Donegal (DGICA) 10-Q 5 Aug 20 2020 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Document Information [Line Items]
Document Type	10-Q
Entity Interactive Data Current	Yes
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
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		23,533,853
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 ($)	Jun. 30, 2020	Dec. 31, 2019
Fixed maturities
Held to maturity, at amortized cost	$ 519,731,423	$ 476,093,782
Available for sale, at fair value	569,942,279	564,951,803
Equity securities, at fair value	52,703,395	55,477,556
Short-term investments, at cost, which approximates fair value	51,342,125	14,030,222
Total investments	1,193,719,222	1,110,553,363
Cash	71,777,366	49,318,930
Accrued investment income	7,663,852	7,066,029
Premiums receivable	187,450,180	165,732,949
Reinsurance receivable	379,340,802	367,021,468
Deferred policy acquisition costs	62,150,533	59,284,859
Deferred tax asset, net	6,729,689	8,514,311
Prepaid reinsurance premiums	174,958,995	142,475,767
Property and equipment, net	4,396,529	4,558,072
Accounts receivable—securities	6,440	4,961
Goodwill	5,625,354	5,625,354
Other intangible assets	958,010	958,010
Other	1,369,687	2,047,058
Total assets	2,096,146,659	1,923,161,131
Liabilities
Unpaid losses and loss expenses	901,823,622	869,673,849
Unearned premiums	562,943,939	510,147,485
Accrued expenses	23,448,271	28,453,744
Reinsurance balances payable	2,260,482	2,116,084
Borrowings under lines of credit	85,000,000	35,000,000
Cash dividends declared to stockholders		4,075,234
Subordinated debentures	5,000,000	5,000,000
Accounts payable – securities	6,160,309	1,119
Income taxes payable	4,978,351	84,831
Due to affiliate	8,015,859	10,069,171
Other	8,656,492	7,524,095
Total liabilities	1,608,287,325	1,472,145,612
Stockholders' Equity
Preferred stock, $.01 par value, authorized 2,000,000 shares; none issued
Additional paid-in capital	273,175,488	268,151,601
Accumulated other comprehensive income	10,367,225	504,170
Retained earnings	245,221,348	223,267,573
Treasury stock, at cost	(41,226,357)	(41,226,357)
Total stockholders' equity	487,859,334	451,015,519
Total liabilities and stockholders' equity	2,096,146,659	1,923,161,131
Class A Common Stock [Member]
Stockholders' Equity
Common stock value	265,138	262,040
Total stockholders' equity	265,138	262,040
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	Jun. 30, 2020	Dec. 31, 2019
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	26,513,779	26,203,935
Common stock, shares outstanding	23,511,191	23,201,347
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 Inco

Consolidated Statements of Income - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Net premiums earned	$ 184,373,768	$ 188,763,313	$ 371,626,546	$ 376,836,555
Investment income, net of investment expenses	7,172,144	7,289,652	14,548,428	14,338,155
Net investment gains	6,485,896	1,566,157	(4,208,947)	19,663,270
Lease income	109,205	112,155	218,472	223,254
Installment payment fees	758,759	1,057,677	1,626,479	2,146,594
Equity in earnings of Donegal Financial Services Corporation				295,000
Total revenues	198,899,772	198,788,954	383,810,978	413,502,828
Expenses:
Net losses and loss expenses	105,349,019	131,507,280	222,595,545	254,617,936
Amortization of deferred policy acquisition costs	29,634,000	30,925,000	59,571,000	61,517,000
Other underwriting expenses	33,567,266	28,208,336	66,164,895	58,893,219
Policyholder dividends	1,683,658	1,969,490	3,525,658	4,319,138
Interest	428,092	303,423	652,422	868,715
Other expenses, net	249,688	337,894	810,238	904,265
Total expenses	170,911,723	193,251,423	353,319,758	381,120,273
Income before income tax expense	27,988,049	5,537,531	30,491,220	32,382,555
Income tax expense	5,309,271	749,077	4,081,321	4,570,937
Net income	$ 22,678,778	$ 4,788,454	$ 26,409,899	$ 27,811,618
Class A Common Stock [Member]
Earnings per common share:
Class A common stock - basic	$ 0.80	$ 0.17	$ 0.93	$ 1
Class A common stock - diluted	0.79	0.17	0.92	0.99
common stock - basic and diluted	0.79	0.17
Class B Common Stock [Member]
Earnings per common share:
Class A common stock - basic	0.72	0.15	0.84	0.90
Class A common stock - diluted	0.72	0.15	0.84	0.90
common stock - basic and diluted	$ 0.72	$ 0.15	$ 0.84	$ 0.90

Consolidated Statements of In_2

Consolidated Statements of Income (Loss) (Parenthetical) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net investment (losses) gains	$ 6,485,896	$ 1,566,157	$ (4,208,947)	$ 19,663,270
Income tax expense	5,309,271	749,077	4,081,321	4,570,937
Reclassification out of Accumulated Other Comprehensive Income [Member]
Net investment (losses) gains	14,493	13,150	436,328	52,414
Income tax expense	$ 3,044	$ 2,762	$ 91,629	$ 11,007

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 22,678,778	$ 4,788,454	$ 26,409,899	$ 27,811,618
Unrealized gain on securities:
Unrealized holding gain during the period, net of income tax expense	6,674,664	5,932,595	10,207,754	12,432,087
Reclassification adjustment for gains included in net income, net of income tax expense	(11,449)	(10,388)	(344,699)	(41,407)
Other comprehensive income	6,663,215	5,922,207	9,863,055	12,390,680
Comprehensive income	$ 29,341,993	$ 10,710,661	$ 36,272,954	$ 40,202,298

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Unrealized holding gain during the period, net of income tax expense	$ 1,774,279	$ 1,593,511	$ 2,713,454	$ 3,304,733
Income tax expense (benefit) on reclassification adjustment for gains	$ 3,044	$ 2,762	$ 91,629	$ 11,007

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity - USD ($)	Total	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Class A Common Stock [Member]	Class B Common Stock [Member]
Beginning balance at Dec. 31, 2018	$ 398,869,901	$ 261,258,423	$ (14,228,059)	$ 192,751,208	$ (41,226,357)	$ 258,194	$ 56,492
Beginning balance, shares at Dec. 31, 2018						25,819,341	5,649,240
Issuance of common stock (stock compensation plans)	404,055	403,722				$ 333
Issuance of common stock (stock compensation plans), shares						33,334
Share-based compensation	442,920	442,920
Net income	23,023,164			23,023,164
Cash dividends declared	(4,752)			(4,752)
Grant of stock options		144,226		(144,226)
Other comprehensive income	6,468,473		6,468,473
Ending balance at Mar. 31, 2019	429,203,761	262,249,291	(7,759,586)	215,625,394	(41,226,357)	$ 258,527	$ 56,492
Ending balance, shares at Mar. 31, 2019						25,852,675	5,649,240
Beginning balance at Dec. 31, 2018	398,869,901	261,258,423	(14,228,059)	192,751,208	(41,226,357)	$ 258,194	$ 56,492
Beginning balance, shares at Dec. 31, 2018						25,819,341	5,649,240
Net income	27,811,618
Other comprehensive income	12,390,680
Ending balance at Jun. 30, 2019	437,853,724	264,320,325	(1,837,379)	216,280,947	(41,226,357)	$ 259,696	$ 56,492
Ending balance, shares at Jun. 30, 2019						25,969,577	5,649,240
Beginning balance at Mar. 31, 2019	429,203,761	262,249,291	(7,759,586)	215,625,394	(41,226,357)	$ 258,527	$ 56,492
Beginning balance, shares at Mar. 31, 2019						25,852,675	5,649,240
Issuance of common stock (stock compensation plans)	752,914	752,354				$ 560
Issuance of common stock (stock compensation plans), shares						55,933
Share-based compensation	1,218,804	1,218,195				$ 609
Share-based compensation, shares						60,969
Net income	4,788,454			4,788,454
Cash dividends declared	(4,032,416)			(4,032,416)
Grant of stock options		100,485		(100,485)
Other comprehensive income	5,922,207		5,922,207
Ending balance at Jun. 30, 2019	437,853,724	264,320,325	(1,837,379)	216,280,947	(41,226,357)	$ 259,696	$ 56,492
Ending balance, shares at Jun. 30, 2019						25,969,577	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
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 income	3,731,121			3,731,121
Cash dividends declared	(5,363)			(5,363)
Grant of stock options		118,525		(118,525)
Other comprehensive 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 income	26,409,899
Other comprehensive income	9,863,055
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
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 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 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

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash Flows from Operating Activities:
Net income	$ 26,409,899	$ 27,811,618
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash items	3,502,046	3,013,417
Net investment losses (gains)	4,208,947	(19,663,270)
Equity in earnings of Donegal Financial Services Corporation		(295,000)
Changes in assets and liabilities:
Losses and loss expenses	32,149,773	30,617,211
Unearned premiums	52,796,454	29,470,779
Premiums receivable	(21,717,231)	(19,555,531)
Deferred acquisition costs	(2,865,674)	(3,659,349)
Deferred income taxes	(837,202)	272,997
Reinsurance receivable	(12,319,334)	(14,260,221)
Prepaid reinsurance premiums	(32,483,228)	(8,589,599)
Accrued investment income	(597,823)	(737,007)
Due to affiliate	(2,053,312)	(4,864,419)
Reinsurance balances payable	144,398	(1,336,217)
Current income taxes	4,893,520	2,072,938
Accrued expenses	(5,005,473)	(261,869)
Other, net	1,809,764	1,154,221
Net adjustments	21,625,625	(6,620,919)
Net cash provided by operating activities	48,035,524	21,190,699
Cash Flows from Investing Activities:
Purchases of fixed maturities, held to maturity	(55,313,641)	(38,094,242)
Purchases of fixed maturities, available for sale	(81,210,780)	(88,098,117)
Purchases of equity securities, available for sale	(5,071,801)	(12,356,474)
Maturity of fixed maturities:
Held to maturity	18,812,367	6,656,093
Available for sale	70,379,590	41,569,635
Sales of fixed maturities, available for sale	15,251,996	20,548,077
Sales of equity securities, available for sale	3,202,672	37,071,301
Net sales (purchases) of property and equipment	32,107	(129,877)
Net purchases of short-term investments	(37,311,903)	(7,704,029)
Net cash used in investing activities	(71,229,393)	(6,614,860)
Cash Flows from Financing Activities:
Cash dividends paid	(8,336,479)	(7,985,652)
Issuance of common stock	3,988,784	1,760,919
Borrowing under lines of credit	50,000,000
Payments on lines of credit		(25,000,000)
Net cash provided by (used in) financing activities	45,652,305	(31,224,733)
Net increase (decrease) in cash	22,458,436	(16,648,894)
Cash at beginning of period	49,318,930	52,594,461
Cash at end of period	71,777,366	35,945,567
Cash paid during period – Interest	$ 664,342	321,585
Net cash paid during period – Taxes		2,200,000
Donegal Financial Services Corporation [Member]
Maturity of fixed maturities:
Sale of investment in Donegal Financial Services Corporation		$ 33,922,773

Organization

Organization	6 Months Ended
	Jun. 30, 2020
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 , Mid-Atlantic, At June 30, 2020, we had three segments: our investment function, our personal lines of insurance and our commercial lines of insurance. The personal lines products of our insurance subsidiaries consist primarily of homeowners and private passenger automobile policies. The commercial lines products of our insurance subsidiaries consist primarily of commercial automobile, commercial multi-peril and workers’ compensation policies. At June 30, 2020, Donegal Mutual held approximately 42 71 Atlantic States, our largest subsidiary, participates in a pooling agreement with Donegal Mutual. Under the pooling agreement, the two companies pool their insurance business and each company receives an allocated percentage of the pooled business. Atlantic States has an 80% share of the results of the pooled business, and Donegal Mutual has a 20% share of the results of the pooled business. 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 entire personal lines or commercial lines accounts. Distinctions within the products Donegal Mutual and our insurance subsidiaries offer relate generally to specific risk profiles targeted within similar classes of business, such as preferred tier products versus standard tier products, but we do not allocate all of the standard risk gradients to any specific company within the Donegal Insurance Group. Therefore, the underwriting profitability of the business the individual companies write directly will vary. However, because the risk characteristics of all business Donegal Mutual and Atlantic States write directly are homogenized within the underwriting pool, Donegal Mutual and Atlantic States share the underwriting results in proportion to their respective participation in the underwriting pool. We and Donegal Mutual sold Donegal Financial Services Corporation (“DFSC”) to Northwest Bancshares, Inc. (“Northwest”) on March 8, 2019, resulting in proceeds valued at approximately $85.8 million in a combination of cash and Northwest common stock. Immediately prior to the closing of the merger, DFSC paid a dividend of approximately $29.2 million to us and Donegal Mutual. As the owner of 48.2% of DFSC’s common stock, we received a dividend payment from DFSC of approximately $14.1 million and consideration from Northwest that included a combination of cash in the amount of $20.5 million and Northwest common stock with a fair value at the closing date of $20.9 million. We recorded a gain of $12.7 million from the sale of DFSC in our results of operations for the first quarter of 2019. We sold the Northwest common stock that we received as part of the consideration during the first quarter of 2019. This transaction represented the culmination of a banking strategy that began with the formation of DFSC in 2000. On July 18, 2013, our board of directors authorized a share repurchase program pursuant to which we have the authority to purchase up to 500,000 shares of our Class A common stock at prices prevailing from time to time in the open market subject to the provisions of applicable rules of the Securities and Exchange Commission (“SEC”) and in privately negotiated transactions. We did not purchase any shares of our Class A common stock under this program during the six months ended June 30, 2020 or 2019. We have purchased a total of 57,658 shares of our Class A common stock under this program from its inception through June 30, 2020.

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2020
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 Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	3 - Earnings 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 two-class Three Months Ended June 30, 2020 2019 Class A Class B Class A Class B (in thousands, except per share data) Basic earnings per share: Numerator: Allocation of net income $ 18,665 $ 4,014 $ 3,941 $ 848 Denominator: Weighted-average shares outstanding 23,451 5,577 22,933 5,577 Basic earnings per share $ 0.80 $ 0.72 $ 0.17 $ 0.15 Diluted earnings per share: Numerator: Allocation of net income $ 18,665 $ 4,014 $ 3,941 $ 848 Denominator: Number of shares used in basic computation 23,451 5,577 22,933 5,577 Weighted-average shares effect of dilutive securities: Director and employee stock options 199 — 200 — Number of shares used in diluted computation 23,650 5,577 23,133 5,577 Diluted earnings per share $ 0.79 $ 0.72 $ 0.17 $ 0.15 Six Months Ended June 30, 2020 2019 Class A Class B Class A Class B (in thousands, except per share data) Basic earnings per share: Numerator: Allocation of net income $ 21,721 $ 4,689 $ 22,790 $ 5,022 Denominator: Weighted-average shares outstanding 23,356 5,577 22,892 5,577 Basic earnings per share $ 0.93 $ 0.84 $ 1.00 $ 0.90 Diluted earnings per share: Numerator: Allocation of net income $ 21,721 $ 4,689 $ 22,790 $ 5,022 Denominator: Number of shares used in basic computation 23,356 5,577 22,892 5,577 Weighted-average shares effect of dilutive securities: Director and employee stock options 193 — 135 — Number of shares used in diluted computation 23,549 5,577 23,027 5,577 Diluted earnings per share $ 0.92 $ 0.84 $ 0.99 $ 0.90 We did not include outstanding options to purchase the following number of shares of Class A common stock in our computation of diluted earnings 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 June 30, Six Months Ended June 30, 2020 2019 2020 2019 Number of options to purchase Class A shares excluded 6,183,992 5,531,561 6,183,992 5,417,725

Reinsurance

Reinsurance	6 Months Ended
	Jun. 30, 2020
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 currently excludes from the pool its underwriting results in four Southwestern states in which Donegal Mutual markets its products together with its insurance subsidiaries as the Mountain States Insurance Group. Donegal Mutual currently plans to place 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 . They require their reinsurers to maintain 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	6 Months Ended
	Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Investments	5 - Investments The amortized cost and estimated fair values of our fixed maturities at June , were as follows: Amortized Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Held to Maturity U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 73,824 $ 4,619 $ — $ 78,443 Obligations of states and political subdivisions 252,121 19,442 223 271,340 Corporate securities 165,640 14,078 1,085 178,633 Mortgage-backed securities 28,146 1,478 — 29,624 Totals $ 519,731 $ 39,617 $ 1,308 $ 558,040 Amortized Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Available for Sale U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 14,847 $ 550 $ — $ 15,397 Obligations of states and political subdivisions 60,906 2,189 — 63,095 Corporate securities 204,155 8,477 461 212,171 Mortgage-backed securities 270,271 9,041 33 279,279 Totals $ 550,179 $ 20,257 $ 494 $ 569,942 At June 30, 2020, our holdings of obligations of states and political subdivisions included general obligation bonds with an aggregate fair value of $ 217.7 204.3 116.7 108.7 45 40 The amortized cost and estimated fair values of our fixed maturities at December 31, 2019 were as follows: Amortized Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Held to Maturity U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 82,916 $ 1,803 $ 69 $ 84,650 Obligations of states and political subdivisions 204,634 14,237 288 218,583 Corporate securities 156,398 8,275 333 164,340 Mortgage-backed securities 32,146 611 16 32,741 Totals $ 476,094 $ 24,926 $ 706 $ 500,314 Amortized Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Available for Sale U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 19,302 $ 82 $ 19 $ 19,365 Obligations of states and political subdivisions 55,162 1,641 7 56,796 Corporate securities 154,946 4,477 180 159,243 Mortgage-backed securities 327,429 2,857 738 329,548 Totals $ 556,839 $ 9,057 $ 944 $ 564,952 At December 31, 2019, our holdings of obligations of states and political subdivisions included general obligation bonds with an aggregate fair value of $182.0 million and an amortized cost of $172.3 million. Our holdings also included special revenue bonds with an aggregate fair value of $93.4 million and an amortized cost of $87.5 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, 2019. Education bonds and water and sewer utility bonds represented 44% and 35%, respectively, of our total investments in special revenue bonds based on their carrying values at December 31, 2019. Many of the issuers of the special revenue bonds we held at December 31, 2019 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 $ 833,690 6.6 We show below the amortized cost and estimated fair value of our fixed maturities at June 30, 2020 by contractual maturity. Amortized Cost Estimated Fair (in thousands) Held to maturity Due in one year or less $ 32,774 $ 33,145 Due after one year through five years 85,516 91,701 Due after five years through ten years 180,630 195,464 Due after ten years 192,665 208,106 Mortgage-backed securities 28,146 29,624 Total held to maturity $ 519,731 $ 558,040 Available for sale Due in one year or less $ 58,794 $ 59,296 Due after one year through five years 100,488 105,594 Due after five years through ten years 99,183 103,688 Due after ten years 21,443 22,085 Mortgage-backed securities 270,271 279,279 Total available for sale $ 550,179 $ 569,942 The cost and estimated fair values of our equity securities at June 30, 2020 were as follows: Cost Gross Gains Gross Losses Estimated Fair (in thousands) Equity securities $ 42,574 $ 11,495 $ 1,366 $ 52,703 The cost and estimated fair values of our equity securities at December 31, 2019 were as follows: Cost Gross Gains Gross Losses Estimated Fair (in thousands) Equity securities $ 43,419 $ 12,180 $ 121 $ 55,478 Gross investment gains and losses before applicable income taxes for the three and six Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in thousands) (in thousands) Gross investment gains: Fixed maturities $ 229 $ 14 $ 652 $ 372 Equity securities 6,474 1,586 3,355 7,572 Investment in affiliate — — — 12,662 6,703 1,600 4,007 20,606 Gross investment losses: Fixed maturities 217 2 218 320 Equity securities — 32 7,998 623 217 34 8,216 943 Net investment gains (losses) $ 6,486 $ 1,566 $ (4,209 ) $ 19,663 We recognized $ 3.4 million We held fixed maturities with unrealized losses representing declines that we considered temporary at June 30, 2020 as follows: Less Than 12 Months More Than 12 Months Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) Obligations of states and political subdivisions $ 7,058 $ 223 $ — $ — Corporate securities 44,522 696 7,195 850 Mortgage-backed securities 1,674 32 459 1 Totals $ 53,254 $ 951 $ 7,654 $ 851 We held fixed maturities with unrealized losses representing declines that we considered temporary at December 31, 2019 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 $ 7,461 $ 46 $ 5,395 $ 42 Obligations of states and political subdivisions 23,339 293 2,327 2 Corporate securities 19,363 263 18,803 250 Mortgage-backed securities 28,507 56 74,089 698 Totals $ $ 658 $ 100,614 $ 992 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 impairment loss in our other comprehensive income, net of applicable taxes. In addition, we may write down securities in an unrealized loss position based on a number of other factors, including when the fair value of an investment is significantly below its cost, when the financial condition of the issuer of a security has deteriorated, the occurrence of industry, issuer or geographic events that have negatively impacted the value of a security and rating agency downgrades. We held 52 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	6 Months Ended
	Jun. 30, 2020
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 data by segment for the three and six months ended June 30, 2020 and 2019 is as follows: Three Months Ended June 30, 2020 2019 (in thousands) Revenues: Premiums earned: Commercial lines $ 101,870 $ 94,788 Personal lines 82,504 93,975 Premiums earned 184,374 188,763 Net investment income 7,172 7,290 Investment gains 6,486 1,566 Other 868 1,170 Total revenues $ 198,900 $ 198,789 Income before income tax expense: Underwriting income (loss): Commercial lines $ 4,472 $ 4,113 Personal lines 8,290 (9,238 ) SAP underwriting income ( loss 12,762 (5,125 ) GAAP adjustments 1,378 1,278 GAAP underwriting income ( loss 14,140 (3,847 ) Net investment income 7,172 7,290 Investment gains 6,486 1,566 Other 190 529 Income before income tax expense $ 27,988 $ 5,538 Six Months Ended June 30, 2020 2019 (in thousands) Revenues: Premiums earned: Commercial lines $ 203,645 $ 186,269 Personal lines 167,982 190,568 Premiums earned 371,627 376,837 Net investment income 14,548 14,338 Investment (losses) gains (4,209 ) 19,663 Equity in earnings of DFSC — 295 Other 1,845 2,370 Total revenues $ 383,811 $ 413,503 Income before income tax expense: Underwriting income (loss): Commercial lines $ 3,906 $ 2,425 Personal lines 13,101 (6,765 ) SAP underwriting income (loss) 17,007 (4,340 ) GAAP adjustments 2,762 1,829 GAAP underwriting income (loss) 19,769 (2,511 ) Net investment income 14,548 14,338 Investment (losses) gains (4,209 ) 19,663 Equity in earnings of DFSC — 295 Other 383 598 Income before income tax expense $ 30,491 $ 32,383

Borrowings

Borrowings	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Borrowings	7 - Borrowings Lines of Credit At June 30, 2020, we credit agreement with Manufacturers and Traders Trust Company (“M&T”) to d o July 31, 2020 The credit agreement required our compliance with certain covenants. These covenants included minimum levels of our net worth, leverage ratio, statutory surplus and the A.M. Best ratings of our insurance subsidiaries. tional indebtedness requirement prior to Atlantic States issuing additional debt to the Federal Home Loan Bank (“FHLB”) of Pittsburgh in March 2020. Effective August 1, 2020, we entered into a new credit agreement with M&T that relates to a $20.0 million unsecured demand line of credit. The line of credit has no expiration date, no annual fees and no covenants. We have 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 has the ability to issue debt to the FHLB of Pittsburgh in exchange for cash advances. In August 2019, Atlantic States exchanged a variable-rate cash advance of $35.0 million that was due in March 2020 for a fixed-rate cash advance of $35.0 million that was outstanding at June 30, 2020. Atlantic States incurred a penalty of $176,000 related to the early termination of its previous cash advance. The new cash advance carries a fixed interest rate of 1.74% and is due in August 2024. In March 2020, Atlantic States issued $50.0 million of debt to the FHLB of Pittsburgh in exchange for a cash advance in the same amount that was outstanding at June 30, 2020. The debt carries a fixed interest rate of 0.83% and is due in March 2021. Atlantic States obtained this contingent liquidity funding in light of uncertainty surrounding the economic impact of the COVID-19 FHLB of Pittsburgh stock purchased and owned $ 3,690,100 Collateral pledged, at par (carrying value $100,792,651) 99,518,118 Borrowing capacity currently available 14,813,722 Subordinated Debentures Donegal Mutual holds a $5.0 million surplus note that MICO issued to increase MICO’s statutory surplus. The surplus note carries an interest rate of 5.00%, and any repayment of principal or payment of interest on the surplus note requires prior approval of the Michigan Department of Insurance and Financial Services.

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2020
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	8 - Share–Based 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 charged compensation expense related to our stock compensation plans against income before income taxes of $ 314,237 65,990 644,541 135,354 1.3 1.6 We received cash from option exercises under all stock compensation plans during the three months ended June 30, 2020 and 2019 of $ 2.2 million 3.1 million 54,221 68,878

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
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 increasin g the potential that the estimated fair value does not reflect the price at which an actual transaction would occur. We utilize nationally 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 June 30, 2020, 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 June 30, 2020, 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 Fair Value Measurements Using Fair Quoted Prices in Significant Other Significant (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 15,397 $ — $ 15,397 $ — Obligations of states and political subdivisions 63,095 — 63,095 — Corporate securities 212,171 — 212,171 — Mortgage-backed securities 279,279 — 279,279 — Equity securities 52,703 48,299 4,404 — Total investments in the fair value hierarchy $ 622,645 $ 48,299 $ 574,346 $ — The following table presents our fair value measurements for our investments in available-for-sale Fair Value Measurements Using Fair Quoted Prices in Significant Other Significant (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 19,364 $ — $ 19,364 $ — Obligations of states and political subdivisions 56,796 — 56,796 — Corporate securities 159,243 — 159,243 — Mortgage-backed securities 329,548 — 329,548 — Equity securities 55,478 53,124 2,354 — Totals $ 620,429 $ 53,124 $ 567,305 $

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	10 - Income Taxes 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 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. At June 30, 2020 and December 31, 2019, respectively, we had no material unrecognized tax benefits or accrued interest and penalties. Tax years 2016 through 2019 remained open for examination at June 30, 2020. 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 $7.5 million for our net state operating loss carryforward. We have determined that we are not required to establish a valuation allowance for our other deferred tax assets of $25.6 million and $26.1 million at June 30, 2020 and December 31, 2019, respectively, because it is more likely than not that we will realize these deferred tax assets through reversals of existing temporary differences, future taxable income and the implementation of tax planning strategies.

Liability for Losses and Loss E

Liability for Losses and Loss Expenses	6 Months Ended
	Jun. 30, 2020
Text Block [Abstract]
Liability for Losses and Loss Expenses	11 - Liability for Losses and Loss Expenses The establishment of an appropriate liability for losses and loss expenses is an inherently uncertain process, and we can provide no assurance that our insurance subsidiaries’ ultimate liability 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 liability 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’ liability for losses and loss expenses as follows: Six Months Ended June 30, 2020 2019 (in thousands) Balance at January 1 $ 869,674 $ 814,665 Less reinsurance recoverable (362,768 ) (339,267 ) Net balance at January 1 506,906 475,398 Incurred related to: Current year 233,460 261,517 Prior years (10,864 ) (6,899 ) Total incurred 222,596 254,618 Paid related to: Current year 97,473 118,045 Prior years 106,716 120,605 Total paid 204,189 238,650 Net balance at end of period 525,313 491,366 Plus reinsurance recoverable 376,511 353,916 Balance at end of period $ 901,824 $ 845,282 Our insurance subsidiaries recognized a decrease in their liability for losses and loss expenses of prior years of $ 10.9 or MICO and Atl compensation line of business. The majority of the 2019 development related to decreases in the liability for losses and loss expenses of prior years for MICO. 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 six 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 expenses. These methods include paid loss development, incurred loss development and the Bornhuetter-Ferguson method. The actuaries base their selection of a point estimate on a judgmental weighting of the estimates each of these methods produce. 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	6 Months Ended
	Jun. 30, 2020
Accounting Changes and Error Corrections [Abstract]
Impact of New Accounting Standards	12 - Impact of New Accounting Standards In February 2016, the FASB issued guidance that requires lessees to recognize leases, including operating leases, on the lessee’s balance sheet, unless a lease is considered a short-term lease. This guidance also requires entities to make new judgments to identify leases. The guidance is effective for annual and interim reporting periods beginning after December 15, 2018 and permits early adoption. Our adoption of this guidance on January 1, 2019 did not have a significant impact on our financial position, results of operations or cash flows. In January 2017, the FASB issued guidance that simplifies the measurement of goodwill by modifying the goodwill impairment test previous guidance required. The guidance requires an entity to perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount and recognize impairment for the amount by which the reporting unit’s carrying amount exceeds its fair value. The guidance is effective for annual and interim reporting periods beginning after December 15, 2019 and permits early adoption. We early adopted this guidance in 2019. The adoption of this guidance did not have a significant impact on our financial position, results of operations or cash flows. In August 2018, the FASB issued guidance that modifies disclosure requirements related to fair value measurements. The guidance removes the requirements to disclose the amounts of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy. The guidance is effective for annual and interim reporting periods beginning after December 15, 2019 and permits early adoption. We early adopted this guidance in 2019. The adoption of this guidance on January 1, 2019 did not have a significant impact on our financial position, results of operations or cash flows. In June 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, 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 is 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. We are in the process of evaluating the impact of the adoption of this guidance on our financial position, results of operations and cash flows .

Risks and Uncertainties

Risks and Uncertainties	6 Months Ended
	Jun. 30, 2020
Risks and Uncertainties [Abstract]
Risks and Uncertainties	13 - Risks and Uncertainties In the first half of 2020, the COVID-19 COVID-19 COVID-19 • the revenues of our insurance subsidiaries may decrease as a result of reduced demand for their insurance products as the ongoing economic disruption adversely impacts current and potential insurance customers; • our insurance subsidiaries may incur an increase in their losses and loss expenses in certain lines of business as a result of COVID-19 • our insurance subsidiaries may incur increased costs related to legal disputes over policy coverages or exclusions and their defense against litigation related to COVID-19; • legislative, judicial and regulatory actions may expand coverage definitions, retroactively mandate coverage or otherwise require our insurance subsidiaries to pay losses for damages that their policies explicitly excluded or did not intend to cover; • legislative, judicial and regulatory actions may require our insurance subsidiaries to reduce or refund premiums, suspend cancellation of policies for non-payment • our insurance subsidiaries may not be able to collect premium balances due to them, resulting in reduced operating cash flows and an increase in premium write-offs that would increase their operating expenses; • our insurance subsidiaries may suffer declines in the market values of their investments as a result of financial market volatility related to COVID-19 • our insurance subsidiaries may experience declines in investment income as a result of lower interest rates that may be available upon reinvestment of the proceeds of maturing investments. • Economic disruption related to COVID-19

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2020
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 per share for our Class A common stock and our Class B common stock: Three Months Ended June 30, 2020 2019 Class A Class B Class A Class B (in thousands, except per share data) Basic earnings per share: Numerator: Allocation of net income $ 18,665 $ 4,014 $ 3,941 $ 848 Denominator: Weighted-average shares outstanding 23,451 5,577 22,933 5,577 Basic earnings per share $ 0.80 $ 0.72 $ 0.17 $ 0.15 Diluted earnings per share: Numerator: Allocation of net income $ 18,665 $ 4,014 $ 3,941 $ 848 Denominator: Number of shares used in basic computation 23,451 5,577 22,933 5,577 Weighted-average shares effect of dilutive securities: Director and employee stock options 199 — 200 — Number of shares used in diluted computation 23,650 5,577 23,133 5,577 Diluted earnings per share $ 0.79 $ 0.72 $ 0.17 $ 0.15 Six Months Ended June 30, 2020 2019 Class A Class B Class A Class B (in thousands, except per share data) Basic earnings per share: Numerator: Allocation of net income $ 21,721 $ 4,689 $ 22,790 $ 5,022 Denominator: Weighted-average shares outstanding 23,356 5,577 22,892 5,577 Basic earnings per share $ 0.93 $ 0.84 $ 1.00 $ 0.90 Diluted earnings per share: Numerator: Allocation of net income $ 21,721 $ 4,689 $ 22,790 $ 5,022 Denominator: Number of shares used in basic computation 23,356 5,577 22,892 5,577 Weighted-average shares effect of dilutive securities: Director and employee stock options 193 — 135 — Number of shares used in diluted computation 23,549 5,577 23,027 5,577 Diluted earnings per share $ 0.92 $ 0.84 $ 0.99 $ 0.90
Summary of Antidilutive Securities Excluded From Computation Of Earnings Per Share	Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 Number of options to purchase Class A shares excluded 6,183,992 5,531,561 6,183,992 5,417,725

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2020
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 June , were as follows: Amortized Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Held to Maturity U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 73,824 $ 4,619 $ — $ 78,443 Obligations of states and political subdivisions 252,121 19,442 223 271,340 Corporate securities 165,640 14,078 1,085 178,633 Mortgage-backed securities 28,146 1,478 — 29,624 Totals $ 519,731 $ 39,617 $ 1,308 $ 558,040 Amortized Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Available for Sale U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 14,847 $ 550 $ — $ 15,397 Obligations of states and political subdivisions 60,906 2,189 — 63,095 Corporate securities 204,155 8,477 461 212,171 Mortgage-backed securities 270,271 9,041 33 279,279 Totals $ 550,179 $ 20,257 $ 494 $ 569,942 The amortized cost and estimated fair values of our fixed maturities at December 31, 2019 were as follows: Amortized Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Held to Maturity U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 82,916 $ 1,803 $ 69 $ 84,650 Obligations of states and political subdivisions 204,634 14,237 288 218,583 Corporate securities 156,398 8,275 333 164,340 Mortgage-backed securities 32,146 611 16 32,741 Totals $ 476,094 $ 24,926 $ 706 $ 500,314 Amortized Gross Unrealized Gross Unrealized Estimated Fair (in thousands) Available for Sale U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 19,302 $ 82 $ 19 $ 19,365 Obligations of states and political subdivisions 55,162 1,641 7 56,796 Corporate securities 154,946 4,477 180 159,243 Mortgage-backed securities 327,429 2,857 738 329,548 Totals $ 556,839 $ 9,057 $ 944 $ 564,952
Summary of Amortized Cost and Estimated Fair Value of Fixed Maturities by Contractual Maturity	Expected maturities may differ from contractual maturities because issuers of the securities may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Cost Estimated Fair (in thousands) Held to maturity Due in one year or less $ 32,774 $ 33,145 Due after one year through five years 85,516 91,701 Due after five years through ten years 180,630 195,464 Due after ten years 192,665 208,106 Mortgage-backed securities 28,146 29,624 Total held to maturity $ 519,731 $ 558,040 Available for sale Due in one year or less $ 58,794 $ 59,296 Due after one year through five years 100,488 105,594 Due after five years through ten years 99,183 103,688 Due after ten years 21,443 22,085 Mortgage-backed securities 270,271 279,279 Total available for sale $ 550,179 $ 569,942
Summary of Cost and Estimated Fair Values of Equity Securities	The cost and estimated fair values of our equity securities at June 30, 2020 were as follows: Cost Gross Gains Gross Losses Estimated Fair (in thousands) Equity securities $ 42,574 $ 11,495 $ 1,366 $ 52,703 The cost and estimated fair values of our equity securities at December 31, 2019 were as follows: Cost Gross Gains Gross Losses Estimated Fair (in thousands) Equity securities $ 43,419 $ 12,180 $ 121 $ 55,478
Summary of Gross Investment Gains and Losses before Applicable Income Taxes	Gross investment gains and losses before applicable income taxes for the three and six Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (in thousands) (in thousands) Gross investment gains: Fixed maturities $ 229 $ 14 $ 652 $ 372 Equity securities 6,474 1,586 3,355 7,572 Investment in affiliate — — — 12,662 6,703 1,600 4,007 20,606 Gross investment losses: Fixed maturities 217 2 218 320 Equity securities — 32 7,998 623 217 34 8,216 943 Net investment gains (losses) $ 6,486 $ 1,566 $ (4,209 ) $ 19,663
Summary of Fixed Maturities with Unrealized Losses	We held fixed maturities with unrealized losses representing declines that we considered temporary at June 30, 2020 as follows: Less Than 12 Months More Than 12 Months Fair Value Unrealized Losses Fair Value Unrealized Losses (in thousands) Obligations of states and political subdivisions $ 7,058 $ 223 $ — $ — Corporate securities 44,522 696 7,195 850 Mortgage-backed securities 1,674 32 459 1 Totals $ 53,254 $ 951 $ 7,654 $ 851 We held fixed maturities with unrealized losses representing declines that we considered temporary at December 31, 2019 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 $ 7,461 $ 46 $ 5,395 $ 42 Obligations of states and political subdivisions 23,339 293 2,327 2 Corporate securities 19,363 263 18,803 250 Mortgage-backed securities 28,507 56 74,089 698 Totals $ $ 658 $ 100,614 $ 992

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Summary of Financial Data by Segment	Financial data by segment for the three and six months ended June 30, 2020 and 2019 is as follows: Three Months Ended June 30, 2020 2019 (in thousands) Revenues: Premiums earned: Commercial lines $ 101,870 $ 94,788 Personal lines 82,504 93,975 Premiums earned 184,374 188,763 Net investment income 7,172 7,290 Investment gains 6,486 1,566 Other 868 1,170 Total revenues $ 198,900 $ 198,789 Income before income tax expense: Underwriting income (loss): Commercial lines $ 4,472 $ 4,113 Personal lines 8,290 (9,238 ) SAP underwriting income ( loss 12,762 (5,125 ) GAAP adjustments 1,378 1,278 GAAP underwriting income ( loss 14,140 (3,847 ) Net investment income 7,172 7,290 Investment gains 6,486 1,566 Other 190 529 Income before income tax expense $ 27,988 $ 5,538 Six Months Ended June 30, 2020 2019 (in thousands) Revenues: Premiums earned: Commercial lines $ 203,645 $ 186,269 Personal lines 167,982 190,568 Premiums earned 371,627 376,837 Net investment income 14,548 14,338 Investment (losses) gains (4,209 ) 19,663 Equity in earnings of DFSC — 295 Other 1,845 2,370 Total revenues $ 383,811 $ 413,503 Income before income tax expense: Underwriting income (loss): Commercial lines $ 3,906 $ 2,425 Personal lines 13,101 (6,765 ) SAP underwriting income (loss) 17,007 (4,340 ) GAAP adjustments 2,762 1,829 GAAP underwriting income (loss) 19,769 (2,511 ) Net investment income 14,548 14,338 Investment (losses) gains (4,209 ) 19,663 Equity in earnings of DFSC — 295 Other 383 598 Income before income tax expense $ 30,491 $ 32,383

Borrowings (Tables)

Borrowings (Tables)	6 Months Ended
	Jun. 30, 2020
FHLB of Pittsburgh [Member]
Amount of FHLB of Indianapolis/Pittsburgh Stock Purchased, Collateral Pledged and Assets Related to MICO's/Atlantic States Agreement	The table below presents the amount of FHLB of Pittsburgh stock Atlantic States purchased, collateral pledged and assets related to Atlantic States’ membership in the FHLB of Pittsburgh at June 30, 2020. FHLB of Pittsburgh stock purchased and owned $ 3,690,100 Collateral pledged, at par (carrying value $100,792,651) 99,518,118 Borrowing capacity currently available 14,813,722

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
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 Fair Value Measurements Using Fair Quoted Prices in Significant Other Significant (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 15,397 $ — $ 15,397 $ — Obligations of states and political subdivisions 63,095 — 63,095 — Corporate securities 212,171 — 212,171 — Mortgage-backed securities 279,279 — 279,279 — Equity securities 52,703 48,299 4,404 — Total investments in the fair value hierarchy $ 622,645 $ 48,299 $ 574,346 $ — The following table presents our fair value measurements for our investments in available-for-sale Fair Value Measurements Using Fair Quoted Prices in Significant Other Significant (in thousands) U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 19,364 $ — $ 19,364 $ — Obligations of states and political subdivisions 56,796 — 56,796 — Corporate securities 159,243 — 159,243 — Mortgage-backed securities 329,548 — 329,548 — Equity securities 55,478 53,124 2,354 — Totals $ 620,429 $ 53,124 $ 567,305 $

Liability for Losses and Loss_2

Liability for Losses and Loss Expenses (Tables)	6 Months Ended
	Jun. 30, 2020
Text Block [Abstract]
Summary of Insurance Subsidiaries' Liability for Losses and Loss Expenses	We summarize activity in our insurance subsidiaries’ liability for losses and loss expenses as follows: Six Months Ended June 30, 2020 2019 (in thousands) Balance at January 1 $ 869,674 $ 814,665 Less reinsurance recoverable (362,768 ) (339,267 ) Net balance at January 1 506,906 475,398 Incurred related to: Current year 233,460 261,517 Prior years (10,864 ) (6,899 ) Total incurred 222,596 254,618 Paid related to: Current year 97,473 118,045 Prior years 106,716 120,605 Total paid 204,189 238,650 Net balance at end of period 525,313 491,366 Plus reinsurance recoverable 376,511 353,916 Balance at end of period $ 901,824 $ 845,282

Organization - Additional Infor

Organization - Additional Information (Detail) $ in Millions	6 Months Ended	83 Months Ended
	Jun. 30, 2020USD ($)Segment	Jun. 30, 2020shares	Mar. 08, 2019USD ($)	Jul. 18, 2013shares
Business Acquisition [Line Items]
Operations commenced date	Aug. 26, 1986
Number of operating segments | Segment	3
Voting power percentage of outstanding common stock	71.00%
Atlantic States [Member]
Business Acquisition [Line Items]
Percentage of share in results of pooled business subsidiary	80.00%
Donegal Mutual [Member]
Business Acquisition [Line Items]
Percentage of share in results of pooled business owned by third party	20.00%
DFSC and North West [Member]
Business Acquisition [Line Items]
Consideration from sale of business	$ 20.5
Consideration from sale of business fair value at closing date	20.9
DFSC and North West [Member] | Donegal Mutual Insurance Company [Member]
Business Acquisition [Line Items]
Consideration from sale of business	85.8
Proceeds from dividend	$ 29.2
Donegal Financial Services Corporation [Member]
Business Acquisition [Line Items]
Outstanding stock ownership percentage	48.20%	48.20%
Gain (Loss) on Sale of Equity Investments	$ 12.7
Donegal Financial Services Corporation [Member] | DFSC and North West [Member]
Business Acquisition [Line Items]
Dividend payment to be received			$ 14.1
Class A Common Stock [Member]
Business Acquisition [Line Items]
Stock ownership percentage held by major shareholder	42.00%
Class A Common Stock [Member] | Stock Repurchase Program Two [Member]
Business Acquisition [Line Items]
Authority to purchase shares | shares				500,000
Common stock shares purchased | shares		57,658
Class B Common Stock [Member]
Business Acquisition [Line Items]
Stock ownership percentage held by major shareholder	84.00%

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Minimum percentage of class A common stock declared dividend excess over class B dividend	10.00%

Earnings Per Share - Summary of

Earnings 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		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Class A Common Stock [Member]
Numerator:
Allocation of net income (loss)	$ 18,665	$ 3,941	$ 21,721	$ 22,790
Denominator:
Weighted-average shares outstanding	23,451	22,933	23,356	22,892
Basic earnings (loss) per share	$ 0.80	$ 0.17	$ 0.93	$ 1
Numerator:
Allocation of net income (loss)	$ 18,665	$ 3,941	$ 21,721	$ 22,790
Denominator:
Number of shares used in basic computation	23,451	22,933	23,356	22,892
Weighted-average shares effect of dilutive securities:
Director and employee stock options	199	200	193	135
Number of shares used in diluted computation	23,650	23,133	23,549	23,027
Diluted earnings (loss) per share	$ 0.79	$ 0.17	$ 0.92	$ 0.99
Class B Common Stock [Member]
Numerator:
Allocation of net income (loss)	$ 4,014	$ 848	$ 4,689	$ 5,022
Denominator:
Weighted-average shares outstanding	5,577	5,577	5,577	5,577
Basic earnings (loss) per share	$ 0.72	$ 0.15	$ 0.84	$ 0.90
Numerator:
Allocation of net income (loss)	$ 4,014	$ 848	$ 4,689	$ 5,022
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 earnings (loss) per share	$ 0.72	$ 0.15	$ 0.84	$ 0.90

Earnings Per Share - Summary _2

Earnings Per Share - Summary of Antidilutive Securities Excluded From Computation Of Earnings Per Share (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Equity Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of options to purchase Class A shares excluded	6,183,992	5,531,561	6,183,992	5,417,725

Reinsurance - Additional Inform

Reinsurance - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2020USD ($)
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 ($)	Jun. 30, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	$ 519,731,423	$ 476,093,782
Held to Maturity, Gross Unrealized Gains	39,617,000	24,926,000
Held to Maturity, Gross Unrealized Losses	1,308,000	706,000
Total held to maturity, Estimated Fair Value	558,040,000	500,314,000
Available for Sale, Amortized Cost	550,179,000	556,839,000
Available for Sale, Gross Unrealized Gains	20,257,000	9,057,000
Available for Sale, Gross Unrealized Losses	494,000	944,000
Available for Sale, Estimated Fair Value	569,942,000	564,952,000
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	73,824,000	82,916,000
Held to Maturity, Gross Unrealized Gains	4,619,000	1,803,000
Held to Maturity, Gross Unrealized Losses		69,000
Total held to maturity, Estimated Fair Value	78,443,000	84,650,000
Available for Sale, Amortized Cost	14,847,000	19,302,000
Available for Sale, Gross Unrealized Gains	550,000	82,000
Available for Sale, Gross Unrealized Losses		19,000
Available for Sale, Estimated Fair Value	15,397,000	19,365,000
Obligations of States and Political Subdivisions [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	252,121,000	204,634,000
Held to Maturity, Gross Unrealized Gains	19,442,000	14,237,000
Held to Maturity, Gross Unrealized Losses	223,000	288,000
Total held to maturity, Estimated Fair Value	271,340,000	218,583,000
Available for Sale, Amortized Cost	60,906,000	55,162,000
Available for Sale, Gross Unrealized Gains	2,189,000	1,641,000
Available for Sale, Gross Unrealized Losses		7,000
Available for Sale, Estimated Fair Value	63,095,000	56,796,000
Corporate Securities [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	165,640,000	156,398,000
Held to Maturity, Gross Unrealized Gains	14,078,000	8,275,000
Held to Maturity, Gross Unrealized Losses	1,085,000	333,000
Total held to maturity, Estimated Fair Value	178,633,000	164,340,000
Available for Sale, Amortized Cost	204,155,000	154,946,000
Available for Sale, Gross Unrealized Gains	8,477,000	4,477,000
Available for Sale, Gross Unrealized Losses	461,000	180,000
Available for Sale, Estimated Fair Value	212,171,000	159,243,000
Mortgage-Backed Securities [Member]
Schedule of Equity Method Investments [Line Items]
Total held to maturity, Amortized Cost	28,146,000	32,146,000
Held to Maturity, Gross Unrealized Gains	1,478,000	611,000
Held to Maturity, Gross Unrealized Losses		16,000
Total held to maturity, Estimated Fair Value	29,624,000	32,741,000
Available for Sale, Amortized Cost	270,271,000	327,429,000
Available for Sale, Gross Unrealized Gains	9,041,000	2,857,000
Available for Sale, Gross Unrealized Losses	33,000	738,000
Available for Sale, Estimated Fair Value	$ 279,279,000	$ 329,548,000

Investments - Additional Inform

Investments - Additional Information (Detail)	Nov. 30, 2013USD ($)	Jun. 30, 2020USD ($)Securities	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
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)		$ 833,690	$ 568,486
Accumulated other comprehensive loss		10,367,225		$ 504,170
Equity [Member]
Schedule of Investments [Line Items]
Gain on equity securities		3.4	6,200,000
Loss on equity securities		4,900,000	$ 39,898
Obligations of States and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Aggregate fair value of bond held		217,700,000		182,000,000
Amortized cost of bond held		204,300,000		172,300,000
Special Revenue Bonds [Member]
Schedule of Investments [Line Items]
Aggregate fair value of bond held		116,700,000		93,400,000
Amortized cost of bond held		$ 108,700,000		$ 87,500,000
Education Bonds [Member]
Schedule of Investments [Line Items]
Percentage of investments in special revenue bonds		45.00%		44.00%
Water and Sewer Utility Bonds [Member]
Schedule of Investments [Line Items]
Percentage of investments in special revenue bonds		40.00%		35.00%
Fixed Maturities [Member]
Schedule of Investments [Line Items]
Number of fixed maturity securities classified as available for sale | Securities		52
Accumulated Net Unrealized Investment Losses [Member]
Schedule of Investments [Line Items]
Accumulated other comprehensive loss		$ 6,600,000		$ 7,500,000
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 ($)	Jun. 30, 2020	Dec. 31, 2019
Held to maturity
Due in one year or less, Amortized Cost	$ 32,774,000
Due after one year through five years, Amortized Cost	85,516,000
Due after five years through ten years, Amortized Cost	180,630,000
Due after ten years, Amortized Cost	192,665,000
Mortgage-backed securities, Amortized Cost	28,146,000
Total held to maturity, Amortized Cost	519,731,423	$ 476,093,782
Available for sale
Due in one year or less, Amortized Cost	58,794,000
Due after one year through five years, Amortized Cost	100,488,000
Due after five years through ten years, Amortized Cost	99,183,000
Due after ten years, Amortized Cost	21,443,000
Mortgage-backed securities, Amortized Cost	270,271,000
Total available for sale, Amortized Cost	550,179,000
Held to maturity
Due in one year or less, Estimated Fair Value	33,145,000
Due after one year through five years, Estimated Fair Value	91,701,000
Due after five years through ten years, Estimated Fair Value	195,464,000
Due after ten years, Estimated Fair Value	208,106,000
Mortgage-backed securities, Estimated Fair Value	29,624,000
Total held to maturity, Estimated Fair Value	558,040,000	500,314,000
Available for sale
Due in one year or less, Estimated Fair Value	59,296,000
Due after one year through five years, Estimated Fair Value	105,594,000
Due after five years through ten years, Estimated Fair Value	103,688,000
Due after ten years, Estimated Fair Value	22,085,000
Mortgage-backed securities, Estimated Fair Value	279,279,000
Total available for sale, Estimated Fair Value	$ 569,942,279	$ 564,951,803

Investments - Summary of Cost a

Investments - Summary of Cost and Estimated Fair Value of Equity Securities (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Cost	$ 42,574,000	$ 43,419,000
Gross Gains	11,495,000	12,180,000
Gross Losses	1,366,000	121,000
Estimated Fair Value	$ 52,703,395	$ 55,477,556

Investments - Summary of Gross

Investments - Summary of Gross Investment Gains and Losses before Applicable Income Taxes (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Gain (Loss) on Securities [Line Items]
Gross investment gains	$ 6,703,000	$ 1,600,000	$ 4,007,000	$ 20,606,000
Gross investment losses	217,000	34,000	8,216,000	943,000
Net investment gains (losses)	6,485,896	1,566,157	(4,208,947)	19,663,270
Fixed Maturities [Member]
Gain (Loss) on Securities [Line Items]
Gross investment gains	229,000	14,000	652,000	372,000
Gross investment losses	217,000	2,000	218,000	320,000
Investments In Affiliates [Member]
Gain (Loss) on Securities [Line Items]
Gross investment gains				12,662,000
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Gross investment gains	$ 6,474,000	1,586,000	3,355,000	7,572,000
Gross investment losses		$ 32,000	$ 7,998,000	$ 623,000

Investments - Summary of Fixed

Investments - Summary of Fixed Maturities with Unrealized Losses (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	$ 53,254	$ 78,670
Less Than 12 Months, Unrealized Losses	951	658
More Than 12 Months, Fair Value	7,654	100,614
More Than 12 Months, Unrealized Losses	851	992
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		7,461
Less Than 12 Months, Unrealized Losses		46
More Than 12 Months, Fair Value		5,395
More Than 12 Months, Unrealized Losses		42
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	7,058	23,339
Less Than 12 Months, Unrealized Losses	223	293
More Than 12 Months, Fair Value		2,327
More Than 12 Months, Unrealized Losses		2
Corporate Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	44,522	19,363
Less Than 12 Months, Unrealized Losses	696	263
More Than 12 Months, Fair Value	7,195	18,803
More Than 12 Months, Unrealized Losses	850	250
Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Less Than 12 Months, Fair Value	1,674	28,507
Less Than 12 Months, Unrealized Losses	32	56
More Than 12 Months, Fair Value	459	74,089
More Than 12 Months, Unrealized Losses	$ 1	$ 698

Segment Information - Summary o

Segment Information - Summary of Financial Data by Segment (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Premiums earned:
Premiums earned	$ 184,373,768	$ 188,763,313	$ 371,626,546	$ 376,836,555
Net investment income	7,172,144	7,289,652	14,548,428	14,338,155
Investment (losses) gains	6,485,896	1,566,157	(4,208,947)	19,663,270
Equity in earnings of DFSC				295,000
Other	868,000	1,170,000	1,845,000	2,370,000
Total revenues	198,899,772	198,788,954	383,810,978	413,502,828
Underwriting income (loss):
SAP underwriting income (loss)	12,762,000	(5,125,000)	17,007,000	(4,340,000)
GAAP adjustments	1,378,000	1,278,000	2,762,000	1,829,000
GAAP underwriting income (loss)	14,140,000	(3,847,000)	19,769,000	(2,511,000)
Net investment income	7,172,144	7,289,652	14,548,428	14,338,155
Investment (losses) gains	6,485,896	1,566,157	(4,208,947)	19,663,270
Equity in earnings of DFSC				295,000
Other	190,000	529,000	383,000	598,000
Income before income tax expense	27,988,049	5,537,531	30,491,220	32,382,555
Commercial Lines [Member]
Premiums earned:
Premiums earned	101,870,000	94,788,000	203,645,000	186,269,000
Underwriting income (loss):
SAP underwriting income (loss)	4,472,000	4,113,000	3,906,000	2,425,000
Personal Lines [Member]
Premiums earned:
Premiums earned	82,504,000	93,975,000	167,982,000	190,568,000
Underwriting income (loss):
SAP underwriting income (loss)	$ 8,290,000	$ (9,238,000)	$ 13,101,000	$ (6,765,000)

Borrowings - Additional Informa

Borrowings - Additional Information (Detail) - USD ($)	Aug. 01, 2020	Jun. 30, 2020	Mar. 31, 2019
Line of Credit Facility [Line Items]
Line of credit expiration month and year		2020-07
Line of credit, interest rate description		interest rates equal to M&T’s current prime rate or the then-current LIBOR rate plus 2.25%
Subsequent Event [Member]
Line of Credit Facility [Line Items]
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		$ 30,000,000
Line of credit covenant description		The credit agreement required our compliance with certain covenants. These covenants included minimum levels of our net worth, leverage ratio, statutory surplus and the A.M. Best ratings of our insurance subsidiaries.
Manufacturers and Traders Trust Company [Member] | Subsequent Event [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		$ 14,813,722
Outstanding advances		35,000,000
Federal home loan bank, fixed rate advances		35,000,000
Pre-Payment of Penalty		176,000
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			$ 30,000,000
Line of credit facility amount outstanding		$ 0
Debt Instrument variable interest rate spread		2.25%
Revolving Credit Facility [Member] | Manufacturers and Traders Trust Company [Member] | Subsequent Event [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%
Line 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 stated interest rate		5.00%
Subordinated Debentures [Member] | West Bend Mutual Insurance Company [Member]
Line of Credit Facility [Line Items]
Surplus note		$ 5,000,000
Subordinated Debentures [Member] | FHLB of Pittsburgh [Member] | Line of Credit [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]	Jun. 30, 2020USD ($)
Amount of FHLB of Indianapolis/Pittsburgh stock purchased, collateral pledged and assets related to MICO's/Atlantic States Agreement
FHLB stock purchased and owned	$ 3,690,100
Collateral pledged, at par	99,518,118
Borrowing capacity currently available	$ 14,813,722

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)	Jun. 30, 2020USD ($)
FHLB of Pittsburgh [Member] | Atlantic States [Member]
Line of Credit Facility [Line Items]
Collateral Pledged at carrying value	$ 100,792,651

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Compensation expense in stock compensation plans	$ 314,237	$ 423,623	$ 644,541	$ 866,276
Income tax benefit of stock compensation plans	65,990	88,961	135,354	181,918
Unrecognized compensation expense related to nonvested share-based compensation granted under the plan	1,300,000		$ 1,300,000
Weighted average period of unrecognized compensation expense			1 year 7 months 6 days
Cash from option exercises	2,200,000	795,182	$ 3,100,000	795,182
Tax benefit for tax deductions related to option exercises	$ 54,221	$ 15,962	$ 68,878	$ 15,962

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	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	$ 569,942	$ 564,952
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	15,397	19,365
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	63,095	56,796
Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	212,171	159,243
Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	279,279	329,548
Assets and Liabilities on Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure		620,429
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	622,645
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	15,397	19,364
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	63,095	56,796
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	212,171	159,243
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	279,279	329,548
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	52,703	55,478
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets and Liabilities on Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure		53,124
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	48,299
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] | 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	0
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] | 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	0
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] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0
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] | Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0
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	48,299	53,124
Significant Other Observable Inputs (Level 2) [Member] | Assets and Liabilities on Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure		567,305
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	574,346
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	15,397	19,364
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	63,095	56,796
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	212,171	159,243
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	279,279	329,548
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	4,404	$ 2,354
Significant Other Unobservable Inputs (Level 3) [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	0
Significant Other Unobservable Inputs (Level 3) [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	0
Significant Other Unobservable Inputs (Level 3) [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	0
Significant Other Unobservable Inputs (Level 3) [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	0
Significant Other Unobservable Inputs (Level 3) [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	0
Significant Other Unobservable Inputs (Level 3) [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	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Other deferred tax assets, net	$ 25.6		$ 26.1
Income tax refund receivable		$ 1.6
Parent Company [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance related to the portion of operating loss carryforwards	$ 7.5
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	2019

Liability for Losses and Loss_3

Liability for Losses and Loss Expenses - Summary of Insurance Subsidiaries' Liability for Losses and Loss Expenses (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Liability for Claims and Claims Adjustment Expense [Abstract]
Balance at January 1	$ 869,673,849	$ 814,665,000
Less reinsurance recoverable	(362,768,000)	(339,267,000)
Net balance at January 1	506,906,000	475,398,000
Incurred related to:
Current year	233,460,000	261,517,000
Prior years	(10,864,000)	(6,899,000)
Total incurred	222,596,000	254,618,000
Paid related to:
Current year	97,473,000	118,045,000
Prior years	106,716,000	120,605,000
Total paid	204,189,000	238,650,000
Net balance at end of period	525,313,000	491,366,000
Plus reinsurance recoverable	376,511,000	353,916,000
Balance at end of period	$ 901,823,622	$ 845,282,000

Liability for Losses and Loss_4

Liability for Losses and Loss Expenses - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
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	$ (10,864)	$ (6,899)
Percentage of 2010 development	2.10%	1.50%