AMERISAFE (AMSF) 10-Q 28 Jul 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 25, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	AMSF
Entity Registrant Name	AMERISAFE INC
Entity Central Index Key	1,018,979
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		19,244,023

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investments:
Fixed maturity securities—held-to-maturity, at amortized cost (fair value $610,551 and $568,931 in 2017 and 2016, respectively)	$ 599,096	$ 562,434
Fixed maturity securities—available-for-sale, at fair value (cost $459,116 and $479,871 in 2017 and 2016, respectively)	462,793	479,097
Equity securities—available-for-sale, at fair value (cost $5,006 and $0 in 2017 and 2016, respectively)	5,068	33
Short-term investments	46,635	29,580
Other investments	7,038	13,330
Total investments	1,120,630	1,084,474
Cash and cash equivalents	53,967	58,936
Amounts recoverable from reinsurers	84,147	83,666
Premiums receivable, net of allowance	190,646	183,005
Deferred income taxes	31,943	33,811
Accrued interest receivable	11,207	11,360
Property and equipment, net	6,345	6,636
Deferred policy acquisition costs	20,882	19,300
Federal income tax recoverable	177
Other assets	39,543	37,668
Total assets	1,559,487	1,518,856
Liabilities:
Reserves for loss and loss adjustment expenses	749,759	742,776
Unearned premiums	165,895	162,028
Reinsurance premiums payable		28
Amounts held for others	34,668	31,974
Policyholder deposits	48,318	49,130
Insurance-related assessments	31,801	31,742
Federal income tax payable		4,017
Accounts payable and other liabilities	36,099	31,510
Payable for investments purchased	11,555	9,501
Total liabilities	1,078,095	1,062,706
Shareholders’ equity:
Common stock: voting—$0.01 par value authorized shares—50,000,000 in 2017 and 2016; 20,502,273 and 20,488,385 shares issued and 19,244,023 and 19,230,135 shares outstanding in 2017 and 2016, respectively	204	204
Additional paid-in capital	209,414	208,390
Treasury stock at cost (1,258,250 shares in 2017 and 2016)	(22,370)	(22,370)
Accumulated earnings	291,728	270,418
Accumulated other comprehensive income (loss), net	2,416	(492)
Total shareholders’ equity	481,392	456,150
Total liabilities and shareholders’ equity	$ 1,559,487	$ 1,518,856

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Fixed maturity securities, fair value	$ 610,551	$ 568,931
Fixed maturity securities, cost	459,116	479,871
Equity securities, cost	$ 5,006	$ 0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	20,502,273	20,488,385
Common stock, shares outstanding	19,244,023	19,230,135
Treasury stock, shares	1,258,250	1,258,250

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues
Gross premiums written	$ 87,039	$ 103,224	$ 182,117	$ 203,606
Ceded premiums written	(2,198)	(2,550)	(4,589)	(5,101)
Net premiums written	84,841	100,674	177,528	198,505
Net premiums earned	82,749	90,728	173,661	186,689
Net investment income	7,471	6,201	14,181	12,245
Net realized gains (losses) on investments	(388)	545	(569)	793
Fee and other income	93	89	194	171
Total revenues	89,925	97,563	187,467	199,898
Expenses
Loss and loss adjustment expenses incurred	46,428	49,171	102,644	95,887
Underwriting and certain other operating costs	7,645	9,749	16,145	17,221
Commissions	5,984	6,491	12,394	13,369
Salaries and benefits	6,554	6,321	12,866	12,105
Policyholder dividends	1,163	1,216	2,534	2,306
Total expenses	67,774	72,948	146,583	140,888
Income before income taxes	22,151	24,615	40,884	59,010
Income tax expense	6,670	7,976	11,879	18,114
Net income	15,481	16,639	29,005	40,896
Net income available to common shareholders	$ 15,481	$ 16,639	$ 29,005	$ 40,896
Earnings per share
Basic	$ 0.81	$ 0.87	$ 1.51	$ 2.14
Diluted	$ 0.81	$ 0.87	$ 1.51	$ 2.13
Shares used in computing earnings per share
Basic	19,162,049	19,096,718	19,156,250	19,077,328
Diluted	19,227,960	19,184,984	19,227,997	19,178,893
Cash dividends declared per common share	$ 0.20	$ 0.18	$ 0.40	$ 0.36

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 15,481	$ 16,639	$ 29,005	$ 40,896
Other comprehensive income:
Unrealized gain on securities, net of tax	1,956	2,929	2,908	5,722
Comprehensive income	$ 17,437	$ 19,568	$ 31,913	$ 46,618

Condensed Consolidated Stateme6

Condensed Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2015						$ 2,587
Comprehensive income	$ 46,618
Ending Balance at Jun. 30, 2016						8,309
Beginning Balance at Mar. 31, 2016						5,380
Comprehensive income	19,568
Ending Balance at Jun. 30, 2016						8,309
Beginning Balance at Dec. 31, 2016	$ 456,150	$ 204	$ 208,390	$ (22,370)	$ 270,418	(492)
Beginning Balance, Shares at Dec. 31, 2016	20,488,385	20,488,385
Treasury Stock Beginning Balance, Shares at Dec. 31, 2016	(1,258,250)			(1,258,250)
Comprehensive income	$ 31,913				29,005	2,908
Restricted common stock issued	396		396
Restricted common stock issued, Shares		13,888
Share-based compensation	628		628
Dividends to shareholders	(7,695)				(7,695)
Ending Balance at Jun. 30, 2017	$ 481,392	$ 204	209,414	$ (22,370)	291,728	2,416
Ending Balance, Shares at Jun. 30, 2017	20,502,273	20,502,273
Treasury Stock Ending Balance, Shares at Jun. 30, 2017	(1,258,250)			(1,258,250)
Beginning Balance at Mar. 31, 2017						460
Comprehensive income	$ 17,437
Ending Balance at Jun. 30, 2017	$ 481,392	$ 204	$ 209,414	$ (22,370)	$ 291,728	$ 2,416
Ending Balance, Shares at Jun. 30, 2017	20,502,273	20,502,273
Treasury Stock Ending Balance, Shares at Jun. 30, 2017	(1,258,250)			(1,258,250)

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities
Net income	$ 29,005	$ 40,896
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	529	594
Net amortization of investments	7,394	8,163
Deferred income taxes	302	291
Net realized (gains) losses on investments	569	(793)
Net realized losses on disposal of assets	2	1
Share-based compensation	937	744
Changes in operating assets and liabilities:
Premiums receivable, net	(7,641)	(22,871)
Accrued interest receivable	153	37
Deferred policy acquisition costs	(1,582)	(263)
Amounts held by others		1,016
Other assets	(1,900)	(756)
Reserves for loss and loss adjustment expenses	6,983	7,516
Unearned premiums	3,867	11,817
Reinsurance balances	(509)	(3,270)
Amounts held for others and policyholder deposits	1,882	4,700
Accounts payable and other liabilities	807	8,539
Net cash provided by operating activities	40,798	56,361
Investing activities
Purchases of investments held-to-maturity	(96,697)	(76,920)
Purchases of investments available-for-sale	(50,193)	(132,699)
Purchases of short-term investments	(30,800)	(12,132)
Proceeds from maturities of investments held-to-maturity	66,276	103,565
Proceeds from sales and maturities of investments available-for-sale	54,062	66,755
Proceeds from sales and maturities of short-term investments	13,610	2,507
Proceeds from redemption of other invested assets	6,000
Purchases of property and equipment	(240)	(850)
Net cash used in investing activities	(37,982)	(49,774)
Financing activities
Proceeds from stock option exercises		501
Tax benefit from share-based payments		546
Dividends to shareholders	(7,785)	(6,960)
Net cash used in financing activities	(7,785)	(5,913)
Change in cash and cash equivalents	(4,969)	674
Cash and cash equivalents at beginning of period	58,936	69,481
Cash and cash equivalents at end of period	$ 53,967	$ 70,155

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	Note 1. Basis of Presentation AMERISAFE, Inc. (the “Company”) is an insurance holding company incorporated in the state of Texas. The accompanying unaudited condensed consolidated financial statements include the accounts of AMERISAFE and its subsidiaries: American Interstate Insurance Company (“AIIC”) and its insurance subsidiaries, Silver Oak Casualty, Inc. (“SOCI”) and American Interstate Insurance Company of Texas (“AIICTX”), Amerisafe Risk Services, Inc. (“RISK”) and Amerisafe General Agency, Inc. (“AGAI”). AIIC and SOCI are property and casualty insurance companies organized under the laws of the state of Nebraska. AIICTX is a property and casualty insurance company organized under the laws of the state of Texas. RISK, a wholly owned subsidiary of the Company, is a claims and safety service company currently servicing only affiliated insurance companies. AGAI, a wholly owned subsidiary of the Company, is a general agent for the Company. AGAI sells insurance, which is underwritten by AIIC, SOCI and AIICTX, as well as by nonaffiliated insurance carriers. The assets and operations of AGAI are not significant to that of the Company and its consolidated subsidiaries. The terms “AMERISAFE,” the “Company,” “we,” “us” or “our” refer to AMERISAFE, Inc. and its consolidated subsidiaries, as the context requires. The Company provides workers’ compensation insurance for small to mid-sized employers engaged in hazardous industries, principally construction, trucking, logging and lumber, manufacturing, and agriculture. Assets and revenues of AIIC represent at least 95% of comparable consolidated amounts of the Company for each of 2017 and 2016. In the opinion of management of the Company, the accompanying unaudited condensed consolidated financial statements contain all adjustments (consisting of normal recurring accruals) necessary to present fairly the financial position, the results of operations and cash flows for the periods presented. The unaudited condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q under the Securities Exchange Act of 1934 and therefore do not include all information and footnotes to be in conformity with accounting principles generally accepted in the United States (“GAAP”). The results for the interim periods are not necessarily indicative of the results of operations that may be expected for the year. The unaudited condensed consolidated financial statements contained herein should be read in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2016. The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Adopted Accounting Guidance In March 2016, the FASB issued ASU 2016-09, Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The new guidance requires that all tax effects related to share-based payments be made through the income statement at the time of settlement as opposed to recognizing excess tax benefits in additional paid-in capital. It also requires the cash flows resulting from share-based payments to be included as an operating activity. In addition to the changes, the guidance permits reporting entities to elect to estimate forfeitures related to share-based payments or recognize them as they occur. The threshold to qualify for equity classification has also been revised to permit withholding up to the maximum statutory tax rates in the applicable jurisdictions. The adoption of this new guidance in the first quarter of 2017 did not have a material impact on our financial condition and results of operations. Prospective Accounting Guidance In May 2014, the FASB Issued ASU 2014-09 (Topic 606): Revenue from Contract s s In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. This guidance requires fair value measurement for equity investments (not including those that result in consolidation of the investee or use the equity method of accounting) and the recognition of changes in fair value to be presented as a component of net income. The guidance also revises the disclosure requirements related to fair value changes of liabilities presented in comprehensive income, eliminates disclosure related to the methods and assumptions underlying fair value for financial instruments measured at amortized cost, and simplifies impairment assessments for equity investments without readily determinable fair values. This standard is effective for us in the first quarter of 2018. Based on the equity investments currently held by the Company, there would not be a material impact on the Company's financial condition and results of operations if the new guidance were to be adopted in the current accounting period. The impact on the Company's results of operations and financial position at the date of adoption of the updated guidance will be determined by the equity investments held by the Company and the economic conditions at that time. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). Under current guidance for lessees, leases are only included on the balance sheet if certain criteria, classifying the contract as a capital lease, are met. The new guidance requires a lessee to recognize a lease liability and a right of use asset for all leases extending beyond twelve months. The new guidance is effective for us in the first quarter of 2019. Upon adoption, leases will be recognized and measured at the beginning of the earliest period presented using a modified retrospective approach. Adoption of the guidance is not expected to have a material effect on the Company’s consolidated financial statements as the Company does not have any significant leases. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses. The new guidance replaces the methodology of credit loss impairment which currently delays the recognition of credit losses until a probable loss has been incurred. The new guidance requires credit losses for securities measured at amortized cost to be determined using current expected credit loss estimates. These estimates are to be derived from historical, current and reasonable supporting forecasts, including prepayments and estimates, and will be recorded through a valuation allowance account that will run through the income statement. The same method will be used for available-for-sale securities, but the valuation allowance will be limited to the amount by which the fair value is below amortized cost. The standard is effective for us in the first quarter of 2020. The Company will continue to monitor the impact as the implementation date approaches. All other issued but not yet effective accounting and reporting standards as of June 30, 2017 are either not applicable to the Company or are not expected to have a material impact on the Company.

Stock Options and Restricted St

Stock Options and Restricted Stock	6 Months Ended
	Jun. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options and Restricted Stock	Note 2. Stock Options and Restricted Stock As of June 30, 2017, the Company has three equity incentive plans: the AMERISAFE 2005 Equity Incentive Plan (the “2005 Incentive Plan”), the AMERISAFE Non-Employee Director Restricted Stock Plan (the “Restricted Stock Plan”) and the AMERISAFE 2012 Equity and Incentive Compensation Plan (the “2012 Incentive Plan”). In connection with the approval of the 2012 Incentive Plan by the Company’s shareholders, no further grants will be made under the 2005 Incentive Plan. All grants made under the 2005 Incentive plan continue in effect, subject to the terms and conditions of the 2005 Incentive Plan. See Note 12 to our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2016 for additional information regarding the Company’s incentive plans. During the six months ended June 30, 2017, the Company granted 7,434 and 6,454 shares of restricted common stock to executive officers and non-employee directors, respectively. The market value of the restricted shares granted totaled $0.7 million. During the six months ended June 30, 2016, the Company granted 27,077 and 5,952 shares of restricted common stock to executive officers and non-employee directors, respectively. The market value of the restricted shares granted totaled $1.9 million. During the six months ended June 30, 2017, no options to purchase shares of common stock were exercised. During the six months ended June 30, 2016, options to purchase 38,879 shares of common stock were exercised. In connection with these exercises, the Company received $0.5 million of stock option proceeds. The Company recognized share-based compensation expense of $0.5 million in the quarters ended June 30, 2017 and 2016. The Company recognized share-based compensation expense of $0.9 million in the six months ended June 30, 2017 and $0.7 million for the same period of 2016.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Note 3. Earnings Per Share The Company computes earnings per share (“EPS”) in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 260, Earnings Per Share Basic EPS is calculated by dividing income available to common shareholders by the weighted-average number of common shares outstanding during the period. The diluted EPS calculation includes potential common shares assumed issued under the treasury stock method, which reflects the potential dilution that would occur if any outstanding options or warrants were exercised or restricted stock becomes vested, and includes the “if converted” method for participating securities if the effect is dilutive. Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (in thousands, except share and per share amounts) Basic EPS Net income available to common shareholders - basic $ 15,481 $ 16,639 $ 29,005 $ 40,896 Basic weighted average common shares 19,162,049 19,096,718 19,156,250 19,077,328 Basic earnings per common share $ 0.81 $ 0.87 $ 1.51 $ 2.14 Diluted EPS Net income available to common shareholders - diluted $ 15,481 $ 16,639 $ 29,005 $ 40,896 Diluted weighted average common shares: Weighted average common shares 19,162,049 19,096,718 19,156,250 19,077,328 Stock options and restricted stock 65,911 88,266 71,747 101,565 Diluted weighted average common shares 19,227,960 19,184,984 19,227,997 19,178,893 Diluted earnings per common share $ 0.81 $ 0.87 $ 1.51 $ 2.13

Investments

Investments	6 Months Ended
	Jun. 30, 2017
Investments Debt And Equity Securities [Abstract]
Investments	Note 4. Investments The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at June 30, 2017 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) States and political subdivisions $ 430,921 $ 10,435 $ (777 ) $ 440,579 Corporate bonds 129,143 438 (176 ) 129,405 U.S. agency-based mortgage-backed securities 9,171 797 (2 ) 9,966 U.S. Treasury securities and obligations of U.S. government agencies 28,113 689 (72 ) 28,730 Asset-backed securities 1,748 139 (16 ) 1,871 Totals $ 599,096 $ 12,498 $ (1,043 ) $ 610,551 The gross unrealized gains and losses on, and the cost or amortized cost and fair value of, those investments classified as available-for-sale at June 30, 2017 are summarized as follows: Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Fixed maturity: States and political subdivisions $ 228,863 $ 6,131 $ (1,456 ) $ 233,538 Corporate bonds 156,842 633 (197 ) 157,278 U.S. agency-based mortgage-backed securities 11,895 8 (913 ) 10,990 U.S. Treasury securities and obligations of U.S. government agencies 61,516 78 (607 ) 60,987 Total fixed maturity 459,116 6,850 (3,173 ) 462,793 Equity securities 5,006 62 — 5,068 Other investments 4,000 3,038 — 7,038 Totals $ 468,122 $ 9,950 $ (3,173 ) $ 474,899 The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at December 31, 2016 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) States and political subdivisions $ 394,875 $ 7,622 $ (3,014 ) $ 399,483 Corporate bonds 143,858 423 (265 ) 144,016 Commercial mortgage-backed securities 70 — — 70 U.S. agency-based mortgage-backed securities 9,967 948 — 10,915 U.S. Treasury securities and obligations of U.S. government agencies 11,737 746 (67 ) 12,416 Asset-backed securities 1,927 163 (59 ) 2,031 Totals $ 562,434 $ 9,902 $ (3,405 ) $ 568,931 The gross unrealized gains and losses on, and the cost or amortized cost and fair value of, those investments classified as available-for-sale at December 31, 2016 are summarized as follows: Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Fixed maturity: States and political subdivisions $ 231,168 $ 4,340 $ (3,215 ) $ 232,293 Corporate bonds 182,350 436 (271 ) 182,515 U.S. agency-based mortgage-backed securities 10,428 17 (1,103 ) 9,342 U.S. Treasury securities and obligations of U.S. government agencies 55,925 — (978 ) 54,947 Total fixed maturity 479,871 4,793 (5,567 ) 479,097 Equity securities — 33 — 33 Other investments 10,000 3,330 — 13,330 Totals $ 489,871 $ 8,156 $ (5,567 ) $ 492,460 A summary of the amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity at June 30, 2017, by contractual maturity, is as follows: Amortized Cost Fair Value (in thousands) Maturity: Within one year $ 120,697 $ 121,160 After one year through five years 235,710 240,121 After five years through ten years 112,733 115,665 After ten years 119,037 121,768 U.S. agency-based mortgage-backed securities 9,171 9,966 Asset-backed securities 1,748 1,871 Totals $ 599,096 $ 610,551 A summary of the amortized cost and fair value of investments in fixed maturity securities, classified as available-for-sale at June 30, 2017, by contractual maturity, is as follows: Amortized Cost Fair Value (in thousands) Maturity: Within one year $ 92,665 $ 92,899 After one year through five years 164,477 165,259 After five years through ten years 35,020 35,254 After ten years 155,059 158,391 U.S. agency-based mortgage-backed securities 11,895 10,990 Totals $ 459,116 $ 462,793 The following table summarizes the fair value and gross unrealized losses on securities, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position: Less Than 12 Months 12 Months or Greater Total Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses (in thousands) June 30, 2017 Held-to-Maturity Fixed maturity securities: States and political subdivisions $ 79,641 $ 622 $ 3,296 $ 155 $ 82,937 $ 777 Corporate bonds 46,659 142 6,242 34 52,901 176 U.S. agency-based mortgage-backed securities 658 2 — — 658 2 U.S. Treasury securities and obligations of U.S. government agencies 22,680 72 — — 22,680 72 Asset-backed securities — — 1,099 16 1,099 16 Total held-to-maturity securities 149,638 838 10,637 205 160,275 1,043 Available-for Sale Fixed maturity securities: States and political subdivisions $ 33,677 $ 1,036 $ 8,798 $ 420 $ 42,475 $ 1,456 Corporate bonds 22,167 79 7,919 118 30,086 197 U.S. agency-based mortgage-backed securities 5,510 46 3,590 867 9,100 913 U.S. Treasury securities and obligations of U.S. government agencies 55,223 607 — — 55,223 607 Total available-for-sale securities 116,577 1,768 20,307 1,405 136,884 3,173 Total $ 266,215 $ 2,606 $ 30,944 $ 1,610 $ 297,159 $ 4,216 Less Than 12 Months 12 Months or Greater Total Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses (in thousands) December 31, 2016 Held-to-Maturity Fixed maturity securities: States and political subdivisions $ 157,507 $ 3,014 $ — $ — $ 157,507 $ 3,014 Corporate bonds 44,654 202 6,292 63 50,946 265 U.S. Treasury securities and obligations of U.S. government agencies 3,968 67 — — 3,968 67 Asset-backed securities — — 1,173 59 1,173 59 Total held-to-maturity securities 206,129 3,283 7,465 122 213,594 3,405 Available-for Sale Fixed maturity securities: States and political subdivisions $ 73,505 $ 2,976 $ 4,523 $ 239 $ 78,028 $ 3,215 Corporate bonds 41,419 111 7,922 160 49,341 271 U.S. agency-based mortgage-backed securities 3,702 48 3,607 1,055 7,309 1,103 U.S. Treasury securities and obligations of U.S. government agencies 54,947 978 — — 54,947 978 Total available-for-sale securities 173,573 4,113 16,052 1,454 189,625 5,567 Total $ 379,702 $ 7,396 $ 23,517 $ 1,576 $ 403,219 $ 8,972 At June 30, 2017, the Company held 187 individual fixed maturity securities that were in an unrealized loss position, of which 21 individual fixed maturity securities were in a continuous unrealized loss position for longer than 12 months. The Company holds investments in a limited partnership hedge fund accounted for under the equity method. The carrying value of this investment is $7.0 million at June 30, 2017. Investment income is recognized as it is earned. The discount or premium on fixed maturity securities is amortized using the “constant yield” method. Anticipated prepayments, where applicable, are considered when determining the amortization of premiums or discounts. Realized investment gains and losses are determined using the specific identification method. We regularly review our investment portfolio to evaluate the necessity of recording impairment losses for other-than-temporary declines in the fair value of specific investments. We consider various factors in determining if a decline in the fair value of an individual security is other-than-temporary. The key factors we consider are: • any reduction or elimination of preferred dividends, or nonpayment of scheduled principal or interest payments; • the financial condition and near-term prospects of the issuer of the applicable security, including any specific events that may affect its operations or earnings; • how long and by how much the fair value of the security has been below its cost or amortized cost; • any downgrades of the security by a rating agency; • our intent not to sell the security for a sufficient time period for it to recover its value; • the likelihood of being forced to sell the security before the recovery of its value; and • an evaluation as to whether there are any credit losses on debt securities. We reviewed all securities with unrealized losses in accordance with the impairment policy described above. The Company determined that the unrealized losses in the fixed maturity securities portfolio related primarily to changes in market interest rates since the date of purchase, current conditions in the capital markets and the impact of those conditions on market liquidity and prices generally. We expect to recover the carrying value of these securities as it is not more likely than not that we will be required to sell the securities before the recovery of the amortized cost basis. During the six months ended June 30, 2017 and 2016, there were no impairment losses recognized for other-than-temporary declines in the fair value of our investments Net realized losses in the six months ended June 30, 2017 were $0.6 million resulting from called fixed maturity securities. Net realized gains in the six months ended June 30, 2016 were $0.8 million resulting from the sale of fixed maturity securities classified as available-for-sale.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Note 5. Income Taxes In accordance with FASB ASC Topic 740, “Income Taxes,” we provide for the recognition and measurement of deferred income tax benefits based on the likelihood of their realization in future years. As of June 30, 2017, the Company had no material unrecognized tax benefits and no adjustments to liabilities or operations were required. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. There were no uncertain tax positions recognized for the periods ended June 30, 2017 and 2016. Tax years 2013 through 2016 are subject to examination by the federal and state taxing authorities.

Loss Reserves

Loss Reserves	6 Months Ended
	Jun. 30, 2017
Insurance [Abstract]
Loss Reserves	Note 6. Loss Reserves We record reserves for estimated losses under insurance policies that we write and for loss adjustment expenses related to the investigation and settlement of policy claims. Our reserves for loss and loss adjustment expenses represent the estimated cost of all reported and unreported loss and loss adjustment expenses incurred and unpaid as of a given point in time. The reserves for loss and loss adjustment expenses are estimated using individual case-basis valuations, statistical analyses and estimates based upon experience for unreported claims and their associated loss and loss adjustment expenses. Such estimates may be more or less than the amounts ultimately paid when the claims are settled. The estimates are subject to the effects of trends in loss severity and frequency. Although considerable variability is inherent in these estimates, management believes that the reserves for loss and loss adjustment expenses are adequate. The estimates are continually reviewed and adjusted as necessary as experience develops or new information becomes known. Any adjustments are included in current operations. See Note 9 to our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2016 for additional information regarding the Company’s loss and loss adjustment expense development. The following table provides a rollforward of the liability for unpaid claims and claim adjustment expenses, net of related amounts recoverable from reinsurers, for six months ended June 30, 2017 and 2016: Six Months Ended June 30, 2017 2016 (in thousands) Balance, beginning of period $ 742,776 $ 718,033 Less amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses 78,256 64,858 Net balance, beginning of period 664,520 653,175 Add incurred related to: Current accident year 119,828 126,764 Prior accident years (17,184 ) (30,877 ) Total incurred 102,644 95,887 Less paid related to: Current accident year 15,298 12,479 Prior accident years 80,571 79,437 Total paid 95,869 91,916 Net balance, end of period 671,295 657,146 Add amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses 78,464 68,403 Balance, end of period $ 749,759 $ 725,549 The foregoing reconciliation reflects favorable development of the net reserves at June 30, 2017 and June 30, 2016. The favorable development reduced loss and loss adjustment expense incurred by $17.2 million and $30.9 million in 2017 and 2016, respectively. The revisions to the Company’s reserves reflect new information gained by claims adjusters in the normal course of adjusting claims and is reflected in the financial statements when the information becomes available. It is typical for more serious claims to take several years or longer to settle and the Company continually revises estimates as more information about claimants’ medical conditions and potential disability becomes known and the claims get closer to being settled. Multiple factors can cause both favorable and unfavorable loss development. The favorable loss development we experienced across accident years was largely due to favorable case reserve development from closed claims and claims where the worker had reached maximum medical improvement.

Comprehensive Income and Accumu

Comprehensive Income and Accumulated Other Comprehensive Income	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Comprehensive Income and Accumulated Other Comprehensive Income	Note 7. Comprehensive Income and Accumulated Other Comprehensive Income Comprehensive income was $17.4 million for the three months ended June 30, 2017, compared to $19.6 million for the three months ended June 30, 2016. Comprehensive income was $31.9 million for the six months ended June 30, 2017, compared to $46.6 million for the same period in 2016. The difference between net income as reported and comprehensive income was due to changes in unrealized gains and losses, net of tax on available-for-sale securities. Comprehensive income includes net income plus unrealized gains (losses) on our available-for-sale investment securities, net of tax. In reporting comprehensive income on a net basis in the statements of income, we used a 35 percent tax rate. The following table illustrates the changes in the balance of each component of accumulated other comprehensive income for each period presented in the interim financial statements. Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (in thousands) Beginning balance $ 460 $ 5,380 $ (492 ) $ 2,587 Other comprehensive income before reclassification 2,038 3,286 3,094 5,986 Amounts reclassified from accumulated other comprehensive income (82 ) (357 ) (186 ) (264 ) Net current period other comprehensive income 1,956 2,929 2,908 5,722 Ending balance $ 2,416 $ 8,309 $ 2,416 $ 8,309 The sale or other-than-temporary impairment of an available-for-sale security results in amounts being reclassified from accumulated other comprehensive income to current period net income. The effects of reclassifications out of accumulated other comprehensive income by the respective line items of net income are presented in the following table. Component of Accumulated Other Comprehensive Income Three Months Ended June 30, Six Months Ended June 30, Affected line item in the statement of income 2017 2016 2017 2016 (in thousands) Unrealized gains on available-for- sale securities $ 126 $ 549 $ 286 $ 406 Net realized gains (losses) on investments 126 549 286 406 Income before income taxes (44 ) (192 ) (100 ) (142 ) Income tax expense $ 82 $ 357 $ 186 $ 264 Net income

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 8. Fair Value Measurements The Company carries available-for-sale securities at fair value in our consolidated financial statements and determines fair value measurements and disclosure in accordance with FASB ASC Topic 820, Fair Value Measurements and Disclosures. The Company determines the fair values of its financial instruments based on the fair value hierarchy established in ASC Topic 820, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard defines fair value, describes three levels of inputs that may be used to measure fair value, and expands disclosures about fair value measurements. Fair value is defined in ASC Topic 820 as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is the price to sell an asset or transfer a liability and, therefore, represents an exit price, not an entry price. Fair value is the exit price in the principal market (or, if lacking a principal market, the most advantageous market) in which the reporting entity would transact. Fair value is a market-based measurement, not an entity-specific measurement, and, as such, is determined based on the assumptions that market participants would use in pricing the asset or liability. The exit price objective of a fair value measurement applies regardless of the reporting entity’s intent and/or ability to sell the asset or transfer the liability at the measurement date. ASC Topic 820 requires the use of valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets and liabilities. The income approach uses valuation techniques to convert future amounts, such as cash flows or earnings, to a single present value amount on a discounted basis. The cost approach is based on the amount that currently would be required to replace the service capacity of an asset, also known as current replacement cost. Valuation techniques used to measure fair value are to be consistently applied. In ASC Topic 820, inputs refer broadly to the assumptions that market participants would use in pricing the asset or liability, including assumptions about risk, for example, the risk inherent in a particular valuation technique used to measure fair value (such as a pricing model) and/or the risk inherent in the inputs to the valuation technique. Inputs may be observable or unobservable: • Observable inputs are inputs that reflect the assumptions market participants would use in pricing the asset or liability developed based on market data obtained from sources independent of the reporting entity. • Unobservable inputs are inputs that reflect the reporting entity’s own assumptions about the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. Valuation techniques used to measure fair value are intended to maximize the use of observable inputs and minimize the use of unobservable inputs. ASC Topic 820 establishes a fair value hierarchy that prioritizes the use of inputs used in valuation techniques into the following three levels: • Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, or inputs that are derived principally from or corroborated by observable market data. • Level 3 inputs are unobservable inputs for the asset or liability. Unobservable inputs are to be used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. In general, fair value is based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. The fair values of the Company’s investments are based upon prices provided by an independent pricing service. The Company has reviewed these prices for reasonableness and has not adjusted any prices received from the independent provider. Securities reported at fair value utilizing Level 1 inputs represent assets whose fair value is determined based upon observable unadjusted quoted market prices for identical assets in active markets. Level 2 securities represent assets whose fair value is determined using observable market information such as previous day trade prices, quotes from less active markets or quoted prices of securities with similar characteristics. There were no transfers between Level 1 and Level 2 during the six months ended June 30, 2017. At June 30, 2017, assets and liabilities measured at fair value on a recurring basis are summarized below: June 30, 2017 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Financial instruments carried at fair value, classified as a part of: Securities available for sale—fixed maturity: States and political subdivisions $ — $ 233,538 $ — $ 233,538 Corporate bonds — 157,278 — 157,278 U.S. agency-based mortgage-backed securities — 10,990 — 10,990 U.S. Treasury securities 60,987 — — 60,987 Total securities available for sale—fixed maturity 60,987 401,806 — 462,793 Securities available for sale—equity: Domestic common stock 5,068 — — 5,068 Total available for sale $ 66,055 $ 401,806 $ — $ 467,861 At June 30, 2017, assets and liabilities measured at amortized cost are summarized below: June 30, 2017 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Securities held-to-maturity—fixed maturity: States and political subdivisions $ — $ 440,579 $ — $ 440,579 Corporate bonds — 129,405 — 129,405 U.S. agency-based mortgage-backed securities — 9,966 — 9,966 U.S. Treasury securities 6,787 — — 6,787 Obligations of U.S. government agencies — 21,943 — 21,943 Asset-backed securities — 1,871 — 1,871 Total held-to-maturity $ 6,787 $ 603,764 $ — $ 610,551 At December 31, 2016, assets and liabilities measured at fair value on a recurring basis are summarized below: December 31, 2016 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Financial instruments carried at fair value, classified as part of: Securities available for sale—fixed maturity: States and political subdivisions $ — $ 232,293 $ — $ 232,293 Corporate bonds — 182,515 — 182,515 U.S. agency-based mortgage-backed securities — 9,342 — 9,342 U.S. Treasury securities and obligations of U.S. government agencies 54,947 — — 54,947 Total available for sale—fixed maturity $ 54,947 $ 424,150 $ — $ 479,097 Securities available for sale—equity: Domestic common stock 33 — — 33 Total available for sale $ 54,980 $ 424,150 $ — $ 479,130 At December 31, 2016, assets and liabilities measured at amortized cost are summarized below: December 31, 2016 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Securities held-to-maturity—fixed maturity: States and political subdivisions $ — $ 399,483 $ — $ 399,483 Corporate bonds — 144,016 — 144,016 Commercial mortgage-backed securities — 70 — 70 U.S. agency-based mortgage-backed securities — 10,915 — 10,915 U.S. Treasury securities 6,779 — — 6,779 Obligations of U.S. government agencies — 5,637 — 5,637 Asset-backed securities — 2,031 — 2,031 Total held-to-maturity $ 6,779 $ 562,152 $ — $ 568,931 The Company determines fair value amounts for financial instruments using available third-party market information. When such information is not available, the Company determines the fair value amounts using appropriate valuation methodologies. Nonfinancial instruments such as real estate, property and equipment, deferred policy acquisition costs, deferred income taxes and loss and loss adjustment expense reserves are excluded from the fair value disclosure. At June 30, 2017, the Company held two securities measured at fair value on a nonrecurring basis due to a recognized impairment of $0.3 million. The securities are valued using Level 2 inputs and had a value of $0.3 million at June 30, 2017. The securities were valued at fair value at the time of impairment and are currently being carried at the adjusted amortized cost. The fair value of the securities was $0.4 million at June 30, 2017. Cash and Cash Equivalents —The carrying amounts reported in the accompanying consolidated balance sheets for these financial instruments approximate their fair values, which are characterized as Level 1 assets. Investments —The fair values for fixed maturity and equity securities are based on prices obtained from an independent pricing service. Equity and treasury securities are characterized as Level 1 assets, as their fair values are based on quoted prices in active markets. Fixed maturity securities, other than treasury securities, are characterized as Level 2 assets, as their fair values are determined using observable market inputs. Short Term Investments —The carrying amounts reported in the accompanying consolidated balance sheets for these financial instruments approximate their fair values. These securities are characterized as Level 2 assets in the fair value hierarchy. Other Investments —Other investments consist of a limited partnership interest that is accounted for under the equity method valued using the net asset value provided by the general partner of the limited partnership, which approximates the fair value of the interest. The limited partnership’s objective is to generate absolute returns by investing long and short in publicly-traded global securities. Redemptions are allowed monthly following a 60-day notice with no lock up periods. The Company has no unfunded commitments related to the limited partnership hedge fund. The following table summarizes the carrying values and corresponding fair values for financial instruments: As of June 30, 2017 As of December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value (in thousands) Assets: Fixed maturity securities—held-to-maturity $ 599,096 $ 610,551 $ 562,434 $ 568,931 Fixed maturity securities—available-for-sale 462,793 462,793 479,097 479,097 Equity securities 5,068 5,068 33 33 Short-term investments 46,635 46,635 29,580 29,580 Other investments 7,038 7,038 13,330 13,330 Cash and cash equivalents 53,967 53,967 58,936 58,936

Treasury Stock

Treasury Stock	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Treasury Stock	Note 9. Treasury Stock The Company’s Board of Directors initiated a share repurchase program in February 2010. In October 2016, the Board reauthorized this program with a limit of $25.0 million with no expiration date. There were no shares repurchased under this program in the six months ended June 30, 2017. Since the beginning of this plan, the Company has repurchased a total of 1,258,250 shares for $22.4 million, or an average price of $17.78, including commissions.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 10. Commitments and Contingencies In February 2015, the Company was notified of an adverse verdict against its subsidiary, AIIC, related to a 2009 workers’ compensation claim in the State of Iowa. The verdict was for $25.3 million, of which $0.3 million was for actual damages and $25.0 million was awarded for punitive damages. The Company posted an appeal bond in the amount of $27.8 million, as required by law. AIIC appealed both the verdict and the damage awards. On May 19, 2017, the Supreme Court of Iowa reversed the judgments for actual and punitive damages and remanded the case for a new trial. On July 21, 2017, the district court entered an order directing that the $27.8 million appeal bond posted by AIIC be returned. The Company maintains reinsurance against catastrophic losses, including court ordered judgments. As of June 30, 2017, the Company’s total reserve for the claim was $2.4 million. The $2.4 million reserve does not include payments that the Company has previously paid in this case. The payments, plus the $2.4 million reserve, total $5.4 million. The Company’s retention is $5.0 million before its reinsurance providers are obligated to reimburse the Company for additional costs. The Company presently believes that the reserve amount, together with its reinsurance coverage, is adequate to satisfy this claim.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Note 11. Subsequent Events On July 25, 2017, the Company’s Board of Directors declared a quarterly cash dividend of $0.20 per share payable on September 22, 2017 to shareholders of record as of September 8, 2017. The Board considers the payment of a regular cash dividend each calendar quarter.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Adopted Accounting Guidance	Adopted Accounting Guidance In March 2016, the FASB issued ASU 2016-09, Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The new guidance requires that all tax effects related to share-based payments be made through the income statement at the time of settlement as opposed to recognizing excess tax benefits in additional paid-in capital. It also requires the cash flows resulting from share-based payments to be included as an operating activity. In addition to the changes, the guidance permits reporting entities to elect to estimate forfeitures related to share-based payments or recognize them as they occur. The threshold to qualify for equity classification has also been revised to permit withholding up to the maximum statutory tax rates in the applicable jurisdictions. The adoption of this new guidance in the first quarter of 2017 did not have a material impact on our financial condition and results of operations.
Prospective Accounting Guidance	Prospective Accounting Guidance In May 2014, the FASB Issued ASU 2014-09 (Topic 606): Revenue from Contract s s In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. This guidance requires fair value measurement for equity investments (not including those that result in consolidation of the investee or use the equity method of accounting) and the recognition of changes in fair value to be presented as a component of net income. The guidance also revises the disclosure requirements related to fair value changes of liabilities presented in comprehensive income, eliminates disclosure related to the methods and assumptions underlying fair value for financial instruments measured at amortized cost, and simplifies impairment assessments for equity investments without readily determinable fair values. This standard is effective for us in the first quarter of 2018. Based on the equity investments currently held by the Company, there would not be a material impact on the Company's financial condition and results of operations if the new guidance were to be adopted in the current accounting period. The impact on the Company's results of operations and financial position at the date of adoption of the updated guidance will be determined by the equity investments held by the Company and the economic conditions at that time. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). Under current guidance for lessees, leases are only included on the balance sheet if certain criteria, classifying the contract as a capital lease, are met. The new guidance requires a lessee to recognize a lease liability and a right of use asset for all leases extending beyond twelve months. The new guidance is effective for us in the first quarter of 2019. Upon adoption, leases will be recognized and measured at the beginning of the earliest period presented using a modified retrospective approach. Adoption of the guidance is not expected to have a material effect on the Company’s consolidated financial statements as the Company does not have any significant leases. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses. The new guidance replaces the methodology of credit loss impairment which currently delays the recognition of credit losses until a probable loss has been incurred. The new guidance requires credit losses for securities measured at amortized cost to be determined using current expected credit loss estimates. These estimates are to be derived from historical, current and reasonable supporting forecasts, including prepayments and estimates, and will be recorded through a valuation allowance account that will run through the income statement. The same method will be used for available-for-sale securities, but the valuation allowance will be limited to the amount by which the fair value is below amortized cost. The standard is effective for us in the first quarter of 2020. The Company will continue to monitor the impact as the implementation date approaches. All other issued but not yet effective accounting and reporting standards as of June 30, 2017 are either not applicable to the Company or are not expected to have a material impact on the Company.

Fair Value Measurements (Polici

Fair Value Measurements (Policies)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	The Company carries available-for-sale securities at fair value in our consolidated financial statements and determines fair value measurements and disclosure in accordance with FASB ASC Topic 820, Fair Value Measurements and Disclosures. The Company determines the fair values of its financial instruments based on the fair value hierarchy established in ASC Topic 820, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard defines fair value, describes three levels of inputs that may be used to measure fair value, and expands disclosures about fair value measurements.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Calculation of Basic and Diluted Earnings Per Share	The diluted EPS calculation includes potential common shares assumed issued under the treasury stock method, which reflects the potential dilution that would occur if any outstanding options or warrants were exercised or restricted stock becomes vested, and includes the “if converted” method for participating securities if the effect is dilutive. Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (in thousands, except share and per share amounts) Basic EPS Net income available to common shareholders - basic $ 15,481 $ 16,639 $ 29,005 $ 40,896 Basic weighted average common shares 19,162,049 19,096,718 19,156,250 19,077,328 Basic earnings per common share $ 0.81 $ 0.87 $ 1.51 $ 2.14 Diluted EPS Net income available to common shareholders - diluted $ 15,481 $ 16,639 $ 29,005 $ 40,896 Diluted weighted average common shares: Weighted average common shares 19,162,049 19,096,718 19,156,250 19,077,328 Stock options and restricted stock 65,911 88,266 71,747 101,565 Diluted weighted average common shares 19,227,960 19,184,984 19,227,997 19,178,893 Diluted earnings per common share $ 0.81 $ 0.87 $ 1.51 $ 2.13

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2017
Gross Unrealized Gains and Losses and Amortized Cost and Fair Value of Investments Classified as Held-to-maturity	The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at June 30, 2017 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) States and political subdivisions $ 430,921 $ 10,435 $ (777 ) $ 440,579 Corporate bonds 129,143 438 (176 ) 129,405 U.S. agency-based mortgage-backed securities 9,171 797 (2 ) 9,966 U.S. Treasury securities and obligations of U.S. government agencies 28,113 689 (72 ) 28,730 Asset-backed securities 1,748 139 (16 ) 1,871 Totals $ 599,096 $ 12,498 $ (1,043 ) $ 610,551 The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at December 31, 2016 are summarized as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) States and political subdivisions $ 394,875 $ 7,622 $ (3,014 ) $ 399,483 Corporate bonds 143,858 423 (265 ) 144,016 Commercial mortgage-backed securities 70 — — 70 U.S. agency-based mortgage-backed securities 9,967 948 — 10,915 U.S. Treasury securities and obligations of U.S. government agencies 11,737 746 (67 ) 12,416 Asset-backed securities 1,927 163 (59 ) 2,031 Totals $ 562,434 $ 9,902 $ (3,405 ) $ 568,931
Gross Unrealized Gains and Losses and Cost or Amortized Cost and Fair Value of Investments Classified as Available-for-sale	The gross unrealized gains and losses on, and the cost or amortized cost and fair value of, those investments classified as available-for-sale at June 30, 2017 are summarized as follows: Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Fixed maturity: States and political subdivisions $ 228,863 $ 6,131 $ (1,456 ) $ 233,538 Corporate bonds 156,842 633 (197 ) 157,278 U.S. agency-based mortgage-backed securities 11,895 8 (913 ) 10,990 U.S. Treasury securities and obligations of U.S. government agencies 61,516 78 (607 ) 60,987 Total fixed maturity 459,116 6,850 (3,173 ) 462,793 Equity securities 5,006 62 — 5,068 Other investments 4,000 3,038 — 7,038 Totals $ 468,122 $ 9,950 $ (3,173 ) $ 474,899 The gross unrealized gains and losses on, and the cost or amortized cost and fair value of, those investments classified as available-for-sale at December 31, 2016 are summarized as follows: Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (in thousands) Fixed maturity: States and political subdivisions $ 231,168 $ 4,340 $ (3,215 ) $ 232,293 Corporate bonds 182,350 436 (271 ) 182,515 U.S. agency-based mortgage-backed securities 10,428 17 (1,103 ) 9,342 U.S. Treasury securities and obligations of U.S. government agencies 55,925 — (978 ) 54,947 Total fixed maturity 479,871 4,793 (5,567 ) 479,097 Equity securities — 33 — 33 Other investments 10,000 3,330 — 13,330 Totals $ 489,871 $ 8,156 $ (5,567 ) $ 492,460
Investment Securities Continuous Unrealized Loss Position	The following table summarizes the fair value and gross unrealized losses on securities, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position: Less Than 12 Months 12 Months or Greater Total Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses (in thousands) June 30, 2017 Held-to-Maturity Fixed maturity securities: States and political subdivisions $ 79,641 $ 622 $ 3,296 $ 155 $ 82,937 $ 777 Corporate bonds 46,659 142 6,242 34 52,901 176 U.S. agency-based mortgage-backed securities 658 2 — — 658 2 U.S. Treasury securities and obligations of U.S. government agencies 22,680 72 — — 22,680 72 Asset-backed securities — — 1,099 16 1,099 16 Total held-to-maturity securities 149,638 838 10,637 205 160,275 1,043 Available-for Sale Fixed maturity securities: States and political subdivisions $ 33,677 $ 1,036 $ 8,798 $ 420 $ 42,475 $ 1,456 Corporate bonds 22,167 79 7,919 118 30,086 197 U.S. agency-based mortgage-backed securities 5,510 46 3,590 867 9,100 913 U.S. Treasury securities and obligations of U.S. government agencies 55,223 607 — — 55,223 607 Total available-for-sale securities 116,577 1,768 20,307 1,405 136,884 3,173 Total $ 266,215 $ 2,606 $ 30,944 $ 1,610 $ 297,159 $ 4,216 Less Than 12 Months 12 Months or Greater Total Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses Fair Value of Investments with Unrealized Losses Gross Unrealized Losses (in thousands) December 31, 2016 Held-to-Maturity Fixed maturity securities: States and political subdivisions $ 157,507 $ 3,014 $ — $ — $ 157,507 $ 3,014 Corporate bonds 44,654 202 6,292 63 50,946 265 U.S. Treasury securities and obligations of U.S. government agencies 3,968 67 — — 3,968 67 Asset-backed securities — — 1,173 59 1,173 59 Total held-to-maturity securities 206,129 3,283 7,465 122 213,594 3,405 Available-for Sale Fixed maturity securities: States and political subdivisions $ 73,505 $ 2,976 $ 4,523 $ 239 $ 78,028 $ 3,215 Corporate bonds 41,419 111 7,922 160 49,341 271 U.S. agency-based mortgage-backed securities 3,702 48 3,607 1,055 7,309 1,103 U.S. Treasury securities and obligations of U.S. government agencies 54,947 978 — — 54,947 978 Total available-for-sale securities 173,573 4,113 16,052 1,454 189,625 5,567 Total $ 379,702 $ 7,396 $ 23,517 $ 1,576 $ 403,219 $ 8,972
Held-to-Maturity Securities [Member]
Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, by Contractual Maturity	A summary of the amortized cost and fair value of investments in fixed maturity securities, classified as held-to-maturity at June 30, 2017, by contractual maturity, is as follows: Amortized Cost Fair Value (in thousands) Maturity: Within one year $ 120,697 $ 121,160 After one year through five years 235,710 240,121 After five years through ten years 112,733 115,665 After ten years 119,037 121,768 U.S. agency-based mortgage-backed securities 9,171 9,966 Asset-backed securities 1,748 1,871 Totals $ 599,096 $ 610,551
Available-for-Sale Securities [Member]
Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, by Contractual Maturity	A summary of the amortized cost and fair value of investments in fixed maturity securities, classified as available-for-sale at June 30, 2017, by contractual maturity, is as follows: Amortized Cost Fair Value (in thousands) Maturity: Within one year $ 92,665 $ 92,899 After one year through five years 164,477 165,259 After five years through ten years 35,020 35,254 After ten years 155,059 158,391 U.S. agency-based mortgage-backed securities 11,895 10,990 Totals $ 459,116 $ 462,793

Loss Reserves (Tables)

Loss Reserves (Tables)	6 Months Ended
	Jun. 30, 2017
Insurance [Abstract]
Rollforward of Liability for Unpaid Claims and Claim Adjustment Expenses, Net of Related Amounts Recoverable from Reinsurers	The following table provides a rollforward of the liability for unpaid claims and claim adjustment expenses, net of related amounts recoverable from reinsurers, for six months ended June 30, 2017 and 2016: Six Months Ended June 30, 2017 2016 (in thousands) Balance, beginning of period $ 742,776 $ 718,033 Less amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses 78,256 64,858 Net balance, beginning of period 664,520 653,175 Add incurred related to: Current accident year 119,828 126,764 Prior accident years (17,184 ) (30,877 ) Total incurred 102,644 95,887 Less paid related to: Current accident year 15,298 12,479 Prior accident years 80,571 79,437 Total paid 95,869 91,916 Net balance, end of period 671,295 657,146 Add amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses 78,464 68,403 Balance, end of period $ 749,759 $ 725,549

Comprehensive Income and Accu24

Comprehensive Income and Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Income (AOCI)	The following table illustrates the changes in the balance of each component of accumulated other comprehensive income for each period presented in the interim financial statements. Three Months Ended June 30, Six Months Ended June 30, 2017 2016 2017 2016 (in thousands) Beginning balance $ 460 $ 5,380 $ (492 ) $ 2,587 Other comprehensive income before reclassification 2,038 3,286 3,094 5,986 Amounts reclassified from accumulated other comprehensive income (82 ) (357 ) (186 ) (264 ) Net current period other comprehensive income 1,956 2,929 2,908 5,722 Ending balance $ 2,416 $ 8,309 $ 2,416 $ 8,309
Reclassification Out of Accumulated Other Comprehensive Income	The effects of reclassifications out of accumulated other comprehensive income by the respective line items of net income are presented in the following table. Component of Accumulated Other Comprehensive Income Three Months Ended June 30, Six Months Ended June 30, Affected line item in the statement of income 2017 2016 2017 2016 (in thousands) Unrealized gains on available-for- sale securities $ 126 $ 549 $ 286 $ 406 Net realized gains (losses) on investments 126 549 286 406 Income before income taxes (44 ) (192 ) (100 ) (142 ) Income tax expense $ 82 $ 357 $ 186 $ 264 Net income

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	At June 30, 2017, assets and liabilities measured at fair value on a recurring basis are summarized below: June 30, 2017 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Financial instruments carried at fair value, classified as a part of: Securities available for sale—fixed maturity: States and political subdivisions $ — $ 233,538 $ — $ 233,538 Corporate bonds — 157,278 — 157,278 U.S. agency-based mortgage-backed securities — 10,990 — 10,990 U.S. Treasury securities 60,987 — — 60,987 Total securities available for sale—fixed maturity 60,987 401,806 — 462,793 Securities available for sale—equity: Domestic common stock 5,068 — — 5,068 Total available for sale $ 66,055 $ 401,806 $ — $ 467,861 At December 31, 2016, assets and liabilities measured at fair value on a recurring basis are summarized below: December 31, 2016 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Financial instruments carried at fair value, classified as part of: Securities available for sale—fixed maturity: States and political subdivisions $ — $ 232,293 $ — $ 232,293 Corporate bonds — 182,515 — 182,515 U.S. agency-based mortgage-backed securities — 9,342 — 9,342 U.S. Treasury securities and obligations of U.S. government agencies 54,947 — — 54,947 Total available for sale—fixed maturity $ 54,947 $ 424,150 $ — $ 479,097 Securities available for sale—equity: Domestic common stock 33 — — 33 Total available for sale $ 54,980 $ 424,150 $ — $ 479,130
Schedule of Assets and Liabilities Measured at Amortized Cost	At June 30, 2017, assets and liabilities measured at amortized cost are summarized below: June 30, 2017 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Securities held-to-maturity—fixed maturity: States and political subdivisions $ — $ 440,579 $ — $ 440,579 Corporate bonds — 129,405 — 129,405 U.S. agency-based mortgage-backed securities — 9,966 — 9,966 U.S. Treasury securities 6,787 — — 6,787 Obligations of U.S. government agencies — 21,943 — 21,943 Asset-backed securities — 1,871 — 1,871 Total held-to-maturity $ 6,787 $ 603,764 $ — $ 610,551 At December 31, 2016, assets and liabilities measured at amortized cost are summarized below: December 31, 2016 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Fair Value (in thousands) Securities held-to-maturity—fixed maturity: States and political subdivisions $ — $ 399,483 $ — $ 399,483 Corporate bonds — 144,016 — 144,016 Commercial mortgage-backed securities — 70 — 70 U.S. agency-based mortgage-backed securities — 10,915 — 10,915 U.S. Treasury securities 6,779 — — 6,779 Obligations of U.S. government agencies — 5,637 — 5,637 Asset-backed securities — 2,031 — 2,031 Total held-to-maturity $ 6,779 $ 562,152 $ — $ 568,931
Summary of Carrying Values and Corresponding Fair Values for Financial Instruments	The following table summarizes the carrying values and corresponding fair values for financial instruments: As of June 30, 2017 As of December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value (in thousands) Assets: Fixed maturity securities—held-to-maturity $ 599,096 $ 610,551 $ 562,434 $ 568,931 Fixed maturity securities—available-for-sale 462,793 462,793 479,097 479,097 Equity securities 5,068 5,068 33 33 Short-term investments 46,635 46,635 29,580 29,580 Other investments 7,038 7,038 13,330 13,330 Cash and cash equivalents 53,967 53,967 58,936 58,936

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Percentage of comparable consolidated amounts	95.00%	95.00%

Stock Options and Restricted 27

Stock Options and Restricted Stock - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)Incentive_Planshares	Jun. 30, 2016USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans | Incentive_Plan			3
Stock options exercised, Shares | shares			0	38,879
Proceeds from stock option exercises | $				$ 501
Share-based compensation expense | $	$ 500	$ 500	$ 900	700
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market value of restricted shares granted | $			$ 700	$ 1,900
Restricted Stock Units (RSUs) [Member] | Executive Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock granted | shares			7,434	27,077
Restricted Stock Units (RSUs) [Member] | Non-employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock granted | shares			6,454	5,952

Earnings Per Share - Calculatio

Earnings Per Share - Calculation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share Basic [Abstract]
Net income available to common shareholders - basic	$ 15,481	$ 16,639	$ 29,005	$ 40,896
Basic weighted average common shares	19,162,049	19,096,718	19,156,250	19,077,328
Basic earnings per common share	$ 0.81	$ 0.87	$ 1.51	$ 2.14
Net income available to common shareholders - diluted	$ 15,481	$ 16,639	$ 29,005	$ 40,896
Weighted average common shares	19,162,049	19,096,718	19,156,250	19,077,328
Stock options and restricted stock	65,911	88,266	71,747	101,565
Diluted weighted average common shares	19,227,960	19,184,984	19,227,997	19,178,893
Diluted earnings per common share	$ 0.81	$ 0.87	$ 1.51	$ 2.13

Investments - Gross Unrealized

Investments - Gross Unrealized Gains and Losses and Amortized Cost and Fair Value of Investments Classified as Held-to-Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Held-to-maturity, Amortized Cost, Totals	$ 599,096	$ 562,434
Held-to-Maturity, Gross Unrealized Gains	12,498	9,902
Held-to-Maturity, Gross Unrealized Losses	(1,043)	(3,405)
Held-to-Maturity, Fair Value	610,551	568,931
States and Political Subdivisions [Member]
Investment [Line Items]
Held-to-maturity, Amortized Cost, Totals	430,921	394,875
Held-to-Maturity, Gross Unrealized Gains	10,435	7,622
Held-to-Maturity, Gross Unrealized Losses	(777)	(3,014)
Held-to-Maturity, Fair Value	440,579	399,483
Corporate Bonds [Member]
Investment [Line Items]
Held-to-maturity, Amortized Cost, Totals	129,143	143,858
Held-to-Maturity, Gross Unrealized Gains	438	423
Held-to-Maturity, Gross Unrealized Losses	(176)	(265)
Held-to-Maturity, Fair Value	129,405	144,016
Commercial Mortgage-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity, Amortized Cost, Totals		70
Held-to-Maturity, Fair Value		70
U.S. Agency-Based Mortgage-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity, Amortized Cost, Totals	9,171	9,967
Held-to-Maturity, Gross Unrealized Gains	797	948
Held-to-Maturity, Gross Unrealized Losses	(2)
Held-to-Maturity, Fair Value	9,966	10,915
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Investment [Line Items]
Held-to-maturity, Amortized Cost, Totals	28,113	11,737
Held-to-Maturity, Gross Unrealized Gains	689	746
Held-to-Maturity, Gross Unrealized Losses	(72)	(67)
Held-to-Maturity, Fair Value	28,730	12,416
Asset-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity, Amortized Cost, Totals	1,748	1,927
Held-to-Maturity, Gross Unrealized Gains	139	163
Held-to-Maturity, Gross Unrealized Losses	(16)	(59)
Held-to-Maturity, Fair Value	$ 1,871	$ 2,031

Investments - Gross Unrealize30

Investments - Gross Unrealized Gains and Losses and Cost or Amortized Cost and Fair Value of Investments Classified as Available-for-Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Available-for-Sale, Cost or Amortized Cost	$ 468,122	$ 489,871
Available-for-Sale, Gross Unrealized Gains	9,950	8,156
Available-for-Sale, Gross Unrealized Losses	(3,173)	(5,567)
Available-for-Sale, Fair Value	474,899	492,460
Other Investments [Member]
Investment [Line Items]
Available-for-Sale, Cost or Amortized Cost	4,000	10,000
Available-for-Sale, Gross Unrealized Gains	3,038	3,330
Available-for-Sale, Fair Value	7,038	13,330
Total Fixed Maturity [Member]
Investment [Line Items]
Available-for-Sale, Cost or Amortized Cost	459,116	479,871
Available-for-Sale, Gross Unrealized Gains	6,850	4,793
Available-for-Sale, Gross Unrealized Losses	(3,173)	(5,567)
Available-for-Sale, Fair Value	462,793	479,097
States and Political Subdivisions [Member]
Investment [Line Items]
Available-for-Sale, Cost or Amortized Cost	228,863	231,168
Available-for-Sale, Gross Unrealized Gains	6,131	4,340
Available-for-Sale, Gross Unrealized Losses	(1,456)	(3,215)
Available-for-Sale, Fair Value	233,538	232,293
Corporate Bonds [Member]
Investment [Line Items]
Available-for-Sale, Cost or Amortized Cost	156,842	182,350
Available-for-Sale, Gross Unrealized Gains	633	436
Available-for-Sale, Gross Unrealized Losses	(197)	(271)
Available-for-Sale, Fair Value	157,278	182,515
U.S. Agency-Based Mortgage-Backed Securities [Member]
Investment [Line Items]
Available-for-Sale, Cost or Amortized Cost	11,895	10,428
Available-for-Sale, Gross Unrealized Gains	8	17
Available-for-Sale, Gross Unrealized Losses	(913)	(1,103)
Available-for-Sale, Fair Value	10,990	9,342
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Investment [Line Items]
Available-for-Sale, Cost or Amortized Cost	61,516	55,925
Available-for-Sale, Gross Unrealized Gains	78
Available-for-Sale, Gross Unrealized Losses	(607)	(978)
Available-for-Sale, Fair Value	60,987	54,947
Equity Securities [Member]
Investment [Line Items]
Available-for-Sale, Cost or Amortized Cost	5,006
Available-for-Sale, Gross Unrealized Gains	62	33
Available-for-Sale, Fair Value	$ 5,068	$ 33

Investments - Summary of Amorti

Investments - Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, Classified as Held-to-Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Within one year, Amortized Cost	$ 120,697
After one year through five years, Amortized Cost	235,710
After five years through ten years, Amortized Cost	112,733
After ten years, Amortized Cost	119,037
Held-to-maturity, Amortized Cost, Totals	599,096	$ 562,434
Within one year, Fair Value	121,160
After one year through five years, Fair Value	240,121
After five years through ten years, Fair Value	115,665
After ten years, Fair Value	121,768
Held-to-maturity, Fair Value, Totals	610,551	$ 568,931
U.S. Agency-Based Mortgage-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity, Amortized Cost	9,171
Held-to-maturity, Fair Value	9,966
Asset-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity, Amortized Cost	1,748
Held-to-maturity, Fair Value	$ 1,871

Investments - Summary of Amor32

Investments - Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, Classified as Available-for-Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Within one year, Amortized Cost	$ 92,665
After one year through five years, Amortized Cost	164,477
After five years through ten years, Amortized Cost	35,020
After ten years, Amortized Cost	155,059
Total , Amortized Cost	459,116	$ 479,871
Within one year, Fair Value	92,899
After one year through five years, Fair Value	165,259
After five years through ten years, Fair Value	35,254
After ten years, Fair Value	158,391
Total, Fair Value	462,793	$ 479,097
U.S. Agency-Based Mortgage-Backed Securities [Member]
Investment [Line Items]
Available-for-sale securities, Amortized Cost	11,895
Available-for-sale securities, Fair value	$ 10,990

Investments - Investment Securi

Investments - Investment Securities Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Less Than 12 Months	$ 149,638	$ 206,129
Held-to-maturity securities, Gross Unrealized Losses, Less Than 12 Months	838	3,283
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	10,637	7,465
Held-to-maturity securities, Gross Unrealized Losses, 12 Months or Greater	205	122
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Total	160,275	213,594
Held-to-maturity securities, Gross Unrealized Losses, Total	1,043	3,405
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	116,577	173,573
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	1,768	4,113
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	20,307	16,052
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	1,405	1,454
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	136,884	189,625
Available-for Sale, Gross Unrealized Losses, Total	3,173	5,567
Fair Value of Investments with Unrealized Losses, Less Than 12 months	266,215	379,702
Gross Unrealized Loss, Less Than 12 Months	2,606	7,396
Fair Value of Investments with Unrealized Losses, 12 Months or Greater	30,944	23,517
Gross Unrealized Losses, 12 Months or Greater	1,610	1,576
Fair Value of Investments with Unrealized Losses, Total	297,159	403,219
Gross Unrealized Losses, Total	4,216	8,972
States and Political Subdivisions [Member]
Investment [Line Items]
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Less Than 12 Months	79,641	157,507
Held-to-maturity securities, Gross Unrealized Losses, Less Than 12 Months	622	3,014
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	3,296
Held-to-maturity securities, Gross Unrealized Losses, 12 Months or Greater	155
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Total	82,937	157,507
Held-to-maturity securities, Gross Unrealized Losses, Total	777	3,014
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	33,677	73,505
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	1,036	2,976
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	8,798	4,523
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	420	239
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	42,475	78,028
Available-for Sale, Gross Unrealized Losses, Total	1,456	3,215
Corporate Bonds [Member]
Investment [Line Items]
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Less Than 12 Months	46,659	44,654
Held-to-maturity securities, Gross Unrealized Losses, Less Than 12 Months	142	202
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	6,242	6,292
Held-to-maturity securities, Gross Unrealized Losses, 12 Months or Greater	34	63
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Total	52,901	50,946
Held-to-maturity securities, Gross Unrealized Losses, Total	176	265
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	22,167	41,419
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	79	111
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	7,919	7,922
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	118	160
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	30,086	49,341
Available-for Sale, Gross Unrealized Losses, Total	197	271
U.S. Agency-Based Mortgage-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Less Than 12 Months	658
Held-to-maturity securities, Gross Unrealized Losses, Less Than 12 Months	2
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Total	658
Held-to-maturity securities, Gross Unrealized Losses, Total	2
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	5,510	3,702
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	46	48
Available-for Sale, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	3,590	3,607
Available-for Sale, Gross Unrealized Losses, 12 Months or Greater	867	1,055
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	9,100	7,309
Available-for Sale, Gross Unrealized Losses, Total	913	1,103
Asset-Backed Securities [Member]
Investment [Line Items]
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, 12 Months or Greater	1,099	1,173
Held-to-maturity securities, Gross Unrealized Losses, 12 Months or Greater	16	59
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Total	1,099	1,173
Held-to-maturity securities, Gross Unrealized Losses, Total	16	59
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Investment [Line Items]
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Less Than 12 Months	22,680	3,968
Held-to-maturity securities, Gross Unrealized Losses, Less Than 12 Months	72	67
Held-to-maturity securities, Fair Value of Investments with Unrealized Losses, Total	22,680	3,968
Held-to-maturity securities, Gross Unrealized Losses, Total	72	67
Available-for Sale, Fair value of Investments with Unrealized Losses, Less Than 12 Months	55,223	54,947
Available-for Sale, Gross Unrealized Losses, Less Than 12 Months	607	978
Available-for Sale, Fair Value of Investments with Unrealized Losses, Total	55,223	54,947
Available-for Sale, Gross Unrealized Losses, Total	$ 607	$ 978

Investments - Additional Inform

Investments - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)Security	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)Security	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Investments Schedule [Abstract]
Individual fixed maturity held in unrealized loss position | Security	187		187
Individual fixed maturity held in unrealized loss position longer than 12 months | Security	21		21
Carrying value of investments	$ 7,038,000		$ 7,038,000		$ 13,330,000
Impairment losses recognized			0	$ 0
Net realized gains (losses) on investments	$ (388,000)	$ 545,000	$ (569,000)	$ 793,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 0
Company recognized uncertain tax positions	$ 0	$ 0

Loss Reserves - Rollforward of

Loss Reserves - Rollforward of Liability for Unpaid Claims and Claim Adjustment Expenses, Net of Related Amounts Recoverable from Reinsurers (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Roll Forward In Liability For Unpaid Claims And Claims Adjustment Expense [Abstract]
Balance, beginning of period	$ 742,776	$ 718,033
Less amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses	78,256	64,858
Net balance, beginning of period	664,520	653,175
Add incurred related to:
Current accident year	119,828	126,764
Prior accident years	(17,184)	(30,877)
Total incurred	102,644	95,887
Less paid related to:
Current accident year	15,298	12,479
Prior accident years	80,571	79,437
Total paid	95,869	91,916
Net balance, end of period	671,295	657,146
Add amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses	78,464	68,403
Balance, end of period	$ 749,759	$ 725,549

Loss Reserves - Additional Info

Loss Reserves - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Insurance [Abstract]
Loss and LAE Related to Prior Periods	$ 17,184	$ 30,877

Comprehensive Income and Accu38

Comprehensive Income and Accumulated Other Comprehensive Income - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Comprehensive income	$ 17,437	$ 19,568	$ 31,913	$ 46,618
Comprehensive income tax rate			35.00%

Comprehensive Income and Accu39

Comprehensive Income and Accumulated Other Comprehensive Income - Schedule of Changes in Accumulated Other Comprehensive Income (AOCI) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			$ 456,150
Ending Balance	$ 481,392		481,392
Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	460	$ 5,380	(492)	$ 2,587
Other comprehensive income before reclassification	2,038	3,286	3,094	5,986
Amounts reclassified from accumulated other comprehensive income	(82)	(357)	(186)	(264)
Net current period other comprehensive income	1,956	2,929	2,908	5,722
Ending Balance	$ 2,416	$ 8,309	$ 2,416	$ 8,309

Comprehensive Income and Accu40

Comprehensive Income and Accumulated Other Comprehensive Income - Reclassification Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	$ 22,151	$ 24,615	$ 40,884	$ 59,010
Income tax expense	(6,670)	(7,976)	(11,879)	(18,114)
Net income	15,481	16,639	29,005	40,896
Changes in Net Unrealized Gains (Losses) on Investment Securities [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains on available-for-sale securities	126	549	286	406
Income before income taxes	126	549	286	406
Income tax expense	(44)	(192)	(100)	(142)
Net income	$ 82	$ 357	$ 186	$ 264

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	$ 474,899	$ 492,460
Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	5,068	33
Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	467,861	479,130
Fair Value, Measurements, Recurring [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	462,793	479,097
Fair Value, Measurements, Recurring [Member] | Common Stock [Member] | Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	5,068	33
Fair Value, Measurements, Recurring [Member] | States and Political Subdivisions [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	233,538	232,293
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	157,278	182,515
Fair Value, Measurements, Recurring [Member] | U.S. Agency-Based Mortgage-Backed Securities [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	10,990	9,342
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Securities [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	60,987	54,947
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	66,055	54,980
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	60,987	54,947
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Common Stock [Member] | Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	5,068	33
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury Securities [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	60,987	54,947
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	401,806	424,150
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	401,806	424,150
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | States and Political Subdivisions [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	233,538	232,293
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Bonds [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	157,278	182,515
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Agency-Based Mortgage-Backed Securities [Member] | Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-Sale, Fair Value	$ 10,990	$ 9,342

Fair Value Measurements - Sch42

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Amortized Cost (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	$ 610,551	$ 568,931
States and Political Subdivisions [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	440,579	399,483
Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	129,405	144,016
U.S. Agency-Based Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	9,966	10,915
U.S. Treasury Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	6,787	6,779
US Government-sponsored Enterprises Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	21,943	5,637
Asset-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	1,871	2,031
Commercial Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value		70
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	6,787	6,779
Fair Value, Inputs, Level 1 [Member] | U.S. Treasury Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	6,787	6,779
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	603,764	562,152
Fair Value, Inputs, Level 2 [Member] | States and Political Subdivisions [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	440,579	399,483
Fair Value, Inputs, Level 2 [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	129,405	144,016
Fair Value, Inputs, Level 2 [Member] | U.S. Agency-Based Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	9,966	10,915
Fair Value, Inputs, Level 2 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	21,943	5,637
Fair Value, Inputs, Level 2 [Member] | Asset-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value	$ 1,871	2,031
Fair Value, Inputs, Level 2 [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held-to-maturity-fixed maturity, Fair Value		$ 70

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities held to maturity, carrying value	$ 599,096	$ 562,434
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Recognized impairment	300
Securities held to maturity, carrying value	300
Securities held to maturity, fair value	$ 400

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Carrying Values and Corresponding Fair Values for Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturity securities-held-to-maturity	$ 610,551	$ 568,931
Securities held to maturity, carrying value	599,096	562,434
Fixed maturity securities-available-for-sale	462,793	479,097
Equity securities	5,068	33
Short-term investments	46,635	29,580
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed maturity securities-held-to-maturity	610,551	568,931
Fixed maturity securities-available-for-sale	462,793	479,097
Equity securities	5,068	33
Short-term investments	46,635	29,580
Other investments	7,038	13,330
Cash and cash equivalents	53,967	58,936
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities held to maturity, carrying value	599,096	562,434
Fixed maturity securities-available-for-sale	462,793	479,097
Equity securities	5,068	33
Short-term investments	46,635	29,580
Other investments	7,038	13,330
Cash and cash equivalents	$ 53,967	$ 58,936

Treasury Stock - Additional Inf

Treasury Stock - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Oct. 25, 2016
Equity [Abstract]
Share repurchase program, new limit amount			$ 25,000,000
Shares repurchased under the program	0
Shares repurchased	1,258,250	1,258,250
Shares repurchased, value	$ 22,400,000
Shares repurchased, average price	$ 17.78

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Jul. 21, 2017	Feb. 28, 2015	Jun. 30, 2017
Loss Contingencies [Line Items]
Retention amount			$ 5
AIIC [Member] | Iowa [Member]
Loss Contingencies [Line Items]
Appeal bond			27.8
AIIC [Member] | 2009 Workers' Compensation Claim [Member] | Iowa [Member]
Loss Contingencies [Line Items]
Workers compensation claim, damages awarded		$ 25.3
Workers compensation claims contingency reserves			2.4
Total amount expensed on workers compensation claim			$ 5.4
AIIC [Member] | Plaintiff Seeking Actual Damages [Member] | Iowa [Member]
Loss Contingencies [Line Items]
Amount of damages		0.3
AIIC [Member] | Plaintiff Seeking Punitive Damages [Member] | Iowa [Member]
Loss Contingencies [Line Items]
Amount of damages		$ 25
Subsequent Event [Member] | AIIC [Member]
Loss Contingencies [Line Items]
Appeal bond returned amount	$ 27.8

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event [Member] - Dividend Declared [Member]	Jul. 25, 2017$ / shares
Subsequent Event [Line Items]
Cash dividend per share	$ 0.20
Date of payment to shareholders entitled to dividends	Sep. 22, 2017
Date of record of shareholders entitled to dividends	Sep. 8, 2017