RLI (RLI) 10-Q 25 Jul 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 12, 2019
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2019
Entity File Number	001-09463
Entity Registrant Name	RLI Corp
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	37-0889946
Entity Address, Address Line One	9025 North Lindbergh Drive
Entity Address, City or Town	Peoria
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	61615
City Area Code	309
Local Phone Number	692-1000
Title of 12(b) Security	Common Stock $0.01 par value
Trading Symbol	RLI
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		44,787,197
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000084246
Amendment Flag	false

Condensed Consolidated Statemen

Condensed Consolidated Statements of Earnings and Comprehensive Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net premiums earned	$ 207,541	$ 196,522	$ 412,230	$ 386,549
Net investment income	16,998	14,577	33,563	28,809
Net realized gains	4,764	20,849	13,832	29,309
Other-than-temporary-impairment (OTTI) losses on investments				(56)
Net unrealized gains (losses) on equity securities	8,810	(12,611)	42,308	(39,383)
Consolidated revenue	238,113	219,337	501,933	405,228
Losses and settlement expenses	103,919	101,653	198,216	194,074
Policy acquisition costs	71,742	66,325	143,034	133,059
Insurance operating expenses	16,948	14,398	33,615	27,783
Interest expense on debt	1,861	1,858	3,722	3,714
General corporate expenses	3,283	2,641	6,559	4,924
Total expenses	197,753	186,875	385,146	363,554
Equity in earnings of unconsolidated investees	8,468	7,100	13,782	12,266
Earnings before income taxes	48,828	39,562	130,569	53,940
Income tax expense:
Income tax expense	8,361	6,311	24,629	8,473
Net earnings	40,467	33,251	105,940	45,467
Other comprehensive earnings (loss), net of tax	27,864	(7,675)	57,165	(34,073)
Comprehensive earnings	$ 68,331	$ 25,576	$ 163,105	$ 11,394
Basic:
Net earnings per share (in dollars per share)	$ 0.91	$ 0.75	$ 2.37	$ 1.03
Comprehensive earnings per share (in dollars per share)	1.53	0.58	3.66	0.26
Diluted:
Net earnings per share (in dollars per share)	0.89	0.74	2.35	1.01
Comprehensive earnings per share (in dollars per share)	$ 1.51	$ 0.57	$ 3.62	$ 0.25
Weighted average number of common shares outstanding
Basic (in shares)	44,704	44,310	44,620	44,266
Diluted (in shares)	45,219	44,742	45,056	44,853
Cash dividends paid per common share	$ 0.23	$ 0.22	$ 0.45	$ 0.43

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fixed income:
Available-for-sale, at fair value (amortized cost - $1,809,429 at 6/30/19 and $1,776,465 at 12/31/18)	$ 1,865,613	$ 1,760,515
Equity securities, at fair value (cost - $259,177 at 6/30/19 and $220,373 at 12/31/18)	421,801	340,483
Other invested assets	55,196	51,542
Cash	24,834	30,140
Total investments and cash	2,414,797	2,194,230
Accrued investment income	14,597	14,033
Premiums and reinsurance balances receivable, net of allowances for uncollectible amounts of $16,829 at 6/30/19 and $16,967 at 12/31/18	158,559	152,576
Ceded unearned premium	78,957	71,174
Reinsurance balances recoverable on unpaid losses and settlement expenses, net of allowances for uncollectible amounts of $9,792 at 6/30/19 and $9,793 at 12/31/18	362,310	364,999
Deferred policy acquisition costs	85,952	84,934
Property and equipment, at cost, net of accumulated depreciation of $58,330 at 6/30/19 and $54,275 at 12/31/18	53,580	54,692
Investment in unconsolidated investees	108,977	94,967
Goodwill and intangibles	54,330	54,534
Other assets	43,050	18,926
TOTAL ASSETS	3,375,109	3,105,065
Liabilities:
Unpaid losses and settlement expenses	1,506,279	1,461,348
Unearned premiums	513,819	496,505
Reinsurance balances payable	21,227	22,591
Funds held	76,331	72,309
Income taxes - deferred	50,487	24,238
Bonds payable, long-term debt	149,208	149,115
Accrued expenses	41,046	45,124
Other liabilities	56,764	26,993
TOTAL LIABILITIES	2,415,161	2,298,223
Shareholders' Equity
Common stock ($0.01 par value, 100,000,000 shares authorized; 67,717,411 shares issued, 44,787,197 shares outstanding at 6/30/19; 67,434,257 shares issued, 44,504,043 shares outstanding at 12/31/18)	677	674
Paid-in capital	315,766	305,660
Accumulated other comprehensive earnings	42,593	(14,572)
Retained earnings	993,911	908,079
Deferred compensation	7,530	8,354
Less: Treasury shares at cost (22,930,214 shares at 6/30/19 and 12/31/18)	(400,529)	(401,353)
TOTAL SHAREHOLDERS' EQUITY	959,948	806,842
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 3,375,109	$ 3,105,065

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Available-for-sale, amortized cost	$ 1,809,429	$ 1,776,465
Equity securities, cost	259,177	220,373
Premiums and reinsurance balances receivable, allowances for uncollectible amounts	16,829	16,967
Reinsurance balances recoverable on unpaid losses and settlement expenses, allowances for uncollectible amounts	9,792	9,793
Property and equipment, accumulated depreciation	$ 58,330	$ 54,275
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	67,717,411	67,434,257
Common stock, shares outstanding (in shares)	44,787,197	44,504,043
Treasury stock, shares (in shares)	22,930,214	22,930,214

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common stock	Paid-in Capital	Accumulated Other Comprehensive Earnings (Loss)	Retained Earnings	Deferred Compensation	Treasury Stock at Cost	Total
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2017	$ 67,079	$ 233,077	$ 157,919	$ 788,522	$ 8,640	$ (401,639)	$ 853,598
Balance (in shares) at Dec. 31, 2017	44,148,355
Increase (Decrease) in Shareholders' Equity
Net earnings				12,216			12,216
Other comprehensive earnings (loss), net of tax			(26,398)				(26,398)
Deferred compensation under Rabbi trust plans					(584)	584
Share-based compensation	$ 104	2,617					2,721
Share-based compensation (in shares)	104,771
Dividends and dividend equivalents				(9,290)			(9,290)
Stockholders' Equity Attributable to Parent, Ending Balance at Mar. 31, 2018	$ 67,183	235,694	(6,973)	930,028	8,056	(401,055)	832,933
Balance (in shares) at Mar. 31, 2018	44,253,126
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2017	$ 67,079	233,077	157,919	788,522	8,640	(401,639)	853,598
Balance (in shares) at Dec. 31, 2017	44,148,355
Increase (Decrease) in Shareholders' Equity
Net earnings							45,467
Other comprehensive earnings (loss), net of tax							(34,073)
Stockholders' Equity Attributable to Parent, Ending Balance at Jun. 30, 2018	$ 673	303,245	(14,648)	953,526	7,936	(400,935)	849,797
Balance (in shares) at Jun. 30, 2018	44,339,939
Increase (Decrease) in Shareholders' Equity
Cumulative-effect adjustment from ASU 2016-01 and 2018-02			(138,494)	138,580			86
Stockholders' Equity Attributable to Parent, Beginning Balance at Mar. 31, 2018	$ 67,183	235,694	(6,973)	930,028	8,056	(401,055)	832,933
Balance (in shares) at Mar. 31, 2018	44,253,126
Increase (Decrease) in Shareholders' Equity
Par value conversion from $1.00 per share to $0.01 per share	$ (66,513)	66,513
Net earnings				33,251			33,251
Other comprehensive earnings (loss), net of tax			(7,675)				(7,675)
Deferred compensation under Rabbi trust plans					(120)	120
Share-based compensation	$ 3	1,038					1,041
Share-based compensation (in shares)	86,813
Dividends and dividend equivalents				(9,753)			(9,753)
Stockholders' Equity Attributable to Parent, Ending Balance at Jun. 30, 2018	$ 673	303,245	(14,648)	953,526	7,936	(400,935)	849,797
Balance (in shares) at Jun. 30, 2018	44,339,939
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2018	$ 674	305,660	(14,572)	908,079	8,354	(401,353)	806,842
Balance (in shares) at Dec. 31, 2018	44,504,043
Increase (Decrease) in Shareholders' Equity
Net earnings				65,473			65,473
Other comprehensive earnings (loss), net of tax			29,301				29,301
Deferred compensation under Rabbi trust plans					(1,039)	1,039
Share-based compensation	$ 1	2,891					2,892
Share-based compensation (in shares)	50,213
Dividends and dividend equivalents				(9,803)			(9,803)
Stockholders' Equity Attributable to Parent, Ending Balance at Mar. 31, 2019	$ 675	308,551	14,729	963,749	7,315	(400,314)	894,705
Balance (in shares) at Mar. 31, 2019	44,554,256
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2018	$ 674	305,660	(14,572)	908,079	8,354	(401,353)	806,842
Balance (in shares) at Dec. 31, 2018	44,504,043
Increase (Decrease) in Shareholders' Equity
Net earnings							105,940
Other comprehensive earnings (loss), net of tax							57,165
Stockholders' Equity Attributable to Parent, Ending Balance at Jun. 30, 2019	$ 677	315,766	42,593	993,911	7,530	(400,529)	959,948
Balance (in shares) at Jun. 30, 2019	44,787,197
Stockholders' Equity Attributable to Parent, Beginning Balance at Mar. 31, 2019	$ 675	308,551	14,729	963,749	7,315	(400,314)	894,705
Balance (in shares) at Mar. 31, 2019	44,554,256
Increase (Decrease) in Shareholders' Equity
Net earnings				40,467			40,467
Other comprehensive earnings (loss), net of tax			27,864				27,864
Deferred compensation under Rabbi trust plans					215	(215)
Share-based compensation	$ 2	7,215					7,217
Share-based compensation (in shares)	232,941
Dividends and dividend equivalents				(10,305)			(10,305)
Stockholders' Equity Attributable to Parent, Ending Balance at Jun. 30, 2019	$ 677	$ 315,766	$ 42,593	$ 993,911	$ 7,530	$ (400,529)	$ 959,948
Balance (in shares) at Jun. 30, 2019	44,787,197

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	May 04, 2018	Dec. 31, 2017
Cash dividends paid per common share	$ 0.23	$ 0.22	$ 0.22	$ 0.21	$ 0.45	$ 0.43
Common stock, par value (in dollars per share)	$ 0.01			$ 1	$ 0.01		$ 0.01	$ 0.01	$ 1

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Net cash provided by operating activities	$ 105,347	$ 100,000
Cash Flows from Investing Activities
Investments purchased	(281,315)	(431,061)
Investments sold	167,300	282,276
Investments called or matured	52,113	67,493
Net change in short-term investments	(35,803)	9,980
Net property and equipment purchased	(3,004)	(3,638)
Other	55	62
Net cash used in investing activities	(100,654)	(74,888)
Cash Flows from Financing Activities
Cash dividends paid	(20,092)	(19,043)
Proceeds from stock option exercises	10,093	3,762
Net cash used in financing activities	(9,999)	(15,281)
Net increase (decrease) in cash	(5,306)	9,831
Cash at the beginning of the period	30,140	24,271
Cash at the end of the period	$ 24,834	$ 34,102

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2019
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES ​ A. DESCRIPTION OF BUSINESS ​ RLI Corp. (the Company) is an insurance holding company that was organized in 1965. As reported in previous SEC filings, RLI Corp. changed its state of incorporation from the State of Illinois to the State of Delaware on May 4, 2018 (the Reincorporation). The Reincorporation was effected by merging RLI Corp., an Illinois corporation (RLI Illinois) into RLI Corp., a Delaware corporation (RLI Delaware). Each outstanding share of RLI Illinois common stock, which had a par value of $1.00 per share, was automatically converted into one outstanding share of RLI Delaware common stock, with a par value of $0.01 per share. In order to reflect the new par value of common stock on the balance sheet, a $66.5 million reclassification from common stock to paid-in-capital was made during the second quarter of 2018. For more information on the Reincorporation, see RLI Corp.’s Form 8-K filed on May 7, 2018. ​ B. BASIS OF PRESENTATION ​ The unaudited condensed consolidated interim financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (GAAP) for interim financial reporting and with the instructions to Form 10-Q and Regulation S-X. Accordingly, they do not include all of the disclosures required by GAAP for complete financial statements. As such, these unaudited condensed consolidated interim financial statements should be read in conjunction with our 2018 Annual Report on Form 10-K. Management believes that the disclosures are adequate to make the information presented not misleading, and all normal and recurring adjustments necessary to present fairly the financial position at June 30, 2019 and the results of operations of RLI Corp. and subsidiaries for all periods presented have been made. The results of operations for any interim period are not necessarily indicative of the operating results for a full year. Certain reclassifications were made to 2018 to conform to the classifications used in the current year. ​ The preparation of the unaudited condensed consolidated interim financial statements requires management to make estimates and assumptions relating to the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the unaudited condensed consolidated interim financial statements and the reported amounts of revenue and expenses during the period. These estimates are inherently subject to change and actual results could differ significantly from these estimates. ​ C. ADOPTED ACCOUNTING STANDARDS ​ ASU 2016-02, Leases (Topic 842) ​ ASU 2016-02 was issued to improve the financial reporting of leasing transactions. Under previous guidance for lessees, leases were only included on the balance sheet if certain criteria, classifying the agreement as a capital lease, were met. This update requires the recognition of a right-of-use asset and a corresponding lease liability, discounted to the present value, for all leases that extend beyond 12 months. For operating leases, the asset and liability are expensed over the lease term on a straight-line basis, with all cash flows included in the operating section of the statement of cash flows. For finance leases, interest on the lease liability is recognized separately from the amortization of the right-of-use asset in the statement of earnings and the repayment of the principal portion of the lease liability is classified as a financing activity while the interest component is included in the operating section of the statement of cash flows. ​ We adopted ASU 2016-02, ASU 2018-10 Codification Improvements to Topic 842: Leases Leases (Topic 842): Targeted Improvements ​ ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities ​ Under previous guidance, the amortization period for callable debt securities held at a premium was generally the contractual life of the instrument. However, if an entity had a large number of similar loans, it could consider estimates of future principal prepayments. For those who chose not to incorporate an estimate of future prepayments, ASU 2017-08 shortens the amortization period for premium on debt securities to the earliest call date, rather than the maturity date, to align the amortization method with how the securities are quoted, priced and traded. After the earliest call date, if the call option is not exercised, the entity shall reset the effective yield using the payment terms of the debt security. Any excess of the amortized cost basis over the amount payable will be amortized to the next call date or to maturity if there are no other call dates. The method of accounting for a discount does not change and will continue to be amortized over the life of the bond. ​ We adopted ASU 2017-08 on January 1, 2019 using a modified-retrospective approach. As we had been incorporating estimates of future principal prepayments when calculating the effective yield for bonds carrying a premium under the old guidance, the adoption of this update did not have a material impact on our financial statements. ​ ASU 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ​ ASU 2018-07 was issued to simplify the accounting for share-based transactions by expanding the scope of Topic 718 from only being applicable to share-based payments to employees to include share-based payment transactions for acquiring goods and services from nonemployees. As a result, nonemployee share-based transactions will be measured by estimating the fair value of the equity instruments at the grant date, taking into consideration the probability of satisfying performance conditions. We adopted ASU 2018-07 on January 1, 2019. Our long-term incentive plan limits the awards of share-based payments to employees and directors of the Company. As our share-based compensation expense to nonemployee directors was $0.3 million in the first six months of 2019, the standard did not have a material impact on our financial statements. ​ D. PROSPECTIVE ACCOUNTING STANDARDS ​ ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ​ ASU 2016-13 was issued to provide more decision-useful information about the expected credit losses on financial instruments. Current GAAP delays the recognition of credit losses until it is probable a loss has been incurred. The update will require a financial asset measured at amortized cost, including reinsurance balances recoverable, to be presented at the net amount expected to be collected by means of an allowance for credit losses that runs through net earnings. Credit losses relating to available-for-sale debt securities will also be recorded through an allowance for credit losses. However, the amendments would limit the amount of the allowance to the amount by which fair value is below amortized cost. The measurement of credit losses on available-for-sale securities is similar under current GAAP, but the update requires the use of the allowance account through which amounts can be reversed, rather than through an irreversible write-down. ​ This ASU is effective for annual and interim reporting periods beginning after December 15, 2019. Early adoption is permitted beginning after December 15, 2018. Upon adoption, the update will be applied using the modified-retrospective approach, by which a cumulative-effect adjustment will be made to retained earnings as of the beginning of the first reporting period in which the guidance is effective. This update will have the most impact on our available-for-sale fixed income portfolio and reinsurance balances recoverable. However, as our fixed income portfolio is weighted towards higher rated bonds (83.0 percent rated A or better at June 30, 2019) and we purchase reinsurance from financially strong reinsurers for which we already have an allowance for uncollectible reinsurance amounts, we do not expect that the effect of adoption will be material. ​ ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement ​ ASU 2018-13 modifies the disclosure requirements for assets and liabilities measured at fair value. The requirements to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels and the valuation processes for Level 3 fair value measurements have all been removed. However, the changes in unrealized gains and losses included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period must be disclosed along with the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements (or other quantitative information if it is more reasonable). Finally, for investments measured at net asset value, the requirements have been modified so that the timing of liquidation and the date when restrictions from redemption might lapse are only disclosed if the investee has communicated the timing to the entity or announced the timing publicly. ​ This ASU is effective for annual and interim reporting periods beginning after December 15, 2019. As the amendments are only disclosure related and we do not currently have any assets or liabilities that are measured based on Level 3 inputs, our financial statements will not be materially impacted by this update. ​ ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract ​ ASU 2018-15 requires a customer in a cloud computing arrangement (i.e. hosting arrangement) that is a service contract to follow the internal-use software guidance to determine which implementation costs to capitalize as assets or expense as incurred. Relevant implementation costs in the development stage are capitalized, while costs incurred during the preliminary project and post-implementation stages are expensed as the activities are performed. Capitalized costs are expensed over the term of the hosting arrangement. This ASU is effective for annual and interim reporting periods beginning after December 15, 2019. Early adoption is permitted. This update can be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. We are currently evaluating how the adoption of this ASU will affect our financial statements. ​ E. INTANGIBLE ASSETS ​ Goodwill and intangible assets totaled $54.3 million and $54.5 million at June 30, 2019 and December 31, 2018, respectively, as detailed in the following table: ​ ​ ​ ​ ​ ​ ​ ​ Goodwill and Intangible Assets ​ ​ June 30, ​ ​ December 31, (in thousands) ​ ​ 2019 ​ ​ 2018 Goodwill ​ ​ ​ ​ ​ ​ Energy surety ​ $ 25,706 ​ $ 25,706 Miscellaneous and contract surety ​ ​ 15,110 ​ ​ 15,110 Small commercial ​ ​ 5,246 ​ ​ 5,246 Total goodwill ​ $ 46,062 ​ $ 46,062 ​ ​ ​ ​ ​ ​ ​ Intangibles ​ ​ ​ ​ ​ ​ State insurance licenses ​ $ 7,500 ​ $ 7,500 Definite-lived intangibles, net of accumulated amortization of $3,266 at 6/30/19 and $3,062 at 12/31/18 ​ ​ 768 ​ ​ 972 Total intangibles ​ $ 8,268 ​ $ 8,472 ​ ​ ​ ​ ​ ​ ​ Total goodwill and intangibles ​ $ 54,330 ​ $ 54,534 ​ All definite-lived intangible assets are amortized against future operating results based on their estimated useful lives. Amortization of intangible assets was $0.1 million for the second quarter of 2019 and $0.2 million for the six-month period ended June 30, 2019, the same as for the comparable periods in 2018. ​ Annual impairment assessment was performed on our energy surety goodwill, miscellaneous and contract surety goodwill, small commercial goodwill and state insurance license indefinite-lived intangible asset during the second quarter of 2019. Based upon these reviews, none of the assets were impaired. In addition, as of June 30, 2019, there were no triggering events that would suggest an updated review was necessary on the above-mentioned goodwill and intangible assets. ​ Adverse loss experience triggered the need to test the medical professional liability reporting unit during the first quarter of 2018, which resulted in a $4.4 million non-cash impairment charge. A fair value for the medical professional liability reporting unit’s agency relationships, carried as a definite-lived intangible, was determined by using a discounted cash flow valuation. The carrying value exceeded the fair value, resulting in a $0.8 million non-cash impairment charge. A fair value for the medical professional liability reporting unit’s goodwill was determined by using a weighted average of a market approach and discounted cash flow valuation. The carrying value exceeded the fair value, resulting in a $3.6 million non-cash impairment charge. Subsequent to the first quarter 2018 impairment, the medical professional liability reporting unit had no remaining goodwill or intangible assets. All impairment charges were recorded as net realized losses in the consolidated statement of earnings. ​ F. EARNINGS PER SHARE ​ Basic earnings per share (EPS) excludes dilution and is computed by dividing income available to common shareholders by the weighted-average number of common shares outstanding for the period. Diluted EPS reflects the dilution that could occur if securities or other contracts to issue common stock or common stock equivalents were exercised or converted into common stock. When inclusion of common stock equivalents increases the earnings per share or reduces the loss per share, the effect on earnings is anti-dilutive. Under these circumstances, the diluted net earnings or net loss per share is computed excluding the common stock equivalents. The following represents a reconciliation of the numerator and denominator of the basic and diluted EPS computations contained in the unaudited condensed consolidated interim financial statements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Period ​ For the Three-Month Period ​ ​ Ended June 30, 2019 ​ Ended June 30, 2018 ​ ​ Income ​ Shares ​ Per Share ​ Income ​ Shares ​ Per Share (in thousands, except per share data) (Numerator) (Denominator) Amount (Numerator) (Denominator) Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 40,467 44,704 $ 0.91 $ 33,251 44,310 $ 0.75 Effect of Dilutive Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options ​ - 515 ​ ​ ​ ​ - 432 ​ ​ ​ Diluted EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 40,467 45,219 $ 0.89 $ 33,251 44,742 $ 0.74 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Six-Month Period ​ For the Six-Month Period ​ ​ Ended June 30, 2019 ​ Ended June 30, 2018 ​ ​ Income ​ Shares ​ Per Share ​ Income ​ Shares ​ Per Share (in thousands, except per share data) (Numerator) (Denominator) Amount (Numerator) (Denominator) Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 105,940 44,620 $ 2.37 $ 45,467 44,266 $ 1.03 Effect of Dilutive Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options ​ - 436 ​ ​ ​ ​ - 587 ​ ​ ​ Diluted EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 105,940 45,056 $ 2.35 $ 45,467 44,853 $ 1.01 ​ G. COMPREHENSIVE EARNINGS ​ Our comprehensive earnings include net earnings plus after-tax unrealized gains and losses on our fixed income portfolio. In reporting other comprehensive earnings on a net basis in the statement of earnings, we used the federal statutory tax rate of 21 percent. ​ Unrealized gains, net of tax, on the fixed income portfolio for the first six months of 2019 were $57.2 million, compared to $34.1 million of unrealized losses, net of tax, during the same period last year. Unrealized gains in the first six months of 2019 were attributable to declining interest rates, which increased the fair value of securities held in the fixed income portfolio. In contrast, rising interest rates decreased the fair value of securities held in the fixed income portfolio in the first six months of 2018. ​ The following table illustrates the changes in the balance of each component of accumulated other comprehensive earnings for each period presented in the unaudited condensed consolidated interim financial statements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ For the Three-Month Periods ​ For the Six-Month Periods ​ ​ Ended June 30, ​ Ended June 30, Unrealized Gains/Losses on Available-for-Sale Securities 2019 2018 2019 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance $ 14,729 $ (6,973) $ (14,572) $ 157,919 Cumulative effect adjustment of ASU 2016-01 ​ ​ - ​ ​ - ​ ​ - ​ ​ (142,219) Adjusted beginning balance ​ $ 14,729 ​ $ (6,973) ​ $ (14,572) ​ $ 15,700 Other comprehensive earnings before reclassifications ​ 28,388 (8,385) ​ 58,183 ​ (34,795) Amounts reclassified from accumulated other comprehensive earnings ​ (524) 710 ​ (1,018) ​ 722 Net current-period other comprehensive earnings (loss) $ 27,864 $ (7,675) $ 57,165 $ (34,073) Reclassification of stranded tax effect per ASU 2018-02 ​ ​ - ​ ​ - ​ ​ - ​ ​ 3,725 Ending balance $ 42,593 $ (14,648) $ 42,593 $ (14,648) ​ In 2018, the adoption of accounting standards resulted in adjustments to accumulated other comprehensive earnings. ASU 2016-01 required equity investments to be measured at fair value with changes in fair value recognized in net earnings. A cumulative-effect adjustment was made as of the beginning of 2018, which moved $142.2 million of net unrealized gains and losses on equity securities from accumulated other comprehensive earnings to retained earnings. ​ ASU 2018-02 addressed issues arising from the enactment of the Tax Cuts and Jobs Act of 2017. Accounting guidance required deferred tax items to be revalued based on the new tax laws with the changes included in net earnings. Since other comprehensive earnings was not affected by the revaluation of the deferred tax items, the accumulated other comprehensive earnings balance was reflective of the historic tax rate instead of the newly enacted rate, which created a stranded tax effect. ASU 2018-02 allowed for the reclassification of our $3.7 million stranded tax effect out of accumulated other comprehensive earnings into retained earnings. ​ The sale or other-than-temporary impairment of an available-for-sale security results in amounts being reclassified from accumulated other comprehensive earnings to current period net earnings. The effects of reclassifications out of accumulated other comprehensive earnings by the respective line items of net earnings are presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount Reclassified from Accumulated Other ​ ​ (in thousands) ​ Comprehensive Earnings ​ ​ ​ ​ For the Three-Month ​ For the Six-Month ​ ​ Component of Accumulated ​ Periods Ended June 30, ​ Periods Ended June 30, ​ Affected line item in the Other Comprehensive Earnings 2019 2018 2019 2018 Statement of Earnings ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized gains and losses on available-for-sale securities ​ $ 664 ​ $ (899) ​ $ 1,289 ​ $ (858) ​ Net realized gains (losses) ​ ​ ​ - ​ ​ - ​ ​ - ​ ​ (56) ​ Other-than-temporary impairment (OTTI) losses on investments ​ ​ $ 664 ​ $ (899) ​ $ 1,289 ​ $ (914) ​ Earnings before income taxes ​ ​ ​ (140) ​ ​ 189 ​ ​ (271) ​ ​ 192 ​ Income tax benefit (expense) ​ ​ $ 524 ​ $ (710) ​ $ 1,018 ​ $ (722) ​ Net earnings (loss) ​

INVESTMENTS

INVESTMENTS	6 Months Ended
	Jun. 30, 2019
INVESTMENTS	2. INVESTMENTS ​ Our investments are primarily composed of fixed income debt securities and common stock equity securities. We carry our equity securities at fair value and categorize all of our debt securities as available-for-sale, which are carried at fair value. When available, we obtain quoted market prices to determine fair value for our investments. If a quoted market price is not available, fair value is estimated using a secondary pricing source or using quoted market prices of similar securities. We have no investment securities for which fair value is determined using Level 3 inputs as defined in note 3 to the unaudited condensed consolidated interim financial statements, “Fair Value Measurements.” ​ Fixed Income Securities - Available-for-Sale ​ The amortized cost and fair value of available-for-sale securities at June 30, 2019 and December 31, 2018 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Available-for-sale ​ June 30, 2019 (in thousands) Cost or Gross Gross ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair Asset Class Cost Gains Losses Value U.S. government ​ $ 194,712 ​ $ 6,774 ​ $ (101) ​ $ 201,385 U.S. agency ​ ​ 29,708 ​ ​ 1,987 ​ ​ - ​ ​ 31,695 Non-U.S. govt. & agency ​ ​ 9,249 ​ ​ 192 ​ ​ (329) ​ ​ 9,112 Agency MBS ​ ​ 402,993 ​ ​ 6,603 ​ ​ (1,400) ​ ​ 408,196 ABS/CMBS* ​ ​ 149,583 ​ ​ 2,440 ​ ​ (147) ​ ​ 151,876 Corporate ​ ​ 701,358 ​ ​ 27,072 ​ ​ (1,632) ​ ​ 726,798 Municipal ​ ​ 321,826 ​ ​ 14,750 ​ ​ (25) ​ ​ 336,551 Total Fixed Income ​ $ 1,809,429 ​ $ 59,818 ​ $ (3,634) ​ $ 1,865,613 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Available-for-sale ​ December 31, 2018 (in thousands) Cost or Gross Gross ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair Asset Class Cost Gains Losses Value U.S. government ​ $ 199,982 ​ $ 1,232 ​ $ (985) ​ $ 200,229 U.S. agency ​ ​ 31,716 ​ ​ 403 ​ ​ (215) ​ ​ 31,904 Non-U.S. govt. & agency ​ ​ 8,170 ​ ​ - ​ ​ (531) ​ ​ 7,639 Agency MBS ​ ​ 402,992 ​ ​ 1,709 ​ ​ (9,448) ​ ​ 395,253 ABS/CMBS* ​ ​ 137,224 ​ ​ 375 ​ ​ (876) ​ ​ 136,723 Corporate ​ ​ 681,909 ​ ​ 2,894 ​ ​ (16,124) ​ ​ 668,679 Municipal ​ ​ 314,472 ​ ​ 6,926 ​ ​ (1,310) ​ ​ 320,088 Total Fixed Income ​ $ 1,776,465 ​ $ 13,539 ​ $ (29,489) ​ $ 1,760,515 *Non-agency asset-backed and commercial mortgage-backed ​ The following table presents the amortized cost and fair value of available-for-sale debt securities by contractual maturity dates as of June 30, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2019 Available-for-sale ​ Amortized ​ Fair (in thousands) Cost Value Due in one year or less ​ $ 51,149 ​ $ 51,233 Due after one year through five years ​ ​ 400,628 ​ ​ 410,544 Due after five years through 10 years ​ ​ 615,648 ​ ​ 643,270 Due after 10 years ​ ​ 189,428 ​ ​ 200,494 Mtge/ABS/CMBS* ​ ​ 552,576 ​ ​ 560,072 Total available-for-sale ​ $ 1,809,429 ​ $ 1,865,613 *Mortgage-backed, asset-backed and commercial mortgage-backed ​ Unrealized Losses on Fixed Income Securities ​ We conduct and document periodic reviews of all fixed income securities with unrealized losses to evaluate whether the impairment is other-than-temporary. The following tables are used as part of our impairment analysis and illustrate the total value of fixed income securities that were in an unrealized loss position as of June 30, 2019 and December 31, 2018. The tables segregate the securities based on type, noting the fair value, amortized cost and unrealized loss on each category of investment as well as in total. The tables further classify the securities based on the length of time they have been in an unrealized loss position. As of June 30, 2019, unrealized losses on fixed income securities, as shown in the following tables, were 0.2 percent of total invested assets. Unrealized losses decreased through the first six months of 2019, as interest rates decreased from the end of 2018, increasing the fair value of securities held in the fixed income portfolio. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2019 ​ December 31, 2018 (in thousands) < 12 Mos. 12 Mos. & Total < 12 Mos. 12 Mos. & Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ — ​ $ 23,525 ​ $ 23,525 ​ $ 7,249 ​ $ 76,073 ​ $ 83,322 Amortized cost ​ ​ — ​ ​ 23,626 ​ ​ 23,626 ​ ​ 7,270 ​ ​ 77,037 ​ ​ 84,307 Unrealized Loss ​ $ — ​ $ (101) ​ $ (101) ​ $ (21) ​ $ (964) ​ $ (985) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. agency ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 8,843 ​ $ 8,843 Amortized cost ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 9,058 ​ ​ 9,058 Unrealized Loss ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (215) ​ $ (215) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-U.S. government ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ — ​ $ 3,625 ​ $ 3,625 ​ $ 5,432 ​ $ 2,207 ​ $ 7,639 Amortized cost ​ ​ — ​ ​ 3,954 ​ ​ 3,954 ​ ​ 5,571 ​ ​ 2,599 ​ ​ 8,170 Unrealized Loss ​ $ — ​ $ (329) ​ $ (329) ​ $ (139) ​ $ (392) ​ $ (531) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Agency MBS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ 1 ​ $ 129,203 ​ $ 129,204 ​ $ 25,345 ​ $ 261,325 ​ $ 286,670 Amortized cost ​ ​ 1 ​ ​ 130,603 ​ ​ 130,604 ​ ​ 25,486 ​ ​ 270,632 ​ ​ 296,118 Unrealized Loss ​ $ — ​ $ (1,400) ​ $ (1,400) ​ $ (141) ​ $ (9,307) ​ $ (9,448) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ABS/CMBS* ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ 16,755 ​ $ 11,628 ​ $ 28,383 ​ $ 46,918 ​ $ 32,137 ​ $ 79,055 Amortized cost ​ ​ 16,823 ​ ​ 11,707 ​ ​ 28,530 ​ ​ 47,146 ​ ​ 32,785 ​ ​ 79,931 Unrealized Loss ​ $ (68) ​ $ (79) ​ $ (147) ​ $ (228) ​ $ (648) ​ $ (876) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ 44,618 ​ $ 32,689 ​ $ 77,307 ​ $ 306,177 ​ $ 147,751 ​ $ 453,928 Amortized cost ​ ​ 45,578 ​ ​ 33,361 ​ ​ 78,939 ​ ​ 315,428 ​ ​ 154,624 ​ ​ 470,052 Unrealized Loss ​ $ (960) ​ $ (672) ​ $ (1,632) ​ $ (9,251) ​ $ (6,873) ​ $ (16,124) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Municipal ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ — ​ $ 8,146 ​ $ 8,146 ​ $ 6,036 ​ $ 55,681 ​ $ 61,717 Amortized cost ​ ​ — ​ ​ 8,171 ​ ​ 8,171 ​ ​ 6,052 ​ ​ 56,975 ​ ​ 63,027 Unrealized Loss ​ $ — ​ $ (25) ​ $ (25) ​ $ (16) ​ $ (1,294) ​ $ (1,310) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total fixed income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ 61,374 ​ $ 208,816 ​ $ 270,190 ​ $ 397,157 ​ $ 584,017 ​ $ 981,174 Amortized cost ​ ​ 62,402 ​ ​ 211,422 ​ ​ 273,824 ​ ​ 406,953 ​ ​ 603,710 ​ ​ 1,010,663 Unrealized Loss ​ $ (1,028) ​ $ (2,606) ​ $ (3,634) ​ $ (9,796) ​ $ (19,693) ​ $ (29,489) * Non-agency asset-backed and commercial mortgage-backed ​ The following table shows the composition of the fixed income securities in unrealized loss positions at June 30, 2019 by the National Association of Insurance Commissioners (NAIC) rating and the generally equivalent Standard & Poor’s (S&P) and Moody’s ratings. The vast majority of the securities are rated by S&P and/or Moody’s. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equivalent ​ Equivalent ​ (dollars in thousands) ​ ​ ​ NAIC S&P Moody’s ​ Amortized ​ Unrealized ​ Percent ​ Rating Rating Rating Cost Fair Value Loss to Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1 ​ AAA/AA/A ​ Aaa/Aa/A ​ $ 203,150 ​ $ 201,403 ​ $ (1,747) ​ 48.1 % 2 ​ BBB ​ Baa ​ ​ 21,914 ​ ​ 21,213 ​ ​ (701) ​ 19.3 % 3 ​ BB ​ Ba ​ ​ 22,336 ​ ​ 21,950 ​ ​ (386) ​ 10.6 % 4 ​ B ​ B ​ ​ 24,877 ​ ​ 24,148 ​ ​ (729) ​ 20.1 % 5 ​ CCC ​ Caa ​ ​ 1,547 ​ ​ 1,476 ​ ​ (71) ​ 2.0 % 6 ​ CC or lower ​ Ca or lower ​ ​ - ​ ​ - ​ ​ - ​ - % ​ ​ ​ ​ Total ​ $ 273,824 ​ $ 270,190 ​ $ (3,634) ​ 100.0 % ​ Evaluating Fixed Income Securities for OTTI ​ The fixed income portfolio contained 279 securities in an unrealized loss position as of June 30, 2019. The $3.6 million in associated unrealized losses represents 0.2 percent of the fixed income portfolio’s cost basis. Of these 279 securities, 122 have been in an unrealized loss position for 12 consecutive months or longer. All fixed income securities in the investment portfolio continue to pay the expected coupon payments under the contractual terms of the securities. Any credit-related impairment on fixed income securities we do not plan to sell and for which we are not more likely than not to be required to sell is recognized in net earnings, with the non-credit related impairment recognized in comprehensive earnings. Based on our analysis, our fixed income portfolio is of high credit quality and we believe we will recover the amortized cost basis of our fixed income securities. We continually monitor the credit quality of our fixed income investments to assess if it is probable that we will receive our contractual or estimated cash flows in the form of principal and interest. We did not recognize any other-than-temporary impairment (OTTI) losses in earnings on the fixed income portfolio in the first six months of 2019. Comparatively, we recognized $0.1 million in OTTI losses in earnings on one fixed income security that we no longer had the intent to hold in the same period in 2018. There were no OTTI losses recognized in other comprehensive earnings on the fixed income portfolio for the periods presented. ​ Unrealized Gains and Losses on Equity Securities ​ Unrealized gains recognized on equity securities still held as of June 30, 2019 were $12.9 million during the second quarter and $54.8 million during the first half of 2019. Comparatively, unrealized gains recognized on equity securities still held as of June 30, 2018 were $9.1 million during the second quarter, while unrealized losses were $4.8 million during the first half of 2018. ​ Other Invested Assets ​ We had $55.2 million of other invested assets at June 30, 2019, compared to $51.5 million at the end of 2018. Other invested assets include investments in low income housing tax credit partnerships (LIHTC), membership in the Federal Home Loan Bank of Chicago (FHLBC) and investments in private funds. Our LIHTC investments are carried at amortized cost and our investment in FHLBC stock is carried at cost. Due to the nature of the LIHTC and our membership in the FHLBC, their carrying amounts approximate fair value. The private funds are carried at fair value, using each investment’s net asset value. ​ Our LIHTC interests had a balance of $19.4 million at June 30, 2019, compared to $20.3 million at December 31, 2018 and recognized a total tax benefit of $0.6 million during the second quarter of 2019, the same as the prior year. For the six-month periods ended June 30, 2019 and 2018, our LIHTC interests recognized a total benefit of $1.2 million and $1.1 million, respectively. Our unfunded commitment for our LIHTC investments totaled $7.1 million at June 30, 2019 and will be paid out in installments through 2035. ​ As of June 30, 2019, $16.3 million of investments were pledged as collateral with the FHLBC to ensure timely access to the secured lending facility that ownership of FHLBC stock provides. As of and during the six month period ending June 30, 2019, there were no outstanding borrowings with the FHLBC. ​ We had $12.4 million of unfunded commitments related to our investments in private funds at June 30, 2019. Additionally, our interest in these investments is generally restricted from being transferred or otherwise redeemed without prior consent by the respective entities. An IPO would allow for the transfer of interest in some situations, while the timed dissolution of the partnership would trigger redemption in others. ​ Cash and Short-term Investments ​ Cash consists of uninvested balances in bank accounts. We had a cash balance of $24.8 million at June 30, 2019, compared to $30.1 million at the end of 2018. As of June 30, 2019, we had $47.4 million of short-term investments that were carried at cost and approximated fair value, compared to $11.6 million at December 31, 2018.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2019
FAIR VALUE MEASUREMENTS	3. FAIR VALUE MEASUREMENTS ​ Assets and Liabilities Recorded at Fair Value on a Recurring Basis ​ Fair value is defined as the price in the principal market that would be received for an asset to facilitate an orderly transaction between market participants on the measurement date. We determined the fair value of certain financial instruments based on their underlying characteristics and relevant transactions in the marketplace. We maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. ​ The following are the levels of the fair value hierarchy and a brief description of the type of valuation inputs that are used to establish each level. Financial assets are classified based upon the lowest level of significant input that is used to determine fair value. ​ Pricing Level 1 ​ Pricing Level 2 ​ Pricing Level 3 ​ As a part of management’s process to determine fair value, we utilize widely recognized, third-party pricing sources to determine our fair values. We have obtained an understanding of the third-party pricing sources’ valuation methodologies and inputs. The following is a description of the valuation techniques used for financial assets that are measured at fair value, including the general classification of such assets pursuant to the fair value hierarchy. ​ Corporate, Agencies, Government and Municipal Bonds: ​ Mortgage-backed Securities (MBS)/Commercial Mortgage-backed Securities (CMBS) and Asset-backed Securities (ABS): ​ For all of our fixed income securities classified as Level 2, as described above, we periodically conduct a review to assess the reasonableness of the fair values provided by our pricing services. Our review consists of a two-pronged approach. First, we compare prices provided by our pricing services to those provided by an additional source. In some cases, we obtain prices from securities brokers and compare them to the prices provided by our pricing services. In both comparisons, if discrepancies are found, we compare our prices to actual reported trade data for like securities. No changes to the fair values supplied by our pricing services have occurred as a result of our reviews. Based on these assessments, we have determined that the fair values of our Level 2 securities provided by our pricing services are reasonable. ​ Common Stock: ​ Due to the relatively short-term nature of cash, short-term investments, accounts receivable and accounts payable, their carrying amounts are reasonable estimates of fair value. Our investments in private funds, classified as other invested assets, are measured using the investment’s net asset value per share and are not categorized within the fair value hierarchy. ​ Assets measured at fair value in the accompanying unaudited condensed consolidated interim financial statements on a recurring basis are summarized below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2019 ​ ​ Fair Value Measurements Using ​ Quoted Prices in Significant Other Significant ​ ​ ​ Active Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ (in thousands) (Level 1) (Level 2) (Level 3) Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fixed income securities - available-for-sale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government ​ $ — ​ $ 201,385 ​ $ — ​ $ 201,385 U.S. agency ​ ​ — ​ ​ 31,695 ​ ​ — ​ ​ 31,695 Non-U.S. govt. & agency ​ ​ — ​ ​ 9,112 ​ ​ — ​ ​ 9,112 Agency MBS ​ ​ — ​ ​ 408,196 ​ ​ — ​ ​ 408,196 ABS/CMBS* ​ ​ — ​ ​ 151,876 ​ ​ — ​ ​ 151,876 Corporate ​ ​ — ​ ​ 726,798 ​ ​ — ​ ​ 726,798 Municipal ​ ​ — ​ ​ 336,551 ​ ​ — ​ ​ 336,551 Total fixed income securities - available-for-sale ​ $ — ​ $ 1,865,613 ​ $ — ​ $ 1,865,613 Equity securities ​ ​ 421,298 ​ ​ 503 ​ ​ — ​ ​ 421,801 Total ​ $ 421,298 ​ $ 1,866,116 ​ $ — ​ $ 2,287,414 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2018 ​ ​ Fair Value Measurements Using ​ ​ Quoted Prices in Significant Other Significant ​ ​ ​ Active Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ (in thousands) (Level 1) (Level 2) (Level 3) Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fixed income securities - available-for-sale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government ​ $ — ​ $ 200,229 ​ $ — ​ $ 200,229 U.S. agency ​ ​ — ​ ​ 31,904 ​ ​ — ​ ​ 31,904 Non-U.S. govt. & agency ​ ​ — ​ ​ 7,639 ​ ​ — ​ ​ 7,639 Agency MBS ​ ​ — ​ ​ 395,253 ​ ​ — ​ ​ 395,253 ABS/CMBS* ​ ​ — ​ ​ 136,723 ​ ​ — ​ ​ 136,723 Corporate ​ ​ — ​ ​ 668,679 ​ ​ — ​ ​ 668,679 Municipal ​ ​ — ​ ​ 320,088 ​ ​ — ​ ​ 320,088 Total fixed income securities - available-for-sale ​ $ — ​ $ 1,760,515 ​ $ — ​ $ 1,760,515 Equity securities ​ ​ 339,985 ​ ​ 498 ​ ​ — ​ ​ 340,483 Total ​ $ 339,985 ​ $ 1,761,013 ​ $ — ​ $ 2,100,998 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * Non-agency asset-backed and commercial mortgage-backed ​ As noted in the above table, we did not have any assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) during the period. Additionally, there were no securities transferred in or out of Levels 1 or 2 during the six-month period ended June 30, 2019.

HISTORICAL LOSS AND LAE DEVELOP

HISTORICAL LOSS AND LAE DEVELOPMENT	6 Months Ended
	Jun. 30, 2019
HISTORICAL LOSS AND LAE DEVELOPMENT	4. HISTORICAL LOSS AND LAE DEVELOPMENT ​ The following table is a reconciliation of our unpaid losses and settlement expenses (LAE) for the first six months of 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Six-Month Periods ​ ​ Ended June 30, ​ (in thousands) 2019 2018 ​ Unpaid losses and LAE at beginning of year ​ ​ ​ ​ ​ ​ ​ Gross ​ $ 1,461,348 ​ $ 1,271,503 ​ Ceded ​ (364,999) ​ (301,991) ​ Net ​ $ 1,096,349 ​ $ 969,512 ​ ​ ​ ​ ​ ​ ​ ​ ​ Increase (decrease) in incurred losses and LAE ​ ​ ​ ​ ​ ​ ​ Current accident year ​ $ 239,053 ​ $ 222,121 ​ Prior accident years ​ (40,837) ​ (28,047) ​ Total incurred ​ $ 198,216 ​ $ 194,074 ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss and LAE payments for claims incurred ​ ​ ​ ​ ​ ​ ​ Current accident year ​ $ (23,624) ​ $ (16,805) ​ Prior accident years ​ (126,972) ​ (118,650) ​ Total paid ​ $ (150,596) ​ $ (135,455) ​ ​ ​ ​ ​ ​ ​ ​ ​ Net unpaid losses and LAE at June 30 ​ $ 1,143,969 ​ $ 1,028,131 ​ ​ ​ ​ ​ ​ ​ ​ ​ Unpaid losses and LAE at June 30 ​ ​ ​ ​ ​ ​ ​ Gross ​ $ 1,506,279 ​ $ 1,343,248 ​ Ceded ​ (362,310) ​ (315,117) ​ Net ​ $ 1,143,969 ​ $ 1,028,131 ​ ​ For the first six months of 2019, incurred losses and LAE included $40.8 million of favorable development on prior years’ loss reserves. The majority of products experienced modest amounts of favorable development on prior accident years, with notable contributions from transportation, general liability, commercial excess and personal umbrella, professional services and surety. Executive products was the exception and experienced adverse development. ​ For the first six months of 2018, incurred losses and LAE included $28.0 million of favorable development on prior years’ loss reserves. Commercial excess and personal umbrella, general liability, marine and surety were drivers of the favorable development. Executive products, transportation and medical professional liability experienced adverse development.

INCOME TAXES

INCOME TAXES	6 Months Ended
	Jun. 30, 2019
INCOME TAXES	5. INCOME TAXES ​ Our effective tax rate for the three and six-month periods ended June 30, 2019 was 17.1 percent and 18.9 percent, respectively, compared to 16.0 percent and 15.7 percent, respectively, for the same periods in 2018. Effective rates are dependent upon components of pretax earnings and the related tax effects. The effective rate was higher for the first six months of 2019 due largely to higher levels of pre-tax earnings, which caused the tax-favored adjustments to be smaller on a percentage basis in 2019 compared to the prior year. ​ Income tax expense attributable to income from operations for the three and six-month periods ended June 30, 2019 and 2018 differed from the amounts computed by applying the U.S. federal tax rate of 21 percent to pretax income by the items detailed in the below table. In interim periods, income taxes are adjusted to reflect the effective tax rate we anticipate for the year, with adjustments flowing through the other items line. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Periods Ended June 30, For the Six-Month Periods Ended June 30, ​ ​ 2019 ​ ​ 2018 ​ ​ 2019 ​ ​ 2018 ​ (in thousands) Amount % Amount % ​ Amount % ​ Amount % ​ Provision for income taxes at the statutory rate of 21% ​ $ 10,254 ​ 21.0 % ​ $ 8,308 ​ 21.0 % ​ $ 27,419 ​ 21.0 % ​ $ 11,327 ​ 21.0 % Increase (reduction) in taxes resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Excess tax benefit on share-based compensation ​ ​ (2,191) ​ (4.5) % ​ ​ (924) ​ (2.3) % ​ ​ (2,932) ​ (2.3) % ​ ​ (2,067) ​ (3.9) % Tax exempt interest income ​ ​ (309) ​ (0.6) % ​ ​ (504) ​ (1.3) % ​ ​ (654) ​ (0.5) % ​ ​ (1,085) ​ (2.0) % Dividends received deduction ​ ​ (214) ​ (0.4) % ​ ​ (169) ​ (0.4) % ​ ​ (417) ​ (0.3) % ​ ​ (366) ​ (0.7) % ESOP dividends paid deduction ​ ​ (140) ​ (0.3) % ​ ​ (145) ​ (0.4) % ​ ​ (277) ​ (0.2) % ​ ​ (284) ​ (0.5) % Other items, net ​ ​ 961 ​ 1.9 % ​ ​ (255) ​ (0.6) % ​ ​ 1,490 ​ 1.2 % ​ ​ 948 ​ 1.8 % Total tax expense ​ $ 8,361 ​ 17.1 % ​ $ 6,311 ​ 16.0 % ​ $ 24,629 ​ 18.9 % ​ $ 8,473 ​ 15.7 % ​

STOCK BASED COMPENSATION

STOCK BASED COMPENSATION	6 Months Ended
	Jun. 30, 2019
STOCK BASED COMPENSATION	6. STOCK BASED COMPENSATION ​ Our RLI Corp. Long-Term Incentive Plan (2010 LTIP) was in place from 2010 to 2015. The 2010 LTIP provided for equity-based compensation, including stock options, up to a maximum of 4,000,000 shares of common stock (subject to adjustment for changes in our capitalization and other events). Between 2010 and 2015, we granted 2,878,000 stock options under the 2010 LTIP. The 2010 LTIP was replaced in 2015. ​ In 2015, our shareholders approved the 2015 RLI Corp. Long-Term Incentive Plan (2015 LTIP), which provides for equity-based compensation and replaced the 2010 LTIP. In conjunction with the adoption of the 2015 LTIP, effective May 7, 2015, options were no longer granted under the 2010 LTIP. Awards under the 2015 LTIP may be in the form of restricted stock, restricted stock units, stock options (non-qualified only), stock appreciation rights, performance units as well as other stock-based awards. Eligibility under the 2015 LTIP is limited to employees and directors of the Company or any affiliate. The granting of awards under the 2015 LTIP is solely at the discretion of the board of directors. The maximum number of shares of common stock available for distribution under the 2015 LTIP is 4,000,000 shares (subject to adjustment for changes in our capitalization and other events). Since the plan’s approval in 2015, we have granted 2,217,710 awards under the 2015 LTIP, including 314,080 thus far in 2019. ​ Stock Options ​ Under the 2015 LTIP, as under the 2010 LTIP, we grant stock options for shares with an exercise price equal to the fair market value of the shares at the date of grant (subject to adjustments for changes in our capitalization, special dividends and other events as set forth in such plans). Options generally vest and become exercisable ratably over a five-year period and expire eight years after grant. ​ For most participants, the requisite service period and vesting period will be the same. For participants who are retirement eligible, defined by the plan as those individuals whose age and years of service equals 75 , the requisite service period is deemed to be met and options are immediately expensed on the date of grant. For participants who will become retirement eligible during the vesting period, the requisite service period over which expense is recognized is the period between the grant date and the attainment of retirement eligibility. Shares issued upon option exercise are newly issued shares. ​ The following tables summarize option activity for the periods ended June 30, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ Weighted ​ Average ​ Aggregate ​ ​ Number of ​ Average ​ Remaining ​ Intrinsic ​ ​ Options ​ Exercise ​ Contractual ​ Value ​ Outstanding Price Life (in 000’s) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding options at January 1, 2019 ​ 1,964,880 ​ $ 54.24 ​ ​ ​ ​ ​ Options granted ​ 292,150 ​ $ 80.36 ​ ​ ​ ​ ​ Options exercised ​ (414,470) ​ $ 44.70 ​ ​ ​ $ 14,941 Options canceled/forfeited ​ (33,600) ​ $ 57.61 ​ ​ ​ ​ ​ Outstanding options at June 30, 2019 ​ 1,808,960 ​ $ 60.59 ​ 5.57 ​ $ 45,448 Exercisable options at June 30, 2019 ​ 672,110 ​ $ 52.17 ​ 4.21 ​ $ 22,544 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ Weighted ​ Average ​ Aggregate ​ ​ Number of ​ Average ​ Remaining ​ Intrinsic ​ ​ Options ​ Exercise ​ Contractual ​ Value ​ Outstanding Price Life (in 000’s) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding options at January 1, 2018 ​ 2,257,015 ​ $ 46.80 ​ ​ ​ ​ ​ Options granted ​ 367,500 ​ $ 63.27 ​ ​ ​ ​ ​ Options exercised ​ (337,000) ​ $ 31.60 ​ ​ ​ $ 11,151 Options canceled/forfeited ​ (5,200) ​ $ 62.04 ​ ​ ​ ​ ​ Outstanding options at June 30, 2018 ​ 2,282,315 ​ $ 51.66 ​ 5.34 ​ $ 33,224 Exercisable options at June 30, 2018 ​ 996,265 ​ $ 44.04 ​ 3.89 ​ $ 22,089 ​ The majority of our stock options are granted annually at our regular board meeting in May. In addition, options are approved at the May meeting for quarterly grants to certain retirement eligible employees. Since stock option grants to retirement eligible employees are fully expensed when issued, the approach allows for a more even expense distribution throughout the year. ​ Thus far in 2019, 292,150 stock options were granted with a weighted average exercise price of $80.36 and a weighted average fair value of $13.33 . We recognized $1.4 million of expense in the second quarter of 2019 and $2.4 million in the first six months of 2019 related to options vesting. Since options granted under our 2015 LTIP are non-qualified, we recorded a tax benefit of $0.3 million in the second quarter of 2019 and $0.5 million in the first six months of 2019 related to this compensation expense. Total unrecognized compensation expense relating to outstanding and unvested options was $6.7 million, which will be recognized over the remainder of the vesting period. Comparatively, we recognized $1.3 million of compensation expense in the second quarter of 2018 and $2.3 million in the first six months of 2018. We recorded a tax benefit of $0.3 million in the second quarter of 2018 and $0.5 million in the first six months of 2018 related to this compensation expense. ​ The fair value of options was estimated using a Black-Scholes based option pricing model with the following weighted average grant-date assumptions and weighted average fair values as of June 30: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average fair value of grants ​ $ 13.33 ​ ​ $ 10.20 ​ Risk-free interest rates ​ ​ 2.42 % ​ ​ 2.69 % Dividend yield ​ ​ 2.69 % ​ ​ 3.15 % Expected volatility ​ ​ 22.71 % ​ ​ 22.88 % Expected option life ​ ​ 4.96 years ​ ​ 5.06 years ​ The risk-free rate was determined based on U.S. treasury yields that most closely approximated the option’s expected life. The dividend yield was determined based on the average annualized quarterly dividends paid during the most recent five-year period and incorporated a consideration for special dividends paid in recent history. The expected volatility was calculated based on the median of the rolling volatilities for the expected life of the options. The expected option life was determined based on historical exercise behavior and the assumption that all outstanding options will be exercised at the midpoint of the current date and remaining contractual term, adjusted for the demographics of the current year’s grant. ​ Restricted Stock Units ​ In addition to stock options, restricted stock units (RSUs) are granted with a value equal to the closing stock price of the Company’s stock on the dates the units are granted. Generally, these units have a three-year cliff vesting. When participants terminate employment with the Company after having met the definition of retirement under the 2015 LTIP, defined as those individuals whose age and years of service equals 75 , the RSUs will become fully vested. In addition, the RSUs have dividend participation, which accrue as additional units and are settled with granted stock units at the end of the vesting period. ​ As of June 30, 2019, 45,350 RSUs have been granted to employees under the 2015 LTIP, including 15,275 in 2019, and 44,431 remain outstanding. We recognized $0.2 million of expense on these units in the second quarter of 2019 and $0.3 million in the first six months of 2019. Total unrecognized compensation expense relating to outstanding and unvested RSUs was $1.5 million, which will be recognized over the remainder of the vesting period. Comparatively, we recognized $0.1 million of expense in the second quarter of 2018 and $0.2 million in the first six months of 2018. ​ In 2018 and 2019, each outside director received RSUs with a fair market value of $50,000 on the date of grant as part of annual director compensation. Director RSUs vest one year from the date of grant. As of June 30, 2019, 15,085 restricted stock units have been granted to directors under the 2015 LTIP, including 6,655 in 2019, and 7,402 remain outstanding. We recognized $0.2 million of compensation expense on these units in the second quarter of 2019 and $0.3 million in the first six months of 2019. Total unrecognized compensation expense relating to outstanding and unvested director RSUs was $0.4 million, which will be recognized over the remainder of the vesting period. Comparatively, we recognized $0.1 million of compensation expense for the three and six-month periods ended June 30, 2018.

OPERATING SEGMENT INFORMATION

OPERATING SEGMENT INFORMATION	6 Months Ended
	Jun. 30, 2019
OPERATING SEGMENT INFORMATION	7. OPERATING SEGMENT INFORMATION ​ Selected information by operating segment is presented in the table below. Additionally, the table reconciles segment totals to total earnings and total revenues. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Periods ​ For the Six-Month Periods REVENUES ​ Ended June 30, ​ Ended June 30, (in thousands) 2019 2018 2019 2018 Casualty ​ $ 138,344 ​ $ 129,613 ​ $ 275,244 ​ $ 255,463 Property ​ ​ 39,972 ​ ​ 37,190 ​ ​ 78,718 ​ ​ 72,372 Surety ​ ​ 29,225 ​ ​ 29,719 ​ ​ 58,268 ​ ​ 58,714 Net premiums earned ​ $ 207,541 ​ $ 196,522 ​ $ 412,230 ​ $ 386,549 Net investment income ​ ​ 16,998 ​ ​ 14,577 ​ ​ 33,563 ​ ​ 28,809 Net realized gains ​ ​ 4,764 ​ ​ 20,849 ​ ​ 13,832 ​ ​ 29,253 Net unrealized gains (losses) on equity securities ​ ​ 8,810 ​ ​ (12,611) ​ ​ 42,308 ​ ​ (39,383) Total consolidated revenue ​ $ 238,113 ​ $ 219,337 ​ $ 501,933 ​ $ 405,228 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ NET EARNINGS ​ ​ ​ ​ (in thousands) 2019 2018 2019 2018 Casualty ​ $ 6,939 ​ $ 2,854 ​ $ 12,282 ​ $ 4,415 Property ​ ​ (436) ​ ​ 3,647 ​ ​ 7,810 ​ ​ 9,529 Surety ​ ​ 8,429 ​ ​ 7,645 ​ ​ 17,273 ​ ​ 17,689 Net underwriting income ​ $ 14,932 ​ $ 14,146 ​ $ 37,365 ​ $ 31,633 Net investment income ​ ​ 16,998 ​ ​ 14,577 ​ ​ 33,563 ​ ​ 28,809 Net realized gains ​ ​ 4,764 ​ ​ 20,849 ​ ​ 13,832 ​ ​ 29,253 Net unrealized gains (losses) on equity securities ​ ​ 8,810 ​ ​ (12,611) ​ ​ 42,308 ​ ​ (39,383) General corporate expense and interest on debt ​ ​ (5,144) ​ ​ (4,499) ​ ​ (10,281) ​ ​ (8,638) Equity in earnings of unconsolidated investees ​ ​ 8,468 ​ ​ 7,100 ​ ​ 13,782 ​ ​ 12,266 Total earnings before income taxes ​ $ 48,828 ​ $ 39,562 ​ $ 130,569 ​ $ 53,940 Income tax expense ​ ​ 8,361 ​ ​ 6,311 ​ ​ 24,629 ​ ​ 8,473 Total net earnings ​ $ 40,467 ​ $ 33,251 ​ $ 105,940 ​ $ 45,467 ​ The following table further summarizes revenues by major product type within each operating segment: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Periods ​ For the Six-Month Periods NET PREMIUMS EARNED ​ Ended June 30, ​ Ended June 30, (in thousands) 2019 2018 2019 2018 Casualty ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial excess and personal umbrella ​ $ 34,340 ​ $ 30,649 ​ $ 66,621 ​ $ 60,601 General liability ​ ​ 25,347 ​ ​ 23,338 ​ ​ 49,235 ​ ​ 46,503 Commercial transportation ​ ​ 20,508 ​ ​ 20,648 ​ ​ 40,912 ​ ​ 39,823 Professional services ​ ​ 19,275 ​ ​ 19,846 ​ ​ 39,574 ​ ​ 39,669 Small commercial ​ ​ 13,315 ​ ​ 12,901 ​ ​ 26,503 ​ ​ 25,791 Executive products ​ ​ 6,381 ​ ​ 5,144 ​ ​ 12,450 ​ ​ 10,196 Other casualty ​ ​ 19,178 ​ ​ 17,087 ​ ​ 39,949 ​ ​ 32,880 Total ​ $ 138,344 ​ $ 129,613 ​ $ 275,244 ​ $ 255,463 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Property ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marine ​ $ 18,579 ​ $ 14,941 ​ $ 35,600 ​ $ 28,798 Commercial property ​ ​ 16,275 ​ ​ 17,856 ​ ​ 33,150 ​ ​ 34,807 Specialty personal ​ ​ 4,792 ​ ​ 4,129 ​ ​ 9,376 ​ ​ 8,271 Other property ​ ​ 326 ​ ​ 264 ​ ​ 592 ​ ​ 496 Total ​ $ 39,972 ​ $ 37,190 ​ $ 78,718 ​ $ 72,372 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Surety ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Miscellaneous ​ $ 11,280 ​ $ 11,719 ​ $ 22,882 ​ $ 23,361 Commercial ​ ​ 7,077 ​ ​ 6,761 ​ ​ 13,811 ​ ​ 13,474 Contract ​ ​ 6,970 ​ ​ 7,012 ​ ​ 13,599 ​ ​ 13,358 Energy ​ ​ 3,898 ​ ​ 4,227 ​ ​ 7,976 ​ ​ 8,521 Total ​ $ 29,225 ​ $ 29,719 ​ $ 58,268 ​ $ 58,714 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Grand Total ​ $ 207,541 ​ $ 196,522 ​ $ 412,230 ​ $ 386,549 ​

LEASES

LEASES	6 Months Ended
	Jun. 30, 2019
LEASES	8. LEASES ​ We adopted ASU 2016-02, Leases on January 1, 2019, which resulted in the recognition of operating leases on the balance sheet in 2019 and forward. See note 1c for more information on the adoption of the ASU. Right-of-use assets are included in the other assets line item and lease liabilities are included in the other liabilities line item of the consolidated balance sheet. We determine if a contract contains a lease at inception and recognize operating lease right-of-use assets and operating lease liabilities based on the present value of the future minimum lease payments at the commencement date. As our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of future payments. Lease agreements may include options to extend or terminate. The options are exercised at our discretion and are included in operating lease liabilities if it is reasonably certain the option will be exercised. Lease agreements have lease and non-lease components, which are accounted for as a single lease component. Lease expense is recognized on a straight-line basis over the lease term. ​ The Company’s operating lease obligations are for branch office facilities. Our leases have remaining lease terms of 1 to 16 years. Expenses associated with leases totaled $6.9 million in 2018, $6.8 million in 2017 and $6.4 million in 2016. The components of lease expense and other lease information as of and during the three and six-month period ended June 30, 2019 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Period ​ For the Six-Month Period (in thousands) ​ Ended June 30, 2019 Ended June 30, 2019 Operating lease cost ​ $ 1,445 ​ $ 2,927 ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in measurement of lease liabilities ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 1,402 ​ $ 2,797 ​ ​ ​ ​ ​ ​ ​ Right-of-use assets obtained in exchange for new operating lease liabilities ​ $ 231 ​ $ 951 ​ ​ ​ ​ ​ ​ ​ Reduction to right-of-use assets resulting from reduction to lease liabilities ​ $ 1,279 ​ $ 1,279 ​ ​ ​ ​ ​ ​ (in thousands) ​ June 30, 2019 Operating lease right-of-use assets ​ $ 24,449 ​ ​ ​ ​ ​ ​ Operating lease liabilities ​ $ 26,640 ​ ​ ​ ​ ​ ​ Weighted-average remaining lease term - operating leases ​ ​ 5.13 years ​ ​ ​ ​ ​ Weighted-average discount rate - operating leases ​ ​ 2.33 % ​ Future minimum lease payments under non-cancellable leases as of June 30, 2019 and December 31, 2018 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ June 30, 2019 ​ December 31, 2018 2019 ​ $ 2,915 ​ $ 5,911 2020 ​ ​ 5,914 ​ ​ 6,019 2021 ​ ​ 5,819 ​ ​ 5,924 2022 ​ ​ 5,753 ​ ​ 5,884 2023 ​ ​ 4,297 ​ ​ 4,459 Thereafter ​ ​ 3,700 ​ ​ 3,968 Total future minimum lease payments ​ $ 28,398 ​ $ 32,165 ​ ​ ​ ​ ​ ​ ​ Less imputed interest ​ ​ (1,758) ​ ​ N/A Total operating lease liability ​ $ 26,640 ​ ​ N/A ​

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2019
DESCRIPTION OF BUSINESS	A. DESCRIPTION OF BUSINESS ​ RLI Corp. (the Company) is an insurance holding company that was organized in 1965. As reported in previous SEC filings, RLI Corp. changed its state of incorporation from the State of Illinois to the State of Delaware on May 4, 2018 (the Reincorporation). The Reincorporation was effected by merging RLI Corp., an Illinois corporation (RLI Illinois) into RLI Corp., a Delaware corporation (RLI Delaware). Each outstanding share of RLI Illinois common stock, which had a par value of $1.00 per share, was automatically converted into one outstanding share of RLI Delaware common stock, with a par value of $0.01 per share. In order to reflect the new par value of common stock on the balance sheet, a $66.5 million reclassification from common stock to paid-in-capital was made during the second quarter of 2018. For more information on the Reincorporation, see RLI Corp.’s Form 8-K filed on May 7, 2018.
BASIS OF PRESENTATION	B. BASIS OF PRESENTATION ​ The unaudited condensed consolidated interim financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (GAAP) for interim financial reporting and with the instructions to Form 10-Q and Regulation S-X. Accordingly, they do not include all of the disclosures required by GAAP for complete financial statements. As such, these unaudited condensed consolidated interim financial statements should be read in conjunction with our 2018 Annual Report on Form 10-K. Management believes that the disclosures are adequate to make the information presented not misleading, and all normal and recurring adjustments necessary to present fairly the financial position at June 30, 2019 and the results of operations of RLI Corp. and subsidiaries for all periods presented have been made. The results of operations for any interim period are not necessarily indicative of the operating results for a full year. Certain reclassifications were made to 2018 to conform to the classifications used in the current year. ​ The preparation of the unaudited condensed consolidated interim financial statements requires management to make estimates and assumptions relating to the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the unaudited condensed consolidated interim financial statements and the reported amounts of revenue and expenses during the period. These estimates are inherently subject to change and actual results could differ significantly from these estimates.
ADOPTED ACCOUNTING STANDARDS	C. ADOPTED ACCOUNTING STANDARDS ​ ASU 2016-02, Leases (Topic 842) ​ ASU 2016-02 was issued to improve the financial reporting of leasing transactions. Under previous guidance for lessees, leases were only included on the balance sheet if certain criteria, classifying the agreement as a capital lease, were met. This update requires the recognition of a right-of-use asset and a corresponding lease liability, discounted to the present value, for all leases that extend beyond 12 months. For operating leases, the asset and liability are expensed over the lease term on a straight-line basis, with all cash flows included in the operating section of the statement of cash flows. For finance leases, interest on the lease liability is recognized separately from the amortization of the right-of-use asset in the statement of earnings and the repayment of the principal portion of the lease liability is classified as a financing activity while the interest component is included in the operating section of the statement of cash flows. ​ We adopted ASU 2016-02, ASU 2018-10 Codification Improvements to Topic 842: Leases Leases (Topic 842): Targeted Improvements ​ ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities ​ Under previous guidance, the amortization period for callable debt securities held at a premium was generally the contractual life of the instrument. However, if an entity had a large number of similar loans, it could consider estimates of future principal prepayments. For those who chose not to incorporate an estimate of future prepayments, ASU 2017-08 shortens the amortization period for premium on debt securities to the earliest call date, rather than the maturity date, to align the amortization method with how the securities are quoted, priced and traded. After the earliest call date, if the call option is not exercised, the entity shall reset the effective yield using the payment terms of the debt security. Any excess of the amortized cost basis over the amount payable will be amortized to the next call date or to maturity if there are no other call dates. The method of accounting for a discount does not change and will continue to be amortized over the life of the bond. ​ We adopted ASU 2017-08 on January 1, 2019 using a modified-retrospective approach. As we had been incorporating estimates of future principal prepayments when calculating the effective yield for bonds carrying a premium under the old guidance, the adoption of this update did not have a material impact on our financial statements. ​ ASU 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ​ ASU 2018-07 was issued to simplify the accounting for share-based transactions by expanding the scope of Topic 718 from only being applicable to share-based payments to employees to include share-based payment transactions for acquiring goods and services from nonemployees. As a result, nonemployee share-based transactions will be measured by estimating the fair value of the equity instruments at the grant date, taking into consideration the probability of satisfying performance conditions. We adopted ASU 2018-07 on January 1, 2019. Our long-term incentive plan limits the awards of share-based payments to employees and directors of the Company. As our share-based compensation expense to nonemployee directors was $0.3 million in the first six months of 2019, the standard did not have a material impact on our financial statements.
PROSPECTIVE ACCOUNTING STANDARDS	D. PROSPECTIVE ACCOUNTING STANDARDS ​ ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ​ ASU 2016-13 was issued to provide more decision-useful information about the expected credit losses on financial instruments. Current GAAP delays the recognition of credit losses until it is probable a loss has been incurred. The update will require a financial asset measured at amortized cost, including reinsurance balances recoverable, to be presented at the net amount expected to be collected by means of an allowance for credit losses that runs through net earnings. Credit losses relating to available-for-sale debt securities will also be recorded through an allowance for credit losses. However, the amendments would limit the amount of the allowance to the amount by which fair value is below amortized cost. The measurement of credit losses on available-for-sale securities is similar under current GAAP, but the update requires the use of the allowance account through which amounts can be reversed, rather than through an irreversible write-down. ​ This ASU is effective for annual and interim reporting periods beginning after December 15, 2019. Early adoption is permitted beginning after December 15, 2018. Upon adoption, the update will be applied using the modified-retrospective approach, by which a cumulative-effect adjustment will be made to retained earnings as of the beginning of the first reporting period in which the guidance is effective. This update will have the most impact on our available-for-sale fixed income portfolio and reinsurance balances recoverable. However, as our fixed income portfolio is weighted towards higher rated bonds (83.0 percent rated A or better at June 30, 2019) and we purchase reinsurance from financially strong reinsurers for which we already have an allowance for uncollectible reinsurance amounts, we do not expect that the effect of adoption will be material. ​ ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement ​ ASU 2018-13 modifies the disclosure requirements for assets and liabilities measured at fair value. The requirements to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels and the valuation processes for Level 3 fair value measurements have all been removed. However, the changes in unrealized gains and losses included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period must be disclosed along with the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements (or other quantitative information if it is more reasonable). Finally, for investments measured at net asset value, the requirements have been modified so that the timing of liquidation and the date when restrictions from redemption might lapse are only disclosed if the investee has communicated the timing to the entity or announced the timing publicly. ​ This ASU is effective for annual and interim reporting periods beginning after December 15, 2019. As the amendments are only disclosure related and we do not currently have any assets or liabilities that are measured based on Level 3 inputs, our financial statements will not be materially impacted by this update. ​ ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract ​ ASU 2018-15 requires a customer in a cloud computing arrangement (i.e. hosting arrangement) that is a service contract to follow the internal-use software guidance to determine which implementation costs to capitalize as assets or expense as incurred. Relevant implementation costs in the development stage are capitalized, while costs incurred during the preliminary project and post-implementation stages are expensed as the activities are performed. Capitalized costs are expensed over the term of the hosting arrangement. This ASU is effective for annual and interim reporting periods beginning after December 15, 2019. Early adoption is permitted. This update can be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. We are currently evaluating how the adoption of this ASU will affect our financial statements.
INTANGIBLE ASSETS	E. INTANGIBLE ASSETS ​ Goodwill and intangible assets totaled $54.3 million and $54.5 million at June 30, 2019 and December 31, 2018, respectively, as detailed in the following table: ​ ​ ​ ​ ​ ​ ​ ​ Goodwill and Intangible Assets ​ ​ June 30, ​ ​ December 31, (in thousands) ​ ​ 2019 ​ ​ 2018 Goodwill ​ ​ ​ ​ ​ ​ Energy surety ​ $ 25,706 ​ $ 25,706 Miscellaneous and contract surety ​ ​ 15,110 ​ ​ 15,110 Small commercial ​ ​ 5,246 ​ ​ 5,246 Total goodwill ​ $ 46,062 ​ $ 46,062 ​ ​ ​ ​ ​ ​ ​ Intangibles ​ ​ ​ ​ ​ ​ State insurance licenses ​ $ 7,500 ​ $ 7,500 Definite-lived intangibles, net of accumulated amortization of $3,266 at 6/30/19 and $3,062 at 12/31/18 ​ ​ 768 ​ ​ 972 Total intangibles ​ $ 8,268 ​ $ 8,472 ​ ​ ​ ​ ​ ​ ​ Total goodwill and intangibles ​ $ 54,330 ​ $ 54,534 ​ All definite-lived intangible assets are amortized against future operating results based on their estimated useful lives. Amortization of intangible assets was $0.1 million for the second quarter of 2019 and $0.2 million for the six-month period ended June 30, 2019, the same as for the comparable periods in 2018. ​ Annual impairment assessment was performed on our energy surety goodwill, miscellaneous and contract surety goodwill, small commercial goodwill and state insurance license indefinite-lived intangible asset during the second quarter of 2019. Based upon these reviews, none of the assets were impaired. In addition, as of June 30, 2019, there were no triggering events that would suggest an updated review was necessary on the above-mentioned goodwill and intangible assets. ​ Adverse loss experience triggered the need to test the medical professional liability reporting unit during the first quarter of 2018, which resulted in a $4.4 million non-cash impairment charge. A fair value for the medical professional liability reporting unit’s agency relationships, carried as a definite-lived intangible, was determined by using a discounted cash flow valuation. The carrying value exceeded the fair value, resulting in a $0.8 million non-cash impairment charge. A fair value for the medical professional liability reporting unit’s goodwill was determined by using a weighted average of a market approach and discounted cash flow valuation. The carrying value exceeded the fair value, resulting in a $3.6 million non-cash impairment charge. Subsequent to the first quarter 2018 impairment, the medical professional liability reporting unit had no remaining goodwill or intangible assets. All impairment charges were recorded as net realized losses in the consolidated statement of earnings.
EARNINGS PER SHARE	F. EARNINGS PER SHARE ​ Basic earnings per share (EPS) excludes dilution and is computed by dividing income available to common shareholders by the weighted-average number of common shares outstanding for the period. Diluted EPS reflects the dilution that could occur if securities or other contracts to issue common stock or common stock equivalents were exercised or converted into common stock. When inclusion of common stock equivalents increases the earnings per share or reduces the loss per share, the effect on earnings is anti-dilutive. Under these circumstances, the diluted net earnings or net loss per share is computed excluding the common stock equivalents. The following represents a reconciliation of the numerator and denominator of the basic and diluted EPS computations contained in the unaudited condensed consolidated interim financial statements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Period ​ For the Three-Month Period ​ ​ Ended June 30, 2019 ​ Ended June 30, 2018 ​ ​ Income ​ Shares ​ Per Share ​ Income ​ Shares ​ Per Share (in thousands, except per share data) (Numerator) (Denominator) Amount (Numerator) (Denominator) Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 40,467 44,704 $ 0.91 $ 33,251 44,310 $ 0.75 Effect of Dilutive Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options ​ - 515 ​ ​ ​ ​ - 432 ​ ​ ​ Diluted EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 40,467 45,219 $ 0.89 $ 33,251 44,742 $ 0.74 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Six-Month Period ​ For the Six-Month Period ​ ​ Ended June 30, 2019 ​ Ended June 30, 2018 ​ ​ Income ​ Shares ​ Per Share ​ Income ​ Shares ​ Per Share (in thousands, except per share data) (Numerator) (Denominator) Amount (Numerator) (Denominator) Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 105,940 44,620 $ 2.37 $ 45,467 44,266 $ 1.03 Effect of Dilutive Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options ​ - 436 ​ ​ ​ ​ - 587 ​ ​ ​ Diluted EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 105,940 45,056 $ 2.35 $ 45,467 44,853 $ 1.01
COMPREHENSIVE EARNINGS	G. COMPREHENSIVE EARNINGS ​ Our comprehensive earnings include net earnings plus after-tax unrealized gains and losses on our fixed income portfolio. In reporting other comprehensive earnings on a net basis in the statement of earnings, we used the federal statutory tax rate of 21 percent. ​ Unrealized gains, net of tax, on the fixed income portfolio for the first six months of 2019 were $57.2 million, compared to $34.1 million of unrealized losses, net of tax, during the same period last year. Unrealized gains in the first six months of 2019 were attributable to declining interest rates, which increased the fair value of securities held in the fixed income portfolio. In contrast, rising interest rates decreased the fair value of securities held in the fixed income portfolio in the first six months of 2018. ​ The following table illustrates the changes in the balance of each component of accumulated other comprehensive earnings for each period presented in the unaudited condensed consolidated interim financial statements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ For the Three-Month Periods ​ For the Six-Month Periods ​ ​ Ended June 30, ​ Ended June 30, Unrealized Gains/Losses on Available-for-Sale Securities 2019 2018 2019 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance $ 14,729 $ (6,973) $ (14,572) $ 157,919 Cumulative effect adjustment of ASU 2016-01 ​ ​ - ​ ​ - ​ ​ - ​ ​ (142,219) Adjusted beginning balance ​ $ 14,729 ​ $ (6,973) ​ $ (14,572) ​ $ 15,700 Other comprehensive earnings before reclassifications ​ 28,388 (8,385) ​ 58,183 ​ (34,795) Amounts reclassified from accumulated other comprehensive earnings ​ (524) 710 ​ (1,018) ​ 722 Net current-period other comprehensive earnings (loss) $ 27,864 $ (7,675) $ 57,165 $ (34,073) Reclassification of stranded tax effect per ASU 2018-02 ​ ​ - ​ ​ - ​ ​ - ​ ​ 3,725 Ending balance $ 42,593 $ (14,648) $ 42,593 $ (14,648) ​ In 2018, the adoption of accounting standards resulted in adjustments to accumulated other comprehensive earnings. ASU 2016-01 required equity investments to be measured at fair value with changes in fair value recognized in net earnings. A cumulative-effect adjustment was made as of the beginning of 2018, which moved $142.2 million of net unrealized gains and losses on equity securities from accumulated other comprehensive earnings to retained earnings. ​ ASU 2018-02 addressed issues arising from the enactment of the Tax Cuts and Jobs Act of 2017. Accounting guidance required deferred tax items to be revalued based on the new tax laws with the changes included in net earnings. Since other comprehensive earnings was not affected by the revaluation of the deferred tax items, the accumulated other comprehensive earnings balance was reflective of the historic tax rate instead of the newly enacted rate, which created a stranded tax effect. ASU 2018-02 allowed for the reclassification of our $3.7 million stranded tax effect out of accumulated other comprehensive earnings into retained earnings. ​ The sale or other-than-temporary impairment of an available-for-sale security results in amounts being reclassified from accumulated other comprehensive earnings to current period net earnings. The effects of reclassifications out of accumulated other comprehensive earnings by the respective line items of net earnings are presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount Reclassified from Accumulated Other ​ ​ (in thousands) ​ Comprehensive Earnings ​ ​ ​ ​ For the Three-Month ​ For the Six-Month ​ ​ Component of Accumulated ​ Periods Ended June 30, ​ Periods Ended June 30, ​ Affected line item in the Other Comprehensive Earnings 2019 2018 2019 2018 Statement of Earnings ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized gains and losses on available-for-sale securities ​ $ 664 ​ $ (899) ​ $ 1,289 ​ $ (858) ​ Net realized gains (losses) ​ ​ ​ - ​ ​ - ​ ​ - ​ ​ (56) ​ Other-than-temporary impairment (OTTI) losses on investments ​ ​ $ 664 ​ $ (899) ​ $ 1,289 ​ $ (914) ​ Earnings before income taxes ​ ​ ​ (140) ​ ​ 189 ​ ​ (271) ​ ​ 192 ​ Income tax benefit (expense) ​ ​ $ 524 ​ $ (710) ​ $ 1,018 ​ $ (722) ​ Net earnings (loss) ​

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of goodwill and intangible assets	​ ​ ​ ​ ​ ​ ​ ​ Goodwill and Intangible Assets ​ ​ June 30, ​ ​ December 31, (in thousands) ​ ​ 2019 ​ ​ 2018 Goodwill ​ ​ ​ ​ ​ ​ Energy surety ​ $ 25,706 ​ $ 25,706 Miscellaneous and contract surety ​ ​ 15,110 ​ ​ 15,110 Small commercial ​ ​ 5,246 ​ ​ 5,246 Total goodwill ​ $ 46,062 ​ $ 46,062 ​ ​ ​ ​ ​ ​ ​ Intangibles ​ ​ ​ ​ ​ ​ State insurance licenses ​ $ 7,500 ​ $ 7,500 Definite-lived intangibles, net of accumulated amortization of $3,266 at 6/30/19 and $3,062 at 12/31/18 ​ ​ 768 ​ ​ 972 Total intangibles ​ $ 8,268 ​ $ 8,472 ​ ​ ​ ​ ​ ​ ​ Total goodwill and intangibles ​ $ 54,330 ​ $ 54,534
Schedule of reconciliation of numerator and denominator of the basic and diluted earnings per share computations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Period ​ For the Three-Month Period ​ ​ Ended June 30, 2019 ​ Ended June 30, 2018 ​ ​ Income ​ Shares ​ Per Share ​ Income ​ Shares ​ Per Share (in thousands, except per share data) (Numerator) (Denominator) Amount (Numerator) (Denominator) Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 40,467 44,704 $ 0.91 $ 33,251 44,310 $ 0.75 Effect of Dilutive Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options ​ - 515 ​ ​ ​ ​ - 432 ​ ​ ​ Diluted EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 40,467 45,219 $ 0.89 $ 33,251 44,742 $ 0.74 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Six-Month Period ​ For the Six-Month Period ​ ​ Ended June 30, 2019 ​ Ended June 30, 2018 ​ ​ Income ​ Shares ​ Per Share ​ Income ​ Shares ​ Per Share (in thousands, except per share data) (Numerator) (Denominator) Amount (Numerator) (Denominator) Amount ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 105,940 44,620 $ 2.37 $ 45,467 44,266 $ 1.03 Effect of Dilutive Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock options ​ - 436 ​ ​ ​ ​ - 587 ​ ​ ​ Diluted EPS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income available to common shareholders $ 105,940 45,056 $ 2.35 $ 45,467 44,853 $ 1.01
Schedule of changes in the balance of each component of accumulated other comprehensive earnings	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ For the Three-Month Periods ​ For the Six-Month Periods ​ ​ Ended June 30, ​ Ended June 30, Unrealized Gains/Losses on Available-for-Sale Securities 2019 2018 2019 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance $ 14,729 $ (6,973) $ (14,572) $ 157,919 Cumulative effect adjustment of ASU 2016-01 ​ ​ - ​ ​ - ​ ​ - ​ ​ (142,219) Adjusted beginning balance ​ $ 14,729 ​ $ (6,973) ​ $ (14,572) ​ $ 15,700 Other comprehensive earnings before reclassifications ​ 28,388 (8,385) ​ 58,183 ​ (34,795) Amounts reclassified from accumulated other comprehensive earnings ​ (524) 710 ​ (1,018) ​ 722 Net current-period other comprehensive earnings (loss) $ 27,864 $ (7,675) $ 57,165 $ (34,073) Reclassification of stranded tax effect per ASU 2018-02 ​ ​ - ​ ​ - ​ ​ - ​ ​ 3,725 Ending balance $ 42,593 $ (14,648) $ 42,593 $ (14,648)
Schedule of effects of reclassifications out of accumulated other comprehensive earnings	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount Reclassified from Accumulated Other ​ ​ (in thousands) ​ Comprehensive Earnings ​ ​ ​ ​ For the Three-Month ​ For the Six-Month ​ ​ Component of Accumulated ​ Periods Ended June 30, ​ Periods Ended June 30, ​ Affected line item in the Other Comprehensive Earnings 2019 2018 2019 2018 Statement of Earnings ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized gains and losses on available-for-sale securities ​ $ 664 ​ $ (899) ​ $ 1,289 ​ $ (858) ​ Net realized gains (losses) ​ ​ ​ - ​ ​ - ​ ​ - ​ ​ (56) ​ Other-than-temporary impairment (OTTI) losses on investments ​ ​ $ 664 ​ $ (899) ​ $ 1,289 ​ $ (914) ​ Earnings before income taxes ​ ​ ​ (140) ​ ​ 189 ​ ​ (271) ​ ​ 192 ​ Income tax benefit (expense) ​ ​ $ 524 ​ $ (710) ​ $ 1,018 ​ $ (722) ​ Net earnings (loss) ​

INVESTMENTS (Tables)

INVESTMENTS (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of amortized cost and fair value of available-for-sale securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Available-for-sale ​ June 30, 2019 (in thousands) Cost or Gross Gross ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair Asset Class Cost Gains Losses Value U.S. government ​ $ 194,712 ​ $ 6,774 ​ $ (101) ​ $ 201,385 U.S. agency ​ ​ 29,708 ​ ​ 1,987 ​ ​ - ​ ​ 31,695 Non-U.S. govt. & agency ​ ​ 9,249 ​ ​ 192 ​ ​ (329) ​ ​ 9,112 Agency MBS ​ ​ 402,993 ​ ​ 6,603 ​ ​ (1,400) ​ ​ 408,196 ABS/CMBS* ​ ​ 149,583 ​ ​ 2,440 ​ ​ (147) ​ ​ 151,876 Corporate ​ ​ 701,358 ​ ​ 27,072 ​ ​ (1,632) ​ ​ 726,798 Municipal ​ ​ 321,826 ​ ​ 14,750 ​ ​ (25) ​ ​ 336,551 Total Fixed Income ​ $ 1,809,429 ​ $ 59,818 ​ $ (3,634) ​ $ 1,865,613 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Available-for-sale ​ December 31, 2018 (in thousands) Cost or Gross Gross ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair Asset Class Cost Gains Losses Value U.S. government ​ $ 199,982 ​ $ 1,232 ​ $ (985) ​ $ 200,229 U.S. agency ​ ​ 31,716 ​ ​ 403 ​ ​ (215) ​ ​ 31,904 Non-U.S. govt. & agency ​ ​ 8,170 ​ ​ - ​ ​ (531) ​ ​ 7,639 Agency MBS ​ ​ 402,992 ​ ​ 1,709 ​ ​ (9,448) ​ ​ 395,253 ABS/CMBS* ​ ​ 137,224 ​ ​ 375 ​ ​ (876) ​ ​ 136,723 Corporate ​ ​ 681,909 ​ ​ 2,894 ​ ​ (16,124) ​ ​ 668,679 Municipal ​ ​ 314,472 ​ ​ 6,926 ​ ​ (1,310) ​ ​ 320,088 Total Fixed Income ​ $ 1,776,465 ​ $ 13,539 ​ $ (29,489) ​ $ 1,760,515 *Non-agency asset-backed and commercial mortgage-backed
Schedule of securities in an unrealized loss position segregated by type and length of time in an unrealized loss position	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2019 ​ December 31, 2018 (in thousands) < 12 Mos. 12 Mos. & Total < 12 Mos. 12 Mos. & Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ — ​ $ 23,525 ​ $ 23,525 ​ $ 7,249 ​ $ 76,073 ​ $ 83,322 Amortized cost ​ ​ — ​ ​ 23,626 ​ ​ 23,626 ​ ​ 7,270 ​ ​ 77,037 ​ ​ 84,307 Unrealized Loss ​ $ — ​ $ (101) ​ $ (101) ​ $ (21) ​ $ (964) ​ $ (985) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. agency ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ — ​ $ — ​ $ — ​ $ — ​ $ 8,843 ​ $ 8,843 Amortized cost ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ 9,058 ​ ​ 9,058 Unrealized Loss ​ $ — ​ $ — ​ $ — ​ $ — ​ $ (215) ​ $ (215) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-U.S. government ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ — ​ $ 3,625 ​ $ 3,625 ​ $ 5,432 ​ $ 2,207 ​ $ 7,639 Amortized cost ​ ​ — ​ ​ 3,954 ​ ​ 3,954 ​ ​ 5,571 ​ ​ 2,599 ​ ​ 8,170 Unrealized Loss ​ $ — ​ $ (329) ​ $ (329) ​ $ (139) ​ $ (392) ​ $ (531) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Agency MBS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ 1 ​ $ 129,203 ​ $ 129,204 ​ $ 25,345 ​ $ 261,325 ​ $ 286,670 Amortized cost ​ ​ 1 ​ ​ 130,603 ​ ​ 130,604 ​ ​ 25,486 ​ ​ 270,632 ​ ​ 296,118 Unrealized Loss ​ $ — ​ $ (1,400) ​ $ (1,400) ​ $ (141) ​ $ (9,307) ​ $ (9,448) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ABS/CMBS* ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ 16,755 ​ $ 11,628 ​ $ 28,383 ​ $ 46,918 ​ $ 32,137 ​ $ 79,055 Amortized cost ​ ​ 16,823 ​ ​ 11,707 ​ ​ 28,530 ​ ​ 47,146 ​ ​ 32,785 ​ ​ 79,931 Unrealized Loss ​ $ (68) ​ $ (79) ​ $ (147) ​ $ (228) ​ $ (648) ​ $ (876) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ 44,618 ​ $ 32,689 ​ $ 77,307 ​ $ 306,177 ​ $ 147,751 ​ $ 453,928 Amortized cost ​ ​ 45,578 ​ ​ 33,361 ​ ​ 78,939 ​ ​ 315,428 ​ ​ 154,624 ​ ​ 470,052 Unrealized Loss ​ $ (960) ​ $ (672) ​ $ (1,632) ​ $ (9,251) ​ $ (6,873) ​ $ (16,124) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Municipal ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ — ​ $ 8,146 ​ $ 8,146 ​ $ 6,036 ​ $ 55,681 ​ $ 61,717 Amortized cost ​ ​ — ​ ​ 8,171 ​ ​ 8,171 ​ ​ 6,052 ​ ​ 56,975 ​ ​ 63,027 Unrealized Loss ​ $ — ​ $ (25) ​ $ (25) ​ $ (16) ​ $ (1,294) ​ $ (1,310) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total fixed income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair value ​ $ 61,374 ​ $ 208,816 ​ $ 270,190 ​ $ 397,157 ​ $ 584,017 ​ $ 981,174 Amortized cost ​ ​ 62,402 ​ ​ 211,422 ​ ​ 273,824 ​ ​ 406,953 ​ ​ 603,710 ​ ​ 1,010,663 Unrealized Loss ​ $ (1,028) ​ $ (2,606) ​ $ (3,634) ​ $ (9,796) ​ $ (19,693) ​ $ (29,489) * Non-agency asset-backed and commercial mortgage-backed
Schedule of credit quality indicators for investments in unrealized loss positions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equivalent ​ Equivalent ​ (dollars in thousands) ​ ​ ​ NAIC S&P Moody’s ​ Amortized ​ Unrealized ​ Percent ​ Rating Rating Rating Cost Fair Value Loss to Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1 ​ AAA/AA/A ​ Aaa/Aa/A ​ $ 203,150 ​ $ 201,403 ​ $ (1,747) ​ 48.1 % 2 ​ BBB ​ Baa ​ ​ 21,914 ​ ​ 21,213 ​ ​ (701) ​ 19.3 % 3 ​ BB ​ Ba ​ ​ 22,336 ​ ​ 21,950 ​ ​ (386) ​ 10.6 % 4 ​ B ​ B ​ ​ 24,877 ​ ​ 24,148 ​ ​ (729) ​ 20.1 % 5 ​ CCC ​ Caa ​ ​ 1,547 ​ ​ 1,476 ​ ​ (71) ​ 2.0 % 6 ​ CC or lower ​ Ca or lower ​ ​ - ​ ​ - ​ ​ - ​ - % ​ ​ ​ ​ Total ​ $ 273,824 ​ $ 270,190 ​ $ (3,634) ​ 100.0 %
Available for sale securities
Schedule of contractual maturity of securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2019 Available-for-sale ​ Amortized ​ Fair (in thousands) Cost Value Due in one year or less ​ $ 51,149 ​ $ 51,233 Due after one year through five years ​ ​ 400,628 ​ ​ 410,544 Due after five years through 10 years ​ ​ 615,648 ​ ​ 643,270 Due after 10 years ​ ​ 189,428 ​ ​ 200,494 Mtge/ABS/CMBS* ​ ​ 552,576 ​ ​ 560,072 Total available-for-sale ​ $ 1,809,429 ​ $ 1,865,613 *Mortgage-backed, asset-backed and commercial mortgage-backed

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of assets measured at fair value on recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of June 30, 2019 ​ ​ Fair Value Measurements Using ​ Quoted Prices in Significant Other Significant ​ ​ ​ Active Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ (in thousands) (Level 1) (Level 2) (Level 3) Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fixed income securities - available-for-sale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government ​ $ — ​ $ 201,385 ​ $ — ​ $ 201,385 U.S. agency ​ ​ — ​ ​ 31,695 ​ ​ — ​ ​ 31,695 Non-U.S. govt. & agency ​ ​ — ​ ​ 9,112 ​ ​ — ​ ​ 9,112 Agency MBS ​ ​ — ​ ​ 408,196 ​ ​ — ​ ​ 408,196 ABS/CMBS* ​ ​ — ​ ​ 151,876 ​ ​ — ​ ​ 151,876 Corporate ​ ​ — ​ ​ 726,798 ​ ​ — ​ ​ 726,798 Municipal ​ ​ — ​ ​ 336,551 ​ ​ — ​ ​ 336,551 Total fixed income securities - available-for-sale ​ $ — ​ $ 1,865,613 ​ $ — ​ $ 1,865,613 Equity securities ​ ​ 421,298 ​ ​ 503 ​ ​ — ​ ​ 421,801 Total ​ $ 421,298 ​ $ 1,866,116 ​ $ — ​ $ 2,287,414 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, 2018 ​ ​ Fair Value Measurements Using ​ ​ Quoted Prices in Significant Other Significant ​ ​ ​ Active Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ (in thousands) (Level 1) (Level 2) (Level 3) Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fixed income securities - available-for-sale ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government ​ $ — ​ $ 200,229 ​ $ — ​ $ 200,229 U.S. agency ​ ​ — ​ ​ 31,904 ​ ​ — ​ ​ 31,904 Non-U.S. govt. & agency ​ ​ — ​ ​ 7,639 ​ ​ — ​ ​ 7,639 Agency MBS ​ ​ — ​ ​ 395,253 ​ ​ — ​ ​ 395,253 ABS/CMBS* ​ ​ — ​ ​ 136,723 ​ ​ — ​ ​ 136,723 Corporate ​ ​ — ​ ​ 668,679 ​ ​ — ​ ​ 668,679 Municipal ​ ​ — ​ ​ 320,088 ​ ​ — ​ ​ 320,088 Total fixed income securities - available-for-sale ​ $ — ​ $ 1,760,515 ​ $ — ​ $ 1,760,515 Equity securities ​ ​ 339,985 ​ ​ 498 ​ ​ — ​ ​ 340,483 Total ​ $ 339,985 ​ $ 1,761,013 ​ $ — ​ $ 2,100,998 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * Non-agency asset-backed and commercial mortgage-backed

HISTORICAL LOSS AND LAE DEVEL_2

HISTORICAL LOSS AND LAE DEVELOPMENT (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of reconciliation of unpaid losses and settlement expenses (LAE)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Six-Month Periods ​ ​ Ended June 30, ​ (in thousands) 2019 2018 ​ Unpaid losses and LAE at beginning of year ​ ​ ​ ​ ​ ​ ​ Gross ​ $ 1,461,348 ​ $ 1,271,503 ​ Ceded ​ (364,999) ​ (301,991) ​ Net ​ $ 1,096,349 ​ $ 969,512 ​ ​ ​ ​ ​ ​ ​ ​ ​ Increase (decrease) in incurred losses and LAE ​ ​ ​ ​ ​ ​ ​ Current accident year ​ $ 239,053 ​ $ 222,121 ​ Prior accident years ​ (40,837) ​ (28,047) ​ Total incurred ​ $ 198,216 ​ $ 194,074 ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss and LAE payments for claims incurred ​ ​ ​ ​ ​ ​ ​ Current accident year ​ $ (23,624) ​ $ (16,805) ​ Prior accident years ​ (126,972) ​ (118,650) ​ Total paid ​ $ (150,596) ​ $ (135,455) ​ ​ ​ ​ ​ ​ ​ ​ ​ Net unpaid losses and LAE at June 30 ​ $ 1,143,969 ​ $ 1,028,131 ​ ​ ​ ​ ​ ​ ​ ​ ​ Unpaid losses and LAE at June 30 ​ ​ ​ ​ ​ ​ ​ Gross ​ $ 1,506,279 ​ $ 1,343,248 ​ Ceded ​ (362,310) ​ (315,117) ​ Net ​ $ 1,143,969 ​ $ 1,028,131 ​

INCOME TAXES (Tables)

INCOME TAXES (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of reconciliation of income tax expense attributable to income from operations with amounts computed by applying the U.S. federal tax rate to pretax income from continuing operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Periods Ended June 30, For the Six-Month Periods Ended June 30, ​ ​ 2019 ​ ​ 2018 ​ ​ 2019 ​ ​ 2018 ​ (in thousands) Amount % Amount % ​ Amount % ​ Amount % ​ Provision for income taxes at the statutory rate of 21% ​ $ 10,254 ​ 21.0 % ​ $ 8,308 ​ 21.0 % ​ $ 27,419 ​ 21.0 % ​ $ 11,327 ​ 21.0 % Increase (reduction) in taxes resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Excess tax benefit on share-based compensation ​ ​ (2,191) ​ (4.5) % ​ ​ (924) ​ (2.3) % ​ ​ (2,932) ​ (2.3) % ​ ​ (2,067) ​ (3.9) % Tax exempt interest income ​ ​ (309) ​ (0.6) % ​ ​ (504) ​ (1.3) % ​ ​ (654) ​ (0.5) % ​ ​ (1,085) ​ (2.0) % Dividends received deduction ​ ​ (214) ​ (0.4) % ​ ​ (169) ​ (0.4) % ​ ​ (417) ​ (0.3) % ​ ​ (366) ​ (0.7) % ESOP dividends paid deduction ​ ​ (140) ​ (0.3) % ​ ​ (145) ​ (0.4) % ​ ​ (277) ​ (0.2) % ​ ​ (284) ​ (0.5) % Other items, net ​ ​ 961 ​ 1.9 % ​ ​ (255) ​ (0.6) % ​ ​ 1,490 ​ 1.2 % ​ ​ 948 ​ 1.8 % Total tax expense ​ $ 8,361 ​ 17.1 % ​ $ 6,311 ​ 16.0 % ​ $ 24,629 ​ 18.9 % ​ $ 8,473 ​ 15.7 % ​

STOCK BASED COMPENSATION (Table

STOCK BASED COMPENSATION (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ Weighted ​ Average ​ Aggregate ​ ​ Number of ​ Average ​ Remaining ​ Intrinsic ​ ​ Options ​ Exercise ​ Contractual ​ Value ​ Outstanding Price Life (in 000’s) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding options at January 1, 2019 ​ 1,964,880 ​ $ 54.24 ​ ​ ​ ​ ​ Options granted ​ 292,150 ​ $ 80.36 ​ ​ ​ ​ ​ Options exercised ​ (414,470) ​ $ 44.70 ​ ​ ​ $ 14,941 Options canceled/forfeited ​ (33,600) ​ $ 57.61 ​ ​ ​ ​ ​ Outstanding options at June 30, 2019 ​ 1,808,960 ​ $ 60.59 ​ 5.57 ​ $ 45,448 Exercisable options at June 30, 2019 ​ 672,110 ​ $ 52.17 ​ 4.21 ​ $ 22,544 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ Weighted ​ Average ​ Aggregate ​ ​ Number of ​ Average ​ Remaining ​ Intrinsic ​ ​ Options ​ Exercise ​ Contractual ​ Value ​ Outstanding Price Life (in 000’s) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding options at January 1, 2018 ​ 2,257,015 ​ $ 46.80 ​ ​ ​ ​ ​ Options granted ​ 367,500 ​ $ 63.27 ​ ​ ​ ​ ​ Options exercised ​ (337,000) ​ $ 31.60 ​ ​ ​ $ 11,151 Options canceled/forfeited ​ (5,200) ​ $ 62.04 ​ ​ ​ ​ ​ Outstanding options at June 30, 2018 ​ 2,282,315 ​ $ 51.66 ​ 5.34 ​ $ 33,224 Exercisable options at June 30, 2018 ​ 996,265 ​ $ 44.04 ​ 3.89 ​ $ 22,089
Schedule of stock option assumptions for fair value estimate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average fair value of grants ​ $ 13.33 ​ ​ $ 10.20 ​ Risk-free interest rates ​ ​ 2.42 % ​ ​ 2.69 % Dividend yield ​ ​ 2.69 % ​ ​ 3.15 % Expected volatility ​ ​ 22.71 % ​ ​ 22.88 % Expected option life ​ ​ 4.96 years ​ ​ 5.06 years

OPERATING SEGMENT INFORMATION (

OPERATING SEGMENT INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of revenues and net earnings by segment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Periods ​ For the Six-Month Periods REVENUES ​ Ended June 30, ​ Ended June 30, (in thousands) 2019 2018 2019 2018 Casualty ​ $ 138,344 ​ $ 129,613 ​ $ 275,244 ​ $ 255,463 Property ​ ​ 39,972 ​ ​ 37,190 ​ ​ 78,718 ​ ​ 72,372 Surety ​ ​ 29,225 ​ ​ 29,719 ​ ​ 58,268 ​ ​ 58,714 Net premiums earned ​ $ 207,541 ​ $ 196,522 ​ $ 412,230 ​ $ 386,549 Net investment income ​ ​ 16,998 ​ ​ 14,577 ​ ​ 33,563 ​ ​ 28,809 Net realized gains ​ ​ 4,764 ​ ​ 20,849 ​ ​ 13,832 ​ ​ 29,253 Net unrealized gains (losses) on equity securities ​ ​ 8,810 ​ ​ (12,611) ​ ​ 42,308 ​ ​ (39,383) Total consolidated revenue ​ $ 238,113 ​ $ 219,337 ​ $ 501,933 ​ $ 405,228 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ NET EARNINGS ​ ​ ​ ​ (in thousands) 2019 2018 2019 2018 Casualty ​ $ 6,939 ​ $ 2,854 ​ $ 12,282 ​ $ 4,415 Property ​ ​ (436) ​ ​ 3,647 ​ ​ 7,810 ​ ​ 9,529 Surety ​ ​ 8,429 ​ ​ 7,645 ​ ​ 17,273 ​ ​ 17,689 Net underwriting income ​ $ 14,932 ​ $ 14,146 ​ $ 37,365 ​ $ 31,633 Net investment income ​ ​ 16,998 ​ ​ 14,577 ​ ​ 33,563 ​ ​ 28,809 Net realized gains ​ ​ 4,764 ​ ​ 20,849 ​ ​ 13,832 ​ ​ 29,253 Net unrealized gains (losses) on equity securities ​ ​ 8,810 ​ ​ (12,611) ​ ​ 42,308 ​ ​ (39,383) General corporate expense and interest on debt ​ ​ (5,144) ​ ​ (4,499) ​ ​ (10,281) ​ ​ (8,638) Equity in earnings of unconsolidated investees ​ ​ 8,468 ​ ​ 7,100 ​ ​ 13,782 ​ ​ 12,266 Total earnings before income taxes ​ $ 48,828 ​ $ 39,562 ​ $ 130,569 ​ $ 53,940 Income tax expense ​ ​ 8,361 ​ ​ 6,311 ​ ​ 24,629 ​ ​ 8,473 Total net earnings ​ $ 40,467 ​ $ 33,251 ​ $ 105,940 ​ $ 45,467
Schedule of net premiums earned by major product type	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Periods ​ For the Six-Month Periods NET PREMIUMS EARNED ​ Ended June 30, ​ Ended June 30, (in thousands) 2019 2018 2019 2018 Casualty ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commercial excess and personal umbrella ​ $ 34,340 ​ $ 30,649 ​ $ 66,621 ​ $ 60,601 General liability ​ ​ 25,347 ​ ​ 23,338 ​ ​ 49,235 ​ ​ 46,503 Commercial transportation ​ ​ 20,508 ​ ​ 20,648 ​ ​ 40,912 ​ ​ 39,823 Professional services ​ ​ 19,275 ​ ​ 19,846 ​ ​ 39,574 ​ ​ 39,669 Small commercial ​ ​ 13,315 ​ ​ 12,901 ​ ​ 26,503 ​ ​ 25,791 Executive products ​ ​ 6,381 ​ ​ 5,144 ​ ​ 12,450 ​ ​ 10,196 Other casualty ​ ​ 19,178 ​ ​ 17,087 ​ ​ 39,949 ​ ​ 32,880 Total ​ $ 138,344 ​ $ 129,613 ​ $ 275,244 ​ $ 255,463 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Property ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marine ​ $ 18,579 ​ $ 14,941 ​ $ 35,600 ​ $ 28,798 Commercial property ​ ​ 16,275 ​ ​ 17,856 ​ ​ 33,150 ​ ​ 34,807 Specialty personal ​ ​ 4,792 ​ ​ 4,129 ​ ​ 9,376 ​ ​ 8,271 Other property ​ ​ 326 ​ ​ 264 ​ ​ 592 ​ ​ 496 Total ​ $ 39,972 ​ $ 37,190 ​ $ 78,718 ​ $ 72,372 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Surety ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Miscellaneous ​ $ 11,280 ​ $ 11,719 ​ $ 22,882 ​ $ 23,361 Commercial ​ ​ 7,077 ​ ​ 6,761 ​ ​ 13,811 ​ ​ 13,474 Contract ​ ​ 6,970 ​ ​ 7,012 ​ ​ 13,599 ​ ​ 13,358 Energy ​ ​ 3,898 ​ ​ 4,227 ​ ​ 7,976 ​ ​ 8,521 Total ​ $ 29,225 ​ $ 29,719 ​ $ 58,268 ​ $ 58,714 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Grand Total ​ $ 207,541 ​ $ 196,522 ​ $ 412,230 ​ $ 386,549 ​

LEASES (Tables)

LEASES (Tables)	6 Months Ended
	Jun. 30, 2019
Schedule of components of lease expense and other lease information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three-Month Period ​ For the Six-Month Period (in thousands) ​ Ended June 30, 2019 Ended June 30, 2019 Operating lease cost ​ $ 1,445 ​ $ 2,927 ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in measurement of lease liabilities ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 1,402 ​ $ 2,797 ​ ​ ​ ​ ​ ​ ​ Right-of-use assets obtained in exchange for new operating lease liabilities ​ $ 231 ​ $ 951 ​ ​ ​ ​ ​ ​ ​ Reduction to right-of-use assets resulting from reduction to lease liabilities ​ $ 1,279 ​ $ 1,279 ​ ​ ​ ​ ​ ​ (in thousands) ​ June 30, 2019 Operating lease right-of-use assets ​ $ 24,449 ​ ​ ​ ​ ​ ​ Operating lease liabilities ​ $ 26,640 ​ ​ ​ ​ ​ ​ Weighted-average remaining lease term - operating leases ​ ​ 5.13 years ​ ​ ​ ​ ​ Weighted-average discount rate - operating leases ​ ​ 2.33 % ​
Schedule of future minimum lease payments under non-cancellable leases	​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ June 30, 2019 ​ December 31, 2018 2019 ​ $ 2,915 ​ $ 5,911 2020 ​ ​ 5,914 ​ ​ 6,019 2021 ​ ​ 5,819 ​ ​ 5,924 2022 ​ ​ 5,753 ​ ​ 5,884 2023 ​ ​ 4,297 ​ ​ 4,459 Thereafter ​ ​ 3,700 ​ ​ 3,968 Total future minimum lease payments ​ $ 28,398 ​ $ 32,165 ​ ​ ​ ​ ​ ​ ​ Less imputed interest ​ ​ (1,758) ​ ​ N/A Total operating lease liability ​ $ 26,640 ​ ​ N/A ​

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Description of Business (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	May 04, 2018	Mar. 31, 2018	Dec. 31, 2017
DESCRIPTION OF BUSINESS
Common Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01	$ 0.01	$ 1	$ 1
Reclassification From Common Stock	$ 66,500
Reclassification Into Paid In Capital	66,500
Common stock
DESCRIPTION OF BUSINESS
Reclassification due to change in par value	(66,513)
Paid-in Capital
DESCRIPTION OF BUSINESS
Reclassification due to change in par value	$ 66,513

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounting Standards (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Percentage Of Fixed Income Portfolio Rated A Or Better	83.00%		83.00%
Operating Lease, Right-of-Use Asset	$ 24,449		$ 24,449
Operating lease liabilities	26,640		26,640
Allocated Share-based Compensation Expense	1,400	$ 1,300	2,400	$ 2,300
Restricted Stock Units (RSUs) [Member]
Allocated Share-based Compensation Expense	200	100	300	200
Outside director | Restricted Stock Units (RSUs) [Member]
Allocated Share-based Compensation Expense	$ 200	$ 100	$ 300	$ 100

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Intangible Assets and EPS (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 46,062,000			$ 46,062,000		$ 46,062,000
State insurance licenses	7,500,000			7,500,000		7,500,000
Definite-lived intangibles, net of accumulated amortization of $3,164 at 3/31/19 and $3,062 at 12/31/18	768,000			768,000		972,000
Total intangibles	8,268,000			8,268,000		8,472,000
Goodwill and intangibles	54,330,000			54,330,000		54,534,000
Accumulated amortization of definite-lived intangibles	3,266,000			3,266,000		3,062,000
Amortization of intangible assets	100,000	$ 100,000		200,000	$ 200,000
Basic EPS, Income (Numerator)
Income available to common shareholders	40,467,000	33,251,000		105,940,000	45,467,000
Diluted EPS, Income (Numerator)
Income available to common shareholders	$ 40,467,000	$ 33,251,000		$ 105,940,000	$ 45,467,000
Basic EPS, Weighted Average Shares (Denominator)
Number of shares outstanding	44,704	44,310		44,620	44,266
Effect of Dilutive Securities, Shares (Denominator)
Stock options (in shares)	515	432		436	587
Diluted EPS, Weighted Average Shares (Denominator)
Number of shares outstanding	45,219	44,742		45,056	44,853
Basic EPS, Per Share Amount
Basic net earnings per share (in dollars per share)	$ 0.91	$ 0.75		$ 2.37	$ 1.03
Diluted EPS, Per Share Amount
Diluted earnings per share (in dollars per share)	$ 0.89	$ 0.74		$ 2.35	$ 1.01
Contractors Bonding and Insurance Company
Business Acquisition [Line Items]
Impairment of indefinite-lived intangible assets	$ 0
Energy Surety
Business Acquisition [Line Items]
Goodwill	25,706,000			$ 25,706,000		25,706,000
Goodwill, Impairment Loss	0
Miscellaneous and Contract Surety
Business Acquisition [Line Items]
Goodwill	15,110,000			15,110,000		15,110,000
Goodwill, Impairment Loss	0
Small commercial
Business Acquisition [Line Items]
Goodwill	5,246,000			$ 5,246,000		$ 5,246,000
Goodwill, Impairment Loss	$ 0
Medical professional liability
Business Acquisition [Line Items]
Goodwill			$ 0
Total intangibles			0
Goodwill and Intangible Asset Impairment			4,400,000
Goodwill, Impairment Loss			3,600,000
Impairment of Intangible Assets, Finite-lived			$ 800,000

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Changes in Accumulated Other Comprehensive Earnings (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
COMPREHENSIVE EARNINGS
Tax rate used (as a percent)	21.00%		21.00%		21.00%	21.00%
Changes in the balance of each component of accumulated other comprehensive earnings
Beginning balance		$ (14,572)			$ (14,572)
Cumulative effect adjustment of ASU 2016-01								$ 142,200
Net current-period other comprehensive earnings (loss)	$ 27,864	29,301	$ (7,675)	$ (26,398)	57,165	$ (34,073)
Reclassification of stranded tax effect per ASU 2018-02						3,700
Ending balance	42,593				42,593
Reclassification Adjustment Out of Accumulated Other Comprehensive Income Abstract
Net realized gains	4,764		20,849		13,832	29,309
Other-than-temporary-impairment (OTTI) losses on investments						(56)
Earnings before income taxes	48,828		39,562		130,569	53,940
Income tax expense	(8,361)		(6,311)		(24,629)	(8,473)
Net earnings	40,467	65,473	33,251	12,216	105,940	45,467
Unrealized Gains and Losses on Available-for-Sale Securities
Changes in the balance of each component of accumulated other comprehensive earnings
Beginning balance	14,729	(14,572)	(6,973)	157,919	(14,572)	157,919
Cumulative effect adjustment of ASU 2016-01								(142,219)
Adjusted beginning balance		14,729		(6,973)			$ (14,572)	$ 15,700
Other comprehensive earnings before reclassifications	28,388		(8,385)		58,183	(34,795)
Amounts reclassified from accumulated other comprehensive earnings	(524)		710		(1,018)	722
Net current-period other comprehensive earnings (loss)	27,864		(7,675)		57,165	(34,073)
Reclassification of stranded tax effect per ASU 2018-02						3,725
Ending balance	42,593	$ 14,729	(14,648)	$ (6,973)	42,593	(14,648)
Reclassifications out of accumulated other comprehensive earnings | Unrealized Gains and Losses on Available-for-Sale Securities
Reclassification Adjustment Out of Accumulated Other Comprehensive Income Abstract
Net realized gains	664		(899)		1,289	(858)
Other-than-temporary-impairment (OTTI) losses on investments						(56)
Earnings before income taxes	664		(899)		1,289	(914)
Income tax expense	(140)		189		(271)	192
Net earnings	$ 524		$ (710)		$ 1,018	$ (722)

INVESTMENTS - Amortized Cost an

INVESTMENTS - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Available-for-sale
Total amortized cost		$ 1,809,429	$ 1,776,465
Available-for-sale Securities, Debt Securities		1,865,613	1,760,515
Amortized Cost
Due in one year or less		51,149
Due after one year through five years		400,628
Due after five years through 10 years		615,648
Due after 10 years		189,428
Mtge/ABS/CMBS	[1]	552,576
Total amortized cost		1,809,429	1,776,465
Fair Value
Due in one year or less		51,233
Due after one year through five years		410,544
Due after five years through 10 years		643,270
Due after 10 years		200,494
Mtge/ABS/CMBS	[1]	560,072
Total fair value		1,865,613	1,760,515
Fair value measured on recurring basis
Available-for-sale
Available-for-sale Securities, Debt Securities		1,865,613	1,760,515
Fair Value
Total fair value		1,865,613	1,760,515
Fair value measured on recurring basis | Significant Unobservable Inputs (Level 3)
INVESTMENTS
Total assets at fair value		0
Debt securities
Available-for-sale
Total amortized cost		1,809,429	1,776,465
Gross unrealized gains		59,818	13,539
Gross unrealized losses		(3,634)	(29,489)
Available-for-sale Securities, Debt Securities		1,865,613	1,760,515
Amortized Cost
Total amortized cost		1,809,429	1,776,465
Fair Value
Total fair value		1,865,613	1,760,515
U.S. government
Available-for-sale
Total amortized cost		194,712	199,982
Gross unrealized gains		6,774	1,232
Gross unrealized losses		(101)	(985)
Available-for-sale Securities, Debt Securities		201,385	200,229
Amortized Cost
Total amortized cost		194,712	199,982
Fair Value
Total fair value		201,385	200,229
U.S. Agency
Available-for-sale
Total amortized cost		29,708	31,716
Gross unrealized gains		1,987	403
Gross unrealized losses			(215)
Available-for-sale Securities, Debt Securities		31,695	31,904
Amortized Cost
Total amortized cost		29,708	31,716
Fair Value
Total fair value		31,695	31,904
Non-U.S. govt. & agency
Available-for-sale
Total amortized cost		9,249	8,170
Gross unrealized gains		192
Gross unrealized losses		(329)	(531)
Available-for-sale Securities, Debt Securities		9,112	7,639
Amortized Cost
Total amortized cost		9,249	8,170
Fair Value
Total fair value		9,112	7,639
Mortgage-backed
Available-for-sale
Total amortized cost		402,993	402,992
Gross unrealized gains		6,603	1,709
Gross unrealized losses		(1,400)	(9,448)
Available-for-sale Securities, Debt Securities		408,196	395,253
Amortized Cost
Total amortized cost		402,993	402,992
Fair Value
Total fair value		408,196	395,253
ABS/CMBS
Available-for-sale
Total amortized cost	[2]	149,583	137,224
Gross unrealized gains	[2]	2,440	375
Gross unrealized losses	[2]	(147)	(876)
Available-for-sale Securities, Debt Securities	[2]	151,876	136,723
Amortized Cost
Total amortized cost	[2]	149,583	137,224
Fair Value
Total fair value	[2]	151,876	136,723
Corporate Debt
Available-for-sale
Total amortized cost		701,358	681,909
Gross unrealized gains		27,072	2,894
Gross unrealized losses		(1,632)	(16,124)
Available-for-sale Securities, Debt Securities		726,798	668,679
Amortized Cost
Total amortized cost		701,358	681,909
Fair Value
Total fair value		726,798	668,679
Municipal
Available-for-sale
Total amortized cost		321,826	314,472
Gross unrealized gains		14,750	6,926
Gross unrealized losses		(25)	(1,310)
Available-for-sale Securities, Debt Securities		336,551	320,088
Amortized Cost
Total amortized cost		321,826	314,472
Fair Value
Total fair value		$ 336,551	$ 320,088
[1]	Mortgage-backed, asset-backed and commercial mortgage-backed
[2]	Non-agency asset-backed and commercial mortgage-backed

INVESTMENTS - Unrealized Losses

INVESTMENTS - Unrealized Losses (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Investment positions with unrealized losses
Unrealized losses relative to total invested assets (as a percent)		0.20%
Unrealized Loss
Total Unrealized Loss		$ (3,600)
Debt securities
Fair value
Less than 12 months		61,374	$ 397,157
12 months and greater		208,816	584,017
Total Fair Value		270,190	981,174
Cost or amortized Cost
Less than 12 months		62,402	406,953
12 months and greater		211,422	603,710
Total Cost or Amortized Cost		273,824	1,010,663
Unrealized Loss
Less than 12 months		(1,028)	(9,796)
12 months and greater		(2,606)	(19,693)
Total Unrealized Loss		$ (3,634)	(29,489)
Percent to Total		100.00%
Debt securities | NAIC Rating 1 | AAA/AA/A | Aaa/Aa/A
Fair value
Total Fair Value		$ 201,403
Cost or amortized Cost
Total Cost or Amortized Cost		203,150
Unrealized Loss
Total Unrealized Loss		$ (1,747)
Percent to Total		48.10%
Debt securities | NAIC Rating 2 | BBB | Baa
Fair value
Total Fair Value		$ 21,213
Cost or amortized Cost
Total Cost or Amortized Cost		21,914
Unrealized Loss
Total Unrealized Loss		$ (701)
Percent to Total		19.30%
Debt securities | NAIC Rating 3 | BB | Ba
Fair value
Total Fair Value		$ 21,950
Cost or amortized Cost
Total Cost or Amortized Cost		22,336
Unrealized Loss
Total Unrealized Loss		$ (386)
Percent to Total		10.60%
Debt securities | NAIC Rating 4 | B | B
Fair value
Total Fair Value		$ 24,148
Cost or amortized Cost
Total Cost or Amortized Cost		24,877
Unrealized Loss
Total Unrealized Loss		$ (729)
Percent to Total		20.10%
Debt securities | NAIC Rating 5 | CCC | Caa
Fair value
Total Fair Value		$ 1,476
Cost or amortized Cost
Total Cost or Amortized Cost		1,547
Unrealized Loss
Total Unrealized Loss		$ (71)
Percent to Total		2.00%
U.S. government
Fair value
Less than 12 months			7,249
12 months and greater		$ 23,525	76,073
Total Fair Value		23,525	83,322
Cost or amortized Cost
Less than 12 months			7,270
12 months and greater		23,626	77,037
Total Cost or Amortized Cost		23,626	84,307
Unrealized Loss
Less than 12 months			(21)
12 months and greater		(101)	(964)
Total Unrealized Loss		(101)	(985)
U.S. Agency
Fair value
12 months and greater			8,843
Total Fair Value			8,843
Cost or amortized Cost
12 months and greater			9,058
Total Cost or Amortized Cost			9,058
Unrealized Loss
12 months and greater			(215)
Total Unrealized Loss			(215)
Non-U.S. govt. & agency
Fair value
Less than 12 months			5,432
12 months and greater		3,625	2,207
Total Fair Value		3,625	7,639
Cost or amortized Cost
Less than 12 months			5,571
12 months and greater		3,954	2,599
Total Cost or Amortized Cost		3,954	8,170
Unrealized Loss
Less than 12 months			(139)
12 months and greater		(329)	(392)
Total Unrealized Loss		(329)	(531)
Mortgage-backed
Fair value
Less than 12 months		1	25,345
12 months and greater		129,203	261,325
Total Fair Value		129,204	286,670
Cost or amortized Cost
Less than 12 months		1	25,486
12 months and greater		130,603	270,632
Total Cost or Amortized Cost		130,604	296,118
Unrealized Loss
Less than 12 months			(141)
12 months and greater		(1,400)	(9,307)
Total Unrealized Loss		(1,400)	(9,448)
ABS/CMBS
Fair value
Less than 12 months	[1]	16,755	46,918
12 months and greater	[1]	11,628	32,137
Total Fair Value	[1]	28,383	79,055
Cost or amortized Cost
Less than 12 months	[1]	16,823	47,146
12 months and greater	[1]	11,707	32,785
Total Cost or Amortized Cost	[1]	28,530	79,931
Unrealized Loss
Less than 12 months	[1]	(68)	(228)
12 months and greater	[1]	(79)	(648)
Total Unrealized Loss	[1]	(147)	(876)
Corporate Debt
Fair value
Less than 12 months		44,618	306,177
12 months and greater		32,689	147,751
Total Fair Value		77,307	453,928
Cost or amortized Cost
Less than 12 months		45,578	315,428
12 months and greater		33,361	154,624
Total Cost or Amortized Cost		78,939	470,052
Unrealized Loss
Less than 12 months		(960)	(9,251)
12 months and greater		(672)	(6,873)
Total Unrealized Loss		(1,632)	(16,124)
Municipal
Fair value
Less than 12 months			6,036
12 months and greater		8,146	55,681
Total Fair Value		8,146	61,717
Cost or amortized Cost
Less than 12 months			6,052
12 months and greater		8,171	56,975
Total Cost or Amortized Cost		8,171	63,027
Unrealized Loss
Less than 12 months			(16)
12 months and greater		(25)	(1,294)
Total Unrealized Loss		$ (25)	$ (1,310)
[1]	Non-agency asset-backed and commercial mortgage-backed

INVESTMENTS Debt Securities and

INVESTMENTS Debt Securities and Common Stock (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)securityposition	Jun. 30, 2018USD ($)security	Jun. 30, 2019USD ($)securityposition	Jun. 30, 2018USD ($)security
Securities in unrealized loss positions
Number of unrealized loss positions | position	279		279
Unrealized loss	$ 3,600		$ 3,600
Other-than-temporary impairment (OTTI) losses				$ 56
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 8,810	$ (12,611)	$ 42,308	$ (39,383)
Debt securities
Securities in unrealized loss positions
Number of unrealized loss positions | position	279		279
Number of securities in unrealized loss positions for 12 months or longer | security	122		122
Unrealized losses as percentage of fixed income portfolio cost basis	0.20%		0.20%
Number of securities with OTTI losses recognized in earnings | security		1		1
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Recognized in Earnings			$ 0	$ 100
Other than Temporary Impairment Losses recognized in other comprehensive earnings			0	0
Equity securities
Securities in unrealized loss positions
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 12,900	$ 9,100	$ 54,800	$ (4,800)

INVESTMENTS Debt and Short-term

INVESTMENTS Debt and Short-term Investments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Other invested assets
Other investments	$ 55,196		$ 55,196		$ 51,542
Investments pledged as collateral	$ 16,300		$ 16,300
Investment in Federal Home Loan Bank Stock	us-gaap:AssetPledgedAsCollateralMember		us-gaap:AssetPledgedAsCollateralMember
Federal Home Loan Bank Borrowings, Fair Value Disclosure	$ 0		$ 0
Cash and Short-term Investments
Cash	24,834		24,834		30,140
Short-term investments, at cost which approximates fair value	47,353		47,353		11,550
Investment In Low Income Housing Tax Credit Partnership Net Of Amortization Member
Other invested assets
Other investments	19,400		19,400		$ 20,300
Total tax benefit on investments in housing tax credit partnership	600	$ 600	1,200	$ 1,100
Qualified Affordable Housing Project Investments, Commitment	7,100		7,100
Investment in Private Funds
Other invested assets
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 12,400		$ 12,400

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) $ in Thousands	Jun. 30, 2019USD ($)security		Dec. 31, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	$ 1,865,613		$ 1,760,515
Equity securities	421,801		340,483
Transfers in (out of) level 1	0
Transfers in (out of) level 2	0
Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	1,865,613		1,760,515
Equity securities	421,801		340,483
Marketable Securities	2,287,414		2,100,998
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	421,298		339,985
Marketable Securities	421,298		339,985
Significant Other Observable Inputs (Level 2) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	1,865,613		1,760,515
Equity securities	503		498
Marketable Securities	1,866,116		1,761,013
U.S. government | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	201,385		200,229
U.S. government | Significant Other Observable Inputs (Level 2) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	201,385		200,229
U.S. Agency | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	31,695		31,904
U.S. Agency | Significant Other Observable Inputs (Level 2) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	31,695		31,904
Non-U.S. govt. & agency | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	9,112		7,639
Non-U.S. govt. & agency | Significant Other Observable Inputs (Level 2) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	9,112		7,639
Mortgage-backed | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	408,196		395,253
Mortgage-backed | Significant Other Observable Inputs (Level 2) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	408,196		395,253
ABS/CMBS | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	151,876	[1]	136,723
ABS/CMBS | Significant Other Observable Inputs (Level 2) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	151,876	[1]	136,723
Corporate Bond Securities | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	726,798		668,679
Corporate Bond Securities | Significant Other Observable Inputs (Level 2) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	726,798		668,679
Municipal | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	336,551		320,088
Municipal | Significant Other Observable Inputs (Level 2) | Fair value measured on recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	$ 336,551		$ 320,088
Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of securities classified as Level 2 in the fair value hierarchy | security	1
[1]	Non-agency asset-backed and commercial mortgage-backed

HISTORICAL LOSS AND LAE DEVEL_3

HISTORICAL LOSS AND LAE DEVELOPMENT - Unpaid Losses and Settlement Expenses (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Unpaid losses and LAE at beginning of year:
Gross	$ 1,461,348	$ 1,271,503
Ceded	(364,999)	(301,991)
Net	1,096,349	969,512
Increase (decrease) in incurred losses and LAE:
Current accident year	239,053	222,121
Prior accident years	(40,837)	(28,047)
Total incurred	198,216	194,074
Loss and LAE payments for claims incurred:
Current accident year	(23,624)	(16,805)
Prior accident year	(126,972)	(118,650)
Total paid	(150,596)	(135,455)
Net	1,143,969	1,028,131
Unpaid losses and LAE at year end
Gross	1,506,279	1,343,248
Ceded	(362,310)	(315,117)
Net	$ 1,143,969	$ 1,028,131

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reconciliation of income tax expense reported to amount computed by applying the U.S. federal tax rate
Provision for income taxes at the statutory rate of 21%	$ 10,254	$ 8,308	$ 27,419	$ 11,327
Excess tax benefit on share-based compensation	(2,191)	(924)	(2,932)	(2,067)
Tax-exempt interest income	(309)	(504)	(654)	(1,085)
Dividends received deduction	(214)	(169)	(417)	(366)
ESOP dividends paid deduction	(140)	(145)	(277)	(284)
Other items, net	961	(255)	1,490	948
Income tax expense	$ 8,361	$ 6,311	$ 24,629	$ 8,473
Reconciliation of income tax expense rate to the U.S. federal tax rate
U.S. federal tax rate (as a percent)	21.00%	21.00%	21.00%	21.00%
Excess tax benefit on share-based compensation	(4.50%)	(2.30%)	(2.30%)	(3.90%)
Effective rate reduction due to tax exempt interest income (as a percent)	(0.60%)	(1.30%)	(0.50%)	(2.00%)
Effective rate reduction due to dividend received (as a percent)	(0.40%)	(0.40%)	(0.30%)	(0.70%)
Effective rate reduction due to dividend paid to ESOP (as a percent)	(0.30%)	(0.40%)	(0.20%)	(0.50%)
Effective rate reduction due to other items, net (as a percent)	1.90%	(0.60%)	1.20%	1.80%
Effective Income Tax Rate Reconciliation, Percent, Total	17.10%	16.00%	18.90%	15.70%

STOCK BASED COMPENSATION (Detai

STOCK BASED COMPENSATION (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended	50 Months Ended	60 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Jun. 30, 2019	May 06, 2015
Weighted Number of Options Outstanding
Outstanding options at the beginning of the period (in shares)			1,964,880	2,257,015	2,257,015
Options granted (in shares)			292,150	367,500
Options exercised (in shares)			(414,470)	(337,000)
Options canceled/forfeited (in shares)			(33,600)	(5,200)
Outstanding options at the end of the period (in shares)	1,808,960	2,282,315	1,808,960	2,282,315	1,964,880	1,808,960
Exercisable options at the end of the period (in shares)	672,110	996,265	672,110	996,265		672,110
Weighted Average Exercise Price
Outstanding options at the beginning of the period (in dollars per share)			$ 54.24	$ 46.80	$ 46.80
Options granted (in dollars per share)			80.36	63.27
Options exercised (in dollars per share)			44.70	31.60
Options canceled/forfeited (in dollars per share)			57.61	62.04
Outstanding options at the end of the period (in dollars per share)	$ 60.59	$ 51.66	60.59	51.66	$ 54.24	$ 60.59
Exercisable options at the end of the period (in dollars per share)	$ 52.17	$ 44.04	$ 52.17	$ 44.04		$ 52.17
Weighted Average Remaining Contractual Life
Weighted-average remaining contractual term of options outstanding			5 years 6 months 25 days	5 years 4 months 2 days
Weighted-average remaining contractual term of exercisable options			4 years 2 months 15 days	3 years 10 months 20 days
Aggregate Intrinsic Value
Options exercised (in dollars)			$ 14,941,000	$ 11,151,000
Outstanding options at the end of the period (in dollars)	$ 45,448,000	$ 33,224,000	45,448,000	33,224,000		$ 45,448,000
Exercisable options at the end of the period (in dollars)	22,544,000	22,089,000	$ 22,544,000	$ 22,089,000		22,544,000
Weighted-average fair value of grants (in dollars per share)			$ 13.33	$ 10.20
Stock-based compensation expenses (in dollars)	1,400,000	1,300,000	$ 2,400,000	$ 2,300,000
Income tax benefit from stock-based compensation (in dollars)	300,000	300,000	500,000	$ 500,000
Unrecognized stock-based compensation expense (in dollars)	6,700,000		$ 6,700,000			6,700,000
Weighted average grant date assumptions and weighted average fair value
Weighted-average fair value of grants (in dollars per share)			$ 13.33	$ 10.20
Risk-free interest rates (as a percent)			2.42%	2.69%
Dividend yield (as a percent)			2.69%	3.15%
Expected volatility (as a percent)			22.71%	22.88%
Expected option life			4 years 11 months 15 days	5 years 21 days
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting period			3 years
Age and period of service of the participant to be eligible for retirement			75 years
Aggregate Intrinsic Value
Stock-based compensation expenses (in dollars)	200,000	100,000	$ 300,000	$ 200,000
Unrecognized stock-based compensation expense (in dollars)	$ 1,500,000		$ 1,500,000			$ 1,500,000
Weighted average grant date assumptions and weighted average fair value
RSUs Granted			15,275			45,350
RSUs Outstanding	44,431		44,431			44,431
Outside director | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting period			1 year
Aggregate Intrinsic Value
Stock-based compensation expenses (in dollars)	$ 200,000	$ 100,000	$ 300,000	$ 100,000
Unrecognized stock-based compensation expense (in dollars)	$ 400,000		$ 400,000			$ 400,000
Weighted average grant date assumptions and weighted average fair value
RSUs Granted			6,655			15,085
RSUs Outstanding	7,402		7,402			7,402
Grant date fair value of RSUs			$ 50,000		$ 50,000
RLI Corp. Long-Term Incentive Plan (LTIP) and Omnibus Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award
Award vesting period			5 years
Term of options			8 years
Age and period of service of the participant to be eligible for retirement			75 years
RLI Corp. Long-Term Incentive Plan (2010 LTIP)
Share-based Compensation Arrangement by Share-based Payment Award
Shares authorized for grant							4,000,000
Weighted Number of Options Outstanding
Options granted (in shares)							2,878,000
RLI Corp. Long-Term Incentive Plan (2015 LTIP)
Share-based Compensation Arrangement by Share-based Payment Award
Shares authorized for grant	4,000,000		4,000,000			4,000,000
Weighted Number of Options Outstanding
Options granted (in shares)			314,080			2,217,710

OPERATING SEGMENT INFORMATION -

OPERATING SEGMENT INFORMATION - Reconciliation of Segment Totals to Total Earnings (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
REVENUES
Net premiums earned	$ 207,541		$ 196,522		$ 412,230	$ 386,549
Net investment income	16,998		14,577		33,563	28,809
Net realized gains	4,764		20,849		13,832	29,253
Net unrealized gains (losses) on equity securities	8,810		(12,611)		42,308	(39,383)
Consolidated revenue	238,113		219,337		501,933	405,228
NET EARNINGS
Net underwriting income	14,932		14,146		37,365	31,633
Net investment income	16,998		14,577		33,563	28,809
Net realized gains	4,764		20,849		13,832	29,253
Net unrealized gains (losses) on equity securities	8,810		(12,611)		42,308	(39,383)
General corporate expense and interest on debt	(5,144)		(4,499)		(10,281)	(8,638)
Equity in earnings of unconsolidated investees	8,468		7,100		13,782	12,266
Earnings before income taxes	48,828		39,562		130,569	53,940
Income tax expense	8,361		6,311		24,629	8,473
Net earnings	40,467	$ 65,473	33,251	$ 12,216	105,940	45,467
Casualty segment
REVENUES
Net premiums earned	138,344		129,613		275,244	255,463
NET EARNINGS
Net underwriting income	6,939		2,854		12,282	4,415
Property segment
REVENUES
Net premiums earned	39,972		37,190		78,718	72,372
NET EARNINGS
Net underwriting income	(436)		3,647		7,810	9,529
Surety segment
REVENUES
Net premiums earned	29,225		29,719		58,268	58,714
NET EARNINGS
Net underwriting income	$ 8,429		$ 7,645		$ 17,273	$ 17,689

OPERATING SEGMENT INFORMATION_2

OPERATING SEGMENT INFORMATION - Major Products (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue by major product
Net premiums earned	$ 207,541	$ 196,522	$ 412,230	$ 386,549
Casualty segment
Revenue by major product
Net premiums earned	138,344	129,613	275,244	255,463
Casualty segment | Commercial excess and personal umbrella
Revenue by major product
Net premiums earned	34,340	30,649	66,621	60,601
Casualty segment | General liability
Revenue by major product
Net premiums earned	25,347	23,338	49,235	46,503
Casualty segment | Transportation
Revenue by major product
Net premiums earned	20,508	20,648	40,912	39,823
Casualty segment | Professional services
Revenue by major product
Net premiums earned	19,275	19,846	39,574	39,669
Casualty segment | Small commercial
Revenue by major product
Net premiums earned	13,315	12,901	26,503	25,791
Casualty segment | Executive products
Revenue by major product
Net premiums earned	6,381	5,144	12,450	10,196
Casualty segment | Other casualty
Revenue by major product
Net premiums earned	19,178	17,087	39,949	32,880
Property segment
Revenue by major product
Net premiums earned	39,972	37,190	78,718	72,372
Property segment | Marine
Revenue by major product
Net premiums earned	18,579	14,941	35,600	28,798
Property segment | Commercial
Revenue by major product
Net premiums earned	16,275	17,856	33,150	34,807
Property segment | Specialty Personal
Revenue by major product
Net premiums earned	4,792	4,129	9,376	8,271
Property segment | Other property
Revenue by major product
Net premiums earned	326	264	592	496
Surety segment
Revenue by major product
Net premiums earned	29,225	29,719	58,268	58,714
Surety segment | Miscellaneous
Revenue by major product
Net premiums earned	11,280	11,719	22,882	23,361
Surety segment | Commercial surety product
Revenue by major product
Net premiums earned	7,077	6,761	13,811	13,474
Surety segment | Contract
Revenue by major product
Net premiums earned	6,970	7,012	13,599	13,358
Surety segment | Energy Surety
Revenue by major product
Net premiums earned	$ 3,898	$ 4,227	$ 7,976	$ 8,521

LEASES - Components of Lease Ex

LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Leases
Expense associated with operating leases			$ 6,900	$ 6,800	$ 6,400
Operating Lease Cost	$ 1,445	$ 2,927
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	1,402	2,797
Right-of-use assets obtained in exchange for new operating lease liabilities	231	951
Reduction to right-of-use asset resulting from reduction to lease liability	1,279	1,279
Operating lease right-of-use assets	$ 24,449	$ 24,449
Operating lease, right-of-use asset, Statement of Financial Position	us-gaap:OtherAssets	us-gaap:OtherAssets
Operating lease liabilities	$ 26,640	$ 26,640
Operating lease liability, Statement of Financial Position	us-gaap:OtherLiabilities	us-gaap:OtherLiabilities
Weighted-average remaining lease term - operating leases	5 years 1 month 17 days	5 years 1 month 17 days
Weighted-average discount rate - operating leases	2.33%	2.33%
Minimum
Leases
Remaining lease terms - operating leases		1 year
Maximum
Leases
Remaining lease terms - operating leases		16 years

LEASES - Future Minimum Lease P

LEASES - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Future minimum lease payments under non-cancellable leases
2019	$ 2,915
2020	5,914
2021	5,819
2022	5,753
2023	4,297
Thereafter	3,700
Total future minimum lease payments	28,398
Less imputed interest	(1,758)
Total operating lease liability	$ 26,640
2019		$ 5,911
2020		6,019
2021		5,924
2022		5,884
2023		4,459
Thereafter		3,968
Total future minimum lease payments		$ 32,165