Safety Insurance (SAFT) 10-Q 7 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2020
Entity File Number	000-50070
Entity Registrant Name	SAFETY INSURANCE GROUP, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-4181699
Entity Address, Address Line One	20 Custom House Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02110
City Area Code	617
Local Phone Number	951-0600
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	SAFT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		15,074,333
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001172052
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Investments:
Fixed maturities, available for sale, at fair value (amortized cost: $1,168,666 and $1,192,357; allowance for expected credit losses of $2,471 at June 30, 2020)	$ 1,219,714	$ 1,228,040
Equity securities, at fair value (cost: $164,991 and $151,121)	178,347	177,637
Other invested assets	35,526	37,278
Total investments	1,433,587	1,442,955
Cash and cash equivalents	44,757	44,407
Accounts receivable, net of allowance for expected credit losses of $914 at June 30, 2020	199,356	193,369
Receivable for securities sold	2,523	1,784
Accrued investment income	8,000	8,404
Taxes recoverable	411	1,003
Receivable from reinsurers related to paid loss and loss adjustment expenses	16,018	11,319
Receivable from reinsurers related to unpaid loss and loss adjustment expenses	116,378	122,372
Ceded unearned premiums	26,073	35,182
Deferred policy acquisition costs	77,350	74,287
Equity and deposits in pools	34,118	29,791
Operating lease right-of-use-assets	33,092	33,998
Other assets	27,251	23,798
Total assets	2,018,914	2,022,669
Liabilities
Loss and loss adjustment expense reserves	599,747	610,566
Unearned premium reserves	440,007	442,219
Accounts payable and accrued liabilities	60,518	75,016
Payable for securities purchased	7,451	6,377
Payable to reinsurers	11,794	12,911
Deferred income taxes	4,413	5,717
Long-term Line of Credit	30,000	0
Operating lease liabilities	33,092	33,998
Other liabilities	14,914	27,459
Total liabilities	1,201,936	1,214,263
Commitments and contingencies (Note 8)
Shareholders' equity
Common stock: $0.01 par value; 30,000,000 shares authorized; 17,724,866 and 17,662,779 shares issued	177	177
Additional paid-in capital	206,130	202,321
Accumulated other comprehensive income, net of taxes	42,302	28,190
Retained earnings	674,349	661,553
Treasury stock, at cost: 2,581,414 and 2,279,570 shares	(105,980)	(83,835)
Total shareholders' equity	816,978	808,406
Total liabilities and shareholders' equity	$ 2,018,914	$ 2,022,669

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Consolidated Balance Sheets
Fixed maturity securities, amortized cost	$ 1,168,666	$ 1,192,357
Fixed maturity securities, allowance for expected credit losses	2,471
Equity securities, at cost	164,991	151,121
Allowance for expected credit losses	$ 914	$ 578
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock shares authorized	30,000,000	30,000,000
Common stock shares issued	17,724,866	17,662,779
Treasury stock shares	2,581,414	2,279,570

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues
Net earned premiums	$ 181,902	$ 196,426	$ 379,797	$ 390,917
Net investment income	9,916	10,574	20,626	22,325
(Losses) Earnings from partnership investments	(3,449)	735	(2,110)	1,570
Net realized (losses) gains on investments	(721)	483	(1,352)	319
Change in net unrealized gains on equity investments	16,828	3,754	(13,160)	15,555
Net impairment losses on investments (a)		(54)		(274)
Credit loss expense	39		(2,471)
Finance and other service income	3,255	4,084	7,484	8,169
Total revenue	207,770	216,002	388,814	438,581
Expenses
Losses and loss adjustment expenses	90,974	122,393	211,720	248,420
Underwriting, operating and related expenses	63,514	60,908	126,596	121,342
Interest expense	130	23	177	45
Total expenses	154,618	183,324	338,493	369,807
Income before income taxes	53,152	32,678	50,321	68,774
Income tax expense	10,658	6,744	9,817	12,894
Net income	$ 42,494	$ 25,934	$ 40,504	$ 55,880
Earnings per Weighted Average Common Share
Basic (in dollars per share)	$ 2.80	$ 1.70	$ 2.66	$ 3.66
Diluted (in dollars per share)	2.78	1.68	2.64	3.63
Cash dividends paid per common share (in dollars per share)	$ 0.90	$ 0.80	$ 1.80	$ 1.60
Number of shares used in computing earnings per share:
Basic (in shares)	15,120,039	15,220,822	15,175,409	15,181,034
Diluted (in shares)	15,237,295	15,346,234	15,292,186	15,326,121

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Consolidated Statements of Comprehensive Income
Net income	$ 42,494	$ 25,934	$ 40,504	$ 55,880
Other comprehensive income, net of tax:
Unrealized holding gains during the period, net of income tax expense of $9,391, $3,502, $3,467 and $8,798.	35,328	13,176	13,044	33,099
Reclassification adjustment for net realized losses (gains) on investments included in net income, net of income tax benefit (expense) of $152, ($102), $284 and ($67).	570	(382)	1,068	(252)
Other comprehensive income, net of tax:	35,898	12,794	14,112	32,847
Comprehensive income	$ 78,392	$ 38,728	$ 54,616	$ 88,727

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Consolidated Statements of Comprehensive Income.
Tax expense on unrealized holding gains during the period	$ 9,391	$ 3,502	$ 3,467	$ 8,798
Tax benefit (expense) on reclassification adjustment for losses (gains) included in net income	$ 152	$ (102)	$ 284	$ (67)

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss), Net of Taxes	Retained EarningsRevision of Prior Period, Accounting Standards Update, Adjustment	Retained Earnings	Treasury Stock	Revision of Prior Period, Accounting Standards Update, Adjustment	Total
Balance at Dec. 31, 2018	$ 176	$ 196,292	$ (10,706)		$ 616,717	$ (83,835)		$ 718,644
Net income (loss)					29,946			29,946
Unrealized gains (losses) on securities available for sale, net of deferred federal income taxes			20,053					20,053
Restricted share awards issued	1	462						463
Recognition of employee share-based compensation, net of deferred federal income taxes		1,260						1,260
Dividends paid and accrued					(12,300)			(12,300)
Balance at Mar. 31, 2019	177	198,014	9,347		631,990	(83,835)		755,693
Balance at Dec. 31, 2018	176	196,292	(10,706)		616,717	(83,835)		718,644
Net income (loss)								55,880
Acquisition of treasury stock								0
Balance at Jun. 30, 2019	177	199,644	22,141		645,553	(83,835)		783,680
Cumulative effect of adoption of updated accounting guidance for callable debt securities at January 1, 2019, net of taxes				$ (2,373)			$ (2,373)
Balance at Mar. 31, 2019	177	198,014	9,347		631,990	(83,835)		755,693
Net income (loss)					25,934			25,934
Unrealized gains (losses) on securities available for sale, net of deferred federal income taxes			12,794					12,794
Recognition of employee share-based compensation, net of deferred federal income taxes		1,630						1,630
Dividends paid and accrued					(12,371)			(12,371)
Balance at Jun. 30, 2019	177	199,644	22,141		645,553	(83,835)		783,680
Cumulative effect of adoption of updated accounting guidance for callable debt securities at January 1, 2019, net of taxes								661,553
Balance at Dec. 31, 2019	177	202,321	28,190		661,553	(83,835)		808,406
Net income (loss)					(1,990)			(1,990)
Unrealized gains (losses) on securities available for sale, net of deferred federal income taxes			(21,786)					(21,786)
Restricted share awards issued		528						528
Recognition of employee share-based compensation, net of deferred federal income taxes		1,215						1,215
Dividends paid and accrued					(13,872)			(13,872)
Acquisition of treasury stock						(10,392)		(10,392)
Balance at Mar. 31, 2020	177	204,064	6,404		645,691	(94,227)		762,109
Balance at Dec. 31, 2019	177	202,321	28,190		661,553	(83,835)		808,406
Net income (loss)								40,504
Acquisition of treasury stock								(22,145)
Balance at Jun. 30, 2020	177	206,130	42,302		674,349	(105,980)		816,978
Balance at Mar. 31, 2020	177	204,064	6,404		645,691	(94,227)		762,109
Net income (loss)					42,494			42,494
Unrealized gains (losses) on securities available for sale, net of deferred federal income taxes			35,898					35,898
Recognition of employee share-based compensation, net of deferred federal income taxes		2,066						2,066
Dividends paid and accrued					(13,836)			(13,836)
Acquisition of treasury stock						(11,753)		(11,753)
Balance at Jun. 30, 2020	$ 177	$ 206,130	$ 42,302		$ 674,349	$ (105,980)		816,978
Cumulative effect of adoption of updated accounting guidance for callable debt securities at January 1, 2019, net of taxes								$ 674,349

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ 40,504	$ 55,880
Adjustments to reconcile net income to net cash provided by operating activities:
Investment amortization, net	3,253	2,782
Fixed Asset depreciation, net	3,278	2,379
Stock based compensation	3,810	3,353
(Credit) Provision for deferred income taxes	(5,028)	1,238
Net realized losses (gains) on investments	1,352	(319)
Net impairment losses on investments		274
Credit loss expense	2,471
Losses (earnings) from partnership investments	6,866	(1,160)
Change in net unrealized gains on equity investments	13,160	(15,555)
Changes in assets and liabilities:
Accounts receivable	(5,987)	(19,596)
Accrued investment income	404	116
Receivable from reinsurers	1,295	(18,958)
Ceded unearned premiums	9,109	(1,926)
Deferred policy acquisition costs	(3,063)	(2,315)
Taxes recoverable	592	(1,671)
Other assets	(5,732)	(4,219)
Loss and loss adjustment expense reserves	(10,819)	4,404
Unearned premium reserves	(2,212)	18,232
Taxes payable		(6,090)
Accounts payable and accrued liabilities	(14,362)	(14,587)
Payable to reinsurers	(1,117)	9,020
Other liabilities	(12,545)	2,135
Net cash provided by operating activities	25,229	13,417
Cash flows from investing activities:
Fixed maturities purchased	(83,172)	(79,891)
Equity securities purchased	(30,611)	(13,721)
Other invested assets purchased	(5,291)	(5,851)
Proceeds from sales and paydowns of fixed maturities	63,228	86,215
Proceeds from maturities, redemptions, and calls of fixed maturities	40,366	14,843
Proceed from sales of equity securities	15,758	12,323
Proceeds from other invested assets redeemed	158	559
Fixed assets purchased	(5,326)	(2,327)
Net cash (used for) provided by investing activities	(4,890)	12,150
Cash flows from financing activities:
Debt	30,000
Dividends paid to shareholders	(27,844)	(25,181)
Acquisition of treasury stock	(22,145)
Net cash used for financing activities	(19,989)	(25,181)
Net increase in cash and cash equivalents	350	386
Cash and cash equivalents at beginning of year	44,407	37,582
Cash and cash equivalents at end of period	$ 44,757	$ 37,968

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2020
Basis of Presentation
Basis of Presentation	1. Basis of Presentation ​ The consolidated financial statements have been prepared on the basis of accounting principles generally accepted in the United States of America (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from these estimates. ​ The consolidated financial statements include Safety Insurance Group, Inc. and its subsidiaries (the “Company”). The subsidiaries consist of Safety Insurance Company, Safety Indemnity Insurance Company, Safety Property and Casualty Insurance Company, Safety Asset Management Corporation (“SAMC”), and Safety Management Corporation, which is SAMC’s holding company. All intercompany transactions have been eliminated. ​ The financial information for the three and six months ended June 30, 2020 and 2019 is unaudited; however, in the opinion of the Company, the information includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the financial condition, results of operations, and cash flows for the periods. The financial information as of December 31, 2019 is derived from the audited financial statements included in the Company's 2019 Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (“SEC”) on February 28, 2020. ​ These unaudited interim consolidated financial statements may not be indicative of financial results for the full year and should be read in conjunction with the audited financial statements included in the Company’s 2019 Annual Report on Form 10-K filed with the SEC on February 28, 2020. ​ The Company is a leading provider of property and casualty insurance focused primarily on the Massachusetts market. The Company’s principal product line is automobile insurance. The Company operates through its insurance company subsidiaries, Safety Insurance Company, Safety Indemnity Insurance Company, and Safety Property and Casualty Insurance Company (together referred to as the “Insurance Subsidiaries”). ​ ​

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2020
Recent Accounting Pronouncements
Recent Accounting Pronouncements	2. Recent Accounting Pronouncements ​ On March 20, 2019, the SEC adopted amendments to Regulation S-K and related rules and forms to modernize and simplify certain disclosure requirements for public companies. The amendments are intended to reduce the costs and burdens of the disclosure process and while continuing to require disclosure of all material information. The amended rules generally were effective on May 2, 2019 and reduced disclosures but some provisions added new requirements. The adoption of the new rules did not have a material impact on the Company’s financial position, results of operations, cash flows, or disclosures. ​ In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement measurement disclosure requirements under ASC 820. The Company’s adoption of ASU 2018-13 on January 1, 2020 did not have an impact on the fair value disclosures included in Note 5 – Investments. In March 2017, the FASB issued ASU 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities , which requires certain premiums on callable debt securities to be amortized to the earliest call date. The amortization period for callable debt securities purchased at a discount will not be impacted. The Company adopted ASU 2017-08 effective January 1, 2019 which resulted in the recognition of ​ In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Statements ​ In February 2016, the FASB issued ASU 2016-02, Leases Codification Improvements to Topic 842, Leases Leases (Topic 842): Targeted Improvements, creates an additional transition method which allows companies to elect to not adjust their comparative period financial information and disclosures for the effects of the new lease standard and also creates a practical expedient for lessors to not separate lease and non-lease components. The Company adopted ASU 2016-02, ASU 2018-10 and ASU 2018-11 effective January 1, 2019 (“the application date”) using the required modified retrospective transition approach. In accordance with the guidance, the Company has elected not to adjust comparative periods. As such, Accounting Standards Codification (“ASC”) 842 will be applied to each lease that had commenced as of the application date with a cumulative effect adjustment as of that date. As of January 1, 2019, a right of use asset and lease liability of were recorded in the Consolidated Balance Sheets. All periods prior to the application date presented in the financial statements will not change and the guidance in ASC 840, Leases , will apply. There was no impact on retained earnings or other components of equity in the Consolidated Balance Sheets as of June 30, 2020 and December 31, 2019. ​ ​

Earnings per Weighted Average C

Earnings per Weighted Average Common Share	6 Months Ended
	Jun. 30, 2020
Earnings per Weighted Average Common Share
Earnings per Weighted Average Common Share	3. Earnings per Weighted Average Common Share ​ Basic earnings per weighted average common share (“EPS”) are calculated by dividing net income by the weighted average number of basic common shares outstanding during the period. Diluted earnings per share amounts are based on the weighted average number of common shares including non-vested performance stock grants. ​ The following table sets forth the computation of basic and diluted EPS for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 Earnings attributable to common shareholders - basic and diluted: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income from continuing operations ​ $ 42,494 ​ $ 25,934 ​ $ 40,504 ​ $ 55,880 Allocation of income for participating shares ​ ​ (195) ​ ​ (134) ​ ​ (190) ​ ​ (300) Net income from continuing operations attributed to common shareholders ​ $ 42,299 ​ $ 25,800 ​ $ 40,314 ​ $ 55,580 Earnings per share denominator - basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total weighted average common shares outstanding, including participating shares ​ ​ 15,189,442 ​ ​ 15,299,691 ​ ​ 15,247,100 ​ ​ 15,262,937 Less: weighted average participating shares ​ ​ (69,403) ​ ​ (78,869) ​ ​ (71,691) ​ ​ (81,903) Basic earnings per share denominator ​ ​ 15,120,039 ​ ​ 15,220,822 ​ ​ 15,175,409 ​ ​ 15,181,034 Common equivalent shares- non-vested performance stock grants ​ 117,256 ​ 125,412 ​ 116,777 ​ 145,087 Diluted earnings per share denominator ​ 15,237,295 ​ 15,346,234 ​ 15,292,186 ​ 15,326,121 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share ​ $ 2.80 ​ $ 1.70 ​ $ 2.66 ​ $ 3.66 Diluted earnings per share ​ $ 2.78 ​ $ 1.68 ​ $ 2.64 ​ $ 3.63 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Undistributed earnings attributable to common shareholders - basic and diluted: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income from continuing operations attributable to common shareholders -Basic ​ $ 2.80 ​ $ 1.70 ​ $ 2.66 ​ $ 3.66 Dividends declared ​ ​ (0.90) ​ ​ (0.80) ​ ​ (1.80) ​ ​ (1.60) Undistributed earnings ​ $ 1.90 ​ $ 0.90 ​ $ 0.86 ​ $ 2.06 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income from continuing operations attributable to common shareholders -Diluted ​ $ 2.78 ​ $ 1.68 ​ $ 2.64 ​ $ 3.63 Dividends declared ​ ​ (0.90) ​ ​ (0.80) ​ ​ (1.80) ​ ​ (1.60) Undistributed earnings ​ $ 1.88 ​ $ 0.88 ​ $ 0.84 ​ $ 2.03 ​ Diluted EPS excludes non-vested performance stock grants with exercise prices and exercise tax benefits greater than the average market price of the Company’s common stock during the period because their inclusion would be anti-dilutive. There were 2,310 and 106 anti-dilutive shares related to non-vested stock grants for the three and six months ended June 30, 2020, respectively, and no anti-dilutive shares related to non-vested stock grants for the three and six months ended June 30, 2019

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2020
Share-Based Compensation
Share-Based Compensation	4. Share-Based Compensation ​ 2018 Long Term Incentive Plan ​ On April 2, 2018, the Company’s Board of Directors adopted the Safety Insurance Group, Inc. 2018 Long-Term Incentive Plan (“the 2018 Plan”), which was subsequently approved by our shareholders at the 2018 Annual Meeting of Shareholders. The 2018 Plan enables the grant of stock awards, performance shares, cash-based performance units, other stock-based awards, stock options, stock appreciation rights, and stock unit awards, each of which may be granted separately or in tandem with other awards. Eligibility to participate includes officers, directors, employees and other individuals who provide bona fide services to the Company. The 2018 Plan supersedes the Company’s 2002 Management Omnibus Incentive Plan (“the 2002 Incentive Plan”). ​ The 2018 Plan establishes an initial pool of 350,000 shares of common stock available for issuance to our employees and other eligible participants. The maximum number of shares of common stock between both the 2018 Plan and 2002 Incentive Plan with respect to which awards may be granted is 2,850,000. No further grants will be allowed under the 2002 Incentive Plan. At June 30, 2020, there were 234,170 shares available for future grant. ​ Accounting and Reporting for Stock-Based Awards ​ Accounting Standards Codification (“ASC”) 718, Compensation —Stock Compensation requires the Company to measure and recognize the cost of employee services received in exchange for an award of equity instruments. Under the provisions of ASC 718, share-based compensation cost is measured at the grant date, based on the fair value of the award, and is recognized as an expense over the requisite service period (generally the vesting period of the equity grant). ​ Restricted Stock ​ Service-based restricted stock awarded in the form of unvested shares is recorded at the market value of the Company’s common stock on the grant date and amortized ratably as compensation expense over the requisite service period. Service-based restricted stock awards generally vest over a three-year period and vest 30% on the first and second anniversaries of the grant date and 40% on the third anniversary of the grant date, except for non-executive employees’ restricted stock awards granted prior to 2018 which vest ratably over a five-year service period and independent directors’ stock awards which vest immediately. Our independent directors are subject to stock ownership guidelines, which require them to have a value four times their annual cash retainer. ​ In addition to service-based awards, the Company grants performance-based restricted shares to certain employees. These performance shares cliff vest after a three-year performance period provided certain performance measures are attained. A portion of these awards, which contain a market condition, vest according to the level of total shareholder return achieved by the Company compared to its property-casualty insurance peers over a three-year period. The remainder, which contain a performance condition, vest according to the level of Company’s combined ratio results compared to a target based on its property-casualty insurance peers. ​ Actual payouts can range from 0% to 200% of target shares awarded depending upon the level of achievement of the respective market and performance conditions during a three calendar-year performance period. Compensation expense for share awards with a performance condition is based on the probable number of awards expected to vest using the performance level most likely to be achieved at the end of the performance period. ​ Performance-based awards with market conditions are accounted for and measured differently from awards that have a performance or service condition. The effect of a market condition is reflected in the award’s fair value on the grant date. That fair value is recognized as compensation cost over the requisite service period regardless of whether the market-based performance objective has been satisfied. ​ All of the Company’s restricted stock awards are issued as incentive compensation and are equity classified. ​ The following table summarizes restricted stock activity under the Incentive Plan during the six months ended June 30, 2020 assuming a target payout for the 2020 performance-based shares. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shares Weighted ​ Performance-based Weighted ​ ​ Under ​ Average ​ Shares Under ​ Average ​ ​ Restriction ​ Fair Value ​ Restriction ​ Fair Value Outstanding at beginning of year 78,202 ​ $ 79.09 ​ 84,105 ​ $ 79.34 Granted 34,799 ​ ​ 90.10 ​ 36,649 (1) ​ 84.68 Vested and unrestricted (43,480) ​ ​ 78.07 ​ (42,123) ​ ​ 73.55 Forfeited ​ (2,694) ​ ​ 87.70 ​ (6,667) ​ ​ 84.86 Outstanding at end of period 66,827 ​ $ 85.14 ​ 71,964 ​ $ 84.94 (1) Includes a true-up of previously awarded performance-based restricted share awards. The updated shares were calculated based on the attainment of pre-established performance objectives and granted under the 2002 Incentive Plan. ​ As of June 30, 2020, there was $8,527 of unrecognized compensation expense related to non-vested restricted stock awards that is expected to be recognized over a weighted average period of 1.7 years. The total fair value of the shares that were vested and unrestricted during the six months ended June 30, 2020 and 2019 was $6,493 and $7,784 , respectively. For the six months ended June 30, 2020 and 2019, the Company recorded compensation expense related to restricted stock of $3,010 and $2,649 , net of income tax benefits of $800 and $704 , respectively.

Investments

Investments	6 Months Ended
	Jun. 30, 2020
Investments
Investments	5. Investments ​ The gross unrealized gains and losses on investments in fixed maturity securities, including redeemable preferred stocks that have characteristics of fixed maturities, and equity securities, including interests in mutual funds, and other invested assets were as follows for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost or Allowance for Gross Unrealized Estimated ​ ​ Amortized ​ Expected Credit ​ ​ ​ ​ ​ Fair ​ ​ Cost ​ Losses ​ Gains ​ Losses (3) ​ Value U.S. Treasury securities ​ $ 1,822 ​ $ — ​ $ 59 ​ $ — ​ $ 1,881 Obligations of states and political subdivisions ​ 225,863 ​ — ​ 8,314 ​ (139) ​ 234,038 Residential mortgage-backed securities (1) ​ 272,484 ​ — ​ 14,131 ​ (28) ​ 286,587 Commercial mortgage-backed securities ​ 105,542 ​ — ​ 8,609 ​ — ​ 114,151 Other asset-backed securities ​ 27,673 ​ — ​ 375 ​ (599) ​ 27,449 Corporate and other securities ​ 535,282 ​ (2,471) ​ 30,039 ​ (7,242) ​ 555,608 Subtotal, fixed maturity securities ​ 1,168,666 ​ (2,471) ​ 61,527 ​ (8,008) ​ 1,219,714 Equity securities (2) ​ 164,991 ​ — ​ 19,213 ​ (5,857) ​ 178,347 Other invested assets (4) ​ 35,526 ​ — ​ — ​ — ​ 35,526 Totals ​ $ 1,369,183 ​ $ (2,471) ​ $ 80,740 ​ $ (13,865) ​ $ 1,433,587 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost or Gross Unrealized Estimated ​ ​ Amortized ​ ​ ​ ​ ​ Fair ​ ​ Cost ​ Gains ​ Losses (3) ​ Value U.S. Treasury securities ​ $ 1,504 ​ $ 8 ​ $ — ​ $ 1,512 ​ Obligations of states and political subdivisions ​ 241,597 ​ 9,799 ​ — ​ 251,396 ​ Residential mortgage-backed securities (1) ​ 301,503 ​ 6,608 ​ (909) ​ 307,202 ​ Commercial mortgage-backed securities ​ 106,902 ​ 3,233 ​ (397) ​ 109,738 ​ Other asset-backed securities ​ 36,068 ​ 218 ​ (64) ​ 36,222 ​ Corporate and other securities ​ 504,783 ​ 18,455 ​ (1,268) ​ 521,970 ​ Subtotal, fixed maturity securities ​ 1,192,357 ​ 38,321 ​ (2,638) ​ 1,228,040 ​ Equity securities (2) ​ 151,121 ​ 27,879 ​ (1,363) ​ 177,637 ​ Other invested assets (4) ​ 37,278 ​ — ​ — ​ 37,278 ​ Totals ​ $ 1,380,756 ​ $ 66,200 ​ $ (4,001) ​ $ 1,442,955 ​ (1) Residential mortgage-backed securities consists primarily of obligations of U.S. Government agencies including collateralized mortgage obligations issued, guaranteed and/or insured by the following issuers: Government National Mortgage Association (GNMA), Federal Home Loan Mortgage Corporation (FHLMC), Federal National Mortgage Association (FNMA) and the Federal Home Loan Bank (FHLB). (2) Equity securities include common stock, preferred stock, mutual funds and interests in mutual funds held to fund the Company’s executive deferred compensation plan. (3) The Company’s investment portfolio included 527 and 229 securities in an unrealized loss position at June 30, 2020 and December 31, 2019, respectively. (4) Other invested assets are accounted for under the equity method which approximated fair value. ​ ​ The amortized cost and the estimated fair value of fixed maturity securities, by maturity, are shown below for the period indicated. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2020 ​ Amortized Estimated ​ ​ Cost ​ Fair Value Due in one year or less ​ $ 67,468 ​ $ 68,303 Due after one year through five years ​ 300,404 ​ 308,520 Due after five years through ten years ​ 306,192 ​ 321,694 Due after ten years through twenty years ​ 87,050 ​ 90,948 Due after twenty years ​ 1,854 ​ 2,063 Asset-backed securities ​ 405,698 ​ 428,186 Totals ​ $ 1,168,666 ​ $ 1,219,714 ​ The gross realized gains and losses on sales of investments were as follows for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2020 2019 2020 2019 Gross realized gains ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fixed maturity securities ​ $ 139 ​ $ 479 ​ $ 1,028 ​ $ 594 Equity securities ​ 1,295 ​ 688 ​ 2,871 ​ 1,641 Gross realized losses ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fixed maturity securities ​ (1,096) ​ (241) ​ (1,397) ​ (908) Equity securities ​ (1,059) ​ (443) ​ (3,854) ​ (1,008) Net realized (losses) gains on investments ​ $ (721) ​ $ 483 ​ $ (1,352) ​ $ 319 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In the normal course of business, the Company enters into transactions involving various types of financial instruments, including investments in fixed maturities and equity securities. Investment transactions have credit exposure to the extent that a counter party may default on an obligation to the Company. Credit risk is a consequence of carrying, trading and investing in securities. To manage credit risk, the Company focuses on higher quality fixed income securities, reviews the credit strength of all companies in which it invests, limits its exposure in any one investment and monitors the portfolio quality, taking into account credit ratings assigned by recognized statistical rating organizations. ​ The following tables as of June 30, 2020 and December 31, 2019 present the gross unrealized losses included in the Company’s investment portfolio and the fair value of those securities aggregated by investment category. The tables also present the length of time that they have been in a continuous unrealized loss position. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2020 ​ ​ Less than 12 Months ​ 12 Months or More ​ Total ​ Estimated Unrealized Estimated Unrealized Estimated Unrealized ​ ​ Fair Value ​ Losses ​ Fair Value ​ Losses ​ Fair Value ​ Losses U.S. Treasury securities ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — Obligations of states and political subdivisions ​ 4,479 ​ 139 ​ — ​ — ​ 4,479 ​ 139 Residential mortgage-backed securities ​ 5,938 ​ 27 ​ 139 ​ 1 ​ 6,077 ​ 28 Commercial mortgage-backed securities ​ — ​ — ​ — ​ — ​ — ​ — Other asset-backed securities ​ 5,407 ​ ​ 330 ​ ​ 8,814 ​ ​ 269 ​ ​ 14,221 ​ ​ 599 Corporate and other securities ​ 127,854 ​ 6,360 ​ 8,901 ​ 882 ​ 136,755 ​ 7,242 Subtotal, fixed maturity securities ​ 143,678 ​ 6,856 ​ 17,854 ​ 1,152 ​ 161,532 ​ 8,008 Equity securities ​ 54,680 ​ 4,334 ​ 11,725 ​ 1,523 ​ 66,405 ​ 5,857 Total temporarily impaired securities ​ $ 198,358 ​ $ 11,190 ​ $ 29,579 ​ $ 2,675 ​ $ 227,937 ​ $ 13,865 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2019 ​ ​ Less than 12 Months ​ 12 Months or More ​ Total ​ Estimated Unrealized Estimated Unrealized Estimated Unrealized ​ ​ Fair Value ​ Losses ​ Fair Value ​ Losses ​ Fair Value ​ Losses U.S. Treasury securities ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — Obligations of states and political subdivisions ​ — ​ — ​ — ​ — ​ — ​ — Residential mortgage-backed securities ​ 61,933 ​ 409 ​ 31,655 ​ 500 ​ 93,588 ​ 909 Commercial mortgage-backed securities ​ 36,398 ​ 397 ​ 866 ​ — ​ 37,264 ​ 397 Other asset-backed securities ​ 21,281 ​ ​ 64 ​ ​ 462 ​ ​ — ​ 21,743 ​ 64 Corporate and other securities ​ 26,386 ​ 481 ​ 13,718 ​ 787 ​ 40,104 ​ 1,268 Subtotal, fixed maturity securities ​ 145,998 ​ 1,351 ​ 46,701 ​ 1,287 ​ 192,699 ​ 2,638 Equity securities ​ 8,849 ​ 391 ​ 14,143 ​ 972 ​ 22,992 ​ 1,363 Total temporarily impaired securities ​ $ 154,847 ​ $ 1,742 ​ $ 60,844 ​ $ 2,259 ​ $ 215,691 ​ $ 4,001 ​ Impairments ​ Beginning January 1, 2020, ASC 326, Credit Losses: Measurement of Credit Losses on Financial Instruments ​ For fixed maturities that the Company does not intend to sell or for which it is more likely than not that the Company would not be required to sell before an anticipated recovery in value, the Company separates the credit loss component of the impairment from the amount related to all other factors and reports the credit loss component as credit loss expense. The impairment related to all other factors (non-credit factors) is reported in other comprehensive income. The allowance is adjusted for any additional credit losses and subsequent recoveries. Upon recognizing a credit loss, the cost basis is not adjusted. ​ For fixed maturities where the Company records a credit loss, a determination is made as to the cause of the impairment and whether the Company expects a recovery in the value. For fixed maturities where the Company expects a recovery in value, the constant effective yield method is utilized, and the investment is amortized to par. ​ For fixed maturity investments the Company intends to sell or for which it is more likely than not that the Company will be required to sell before an anticipated recovery in value, the full amount of the impairment is included in credit loss expense. The new cost basis of the investment is the previous amortized cost basis less the impairment recognized in credit loss expense. The new cost basis is not adjusted for any subsequent recoveries in fair value. ​ The Company uses a systematic methodology to evaluate declines in fair values below cost or amortized cost of our investments. Some of the factors considered in assessing impairment of fixed maturities due to credit losses include the extent to which the fair value is less than amortized cost, the financial condition of and the near and long-term prospects of the issuer, whether the debtor is current on its contractually obligated interest and principal payments, changes to the rating of the security by a rating agency, the historical volatility of the fair value of the security and whether it is more like than not that the Company will be required to sell the investment prior to an anticipated recovery in value. ​ The Company’s analysis of its fixed maturity portfolio at June 30, 2020 resulted in a decrease in the allowance for expected credit losses and credit loss expense of $39 for the three months ended June 30, 2020. For the six months ended June 30, 2020 the Company concluded that of unrealized losses were due to credit factors and were recorded as an allowance for expected credit losses and credit loss expense. The Company concluded that outside of the securities that were recognized as credit impaired, the unrealized losses recorded on the fixed maturity portfolio at June 30, 2020 resulted from fluctuations in market interest rates and other temporary market conditions as opposed to fundamental changes in the credit quality of the issuers of such securities. Based upon the analysis performed, the Company’s decision to hold these securities, the Company’s current level of liquidity and our history of positive operating cash flows, management believes it is more likely than not that it will not be required to sell any of its securities before the anticipated recovery in the fair value to its amortized cost basis. ​ The Company recognized other-than-temporary impairment losses of and during the three and six months ended June 30, 2019, respectively which Investments – Debt and Equity Securities ​ The Company holds no subprime mortgage debt securities. All of the Company’s holdings in mortgage-backed securities are either U.S. Government or Agency guaranteed or are rated investment grade by either Moody’s or Standard & Poor’s. ​ The following tables represent a reconciliation of the beginning and ending balances of the allowance for expected credit losses on fixed maturities classified as available for sale. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2020 ​ ​ ​ ​ ​ ​ ​ Corporate and other ​ ​ ​ securities Balance April 1, 2020 ​ ​ $ 2,510 Credit losses on securities with no previously recorded credit losses ​ ​ — Net increases (decreases) in allowance on previously impaired securities ​ ​ (39) Reduction due to sales ​ ​ — Writeoffs charged against allowance ​ ​ — Recoveries of amounts previously written off ​ ​ — Balance June 30, 2020 ​ ​ $ 2,471 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2020 ​ ​ ​ ​ ​ Corporate and other ​ ​ securities Balance January 1, 2020 ​ $ — Credit losses on securities with no previously recorded credit losses ​ 2,471 Net increases (decreases) in allowance on previously impaired securities ​ — Reduction due to sales ​ — Writeoffs charged against allowance ​ — Recoveries of amounts previously written off ​ — Balance June 30, 2020 ​ $ 2,471 ​ ​ Net Investment Income ​ The components of net investment income were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2020 2019 2020 2019 Interest on fixed maturity securities ​ $ 9,667 ​ $ 9,717 ​ $ 19,426 ​ $ 20,844 Dividends on equity securities ​ 1,034 ​ 1,117 ​ 2,240 ​ 2,199 Equity in earnings of other invested assets ​ 9 ​ 478 ​ 525 ​ 760 Interest on other assets ​ 7 ​ 8 ​ 14 ​ 17 Total investment income ​ 10,717 ​ 11,320 ​ 22,205 ​ 23,820 Investment expenses ​ 801 ​ 746 ​ 1,579 ​ 1,495 Net investment income ​ $ 9,916 ​ $ 10,574 ​ $ 20,626 ​ $ 22,325 ​ Fair Value of Financial Instruments ​ ASC 820, Fair Value Measurements and Disclosure ​ Level 1 — Valuations based on quoted prices in active markets for identical assets and liabilities; ​ Level 2 — Valuations based on observable inputs that do not meet the criteria for Level 1, including quoted prices in inactive markets and quoted prices in active markets for similar, but not identical instruments; and ​ Level 3 — Valuations based on unobservable inputs. ​ Fair values for the Company’s fixed maturity securities are based on prices provided by its custodian bank and its investment managers. Both the Company’s custodian bank and investment managers use a variety of independent, nationally recognized pricing services to determine market valuations. If the pricing service cannot provide fair value determinations, the Company obtains non-binding price quotes from broker-dealers. A minimum of two quoted prices is obtained for the majority of the Company’s available-for-sale fixed maturity securities in its investment portfolio. The Company uses a third-party pricing service as its primary provider of quoted prices from third-party pricing services and broker-dealers. To provide reasonable assurance of the validity of each price or quote, a secondary third-party pricing service or broker-dealer quote is obtained from the Company’s custodian or investment managers. An examination of the pricing data is then performed for each security. If the variance between the primary and secondary price quotes for a security is within an accepted tolerance level, the quoted price obtained from the Company’s primary source is used for the security. If the variance between the primary and secondary price quotes exceeds an accepted tolerance level, the Company obtains a quote from an alternative source, if possible, and documents and resolves any differences between the pricing sources. In addition, the Company may request that its investment managers and its traders provide input as to which vendor is providing prices that its traders believe are reflective of fair value for the security. Following this process, the Company may decide to value the security in its financial statements using the secondary or alternative source if it believes that pricing is more reflective of the security’s value than the primary pricing provided by its custodian bank. The Company analyzes market valuations received to verify reasonableness, to understand the key assumptions used and their sources, and to determine an appropriate ASC 820 fair value hierarchy level based upon trading activity and the observability of market inputs. Based on this evaluation and investment class analysis, each price is classified into Level 1, 2 or 3. ​ Fair values of instruments are based on (i) quoted prices in active markets for identical assets (Level 1), (ii) quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-derived valuations in which all significant inputs are observable in active markets (Level 2) or (iii) valuations derived from valuation techniques in which one or more significant inputs are unobservable in the marketplace (Level 3). ​ The Company’s Level 1 securities consist of equity securities whose values are based on quoted prices in active markets for identical assets. The Company’s Level 2 securities are comprised of available-for-sale fixed maturity securities whose fair value was determined using observable market inputs. The Company’s Level 3 security consists of an investment in the Federal Home Loan Bank of Boston related to Safety Insurance Company’s membership stock, which is not redeemable in a short-term time frame. Fair values for securities for which quoted market prices were unavailable were estimated based upon reference to observable inputs such as benchmark interest rates, market comparables, and other relevant inputs. Investments valued using these inputs include U.S. Treasury securities, obligations of states and political subdivisions, corporate and other securities, commercial and residential mortgage-backed securities, and other asset-backed securities. Inputs into the fair value application that are utilized by asset class include but are not limited to: ​ ● Obligations of states and political subdivisions : overall credit quality, including assessments of market sectors and the level and variability of sources of payment such as general obligation, revenue or lease; credit support such as insurance, state or local economic and political base, prefunded and escrowed to maturity covenants. ​ ● Corporate and other securities : overall credit quality, the establishment of a risk adjusted credit spread over the applicable risk-free yield curve for discounted cash flow valuations; assessments of the level of industry economic sensitivity, company financial policies, indenture restrictive covenants, and/or security and collateral. ​ ● Residential mortgage-backed securities , U.S. agency pass-throughs, collateralized mortgage obligations (“CMOs”), non U.S. agency CMOs : estimates of prepayment speeds based upon historical prepayment rate trends, underlying collateral interest rates, original weighted average maturity, vintage year, borrower credit quality characteristics, interest rate and yield curve forecasts, U.S. government support programs, tax policies, and delinquency/default trends. ​ ● Commercial mortgage-backed securities : overall credit quality, including assessments of the level and variability of credit support and collateral type such as office, retail, or lodging, predictability of cash flows for the deal structure, prevailing economic market conditions. ​ ● Other asset-backed securities : overall credit quality, estimates of prepayment speeds based upon historical trends and characteristics of underlying loans, including assessments of the level and variability of collateral, revenue generating agreements, area licenses agreements, product sourcing agreements and equipment and property leases. ​ ● Federal Home Loan Bank of Boston (“FHLB-Boston”): value is equal to the cost of the member stock purchased. ​ In order to ensure the fair value determination is representative of an exit price (consistent with ASC 820), the Company’s procedures for validating quotes or prices obtained from third parties include, but are not limited to, obtaining a minimum of two price quotes for each fixed maturity security if possible, as discussed above, the periodic testing of sales activity to determine if there are any significant differences between the market price used to value the security as of the balance sheet date and the sales price of the security for sales that occurred around the balance sheet date, and the periodic review of reports provided by its external investment manager regarding those securities with ratings changes and securities placed on its “Watch List.” In addition, valuation techniques utilized by pricing services and prices obtained from external sources are reviewed by the Company’s external investment manager, whose investment professionals are familiar with the securities being priced and the markets in which they trade, to ensure the fair value determination is representative of an exit price (consistent with ASC 820). ​ All unadjusted estimates of fair value for our fixed maturities priced by the pricing services as described above are included in the amounts disclosed in Level 2. With the exception of the FHLB-Boston security, which is categorized as a Level 3 security, the Company’s entire portfolio was priced based upon quoted market prices or other observable inputs as of June 30, 2020. There were no significant changes to the valuation process during the six months ended June 30, 2020. As of June 30, 2020 and December 31, 2019, no quotes or prices obtained were adjusted by management. All broker quotes obtained were non-binding. ​ At June 30, 2020 and December 31, 2019, investments in fixed maturities classified as available-for-sale had a fair value which equaled carrying value of $1,219,714 and $1,228,040 , respectively. We have ​ The following tables summarize the Company’s total fair value measurements for investments for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2020 ​ Total Level 1 Inputs Level 2 Inputs Level 3 Inputs U.S. Treasury securities ​ $ 1,881 ​ $ — ​ $ 1,881 ​ $ — Obligations of states and political subdivisions ​ 234,038 ​ — ​ 234,038 ​ — Residential mortgage-backed securities ​ 286,587 ​ — ​ 286,587 ​ — Commercial mortgage-backed securities ​ 114,151 ​ — ​ 114,151 ​ — Other asset-backed securities ​ 27,449 ​ — ​ 27,449 ​ — Corporate and other securities ​ 555,608 ​ — ​ 555,608 ​ — Equity securities ​ 145,911 ​ 144,213 ​ — ​ 1,698 Total investment securities ​ $ 1,365,625 ​ $ 144,213 ​ $ 1,219,714 ​ $ 1,698 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2019 ​ Total Level 1 Inputs Level 2 Inputs Level 3 Inputs U.S. Treasury securities ​ $ 1,512 ​ $ — ​ $ 1,512 ​ $ — Obligations of states and political subdivisions ​ 251,396 ​ — ​ 251,396 ​ — Residential mortgage-backed securities ​ 307,202 ​ — ​ 307,202 ​ — Commercial mortgage-backed securities ​ 109,738 ​ — ​ 109,738 ​ — Other asset-backed securities ​ 36,222 ​ — ​ 36,222 ​ — Corporate and other securities ​ 521,970 ​ — ​ 521,970 ​ — Equity securities ​ 144,877 ​ 144,361 ​ — ​ 516 Total investment securities ​ $ 1,372,917 ​ $ 144,361 ​ $ 1,228,040 ​ $ 516 ​ There were no transfers between Level 1 and Level 2 during the three and six months ended June 30, 2020 and 2019. The following table summarizes the changes in the Company’s Level 3 fair value securities for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2020 2019 2020 2019 ​ ​ Level 3 ​ Level 3 Level 3 ​ Level 3 ​ ​ Fair Value ​ Fair Value Fair Value ​ Fair Value ​ ​ Securities ​ Securities Securities ​ Securities Balance at beginning of period ​ $ 1,686 ​ $ 383 ​ $ 516 ​ $ 680 Net gains and losses included in earnings ​ — ​ — ​ — ​ — Net gains included in other comprehensive income ​ — ​ — ​ — ​ — Purchases ​ 12 ​ 103 ​ 1,182 ​ 103 Sales ​ ​ — ​ ​ — ​ ​ — ​ ​ (297) Transfers into Level 3 ​ ​ — ​ — ​ — ​ — Transfers out of Level 3 ​ — ​ — ​ — ​ — Balance at end of period ​ $ 1,698 ​ $ 486 ​ $ 1,698 ​ $ 486 Amount of total losses included in earnings attributable to the change in unrealized losses related to assets still held at end of period ​ $ — ​ $ — ​ $ — ​ $ — ​ Transfers in and out of Level 3 are attributable to changes in the ability to observe significant inputs in determining fair value exit pricing. As noted in the table above, no transfers were made in or out of Level 3 during the six months ended June 30, 2020 and 2019. The Company held one Level 3 security at June 30, 2020 and June 30, 2019. ​ As of June 30, 2020 and December 31, 2019, there were approximately $32,436 and $32,760 , respectively, in a real estate investment trust (“REIT”). The REIT is excluded from the fair value hierarchy because the fair value is recorded using the net asset value per share practical expedient. The net asset value per share of this REIT is derived from member ownership in the capital venture to which a proportionate share of independently appraised net assets is attributed. The fair value was determined using the trust’s net asset value obtained from its audited financial statements. The Company is required to submit a request 45 days before a quarter end to dispose of the security.

Allowance for Expected Credit L

Allowance for Expected Credit Losses	6 Months Ended
	Jun. 30, 2020
Allowance for Expected Credit Losses
Allowance for Expected Credit Losses	​ 6. Allowance for Expected Credit Losses ​ Beginning on January 1, 2020, credit losses are recognized through an allowance account. See Note 2 – Recent Accounting Pronouncements for additional information and Note 5 – Investments for information about the allowance for expected credit losses on AFS debt securities. ​ The Company’s financial instruments measured at amortized cost include premiums and accounts receivable, and reinsurance recoverables. ​ Premiums and accounts receivable are reported net of an allowance for expected credit losses. The allowance is based upon the Company’s ongoing review of amounts outstanding, historical loss data, including delinquencies and write-offs, current and forecasted economic conditions and other relevant factors. Credit risk is partially mitigated by the Company’s ability to cancel the policy if the policyholder does not pay the premium and the Company writes off premiums receivable balances that are more than 90 days overdue. ​ The following tables present the balances of premiums receivable, net of the allowance for expected credit losses, at June 30, 2020 and January 1, 2020, and changes in the allowance for expected credit losses for the three and six months ended June 30, 2020. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At and For the ​ ​ At and For the ​ ​ ​ Three Months Ended June 30, 2020 ​ ​ Six Months Ended June 30, 2020 ​ ​ Accounts Receivable Net of Allowance for Expected Credit Losses ​ ​ Allowance for Expected Credit Losses ​ ​ Accounts Receivable Net of Allowance for Expected Credit Losses ​ ​ Allowance for Expected Credit Losses Balance, beginning of period ​ $ 189,671 ​ $ 334 ​ $ 193,369 ​ $ 578 Current period change for expected credit losses ​ ​ ​ 626 ​ ​ ​ 2,202 Writeoffs of uncollectable accounts receivable ​ ​ ​ (46) ​ ​ ​ (1,866) Balance, end of period ​ $ 199,356 ​ $ 914 ​ $ 199,356 ​ $ 914 ​ ​ Reinsurance recoverables include amounts due from reinsurers for both paid and unpaid losses. The Company cedes insurance to Commonwealth Automobile Reinsurers (“CAR”) and to other reinsurers. The Company has a property catastrophe excess of loss agreement and a casualty excess of loss agreement that qualify as reinsurance treaties and are designed to protect against large or unusual loss and LAE activity. Reinsurance contracts do not relieve the Company from its obligations to policyholders. Failure of reinsurers to honor their obligations could result in losses to the Company. The Company evaluates the financial condition of its reinsurers and monitors economic characteristics of the reinsurers to minimize its exposure to significant losses from reinsurer insolvencies. The Company reports its reinsurance recoverables net of an allowance for estimated uncollectable reinsurance. A probability-of-default methodology which reflects current and forecasted economic conditions is used to estimate the amount of uncollectible reinsurance due to credit-related factors and the estimate is reported in an allowance for estimated uncollectible reinsurance. Amounts deemed to be uncollectible, including amounts due from known insolvent reinsurers, are written off against the allowance. Changes in the allowance, as well as any subsequent collections of amounts previously written off, are reported as part of claims and claim adjustment expenses. ​ The majority of the Company’s reinsurance recoverable on paid and unpaid losses is a result of our participation as a servicing carrier in the CAR Commercial Automobile Program and the Taxi/Limo Program, which represents 98% of the total reinsurance recoverable on paid and unpaid losses at June 30, 2020. The remaining 2% of amounts due from reinsurers are related to our other excess of loss and quota share contracts. For amounts due under these contracts, the Company utilizes updated A.M. Best credit ratings on a quarterly basis to determine the allowance for expected credit losses. As of June 30, 2020, all reinsurers under these programs are rated “A” or better by A.M. Best. Certain of the Company's reinsurance recoverables are collateralized by letters of credit, funds held or trust agreements. The Company’s analysis concludes that there are no expected credit losses at June 30, 2020.

Loss and Loss Adjustment Expens

Loss and Loss Adjustment Expense Reserves	6 Months Ended
	Jun. 30, 2020
Loss and Loss Adjustment Expense Reserves
Loss and Loss Adjustment Expense Reserves	7. Loss and Loss Adjustment Expense Reserves ​ The following table sets forth a reconciliation of beginning and ending reserves for losses and loss adjustment expenses (“LAE”), as shown in the Company’s consolidated financial statements for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, ​ 2020 2019 Reserves for losses and LAE at beginning of year ​ $ 610,566 ​ $ 584,719 Less receivable from reinsurers related to unpaid losses and LAE ​ (122,372) ​ (108,398) Net reserves for losses and LAE at beginning of year ​ 488,194 ​ 476,321 Incurred losses and LAE, related to: ​ ​ ​ ​ ​ ​ Current year ​ 231,048 ​ 270,757 Prior years ​ (19,328) ​ (22,337) Total incurred losses and LAE ​ 211,720 ​ 248,420 Paid losses and LAE related to: ​ ​ ​ ​ ​ ​ Current year ​ 105,043 ​ 139,220 Prior years ​ 111,502 ​ 108,626 Total paid losses and LAE ​ 216,545 ​ 247,846 Net reserves for losses and LAE at end of period ​ 483,369 ​ 476,895 Plus receivable from reinsurers related to unpaid losses and LAE ​ 116,378 ​ 112,228 Reserves for losses and LAE at end of period ​ $ 599,747 ​ $ 589,123 ​ At the end of each period, the reserves were re-estimated for all prior accident years. The Company’s prior year reserves decreased by 30, 2020 and 2019, respectively, and resulted from re-estimations of prior year’s ultimate loss and LAE liabilities. The decreases in prior years reserves during the six months ended June 30, 2020 and 2019, are primarily composed of reductions in our retained automobile and retained homeowners lines reserves. ​

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies
Commitments and Contingencies	8. Commitments and Contingencies ​ Various claims, generally incidental to the conduct of normal business, are pending or alleged against the Company from time to time. In the opinion of management, based in part on the advice of legal counsel, the ultimate resolution of such claims will not have a material adverse effect on the Company’s consolidated financial statements. However, if estimates of the ultimate resolutions of those proceedings are revised, liabilities related to those proceedings could be adjusted in the near term. ​ Massachusetts law requires that insurers licensed to do business in Massachusetts participate in the Massachusetts Insurers Insolvency Fund (“Insolvency Fund”). Members of the Insolvency Fund are assessed a proportionate share of the obligations and expenses of the Insolvency Fund in connection with an insolvent insurer. It is anticipated that there will be additional assessments from time to time relating to various insolvencies. Although the timing and amounts of any future assessments are not known, based upon existing knowledge, management’s opinion is that such future assessments are not expected to have a material effect upon the financial position of the Company.

Debt

Debt	6 Months Ended
	Jun. 30, 2020
Debt
Debt	9. Debt ​ On August 10, 2018, the Company extended its Revolving Credit Agreement (the “Credit Agreement”) with Citizens Bank, N.A. (formerly known as RBS Citizens, N.A. (“Citizens Bank”)) to a maturity date of August 10, 2023. The Credit Agreement provides a $30,000 revolving credit facility with an accordion feature allowing for future expansion of the committed amount up to $50,000 . Loans under the credit facility bear interest at the Company’s option at either (i) the LIBOR rate plus 1.25% per annum or (ii) the higher of Citizens Bank prime rate or 0.5% above the federal funds rate plus 1.25% per annum. Interest only is payable prior to maturity. ​ The Company’s obligations under the credit facility are secured by pledges of its assets and the capital stock of its operating subsidiaries. The credit facility is guaranteed by the Company’s non-insurance company subsidiaries. The credit facility contains covenants including requirements to maintain minimum risk-based capital ratios and statutory surplus of Safety Insurance Company as well as limitations or restrictions on indebtedness, liens, and other matters. As of June 30, 2020, the Company was in compliance with all covenants. In addition, the credit facility includes customary events of default, including a cross-default provision permitting the lenders to accelerate the facility if the Company (i) defaults in any payment obligation under debt having a principal amount in excess of ​ The Company had no amounts outstanding on its credit facility at June 30, 2020 and December 31, 2019. The credit facility commitment fee included in interest expense was computed at a rate of ​ The Company is a member of the FHLB-Boston. Membership in the FHLB-Boston allows the Company to borrow money at competitive interest rates provided the loan is collateralized by specific U.S Government residential mortgage backed securities. At June 30, 2020, the Company has the ability to borrow using eligible invested assets that would be used as collateral. ​ On March 17, 2020, the Company borrowed $30,000 from the FHLB-Boston for a term of five-years , bearing interest at a rate of 1.42% . Interest is payable monthly and the principal is due on the maturity date of March 17, 2025 but may be prepaid in whole or in part by the Company in advance with a minor penalty for prepayment. The loan is fully collateralized by specific U.S. Government residential mortgage backed securities. The Company had no amounts outstanding from the FHLB-Boston at December 31, 2019. ​ Interest expense on the FHLB-Boston borrowing was $107 and $125 for the three and six months ended June 30, 2020, respectively. There was no interest expense for the three and six months ended June 30, 2019

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2020
Income Taxes
Income Taxes	10. Income Taxes ​ Federal income tax expense for the six months ended June 30, 2020 and 2019 has been computed using estimated effective tax rates. These rates are revised, if necessary, at the end of each successive interim period to reflect the current estimates of the annual effective tax rates. The effective rate in 2020 was lower than the statutory rate primarily due to effects of tax-exempt investment income and the impact of stock-based compensation. ​ ​ The Company believes that the positions taken on its income tax returns for open tax years will be sustained upon examination by the Internal Revenue Service (“IRS”). Therefore, the Company has not recorded any liability for uncertain tax positions under ASC 740, Income Taxes ​ During the six months ended June 30, 2020, there were no material changes to the amount of the Company’s unrecognized tax benefits or to any assumptions regarding the amount of its ASC 740 liability. ​ All tax years prior to 2016 are closed. There are no current examinations ongoing. ​ In the Company’s opinion, adequate tax liabilities have been established for all open years. However, the amount of these tax liabilities could be revised in the near term if estimates of the Company’s ultimate liability are revised. ​

Share Repurchase Program

Share Repurchase Program	6 Months Ended
	Jun. 30, 2020
Share Repurchase Program
Share Repurchase Program	11. Share Repurchase Program ​ On August 3, 2007, the Board of Directors approved a share repurchase program of up to $30,000 of the Company’s outstanding common shares. The Board of Directors had cumulatively authorized increases to the existing share repurchase program of up to ​ During the three and six months ended June 30, 2020, the Company purchased 158,552 and 301,844 shares, respectively, on the open market under the program at a cost of $11,753 and $22,145, respectively. No share purchases were made by the Company under the program during the six months ended June 30, 2019. As of June 30, 2020, the Company has purchased ​

Leases

Leases	6 Months Ended
	Jun. 30, 2020
Leases
Leases	12. Leases ​ The Company has various non-cancelable, long-term operating leases, the largest of which are for office space including the corporate headquarters, VIP claims centers and law offices. Other operating leases consist of auto leases and various office equipment. The Company has no finance leases. Our leases have remaining lease terms of one year to ten years , some of which include options to extend the leases for up to five years . ​ The Company adopted ASU 2016-02, ASU 2018-10 and ASU 2018-11 effective January 1, 2019 (“the application date”) using the required modified retrospective transition approach. In accordance with the guidance, the Company has elected not to adjust comparative periods. As such ASC 842 will be applied to each lease that had commenced as of the application date with a cumulative effect adjustment as of that date. All periods before the application date presented in the financial statements will not change and the guidance in ASC 840 will apply. The Company has elected to apply the package of practical expedients provided in ASC 842 to all leases. In addition, the Company has elected not to apply the hindsight practical expedient or the land easement practical expedient. ​ In calculating lease liabilities the Company uses its incremental borrowing rate as of the application date based on original lease terms. The components of lease expense were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, ​ ​ 2020 ​ ​ 2019 ​ 2020 ​ 2019 Operating lease cost ​ $ 1,147 ​ $ 1,154 ​ $ 2,298 ​ 2,308 ​ Other information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, ​ ​ 2020 ​ ​ 2019 ​ 2020 ​ ​ 2019 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases $ 1,263 ​ $ 1,256 ​ $ 2,545 ​ $ 2,512 Weighted average remaining lease term ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ ​ ​ ​ ​ ​ 8.01 Years ​ ​ 9.02 Years Weighted average discount rate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ ​ ​ ​ ​ ​ 2.37% ​ ​ 3.45% ​ Maturities of lease liabilities were as follows: ​ ​ ​ ​ 2020 $ 2,494 2021 4,845 2022 4,286 2023 3,880 2024 ​ 3,875 2025 and after 15,405 Total lease payments ​ 34,785 Less imputed interest ​ (1,693) Total $ 33,092 ​

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events
Subsequent Events	13. Subsequent Events ​

Earnings per Weighted Average_2

Earnings per Weighted Average Common Share (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings per Weighted Average Common Share
Computation of basic and diluted EPS	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 Earnings attributable to common shareholders - basic and diluted: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income from continuing operations ​ $ 42,494 ​ $ 25,934 ​ $ 40,504 ​ $ 55,880 Allocation of income for participating shares ​ ​ (195) ​ ​ (134) ​ ​ (190) ​ ​ (300) Net income from continuing operations attributed to common shareholders ​ $ 42,299 ​ $ 25,800 ​ $ 40,314 ​ $ 55,580 Earnings per share denominator - basic and diluted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total weighted average common shares outstanding, including participating shares ​ ​ 15,189,442 ​ ​ 15,299,691 ​ ​ 15,247,100 ​ ​ 15,262,937 Less: weighted average participating shares ​ ​ (69,403) ​ ​ (78,869) ​ ​ (71,691) ​ ​ (81,903) Basic earnings per share denominator ​ ​ 15,120,039 ​ ​ 15,220,822 ​ ​ 15,175,409 ​ ​ 15,181,034 Common equivalent shares- non-vested performance stock grants ​ 117,256 ​ 125,412 ​ 116,777 ​ 145,087 Diluted earnings per share denominator ​ 15,237,295 ​ 15,346,234 ​ 15,292,186 ​ 15,326,121 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic earnings per share ​ $ 2.80 ​ $ 1.70 ​ $ 2.66 ​ $ 3.66 Diluted earnings per share ​ $ 2.78 ​ $ 1.68 ​ $ 2.64 ​ $ 3.63 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Undistributed earnings attributable to common shareholders - basic and diluted: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income from continuing operations attributable to common shareholders -Basic ​ $ 2.80 ​ $ 1.70 ​ $ 2.66 ​ $ 3.66 Dividends declared ​ ​ (0.90) ​ ​ (0.80) ​ ​ (1.80) ​ ​ (1.60) Undistributed earnings ​ $ 1.90 ​ $ 0.90 ​ $ 0.86 ​ $ 2.06 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income from continuing operations attributable to common shareholders -Diluted ​ $ 2.78 ​ $ 1.68 ​ $ 2.64 ​ $ 3.63 Dividends declared ​ ​ (0.90) ​ ​ (0.80) ​ ​ (1.80) ​ ​ (1.60) Undistributed earnings ​ $ 1.88 ​ $ 0.88 ​ $ 0.84 ​ $ 2.03

Share-Based Compensation (Table

Share-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Share-Based Compensation
Schedule of restricted stock and performance-based restricted stock activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shares Weighted ​ Performance-based Weighted ​ ​ Under ​ Average ​ Shares Under ​ Average ​ ​ Restriction ​ Fair Value ​ Restriction ​ Fair Value Outstanding at beginning of year 78,202 ​ $ 79.09 ​ 84,105 ​ $ 79.34 Granted 34,799 ​ ​ 90.10 ​ 36,649 (1) ​ 84.68 Vested and unrestricted (43,480) ​ ​ 78.07 ​ (42,123) ​ ​ 73.55 Forfeited ​ (2,694) ​ ​ 87.70 ​ (6,667) ​ ​ 84.86 Outstanding at end of period 66,827 ​ $ 85.14 ​ 71,964 ​ $ 84.94

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2020
Investments
Gross unrealized gains and losses on investments in securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost or Allowance for Gross Unrealized Estimated ​ ​ Amortized ​ Expected Credit ​ ​ ​ ​ ​ Fair ​ ​ Cost ​ Losses ​ Gains ​ Losses (3) ​ Value U.S. Treasury securities ​ $ 1,822 ​ $ — ​ $ 59 ​ $ — ​ $ 1,881 Obligations of states and political subdivisions ​ 225,863 ​ — ​ 8,314 ​ (139) ​ 234,038 Residential mortgage-backed securities (1) ​ 272,484 ​ — ​ 14,131 ​ (28) ​ 286,587 Commercial mortgage-backed securities ​ 105,542 ​ — ​ 8,609 ​ — ​ 114,151 Other asset-backed securities ​ 27,673 ​ — ​ 375 ​ (599) ​ 27,449 Corporate and other securities ​ 535,282 ​ (2,471) ​ 30,039 ​ (7,242) ​ 555,608 Subtotal, fixed maturity securities ​ 1,168,666 ​ (2,471) ​ 61,527 ​ (8,008) ​ 1,219,714 Equity securities (2) ​ 164,991 ​ — ​ 19,213 ​ (5,857) ​ 178,347 Other invested assets (4) ​ 35,526 ​ — ​ — ​ — ​ 35,526 Totals ​ $ 1,369,183 ​ $ (2,471) ​ $ 80,740 ​ $ (13,865) ​ $ 1,433,587 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost or Gross Unrealized Estimated ​ ​ Amortized ​ ​ ​ ​ ​ Fair ​ ​ Cost ​ Gains ​ Losses (3) ​ Value U.S. Treasury securities ​ $ 1,504 ​ $ 8 ​ $ — ​ $ 1,512 ​ Obligations of states and political subdivisions ​ 241,597 ​ 9,799 ​ — ​ 251,396 ​ Residential mortgage-backed securities (1) ​ 301,503 ​ 6,608 ​ (909) ​ 307,202 ​ Commercial mortgage-backed securities ​ 106,902 ​ 3,233 ​ (397) ​ 109,738 ​ Other asset-backed securities ​ 36,068 ​ 218 ​ (64) ​ 36,222 ​ Corporate and other securities ​ 504,783 ​ 18,455 ​ (1,268) ​ 521,970 ​ Subtotal, fixed maturity securities ​ 1,192,357 ​ 38,321 ​ (2,638) ​ 1,228,040 ​ Equity securities (2) ​ 151,121 ​ 27,879 ​ (1,363) ​ 177,637 ​ Other invested assets (4) ​ 37,278 ​ — ​ — ​ 37,278 ​ Totals ​ $ 1,380,756 ​ $ 66,200 ​ $ (4,001) ​ $ 1,442,955 ​ (1) Residential mortgage-backed securities consists primarily of obligations of U.S. Government agencies including collateralized mortgage obligations issued, guaranteed and/or insured by the following issuers: Government National Mortgage Association (GNMA), Federal Home Loan Mortgage Corporation (FHLMC), Federal National Mortgage Association (FNMA) and the Federal Home Loan Bank (FHLB). (2) Equity securities include common stock, preferred stock, mutual funds and interests in mutual funds held to fund the Company’s executive deferred compensation plan. (3) The Company’s investment portfolio included 527 and 229 securities in an unrealized loss position at June 30, 2020 and December 31, 2019, respectively. (4) Other invested assets are accounted for under the equity method which approximated fair value.
Amortized cost and the estimated fair value of fixed maturity securities, by maturity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2020 ​ Amortized Estimated ​ ​ Cost ​ Fair Value Due in one year or less ​ $ 67,468 ​ $ 68,303 Due after one year through five years ​ 300,404 ​ 308,520 Due after five years through ten years ​ 306,192 ​ 321,694 Due after ten years through twenty years ​ 87,050 ​ 90,948 Due after twenty years ​ 1,854 ​ 2,063 Asset-backed securities ​ 405,698 ​ 428,186 Totals ​ $ 1,168,666 ​ $ 1,219,714
Gross realized gains and losses on sales of investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2020 2019 2020 2019 Gross realized gains ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fixed maturity securities ​ $ 139 ​ $ 479 ​ $ 1,028 ​ $ 594 Equity securities ​ 1,295 ​ 688 ​ 2,871 ​ 1,641 Gross realized losses ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fixed maturity securities ​ (1,096) ​ (241) ​ (1,397) ​ (908) Equity securities ​ (1,059) ​ (443) ​ (3,854) ​ (1,008) Net realized (losses) gains on investments ​ $ (721) ​ $ 483 ​ $ (1,352) ​ $ 319 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Gross unrealized losses included in the Company's investment portfolio and the fair value of those securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2020 ​ ​ Less than 12 Months ​ 12 Months or More ​ Total ​ Estimated Unrealized Estimated Unrealized Estimated Unrealized ​ ​ Fair Value ​ Losses ​ Fair Value ​ Losses ​ Fair Value ​ Losses U.S. Treasury securities ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — Obligations of states and political subdivisions ​ 4,479 ​ 139 ​ — ​ — ​ 4,479 ​ 139 Residential mortgage-backed securities ​ 5,938 ​ 27 ​ 139 ​ 1 ​ 6,077 ​ 28 Commercial mortgage-backed securities ​ — ​ — ​ — ​ — ​ — ​ — Other asset-backed securities ​ 5,407 ​ ​ 330 ​ ​ 8,814 ​ ​ 269 ​ ​ 14,221 ​ ​ 599 Corporate and other securities ​ 127,854 ​ 6,360 ​ 8,901 ​ 882 ​ 136,755 ​ 7,242 Subtotal, fixed maturity securities ​ 143,678 ​ 6,856 ​ 17,854 ​ 1,152 ​ 161,532 ​ 8,008 Equity securities ​ 54,680 ​ 4,334 ​ 11,725 ​ 1,523 ​ 66,405 ​ 5,857 Total temporarily impaired securities ​ $ 198,358 ​ $ 11,190 ​ $ 29,579 ​ $ 2,675 ​ $ 227,937 ​ $ 13,865 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2019 ​ ​ Less than 12 Months ​ 12 Months or More ​ Total ​ Estimated Unrealized Estimated Unrealized Estimated Unrealized ​ ​ Fair Value ​ Losses ​ Fair Value ​ Losses ​ Fair Value ​ Losses U.S. Treasury securities ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — ​ $ — Obligations of states and political subdivisions ​ — ​ — ​ — ​ — ​ — ​ — Residential mortgage-backed securities ​ 61,933 ​ 409 ​ 31,655 ​ 500 ​ 93,588 ​ 909 Commercial mortgage-backed securities ​ 36,398 ​ 397 ​ 866 ​ — ​ 37,264 ​ 397 Other asset-backed securities ​ 21,281 ​ ​ 64 ​ ​ 462 ​ ​ — ​ 21,743 ​ 64 Corporate and other securities ​ 26,386 ​ 481 ​ 13,718 ​ 787 ​ 40,104 ​ 1,268 Subtotal, fixed maturity securities ​ 145,998 ​ 1,351 ​ 46,701 ​ 1,287 ​ 192,699 ​ 2,638 Equity securities ​ 8,849 ​ 391 ​ 14,143 ​ 972 ​ 22,992 ​ 1,363 Total temporarily impaired securities ​ $ 154,847 ​ $ 1,742 ​ $ 60,844 ​ $ 2,259 ​ $ 215,691 ​ $ 4,001
Reconciliation of beginning and ending balances of allowance for expected credit losses on fixed maturities classified as available for sale	​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2020 ​ ​ ​ ​ ​ ​ ​ Corporate and other ​ ​ ​ securities Balance April 1, 2020 ​ ​ $ 2,510 Credit losses on securities with no previously recorded credit losses ​ ​ — Net increases (decreases) in allowance on previously impaired securities ​ ​ (39) Reduction due to sales ​ ​ — Writeoffs charged against allowance ​ ​ — Recoveries of amounts previously written off ​ ​ — Balance June 30, 2020 ​ ​ $ 2,471 ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2020 ​ ​ ​ ​ ​ Corporate and other ​ ​ securities Balance January 1, 2020 ​ $ — Credit losses on securities with no previously recorded credit losses ​ 2,471 Net increases (decreases) in allowance on previously impaired securities ​ — Reduction due to sales ​ — Writeoffs charged against allowance ​ — Recoveries of amounts previously written off ​ — Balance June 30, 2020 ​ $ 2,471
Components of net investment income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2020 2019 2020 2019 Interest on fixed maturity securities ​ $ 9,667 ​ $ 9,717 ​ $ 19,426 ​ $ 20,844 Dividends on equity securities ​ 1,034 ​ 1,117 ​ 2,240 ​ 2,199 Equity in earnings of other invested assets ​ 9 ​ 478 ​ 525 ​ 760 Interest on other assets ​ 7 ​ 8 ​ 14 ​ 17 Total investment income ​ 10,717 ​ 11,320 ​ 22,205 ​ 23,820 Investment expenses ​ 801 ​ 746 ​ 1,579 ​ 1,495 Net investment income ​ $ 9,916 ​ $ 10,574 ​ $ 20,626 ​ $ 22,325
Fair Value Measurements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2020 ​ Total Level 1 Inputs Level 2 Inputs Level 3 Inputs U.S. Treasury securities ​ $ 1,881 ​ $ — ​ $ 1,881 ​ $ — Obligations of states and political subdivisions ​ 234,038 ​ — ​ 234,038 ​ — Residential mortgage-backed securities ​ 286,587 ​ — ​ 286,587 ​ — Commercial mortgage-backed securities ​ 114,151 ​ — ​ 114,151 ​ — Other asset-backed securities ​ 27,449 ​ — ​ 27,449 ​ — Corporate and other securities ​ 555,608 ​ — ​ 555,608 ​ — Equity securities ​ 145,911 ​ 144,213 ​ — ​ 1,698 Total investment securities ​ $ 1,365,625 ​ $ 144,213 ​ $ 1,219,714 ​ $ 1,698 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2019 ​ Total Level 1 Inputs Level 2 Inputs Level 3 Inputs U.S. Treasury securities ​ $ 1,512 ​ $ — ​ $ 1,512 ​ $ — Obligations of states and political subdivisions ​ 251,396 ​ — ​ 251,396 ​ — Residential mortgage-backed securities ​ 307,202 ​ — ​ 307,202 ​ — Commercial mortgage-backed securities ​ 109,738 ​ — ​ 109,738 ​ — Other asset-backed securities ​ 36,222 ​ — ​ 36,222 ​ — Corporate and other securities ​ 521,970 ​ — ​ 521,970 ​ — Equity securities ​ 144,877 ​ 144,361 ​ — ​ 516 Total investment securities ​ $ 1,372,917 ​ $ 144,361 ​ $ 1,228,040 ​ $ 516
Changes in Company's Level 3 Fair value securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2020 2019 2020 2019 ​ ​ Level 3 ​ Level 3 Level 3 ​ Level 3 ​ ​ Fair Value ​ Fair Value Fair Value ​ Fair Value ​ ​ Securities ​ Securities Securities ​ Securities Balance at beginning of period ​ $ 1,686 ​ $ 383 ​ $ 516 ​ $ 680 Net gains and losses included in earnings ​ — ​ — ​ — ​ — Net gains included in other comprehensive income ​ — ​ — ​ — ​ — Purchases ​ 12 ​ 103 ​ 1,182 ​ 103 Sales ​ ​ — ​ ​ — ​ ​ — ​ ​ (297) Transfers into Level 3 ​ ​ — ​ — ​ — ​ — Transfers out of Level 3 ​ — ​ — ​ — ​ — Balance at end of period ​ $ 1,698 ​ $ 486 ​ $ 1,698 ​ $ 486 Amount of total losses included in earnings attributable to the change in unrealized losses related to assets still held at end of period ​ $ — ​ $ — ​ $ — ​ $ —

Allowance for Expected Credit_2

Allowance for Expected Credit Losses (Tables)	6 Months Ended
	Jun. 30, 2020
Allowance for Expected Credit Losses
Accounts receivable, net of allowance for expected credit losses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ At and For the ​ ​ At and For the ​ ​ ​ Three Months Ended June 30, 2020 ​ ​ Six Months Ended June 30, 2020 ​ ​ Accounts Receivable Net of Allowance for Expected Credit Losses ​ ​ Allowance for Expected Credit Losses ​ ​ Accounts Receivable Net of Allowance for Expected Credit Losses ​ ​ Allowance for Expected Credit Losses Balance, beginning of period ​ $ 189,671 ​ $ 334 ​ $ 193,369 ​ $ 578 Current period change for expected credit losses ​ ​ ​ 626 ​ ​ ​ 2,202 Writeoffs of uncollectable accounts receivable ​ ​ ​ (46) ​ ​ ​ (1,866) Balance, end of period ​ $ 199,356 ​ $ 914 ​ $ 199,356 ​ $ 914

Loss and Loss Adjustment Expe_2

Loss and Loss Adjustment Expense Reserves (Tables)	6 Months Ended
	Jun. 30, 2020
Loss and Loss Adjustment Expense Reserves
Schedule of reconciliation of beginning and ending reserves for losses and loss adjustment expenses (LAE)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, ​ 2020 2019 Reserves for losses and LAE at beginning of year ​ $ 610,566 ​ $ 584,719 Less receivable from reinsurers related to unpaid losses and LAE ​ (122,372) ​ (108,398) Net reserves for losses and LAE at beginning of year ​ 488,194 ​ 476,321 Incurred losses and LAE, related to: ​ ​ ​ ​ ​ ​ Current year ​ 231,048 ​ 270,757 Prior years ​ (19,328) ​ (22,337) Total incurred losses and LAE ​ 211,720 ​ 248,420 Paid losses and LAE related to: ​ ​ ​ ​ ​ ​ Current year ​ 105,043 ​ 139,220 Prior years ​ 111,502 ​ 108,626 Total paid losses and LAE ​ 216,545 ​ 247,846 Net reserves for losses and LAE at end of period ​ 483,369 ​ 476,895 Plus receivable from reinsurers related to unpaid losses and LAE ​ 116,378 ​ 112,228 Reserves for losses and LAE at end of period ​ $ 599,747 ​ $ 589,123

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2020
Leases
Schedule of operating lease cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, ​ ​ 2020 ​ ​ 2019 ​ 2020 ​ 2019 Operating lease cost ​ $ 1,147 ​ $ 1,154 ​ $ 2,298 ​ 2,308
Schedule of other information related to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, ​ ​ 2020 ​ ​ 2019 ​ 2020 ​ ​ 2019 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases $ 1,263 ​ $ 1,256 ​ $ 2,545 ​ $ 2,512 Weighted average remaining lease term ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ ​ ​ ​ ​ ​ 8.01 Years ​ ​ 9.02 Years Weighted average discount rate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ ​ ​ ​ ​ ​ 2.37% ​ ​ 3.45%
Schedule of the maturities of lease liabilities	​ ​ ​ ​ 2020 $ 2,494 2021 4,845 2022 4,286 2023 3,880 2024 ​ 3,875 2025 and after 15,405 Total lease payments ​ 34,785 Less imputed interest ​ (1,693) Total $ 33,092

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Retained earnings	$ 674,349		$ 661,553
Fixed maturity securities, allowance for expected credit losses	$ 2,471	$ 2,510
Revision of Prior Period, Change in Accounting Principle, Adjustment | Accounting Standards Update 2016-02
Retained earnings				$ 35,984
Revision of Prior Period, Change in Accounting Principle, Adjustment | Accounting Standards Update 2017-08
Retained earnings				$ 2,373

Earnings per Weighted Average_3

Earnings per Weighted Average Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings per Weighted Average Common Share
Net income from continuing operations	$ 42,494	$ (1,990)	$ 25,934	$ 29,946	$ 40,504	$ 55,880
Allocation of income for participating shares	(195)		(134)		(190)	(300)
Net income from continuing operations attributed to common shareholders	$ 42,299		$ 25,800		$ 40,314	$ 55,580
Total weighted average common shares outstanding, including participating shares	15,189,442		15,299,691		15,247,100	15,262,937
Less: weighted average participating shares	(69,403)		(78,869)		(71,691)	(81,903)
Basic earnings per share denominator	15,120,039		15,220,822		15,175,409	15,181,034
Common equivalent shares- non-vested performance stock grants	117,256		125,412		116,777	145,087
Diluted earnings per share denominator	15,237,295		15,346,234		15,292,186	15,326,121
Basic earnings per share (in dollars per share)	$ 2.80		$ 1.70		$ 2.66	$ 3.66
Diluted earnings per share (in dollars per share)	2.78		1.68		2.64	3.63
Undistributed earnings attributable to common shareholders - basic and diluted:
Net income from continuing operations attributable to common shareholders -Basic	2.80		1.70		2.66	3.66
Dividends declared	(0.90)		(0.80)		(1.80)	(1.60)
Undistributed earnings	1.90		0.90		0.86	2.06
Undistributed earnings attributable to common shareholders - diluted
Net income from continuing operations attributable to common shareholders -Diluted	2.78		1.68		2.64	3.63
Dividends declared	(0.90)		(0.80)		(1.80)	(1.60)
Undistributed earnings	$ 1.88		$ 0.88		$ 0.84	$ 2.03
Antidilutive common shares	2,310		0		106	0

Share-Based Compensation (Detai

Share-Based Compensation (Details) - shares	Jun. 30, 2020	Apr. 02, 2018
Maximum number of shares of common stock with respect to which awards may be granted	2,850,000
Number of shares available for future grant	234,170
2018 Long Term Incentive Plan
Maximum number of shares of common stock with respect to which awards may be granted		350,000

Share-Based Compensation Restri

Share-Based Compensation Restricted Stock Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Weighted Average Fair Value
Unrecognized compensation expense related to non-vested restricted stock awards	$ 8,527
Weighted average period expected for recognition of compensation expense related to non-vested restricted stock awards	1 year 8 months 12 days
Total fair value of the shares that were vested and unrestricted during the period	$ 6,493	$ 7,784
Compensation Expense, Net of Tax	3,010	2,649
Income tax benefits from compensation expense	$ 800	$ 704
Performance-based Shares Under Restriction
Share-Based Compensation
Vesting period	3 years
Shares Under Restriction
Outstanding at beginning of year (in shares)	84,105
Granted (in shares)	36,649
Vested and unrestricted (in shares)	(42,123)
Forfeited (in shares)	(6,667)
Outstanding at end of period (in shares)	71,964
Weighted Average Fair Value
Outstanding at beginning of year (in dollars per share)	$ 79.34
Granted (in dollars per share)	84.68
Vested and unrestricted (in dollars per share)	73.55
Forfeited (in dollars per share)	84.86
Outstanding at end of period (in dollars per share)	$ 84.94
Performance-based Shares Under Restriction | Minimum
Share-Based Compensation
Actual Payouts (as a percent)	0.00%
Performance-based Shares Under Restriction | Maximum
Share-Based Compensation
Actual Payouts (as a percent)	200.00%
Restricted Stock
Shares Under Restriction
Outstanding at beginning of year (in shares)	78,202
Granted (in shares)	34,799
Vested and unrestricted (in shares)	(43,480)
Forfeited (in shares)	(2,694)
Outstanding at end of period (in shares)	66,827
Weighted Average Fair Value
Outstanding at beginning of year (in dollars per share)	$ 79.09
Granted (in dollars per share)	90.10
Vested and unrestricted (in dollars per share)	78.07
Forfeited (in dollars per share)	87.70
Outstanding at end of period (in dollars per share)	$ 85.14
Restricted Stock | Non-executive
Share-Based Compensation
Vesting period	5 years
Restricted Stock | Executives and non-executives (2018 and after)
Share-Based Compensation
Vesting period	3 years
Restricted Stock | First anniversary of grant date | Executives and non-executives (2018 and after)
Share-Based Compensation
Actual Payouts (as a percent)	30.00%
Restricted Stock | Second anniversary of grant date | Executives and non-executives (2018 and after)
Share-Based Compensation
Actual Payouts (as a percent)	30.00%
Restricted Stock | Third anniversary of grant date | Executives and non-executives (2018 and after)
Share-Based Compensation
Actual Payouts (as a percent)	40.00%

Investments (Details)

Investments (Details) $ in Thousands	Jun. 30, 2020USD ($)security	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)security
Marketable Securities
Fixed maturity securities, amortized cost	$ 1,168,666		$ 1,192,357
Fixed maturity securities, allowance for expected credit losses	(2,471)	$ (2,510)
Fixed maturity securities, Gross Unrealized Gains	61,527		38,321
Fixed maturity securities, Gross Unrealized Losses	(8,008)		(2,638)
Fixed maturity securities, Estimated Fair Value	1,219,714		1,228,040
Equity securities, Cost or Amortized Cost	164,991		151,121
Equity securities, Estimated Fair Value	178,347		177,637
Other invested assets, Cost or Amortized Cost	35,526		37,278
Cost or Amortized Cost	1,369,183		1,380,756
Gross Unrealized Gains	80,740		66,200
Gross Unrealized Losses	(13,865)		(4,001)
Estimated Fair Value	$ 1,433,587		$ 1,442,955
Number of securities in an unrealized loss position | security	527		229
U.S. Treasury securities
Marketable Securities
Fixed maturity securities, amortized cost	$ 1,822		$ 1,504
Fixed maturity securities, Gross Unrealized Gains	59		8
Fixed maturity securities, Estimated Fair Value	1,881		1,512
Obligations of states and political subdivisions
Marketable Securities
Fixed maturity securities, amortized cost	225,863		241,597
Fixed maturity securities, Gross Unrealized Gains	8,314		9,799
Fixed maturity securities, Gross Unrealized Losses	(139)
Fixed maturity securities, Estimated Fair Value	234,038		251,396
Residential mortgage-backed securities
Marketable Securities
Fixed maturity securities, amortized cost	272,484		301,503
Fixed maturity securities, Gross Unrealized Gains	14,131		6,608
Fixed maturity securities, Gross Unrealized Losses	(28)		(909)
Fixed maturity securities, Estimated Fair Value	286,587		307,202
Commercial mortgage-backed securities
Marketable Securities
Fixed maturity securities, amortized cost	105,542		106,902
Fixed maturity securities, Gross Unrealized Gains	8,609		3,233
Fixed maturity securities, Gross Unrealized Losses			(397)
Fixed maturity securities, Estimated Fair Value	114,151		109,738
Other asset-backed securities
Marketable Securities
Fixed maturity securities, amortized cost	27,673		36,068
Fixed maturity securities, Gross Unrealized Gains	375		218
Fixed maturity securities, Gross Unrealized Losses	(599)		(64)
Fixed maturity securities, Estimated Fair Value	27,449		36,222
Corporate and other securities
Marketable Securities
Fixed maturity securities, amortized cost	535,282		504,783
Fixed maturity securities, allowance for expected credit losses	(2,471)	$ (2,510)
Fixed maturity securities, Gross Unrealized Gains	30,039		18,455
Fixed maturity securities, Gross Unrealized Losses	(7,242)		(1,268)
Fixed maturity securities, Estimated Fair Value	555,608		521,970
Equity securities
Marketable Securities
Equity securities, Cost or Amortized Cost	164,991		151,121
Equity securities, Gross Unrealized Gains	19,213		27,879
Equity securities, Gross Unrealized Losses	(5,857)		(1,363)
Equity securities, Estimated Fair Value	178,347		177,637
Other invested assets
Marketable Securities
Other invested assets, Cost or Amortized Cost	35,526		37,278
Other invested assets, Estimated Fair Value	$ 35,526		$ 37,278

Investments Amortized Cost and

Investments Amortized Cost and Estimated Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized Cost
Due in one year or less, Amortized Cost	$ 67,468
Due after one year through five years, Amortized Cost	300,404
Due after five years though ten years, Amortized Cost	306,192
Due after ten years through twenty years, Amortized Cost	87,050
Due after twenty years, Amortized Cost	1,854
Asset-backed securities, Amortized Cost	405,698
Totals, Amortized Cost	1,168,666	$ 1,192,357
Estimated Fair Value
Due in one year or less, Fair Value	68,303
Due after one year through five years, Fair Value	308,520
Due after five years through ten years, Fair Value	321,694
Due after ten years through twenty years, Fair Value	90,948
Due after twenty years, Fair Value	2,063
Asset-backed securities, Fair Value	428,186
Totals, Fair Value	$ 1,219,714	$ 1,228,040

Investments Gross Realized Gain

Investments Gross Realized Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Marketable Securities [Line Items]
Net realized (losses) gains on investments	$ (721)	$ 483	$ (1,352)	$ 319
Fixed maturity securities
Marketable Securities [Line Items]
Gross realized gains fixed maturity securities	139	479	1,028	594
Gross realized losses fixed maturities	(1,096)	(241)	(1,397)	(908)
Equity securities
Marketable Securities [Line Items]
Gross realized gains equity securities	1,295	688	2,871	1,641
Gross realized losses equity securities	$ (1,059)	$ (443)	$ (3,854)	$ (1,008)

Investments Gross Unrealized Lo

Investments Gross Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Marketable Securities
Estimated Fair Value, Less than 12 Months	$ 198,358	$ 154,847
Estimated Fair Value, 12 Months or More	29,579	60,844
Estimated Fair Value, Total	227,937	215,691
Unrealized Losses, Less than 12 Months	11,190	1,742
Unrealized Losses, 12 Months or More	2,675	2,259
Unrealized Losses, Total	13,865	4,001
Fixed maturity securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	143,678	145,998
Estimated Fair Value, 12 Months or More	17,854	46,701
Estimated Fair Value, Total	161,532	192,699
Unrealized Losses, Less than 12 Months	6,856	1,351
Unrealized Losses, 12 Months or More	1,152	1,287
Unrealized Losses, Total	8,008	2,638
Obligations of states and political subdivisions
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	4,479
Estimated Fair Value, Total	4,479
Unrealized Losses, Less than 12 Months	139
Unrealized Losses, Total	139
Residential mortgage-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	5,938	61,933
Estimated Fair Value, 12 Months or More	139	31,655
Estimated Fair Value, Total	6,077	93,588
Unrealized Losses, Less than 12 Months	27	409
Unrealized Losses, 12 Months or More	1	500
Unrealized Losses, Total	28	909
Commercial mortgage-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months		36,398
Estimated Fair Value, 12 Months or More		866
Estimated Fair Value, Total		37,264
Unrealized Losses, Less than 12 Months		397
Unrealized Losses, Total		397
Other asset-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	5,407	21,281
Estimated Fair Value, 12 Months or More	8,814	462
Estimated Fair Value, Total	14,221	21,743
Unrealized Losses, Less than 12 Months	330	64
Unrealized Losses, 12 Months or More	269
Unrealized Losses, Total	599	64
Corporate and other securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	127,854	26,386
Estimated Fair Value, 12 Months or More	8,901	13,718
Estimated Fair Value, Total	136,755	40,104
Unrealized Losses, Less than 12 Months	6,360	481
Unrealized Losses, 12 Months or More	882	787
Unrealized Losses, Total	7,242	1,268
Equity securities
Equity Securities
Estimated Fair Value, Less than 12 Months	54,680	8,849
Estimated Fair Value, 12 Months or More	11,725	14,143
Estimated Fair Value, Total	66,405	22,992
Unrealized Losses, Less than 12 Months	4,334	391
Unrealized Losses, 12 Months or More	1,523	972
Unrealized Losses, Total	$ 5,857	$ 1,363

Investments Other (Details)

Investments Other (Details) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2019USD ($)item	Jun. 30, 2020USD ($)item	Jun. 30, 2019USD ($)item	Dec. 31, 2019USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings
Other-than-temporary impairments recognized under ASC 320	$ 54		$ 274
Available-for-sale investments		$ 1,219,714		$ 1,228,040
Short-term Investments		$ 0		$ 0
Level 3 Securities Held Number | item	1	1	1
Subprime mortgage debt securities
Other-Than-Temporary Impairments
Securities held		$ 0

Investments Allowance for Expec

Investments Allowance for Expected Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Marketable Securities
Balance	$ 2,510
Credit losses on securities with no previously recorded credit losses	(39)	$ 2,471
Net increases (decreases) in allowance on previously impaired securities	(39)
Balance	2,471	2,471
Corporate and other securities
Marketable Securities
Balance	2,510
Credit losses on securities with no previously recorded credit losses		2,471
Net increases (decreases) in allowance on previously impaired securities	(39)
Balance	$ 2,471	$ 2,471

Investments Components of Net I

Investments Components of Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Components of net investment income
Interest on fixed maturity securities	$ 9,667	$ 9,717	$ 19,426	$ 20,844
Dividends on equity securities	1,034	1,117	2,240	2,199
Equity in earnings of other invested assets	9	478	525	760
Interest on other assets	7	8	14	17
Total investment income	10,717	11,320	22,205	23,820
Investment expenses	801	746	1,579	1,495
Net investment income	$ 9,916	$ 10,574	$ 20,626	$ 22,325

Investments Fair Value Measurem

Investments Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	$ 1,219,714	$ 1,228,040
Equity securities, Estimated Fair Value	178,347	177,637
Level 1 Inputs
Fair value of financial instruments
Marketable Securities, Total	144,213	144,361
Level 1 Inputs | Equity securities
Fair value of financial instruments
Equity securities, Estimated Fair Value	144,213	144,361
Level 2 Inputs
Fair value of financial instruments
Marketable Securities, Total	1,219,714	1,228,040
Level 2 Inputs | U.S. Treasury securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	1,881	1,512
Level 2 Inputs | Obligations of states and political subdivisions
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	234,038	251,396
Level 2 Inputs | Residential mortgage-backed securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	286,587	307,202
Level 2 Inputs | Commercial mortgage-backed securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	114,151	109,738
Level 2 Inputs | Other asset-backed securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	27,449	36,222
Level 2 Inputs | Corporate and other securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	555,608	521,970
Level 3 Inputs
Fair value of financial instruments
Marketable Securities, Total	1,698	516
Level 3 Inputs | Equity securities
Fair value of financial instruments
Equity securities, Estimated Fair Value	1,698	516
Total
Fair value of financial instruments
Marketable Securities, Total	1,365,625	1,372,917
Total | U.S. Treasury securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	1,881	1,512
Total | Obligations of states and political subdivisions
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	234,038	251,396
Total | Residential mortgage-backed securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	286,587	307,202
Total | Commercial mortgage-backed securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	114,151	109,738
Total | Other asset-backed securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	27,449	36,222
Total | Corporate and other securities
Fair value of financial instruments
Fixed maturity securities, Estimated Fair Value	555,608	521,970
Total | Equity securities
Fair value of financial instruments
Equity securities, Estimated Fair Value	$ 145,911	$ 144,877

Investments Level 3 and Other (

Investments Level 3 and Other (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Transfers between Levels
Transfers from Level 1 to Level 2	$ 0	$ 0	$ 0	$ 0
Transfers from Level 2 to Level 1	0	0	0	0
Changes in the Company's Level 3 fair value securities
Balance at beginning of period	1,686	383	516	680
Purchases	12	103	1,182	103
Sales				(297)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance at end of period	1,698	$ 486	1,698	$ 486
Alternative investments fair value	$ 32,436		$ 32,436		$ 32,760
Period of advance notice before quarter end			45 days

Allowance for Expected Credit_3

Allowance for Expected Credit Losses Balances of Premiums Receivable (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Balance, beginning of period	$ 189,671	$ 193,369
Balance, end of period	199,356	199,356
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	334	578
Current period change for expected credit losses	626	2,202
Writeoffs of uncollectable accounts receivable	(46)	(1,866)
Balance, end of period	$ 914	$ 914

Allowance for Expected Credit_4

Allowance for Expected Credit Losses (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020USD ($)
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expected credit losses	$ 0
CAR Commercial Automobile Program and the Taxi/Limo Program
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage of reinsurance recoverable	98.00%
Other Contracts
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Percentage of reinsurance recoverable	2.00%

Loss and Loss Adjustment Expe_3

Loss and Loss Adjustment Expense Reserves (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Loss and Loss Adjustment Expense Reserves
Reserves for losses and LAE at beginning of year	$ 610,566	$ 584,719
Less receivable from reinsurers related to unpaid losses and LAE	(122,372)	(108,398)
Net reserves for losses and LAE at beginning of year	488,194	476,321
Incurred losses and LAE, related to:
Current year	231,048	270,757
Prior years	(19,328)	(22,337)
Total incurred losses and LAE	211,720	248,420
Paid losses and LAE related to:
Current year	105,043	139,220
Prior years	111,502	108,626
Total paid losses and LAE	216,545	247,846
Net reserves for losses and LAE at end of period	483,369	476,895
Plus receivable from reinsurers related to unpaid losses and LAE	116,378	112,228	$ 122,372
Reserves for losses and LAE at end of period	599,747	589,123
Prior years	$ 19,328	$ 22,337

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 17, 2020	Dec. 31, 2019
Debt
Outstanding amount	$ 30,000		$ 30,000			$ 0
Advance term			5 years
Interest Expense, Borrowings	$ 107	$ 0	$ 125	$ 0
Interest-bearing FHLB
Debt
Interest rate percentage	1.42%		1.42%
Revolving Credit Agreement | LIBOR rate
Debt
Variable interest rate basis			LIBOR
Spread on variable rate (as a percent)			1.25%
Revolving Credit Agreement | Prime rate
Debt
Variable interest rate basis			prime rate
Revolving Credit Agreement | Federal Funds Effective Swap Rate
Debt
Variable interest rate basis			federal funds rate
Spread on variable rate (as a percent)			1.25%
Additional spread on variable rate (as a percent)	0.50%		0.50%
RBS Citizens | Revolving Credit Agreement
Debt
Current borrowing capacity	$ 30,000	$ 30,000	$ 30,000	$ 30,000
Maximum borrowing capacity	50,000		50,000
Default trigger, principal amount	10,000		10,000
Outstanding amount	0		$ 0			$ 0
Commitment fee (as a percent)			0.25%	0.25%
F H L B Boston
Debt
Outstanding amount					$ 30,000
Maximum borrowing capacity using eligible invested assets as collateral	$ 270,211		$ 270,211

Share Repurchase Program (Detai

Share Repurchase Program (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Aug. 03, 2007
Share Repurchase Program
Share Repurchase Program	$ 150,000		$ 150,000			$ 30,000
Number of common shares purchased during period under the program	158,552		301,844
Acquisition of treasury stock	$ 11,753	$ 10,392	$ 22,145	$ 0
Treasury stock shares	2,581,414		2,581,414		2,279,570
Treasury stock, at cost	$ 105,980		$ 105,980		$ 83,835

Leases - Remaining Lease Term (

Leases - Remaining Lease Term (Details)	6 Months Ended
	Jun. 30, 2020
Leases
Lease, Practical Expedients, Package	true
Lease, Practical Expedient, Use of Hindsight	false
Operating lease, existence of option to extend	true
Minimum
Leases
Operating lease, remaining lease term	1 year
Maximum
Leases
Operating lease, remaining lease term	10 years
Operating lease, renewal term	5 years

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases
Operating lease cost	$ 1,147	$ 1,154	$ 2,298	$ 2,308
Operating cash flows from operating leases	$ 1,263	$ 1,256	$ 2,545	$ 2,512
Weighted average remaining lease term Operating leases	8 years 3 days	9 years 7 days	8 years 3 days	9 years 7 days
Weighted average discount rate Operating leases	2.37%	3.45%	2.37%	3.45%

Leases (Maturities) (Details)

Leases (Maturities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Leases
2020	$ 2,494
2021	4,845
2022	4,286
2023	3,880
2024	3,875
2025 and after	15,405
Total lease payments	34,785
Less imputed interest	(1,693)
Total	$ 33,092	$ 33,998