of losses arising in taxable years beginning after December 31, 2017 and before January 1, 2021 to each of the five taxable years preceding the taxable year of such loss. As a result, we filed amended tax returns in 2020 to carry back net operating losses from taxable year 2018 to past tax years. We recorded a tax benefit of $1.6 million in the first quarter of 2020 in anticipation of a refund of taxes we paid in prior years as a result of the carryback.

Liabilities for Losses and Loss

Liabilities for Losses and Loss Expenses	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Liabilities for Losses and Loss Expenses	11 - Liabilities for Losses and Loss Expenses The establishment of appropriate liabilities for losses and loss expenses is an inherently uncertain process, and we can provide no assurance that our insurance subsidiaries’ ultimate liabilities for losses and loss expenses will not exceed their loss and loss expense reserves and have an adverse effect on our results of operations and financial condition. Furthermore, we cannot predict the timing, frequency and extent of adjustments to our insurance subsidiaries’ estimated future liabilities, because the historical conditions and events that serve as a basis for our insurance subsidiaries’ estimates of ultimate claim costs may change. As is the case for substantially all property and casualty insurance companies, our insurance subsidiaries have found it necessary in the past to increase their estimated future liabilities for losses and loss expenses in certain periods, and, in other periods, their estimated future liabilities for losses and loss expenses have exceeded their actual liabilities for losses and loss expenses. Changes in our insurance subsidiaries’ estimate of their liabilities for losses and loss expenses generally reflect actual payments and their evaluation of information received subsequent to the prior reporting period. We summarize activity in our insurance subsidiaries’ liabilities for losses and loss expenses as follows: Nine 2021 2020 (in thousands) Balance at January 1 $ 962,007 $ 869,674 Less reinsurance recoverable (404,818 ) (362,768 ) Net balance at January 1 557,189 506,906 Incurred related to: Current year 407,193 353,798 Prior years (25,874 ) (10,321 ) Total incurred 381,319 343,477 Paid related to: Current year 183,165 169,610 Prior years 149,910 139,024 Total paid 333,075 308,634 Net balance at end of period 605,433 541,749 Plus reinsurance recoverable 444,730 400,181 Balance at end of period $ 1,050,163 $ 941,930 Our insurance subsidiaries 25.9 s 4.6 Short-duration contracts are contracts for which our insurance subsidiaries receive premiums that they recognize as revenue over the period of the contract in proportion to the amount of insurance protection our insurance subsidiaries provide. Our insurance subsidiaries consider the policies they issue to be short-duration contracts. We consider the material lines of business of our insurance subsidiaries to be personal automobile, homeowners, commercial automobile, commercial multi-peril and workers’ compensation. Our insurance subsidiaries determine incurred but not reported (“IBNR”) reserves by subtracting the cumulative loss and loss expense amounts our insurance subsidiaries have paid and the case reserves our insurance subsidiaries have established at the balance sheet date from their actuaries’ estimate of the ultimate cost of losses and loss expenses. Accordingly, the IBNR reserves of our insurance subsidiaries include their actuaries’ projections of the cost of unreported claims as well as their actuaries’ projected development of case reserves on known claims and reopened claims. Our insurance subsidiaries’ methodology for estimating IBNR reserves has been in place for many years, and their actuaries made no significant changes to that methodology during the nine months ended September 30, 2021. The actuaries for our insurance subsidiaries generally prepare an initial estimate for ultimate losses and loss expenses for the current accident year by multiplying earned premium by an expected loss ratio for each line of business our insurance subsidiaries write. Expected loss ratios represent the actuaries’ expectation of losses at the time our insurance subsidiaries price and write their policies and before the emergence of any actual claims experience. The actuaries determine an expected loss ratio by analyzing historical experience and adjusting for loss cost trends, loss frequency and severity trends, premium rate level changes, reported and paid loss emergence patterns and other known or observed factors. The actuaries use a variety of actuarial methods to estimate the ultimate cost of losses and loss e x The actuaries consider loss frequency and severity trends when they develop expected loss ratios and point estimates. Loss frequency is a measure of the number of claims per unit of insured exposure, and loss severity is a measure of the average size of claims. Factors that affect loss frequency include changes in weather patterns and economic activity. Factors that affect loss severity include changes in policy limits, reinsurance retentions, inflation rates and judicial interpretations. Our insurance subsidiaries create a claim file when they receive notice of an actual demand for payment, an event that may lead to a demand for payment or when they otherwise determine that a demand for payment could potentially lead to a future demand for payment on another coverage under the same policy or another policy they have issued. In recent years, our insurance subsidiaries have noted an increase in the period of time between the occurrence of a casualty loss event and the date at which they receive notice of a liability claim. Changes in the length of time between the loss occurrence date and the claim reporting date affect the actuaries’ ability to predict loss frequency accurately and the amount of IBNR reserves our insurance subsidiaries require. Our insurance subsidiaries generally create a claim file for a policy at the claimant level by type of coverage and generally recognize one count for each claim event. In certain lines of business where it is common for multiple parties to claim damages arising from a single claim event, our insurance subsidiaries recognize one count for each claimant involved in the event. Atlantic States recognizes one count for each claim event, or claimant involved in a multiple-party claim event, related to losses Atlantic States assumes through its participation in its pooling agreement with Donegal Mutual. Our insurance subsidiaries accumulate the claim counts and report them by line of business.

Impact of New Accounting Standa

Impact of New Accounting Standards	9 Months Ended
	Sep. 30, 2021
Accounting Changes and Error Corrections [Abstract]
Impact of New Accounting Standards	12 - Impact of New Accounting Standards In September 2016, the FASB issued guidance that amends previous guidance on the impairment of financial instruments by adding an impairment model that requires an entity to recognize expected credit losses as an allowance rather than impairments as credit losses are incurred. The intent of this guidance is to reduce complexity and result in a more timely recognition of expected credit losses. In November 2019, the FASB issued guidance that delays the effective date for “smaller reporting companies,” as defined in Item 10(f)(1) of Regulation S-K, to In December 2019, the FASB issued guidance that simplifies accounting for income taxes. The guidance eliminates certain exceptions related to the approach for intra-period tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The guidance was effective January 1, 2021, using the retrospective method or modified retrospective method for certain changes and the prospective method for all other changes, and permits early adoption. Our adoption of this guidance on January 1, 2021 did not have a significant impact on our financial position, results of operations or cash flows.

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Summary of Reconciliation of Numerators and Denominators Used in Basic and Diluted Per Share Computations	The table below presents for the periods indicated a reconciliation of the numerators and denominators we used to compute basic and diluted net income (loss) per share for our Class A common stock and our Class B common stock: Three Months Ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except per share data) Basic (loss) earnings per share: Numerator: Allocation of net (loss) income $ (5,592 ) $ (1,120 ) $ 9,768 $ 2,069 Denominator: Weighted-average shares outstanding 25,676 5,577 23,767 5,577 Basic (loss) earnings per share $ (0.22 ) $ (0.20 ) $ 0.41 $ 0.37 Diluted (loss) earnings per share: Numerator: Allocation of net (loss) income $ (5,592 ) $ (1,120 ) $ 9,768 $ 2,069 Denominator: Number of shares used in basic computation 25,676 5,577 23,767 5,577 Weighted-average shares effect of dilutive securities: Director and employee stock options — — 170 — Number of shares used in diluted computation 25,676 5,577 23,937 5,577 Diluted (loss) earnings per share $ (0.22 ) $ (0.20 ) $ 0.41 $ 0.37 Nine Months Ended September 30, 2021 2020 Class A Class B Class A Class B (in thousands, except per share data) Basic earnings per share: Numerator: Allocation of net income $ 16,682 $ 3,300 $ 31,495 $ 6,752 Denominator: Weighted-average shares outstanding 25,265 5,577 23,494 5,577 Basic earnings per share $ 0.66 $ 0.59 $ 1.34 $ 1.21 Diluted earnings per share: Numerator: Allocation of net income $ 16,682 $ 3,300 $ 31,495 $ 6,752 Denominator: Number of shares used in basic computation 25,265 5,577 23,494 5,577 Weighted-average shares effect of dilutive sec u Director and employee stock options 179 — 185 — Number of shares used in diluted computation 25,444 5,577 23,679 5,577 Diluted earnings per share $ 0.66 $ 0.59 $ 1.33 $ 1.21
Summary of Antidilutive Securities Excluded From Computation Of Earnings Per Share	Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Number of options to purchase Class A shares excluded — 6,180,592 4,839,910 6,180,592

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost and Estimated Fair Values of Fixed Maturities	The amortized cost and estimated fair values of our fixed maturities at September 30, 2021 were as follows: Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Held to Maturity U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 93,686 $ 2,455 $ 829 $ 95,312 Obligations of states and political subdivisions 355,461 17,087 1,449 371,099 Corporate securities 194,188 13,496 644 207,040 Mortgage-backed securities 17,745 911 — 18,656 Totals $ 661,080 $ 33,949 $ 2,922 $ 692,107 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Available for Sale U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 27,500 $ 206 $ 277 $ 27,429 Obligations of states and political subdivisions 57,221 2,048 67 59,202 Corporate securities 203,519 8,588 365 211,742 Mortgage-backed securities 218,273 4,590 745 222,118 Totals $ 506,513 $ 15,432 $ 1,454 $ 520,491 The amortized cost and estimated fair values of our fixed maturities at December 31, 2020 were as follows: Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Held to Maturity U.S. $ 77,435 $ 3,984 $ 223 $ 81,196 Obligations of states and political subdivisions 312,319 23,212 143 335,388 Corporate securities 173,270 18,172 206 191,236 Mortgage-backed securities 23,585 1,236 — 24,821 Totals $ 586,609 $ 46,604 $ 572 $ 632,641 Amortized Cost Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Available for Sale U.S. $ 47,512 $ 424 $ 121 $ 47,815 Obligations of states and political subdivisions 66,287 2,690 12 68,965 Corporate securities 202,396 10,496 184 212,708 Mortgage-backed securities 218,763 6,902 17 225,648 Totals $ 534,958 $ 20,512 $ 334 $ 555,136
Summary of Amortized Cost and Estimated Fair Value of Fixed Maturities by Contractual Maturity	Amortized Cost Estimated Fair (in thousands) Held to maturity Due in one year or less $ 36,112 $ 36,838 Due after one year through five years 82,968 87,988 Due after five years through ten years 232,949 244,151 Due after ten years 291,306 304,474 Mortgage-backed securities 17,745 18,656 Total held to maturity $ 661,080 $ 692,107 Available for sale Due in one year or less $ 22,414 $ 22,809 Due after one year through five years 120,648 126,744 Due after five years through ten years 113,678 116,556 Due after ten years 31,500 32,264 Mortgage-backed securities 218,273 222,118 Total available for sale $ 506,513 $ 520,491
Summary of Cost and Estimated Fair Values of Equity Securities	The cost and estimated fair values of our equity securities at September 30, 2021 were as follows: Cost Gross Gains Gross Losses Estimated Fair (in thousands) Equity securities $ 50,864 $ 20,576 $ 257 $ 71,183 The cost and estimated fair values of our equity securities at December 31, 2020 were as follows: Cost Gross Gains Gross Losses Estimated Fair (in thousands) Equity securities $ 42,410 $ 17,103 $ 957 $ 58,556
Summary of Gross Investment Gains and Losses before Applicable Income Taxes	Gross investment gains and losses before applicable income taxes for the three months and nine months ended September 30, 2021 and 2020 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 (in thousands) (in thousands) Gross investment gains: Fixed maturities $ 86 $ 159 $ 610 $ 811 Equity securities — 3,131 5,287 5,617 86 3,290 5,897 6,428 Gross investment losses: Fixed maturities 82 22 156 240 Equity securities 1,574 — 601 7,128 1,656 22 757 7,368 Net investment (losses) gains $ (1,570 ) $ 3,268 $ 5,140 $ (940 )
Summary of Fixed Maturities with Unrealized Losses	We held fixed maturities with unrealized losses representing declines that we considered temporary at September 30, 2021 as follows: Less Than 12 Months More Than 12 Months Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 36,355 $ 566 $ 17,458 $ 540 Obligations of states and political subdivisions 77,320 1,327 6,532 189 Corporate securities 56,319 726 3,217 283 Mortgage-backed securities 75,372 742 133 3 Totals $ 245,366 $ 3,361 $ 27,340 $ 1,015 We held fixed maturities with unrealized losses representing declines that we considered temporary at December 31, 2020 as follows: Less Than 12 Months More Than 12 Months Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 29,144 $ 345 $ — $ — Obligations of states and political subdivisions 9,362 154 — — Corporate securities 26,143 115 8,230 276 Mortgage-backed securities 3,091 15 236 1 Totals $ 67,740 $ 629 $ 8,466 $ 277

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Summary of Financial Data by Segment	Financial data by segment for the three and nine months ended September 30, 2021 and 2020 is as follows: Three Months Ended September 30, 2021 2020 (in thousands) Revenues: Premiums earned: Commercial lines $ 119,709 $ 103,436 Personal lines 76,526 81,490 GAAP premiums earned 196,235 184,926 Net investment income 7,764 7,403 Investment (losses) (1,570 ) 3,268 Other 677 915 Total revenues $ 203,106 $ 196,512 (Loss) income (benefit) Underwriting (loss) Commercial lines $ (10,962 ) $ (1,703 ) Personal lines (4,976 ) 6,427 SAP underwriting (loss) (15,938 ) 4,724 GAAP adjustments 864 (1,576 ) GAAP underwriting (loss) (15,074 ) 3,148 Net investment income 7,764 7,403 Investment (losses) (1,570 ) 3,268 Other 250 513 (Loss) income (benefit) $ (8,630 ) $ 14,332 Nine Months Ended September 30, 2021 2020 (in thousands) Revenues: Premiums earned: Commercial lines $ 344,234 $ 307,080 Personal lines 231,741 249,472 GAAP premiums earned 575,975 556,552 Net investment income 22,926 21,952 Investment gains (losses) 5,140 (940 ) Other 2,181 2,759 Total revenues $ 606,222 $ 580,323 Income before income tax expense: Underwriting (loss) income: Commercial lines $ (17,437 ) $ 2,203 Personal lines 608 19,528 SAP underwriting (loss) income (16,829 ) 21,731 GAAP adjustments 12,101 1,186 GAAP underwriting (loss) (4,728 ) 22,917 Net investment income 22,926 21,952 Investment gains (losses) 5,140 (940 ) Other 480 894 Income before income tax expense $ 23,818 $ 44,823

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2021
FHLB of Pittsburgh [Member]
Amount of FHLB of Indianapolis/Pittsburgh Stock Purchased, Collateral Pledged and Assets Related to MICO's/Atlantic States Agreement	FHLB of Pittsburgh stock purchased and owned $ 1,575,600 Collateral pledged, at par (carrying value $41,831,206) 41,155,784 Borrowing capacity currently available 5,504,094

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements for Investments in Available-for-Sale Fixed Maturity and Equity Securities	The following table presents our fair value measurements for our investments in available-for-sale fi x , : Fair Value Measurements Using Fair Value Quoted Prices in Significant Other Significant (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 27,429 $ — $ 27,429 $ — Obligations of states and political subdivisions 59,202 — 59,202 — Corporate securities 211,742 — 211,742 — Mortgage-backed securities 222,118 — 222,118 — Equity securities 71,183 68,893 2,290 — Total investments in the fair value hierarchy $ 591,674 $ 68,893 $ 522,781 $ — The following table presents our fair value measurements for our investments in a v Fair Value Measurements Using Fair Value Quoted Prices in Significant Other Significant (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 47,815 $ — $ 47,815 $ — Obligations of states and political subdivisions 68,965 — 68,965 — Corporate securities 212,708 — 212,708 — Mortgage-backed securities 225,648 — 225,648 — Equity securities 58,556 54,152 4,404 — Totals $ 613,692 $ 54,152 $ 559,540 $ —

Liabilities for Losses and Lo_2

Liabilities for Losses and Loss Expenses (Tables)	9 Months Ended
	Sep. 30, 2021
Text Block [Abstract]
Summary of Insurance Subsidiaries' Liabilities for Losses and Loss Expenses	We summarize activity in our insurance subsidiaries’ liabilities for losses and loss expenses as follows: Nine 2021 2020 (in thousands) Balance at January 1 $ 962,007 $ 869,674 Less reinsurance recoverable (404,818 ) (362,768 ) Net balance at January 1 557,189 506,906 Incurred related to: Current year 407,193 353,798 Prior years (25,874 ) (10,321 ) Total incurred 381,319 343,477 Paid related to: Current year 183,165 169,610 Prior years 149,910 139,024 Total paid 333,075 308,634 Net balance at end of period 605,433 541,749 Plus reinsurance recoverable 444,730 400,181 Balance at end of period $ 1,050,163 $ 941,930

Organization - Additional Infor

Organization - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2021Segment
Business Acquisition [Line Items]
Operations commenced date	Aug. 26, 1986
Number of operating segments	3
Atlantic States [Member]
Business Acquisition [Line Items]
Voting power percentage of outstanding common stock	70.00%
Percentage of share in results of pooled business subsidiary	80.00%
Donegal Mutual [Member]
Business Acquisition [Line Items]
Premiums and losses related to certain products	100.00%
Class A Common Stock [Member]
Business Acquisition [Line Items]
Stock ownership percentage held by major shareholder	41.00%
Class B Common Stock [Member]
Business Acquisition [Line Items]
Stock ownership percentage held by major shareholder	84.00%

Earnings (Loss) Per Share - Add

Earnings (Loss) Per Share - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Minimum percentage of class A common stock declared dividend excess over class B dividend	10.00%

Earnings (Loss) Per Share - Sum

Earnings (Loss) Per Share - Summary of Reconciliation of Numerators and Denominators Used in Basic and Diluted Per Share Computations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Class A Common Stock [Member]
Numerator:
Allocation of net (loss) income	$ (5,592)	$ 9,768	$ 16,682	$ 31,495
Denominator:
Weighted-average shares outstanding	25,676	23,767	25,265	23,494
Basic earnings (loss) per share:	$ (0.22)	$ 0.41	$ 0.66	$ 1.34
Numerator:
Allocation of net income (loss)	$ (5,592)	$ 9,768	$ 16,682	$ 31,495
Denominator:
Number of shares used in basic computation	25,676	23,767	25,265	23,494
Weighted-average shares effect of dilutive securities
Director and employee stock options		170	179	185
Number of shares used in diluted computation	25,676	23,937	25,444	23,679
Diluted (loss) earnings per share	$ (0.22)	$ 0.41	$ 0.66	$ 1.33
Class B Common Stock [Member]
Numerator:
Allocation of net (loss) income	$ (1,120)	$ 2,069	$ 3,300	$ 6,752
Denominator:
Weighted-average shares outstanding	5,577	5,577	5,577	5,577
Basic earnings (loss) per share:	$ (0.20)	$ 0.37	$ 0.59	$ 1.21
Numerator:
Allocation of net income (loss)	$ (1,120)	$ 2,069	$ 3,300	$ 6,752
Denominator:
Number of shares used in basic computation	5,577	5,577	5,577	5,577
Weighted-average shares effect of dilutive securities
Number of shares used in diluted computation	5,577	5,577	5,577	5,577
Diluted (loss) earnings per share	$ (0.20)	$ 0.37	$ 0.59	$ 1.21

Earnings (Loss) Per Share - S_2

Earnings (Loss) Per Share - Summary of Antidilutive Securities Excluded From Computation Of Earnings Per Share (Detail) - shares	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Equity Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of options to purchase Class A shares excluded	6,180,592	4,839,910	6,180,592

Reinsurance - Additional Inform

Reinsurance - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2021USD ($)
Ceded Credit Risk [Line Items]
Loss reinsurance, set retention amount for property losses	$ 2,000,000
Third Party Reinsurance [Member]
Ceded Credit Risk [Line Items]
Percentage of accumulation of losses	100.00%
Catastrophe reinsurance, set retention amount	$ 15,000,000
Maximum amount of loss coverage under reinsurance agreement of property catastrophe	$ 185,000,000
Atlantic States [Member]
Ceded Credit Risk [Line Items]
Percentage of share in results of pooled business subsidiary	80.00%
Donegal Mutual [Member]
Ceded Credit Risk [Line Items]
Percentage of share in results of pooled business owned by third party	20.00%
Percentage of accumulation of losses	100.00%
Catastrophe reinsurance, set retention amount	$ 2,000,000
Maximum amount of loss coverage under reinsurance agreement of property catastrophe	13,000,000
Additional coverage amount	$ 5,000,000

Investments - Summary of Amorti

Investments - Summary of Amortized Cost and Estimated Fair Values of Fixed Maturities (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	$ 661,080,363	$ 586,609,439
Held to Maturity, Gross Unrealized Gains	33,949,000	46,604,000
Held to Maturity, Gross Unrealized Losses	2,922,000	572,000
Total held to maturity, Estimated Fair Value	692,107,000	632,641,000
Available for Sale, Amortized Cost	506,513,000	534,958,000
Available for Sale, Gross Unrealized Gains	15,432,000	20,512,000
Available for Sale, Gross Unrealized Losses	1,454,000	334,000
Available for Sale, Estimated Fair Value	520,491,000	555,136,000
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	93,686,000	77,435,000
Held to Maturity, Gross Unrealized Gains	2,455,000	3,984,000
Held to Maturity, Gross Unrealized Losses	829,000	223,000
Total held to maturity, Estimated Fair Value	95,312,000	81,196,000
Available for Sale, Amortized Cost	27,500,000	47,512,000
Available for Sale, Gross Unrealized Gains	206,000	424,000
Available for Sale, Gross Unrealized Losses	277,000	121,000
Available for Sale, Estimated Fair Value	27,429,000	47,815,000
Obligations of States and Political Subdivisions [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	355,461,000	312,319,000
Held to Maturity, Gross Unrealized Gains	17,087,000	23,212,000
Held to Maturity, Gross Unrealized Losses	1,449,000	143,000
Total held to maturity, Estimated Fair Value	371,099,000	335,388,000
Available for Sale, Amortized Cost	57,221,000	66,287,000
Available for Sale, Gross Unrealized Gains	2,048,000	2,690,000
Available for Sale, Gross Unrealized Losses	67,000	12,000
Available for Sale, Estimated Fair Value	59,202,000	68,965,000
Corporate Securities [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	194,188,000	173,270,000
Held to Maturity, Gross Unrealized Gains	13,496,000	18,172,000
Held to Maturity, Gross Unrealized Losses	644,000	206,000
Total held to maturity, Estimated Fair Value	207,040,000	191,236,000
Available for Sale, Amortized Cost	203,519,000	202,396,000
Available for Sale, Gross Unrealized Gains	8,588,000	10,496,000
Available for Sale, Gross Unrealized Losses	365,000	184,000
Available for Sale, Estimated Fair Value	211,742,000	212,708,000
Mortgage-Backed Securities [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	17,745,000	23,585,000
Held to Maturity, Gross Unrealized Gains	911,000	1,236,000
Held to Maturity, Gross Unrealized Losses	0	0
Total held to maturity, Estimated Fair Value	18,656,000	24,821,000
Available for Sale, Amortized Cost	218,273,000	218,763,000
Available for Sale, Gross Unrealized Gains	4,590,000	6,902,000
Available for Sale, Gross Unrealized Losses	745,000	17,000
Available for Sale, Estimated Fair Value	$ 222,118,000	$ 225,648,000

Investments - Additional Inform

Investments - Additional Information (Detail)	Nov. 30, 2013USD ($)	Sep. 30, 2021USD ($)Securities	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Schedule of Investments [Line Items]
Net unrealized losses arising prior to reclassification date	$ 15,100,000
Amortization of unrealized losses recorded in accumulated other comprehensive income (loss)		$ 738,815	$ 1,100,000
Accumulated other comprehensive loss		6,825,161		$ 11,130,612
Gain on equity securities		4,700,000	5,600,000
Loss on equity securities		248,146	$ 3,600,000
Obligations of States and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Aggregate fair value of bond held		275,400,000		263,600,000
Amortized cost of bond held		264,200,000		247,500,000
Special Revenue Bonds [Member]
Schedule of Investments [Line Items]
Aggregate fair value of bond held		154,900,000		140,800,000
Amortized cost of bond held		$ 148,500,000		$ 131,100,000
Education Bonds [Member]
Schedule of Investments [Line Items]
Percentage of investments in special revenue bonds		47.00%		44.00%
Water and Sewer Utility Bonds [Member]
Schedule of Investments [Line Items]
Percentage of investments in special revenue bonds		35.00%		39.00%
Fixed Maturities [Member]
Schedule of Investments [Line Items]
Number of fixed maturity securities classified as available for sale | Securities		139
Accumulated Net Unrealized Investment Losses [Member]
Schedule of Investments [Line Items]
Accumulated other comprehensive loss		$ 5,300,000		$ 6,100,000
Minimum [Member]
Schedule of Investments [Line Items]
Percentage of which the company held security of any issuer		10.00%		10.00%

Investments - Summary of Amor_2

Investments - Summary of Amortized Cost and Estimated Fair Value of Fixed Maturities by Contractual Maturity (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Held to maturity
Due in one year or less, Amortized Cost	$ 36,112,000
Due after one year through five years, Amortized Cost	82,968,000
Due after five years through ten years, Amortized Cost	232,949,000
Due after ten years, Amortized Cost	291,306,000
Mortgage-backed securities, Amortized Cost	17,745,000
Total held to maturity, Amortized Cost	661,080,363	$ 586,609,439
Available for sale
Due in one year or less, Amortized Cost	22,414,000
Due after one year through five years, Amortized Cost	120,648,000
Due after five years through ten years, Amortized Cost	113,678,000
Due after ten years, Amortized Cost	31,500,000
Mortgage-backed securities, Amortized Cost	218,273,000
Total available for sale, Amortized Cost	506,513,000
Held to maturity
Due in one year or less, Estimated Fair Value	36,838,000
Due after one year through five years, Estimated Fair Value	87,988,000
Due after five years through ten years, Estimated Fair Value	244,151,000
Due after ten years, Estimated Fair Value	304,474,000
Mortgage-backed securities, Estimated Fair Value	18,656,000
Total held to maturity, Estimated Fair Value	692,107,000	632,641,000
Available for sale
Due in one year or less, Estimated Fair Value	22,809,000
Due after one year through five years, Estimated Fair Value	126,744,000
Due after five years through ten years, Estimated Fair Value	116,556,000
Due after ten years, Estimated Fair Value	32,264,000
Mortgage-backed securities, Estimated Fair Value	222,118,000
Total available for sale, Estimated Fair Value	$ 520,490,593	$ 555,136,017

Investments - Summary of Cost a

Investments - Summary of Cost and Estimated Fair Value of Equity Securities (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Cost	$ 50,864,000	$ 42,410,000
Gross Gains	20,576,000	17,103,000
Gross Losses	257,000	957,000
Estimated Fair Value	$ 71,182,988	$ 58,556,173

Investments - Summary of Gross

Investments - Summary of Gross Investment Gains and Losses before Applicable Income Taxes (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Gain (Loss) on Securities [Line Items]
Gross investment gains	$ 86,000	$ 3,290,000	$ 5,897,000	$ 6,428,000
Gross investment losses	1,656,000	22,000	757,000	7,368,000
Net investment (losses) gains	(1,570,476)	3,268,459	5,139,609	(940,488)
Fixed Maturities [Member]
Gain (Loss) on Securities [Line Items]
Gross investment gains	86,000	159,000	610,000	811,000
Gross investment losses	82,000	22,000	156,000	240,000
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Gross investment gains	0	3,131,000	5,287,000	5,617,000
Gross investment losses	$ 1,574,000	$ 0	$ 601,000	$ 7,128,000

Investments - Summary of Fixed

Investments - Summary of Fixed Maturities with Unrealized Losses (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	$ 245,366	$ 67,740
Less Than 12 Months, Unrealized Losses	3,361	629
More Than 12 Months, Fair Value	27,340	8,466
More Than 12 Months, Unrealized Losses	1,015	277
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	36,355	29,144
Less Than 12 Months, Unrealized Losses	566	345
More Than 12 Months, Fair Value	17,458
More Than 12 Months, Unrealized Losses	540
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	77,320	9,362
Less Than 12 Months, Unrealized Losses	1,327	154
More Than 12 Months, Fair Value	6,532
More Than 12 Months, Unrealized Losses	189
Corporate Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	56,319	26,143
Less Than 12 Months, Unrealized Losses	726	115
More Than 12 Months, Fair Value	3,217	8,230
More Than 12 Months, Unrealized Losses	283	276
Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	75,372	3,091
Less Than 12 Months, Unrealized Losses	742	15
More Than 12 Months, Fair Value	133	236
More Than 12 Months, Unrealized Losses	$ 3	$ 1

Segment Information - Summary o

Segment Information - Summary of Financial Data by Segment (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Premiums earned:
Premiums earned	$ 196,234,626	$ 184,925,733	$ 575,974,891	$ 556,552,279
Net investment income	7,763,562	7,403,251	22,926,320	21,951,679
Investment (losses) gains	(1,570,476)	3,268,459	5,139,609	(940,488)
Total revenues	203,106,181	196,512,266	606,222,022	580,323,244
Underwriting (loss) income:
Net investment income	7,763,562	7,403,251	22,926,320	21,951,679
Net investment (losses) gains	(1,570,476)	3,268,459	5,139,609	(940,488)
(Loss) income before income tax (benefit) expense	(8,629,676)	14,331,584	23,817,834	44,822,804
Operating Segments [Member]
Premiums earned:
Premiums earned	196,235,000	184,926,000	575,975,000	556,552,000
Net investment income	7,764,000	7,403,000	22,926,000	21,952,000
Investment (losses) gains	(1,570,000)	3,268,000	5,140,000	(940,000)
Other	677,000	915,000	2,181,000	2,759,000
Total revenues	203,106,000	196,512,000	606,222,000	580,323,000
Underwriting (loss) income:
SAP underwriting (loss) income	(15,938,000)	4,724,000	(16,829,000)	21,731,000
GAAP adjustments	864,000	(1,576,000)	12,101,000	1,186,000
GAAP underwriting income	(15,074,000)	3,148,000	(4,728,000)	22,917,000
Net investment income	7,764,000	7,403,000	22,926,000	21,952,000
Net investment (losses) gains	(1,570,000)	3,268,000	5,140,000	(940,000)
Other	250,000	513,000	480,000	894,000
(Loss) income before income tax (benefit) expense	(8,630,000)	14,332,000	23,818,000	44,823,000
Commercial Lines [Member] | Operating Segments [Member]
Premiums earned:
Premiums earned	119,709,000	103,436,000	344,234,000	307,080,000
Underwriting (loss) income:
SAP underwriting (loss) income	(10,962,000)	(1,703,000)	(17,437,000)	2,203,000
Personal Lines [Member] | Operating Segments [Member]
Premiums earned:
Premiums earned	76,526,000	81,490,000	231,741,000	249,472,000
Underwriting (loss) income:
SAP underwriting (loss) income	$ (4,976,000)	$ 6,427,000	$ 608,000	$ 19,528,000

Borrowings - Additional Informa

Borrowings - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2021	Aug. 01, 2020
Line of Credit Facility [Line Items]
Line of credit expiration month and year	2020-08
Line of credit, interest rate description	interest rates equal to the then-current LIBOR rate plus 2.00%
Manufacturers and Traders Trust Company [Member]
Line of Credit Facility [Line Items]
Line of credit facility remaining borrowing capacity	$ 20,000,000
FHLB of Pittsburgh [Member] | Atlantic States [Member]
Line of Credit Facility [Line Items]
Right to request for extension of credit agreement with Manufacturers and Traders Trust Company	5,504,094
Federal home loan bank, fixed rate advances	$ 35,000,000
Revolving Credit Facility [Member] | Manufacturers and Traders Trust Company [Member]
Line of Credit Facility [Line Items]
Right to request for extension of credit agreement with Manufacturers and Traders Trust Company		$ 20,000,000
Debt instrument stated interest rate	2.00%
Lines of Credit [Member] | FHLB of Pittsburgh [Member] | Atlantic States [Member]
Line of Credit Facility [Line Items]
Interest rate on advances	1.74%
Subordinated Debentures [Member]
Line of Credit Facility [Line Items]
Debt instrument, Increase, accrued interest	$ 5,000,000
Repayments of debt	178,082
Subordinated Debentures [Member] | Lines of Credit [Member] | FHLB of Pittsburgh [Member] | March 2021 Due [Member]
Line of Credit Facility [Line Items]
Outstanding advances	$ 50,000,000
Interest rate on advances	0.83%

Borrowings - Amount of FHLB of

Borrowings - Amount of FHLB of Indianapolis/Pittsburgh Stock Purchased, Collateral Pledged and Assets Related to MICO's/Atlantic States Agreement (Detail) - Atlantic States [Member] - FHLB of Pittsburgh [Member]	Sep. 30, 2021USD ($)
Amount of FHLB of Indianapolis/Pittsburgh stock purchased, collateral pledged and assets related to MICO's/Atlantic States Agreement
FHLB stock purchased and owned	$ 1,575,600
Collateral pledged, at par	41,155,784
Borrowing capacity currently available	$ 5,504,094

Borrowings - Amount of FHLB o_2

Borrowings - Amount of FHLB of Indianapolis/Pittsburgh Stock Purchased, Collateral Pledged and Assets Related to MICO's/Atlantic States Agreement (Parenthetical) (Detail)	Sep. 30, 2021USD ($)
FHLB of Pittsburgh [Member] | Atlantic States [Member]
Line of Credit Facility [Line Items]
Collateral Pledged at carrying value	$ 41,831,206

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation expense in stock compensation plans	$ 181,595	$ 219,051	$ 778,763	$ 863,592
Income tax benefit of stock compensation plans	38,135	46,001	163,540	181,354
Unrecognized compensation expense related to nonvested share-based compensation granted under the plan	852,888		$ 852,888
Weighted average period of unrecognized compensation expense			1 year 4 months 24 days
Cash from option exercises	764,956	8,100,000	$ 12,200,000	11,200,000
Tax benefit for tax deductions related to option exercises	$ 16,655	$ 163,245	$ 437,790	$ 232,123

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurements for Investments in Available-for-Sale Fixed Maturity and Equity Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	$ 520,491	$ 555,136
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	27,429	47,815
Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	59,202	68,965
Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	211,742	212,708
Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	222,118	225,648
Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	591,674	613,692
Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	27,429	47,815
Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	59,202	68,965
Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	211,742	212,708
Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	222,118	225,648
Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	71,183	58,556
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	68,893	54,152
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	68,893	54,152
Significant Other Observable Inputs (Level 2) [Member] | Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	522,781	559,540
Significant Other Observable Inputs (Level 2) [Member] | Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	27,429	47,815
Significant Other Observable Inputs (Level 2) [Member] | Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	59,202	68,965
Significant Other Observable Inputs (Level 2) [Member] | Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	211,742	212,708
Significant Other Observable Inputs (Level 2) [Member] | Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	222,118	225,648
Significant Other Observable Inputs (Level 2) [Member] | Assets and Liabilities on Recurring Basis [Member] | Total Investments in the Fair Value Hierarchy [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	$ 2,290	$ 4,404

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Mar. 31, 2020
Operating Loss Carryforwards [Line Items]
Other deferred tax assets, net	$ 28,100,000	$ 26,700,000
Income taxes receivable	6,356,968	$ 3,089,369	$ 1,600,000
Parent Company [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance related to the portion of operating loss carryforwards	$ 7,900,000
Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Tax years open for examination	2016
Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Tax years open for examination	2020

Liabilities for Losses and Lo_3

Liabilities for Losses and Loss Expenses - Summary of Insurance Subsidiaries' Liabilities for Losses and Loss Expenses (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Liability for Claims and Claims Adjustment Expense [Abstract]
Balance at January 1	$ 962,007,437	$ 869,674,000
Less reinsurance recoverable	(404,818,000)	(362,768,000)
Net balance at January 1	557,189,000	506,906,000
Incurred related to:
Current year	407,193,000	353,798,000
Prior years	(25,874,000)	(10,321,000)
Total incurred	381,319,000	343,477,000
Paid related to:
Current year	183,165,000	169,610,000
Prior years	149,910,000	139,024,000
Total paid	333,075,000	308,634,000
Net balance at end of period	605,433,000	541,749,000
Plus reinsurance recoverable	444,730,000	400,181,000
Balance at end of period	$ 1,050,163,161	$ 941,930,000

Liabilities for Losses and Lo_4

Liabilities for Losses and Loss Expenses - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Increase (Decrease) in liability for losses and loss expenses of prior years	$ (25,874)	$ (10,321)
Percentage of 2010 development	4.60%	2.00%