James River (JRVR) 10-Q 30 Apr 20 2020 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 28, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-36777
Entity Registrant Name	JAMES RIVER GROUP HOLDINGS, LTD.
Entity Incorporation, State or Country Code	D0
Entity Tax Identification Number	98-0585280
Entity Address, Address Line One	90 Pitts Bay Road
Entity Address, Address Line Two	2nd Floor
Entity Address, Address Line Three	Wellesley House
Entity Address, City or Town	Pembroke
Entity Address, Postal Zip Code	HM08
Entity Address, Country	BM
City Area Code	441
Local Phone Number	278-4580
Title of 12(b) Security	Common Shares, par value $0.0002 per share
Trading Symbol	JRVR
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Central Index Key	0001620459
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		30,520,428
Document Period End Date	Mar. 31, 2020
Amendment Flag	false
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2020

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Invested assets:
Fixed maturity securities, available-for-sale, at fair value (amortized cost: 2020 – $1,540,822; 2019 – $1,398,533)	$ 1,570,605	$ 1,433,626
Equity securities, at fair value (cost: 2020 – $77,218; 2019 – $73,244)	71,394	80,735
Bank loan participations (2020: at fair value; 2019: held-for-investment, at amortized cost, net of allowance)	202,888
Bank loan participations (2020: at fair value; 2019: held-for-investment, at amortized cost, net of allowance)		260,864
Short-term investments	71,058	156,925
Other invested assets	47,697	61,210
Total invested assets	1,963,642	1,993,360
Cash and cash equivalents	291,223	206,912
Restricted cash equivalents	1,107,321	1,199,164
Accrued investment income	13,781	13,597
Premiums receivable and agents’ balances, net	312,842	369,462
Reinsurance recoverable on unpaid losses, net	691,669	668,045
Reinsurance recoverable on paid losses	42,201	33,221
Prepaid reinsurance premiums	205,175	178,976
Deferred policy acquisition costs	58,618	62,006
Intangible assets, net	36,791	36,940
Goodwill	181,831	181,831
Other assets	91,716	80,891
Total assets	4,996,810	5,024,405
Liabilities:
Reserve for losses and loss adjustment expenses	2,043,358	2,045,506
Unearned premiums	539,564	524,377
Payables to reinsurers	109,499	108,059
Funds held	1,107,321	1,199,164
Senior debt	277,300	158,300
Junior subordinated debt	104,055	104,055
Accrued expenses	51,808	58,416
Other liabilities	43,588	47,947
Total liabilities	4,276,493	4,245,824
Commitments and contingent liabilities	0	0
Shareholders’ equity:
Common Shares – 2020 and 2019: $0.0002 par value; 200,000,000 shares authorized; 30,520,428 and 30,424,391 shares issued and outstanding, respectively	6	6
Preferred Shares – 2020 and 2019: $0.00125 par value; 20,000,000 shares authorized; no shares issued and outstanding	0	0
Additional paid-in capital	657,704	657,875
Retained earnings	35,412	89,586
Accumulated other comprehensive income	27,195	31,114
Total shareholders’ equity	720,317	778,581
Total liabilities and shareholders’ equity	$ 4,996,810	$ 5,024,405

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Fixed maturity securities, available-for-sale, at amortized cost	$ 1,540,822	$ 1,398,533
Equity securities, at cost	$ 77,218	$ 73,244
Common stock, par value (in dollars per share)	$ 0.0002	$ 0.0002
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	30,520,428	30,424,391
Common stock, shares outstanding (in shares)	30,520,428	30,424,391
Preferred stock, par value (in dollars per share)	$ 0.00125	$ 0.00125
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Condensed Consolidated Statemen

Condensed Consolidated Statements of (Loss) Income and Comprehensive (Loss) Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues
Gross written premiums	$ 283,841	$ 327,334
Ceded written premiums	(149,187)	(119,593)
Net written premiums	134,654	207,741
Change in net unearned premiums	11,264	(17,589)
Net earned premiums	145,918	190,152
Net investment income	20,836	19,431
Net realized and unrealized (losses) gains on investments	(58,407)	1,625
Other income	1,937	2,919
Total revenues	110,284	214,127
Expenses
Losses and loss adjustment expenses	96,856	139,927
Other operating expenses	51,621	45,752
Interest expense	2,876	2,808
Amortization of intangible assets	149	149
Total expenses	151,502	188,636
(Loss) income before taxes	(41,218)	25,491
Income tax (benefit) expense	(4,403)	2,763
Net (loss) income	(36,815)	22,728
Other comprehensive (loss) income:
Net unrealized (losses) gains, net of taxes of $(1,391) in 2020 and $1,446 in 2019	(3,919)	20,260
Total comprehensive (loss) income	$ (40,734)	$ 42,988
Per share data:
Basic (loss) earnings per share (in dollars per share)	$ (1.21)	$ 0.76
Diluted (loss) earnings per share (in dollars per share)	(1.21)	0.75
Dividend declared per share (in dollars per share)	$ 0.30	$ 0.30
Weighted-average common shares outstanding:
Basic (in shares)	30,476,307	30,059,398
Diluted (in shares)	30,476,307	30,472,304

Condensed Consolidated Statem_2

Condensed Consolidated Statements of (Loss) Income and Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Tax on net unrealized gains (losses)	$ (1,391)	$ 1,446

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Shares	Preferred Shares	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance (in shares) at Dec. 31, 2018		29,988,460
Balance at Dec. 31, 2018	$ 709,241	$ 6	$ 0	$ 645,310	$ 79,753	$ (15,828)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	22,728				22,728
Other comprehensive income (loss)	20,260					20,260
Dividends	(9,144)				(9,144)
Exercise of stock options (in shares)		98,975
Exercise of stock options	2,632			2,632
Vesting of RSUs (in shares)		74,610
Vesting of RSUs	(1,374)			(1,374)
Compensation expense under share incentive plans	1,674			1,674
Balance (in shares) at Mar. 31, 2019		30,162,045
Balance at Mar. 31, 2019	$ 754,297	$ 6	0	648,242	101,617	4,432
Balance (in shares) at Dec. 31, 2019	30,424,391	30,424,391
Balance at Dec. 31, 2019	$ 778,581	$ 6	0	657,875	89,586	31,114
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(36,815)				(36,815)
Other comprehensive income (loss)	(3,919)					(3,919)
Dividends	(9,267)				(9,267)
Vesting of RSUs (in shares)		96,037
Vesting of RSUs	(2,038)			(2,038)
Compensation expense under share incentive plans	$ 1,867			1,867
Balance (in shares) at Mar. 31, 2020	30,520,428	30,520,428
Balance at Mar. 31, 2020	$ 720,317	$ 6	$ 0	$ 657,704	$ 35,412	$ 27,195

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities
Net cash (used in) provided by operating activities	$ (65,305)	$ 35,450
Securities available-for-sale:
Purchases – fixed maturity securities	(182,205)	(130,362)
Sales – fixed maturity securities	4,513	45,466
Maturities and calls – fixed maturity securities	34,861	39,215
Purchases – equity securities	(7,435)	(2,753)
Sales – equity securities	3,295	263
Bank loan participations:
Purchases	(18,408)	(21,746)
Sales	9,735	6,602
Maturities	13,220	11,355
Other invested assets:
Purchases	(438)	0
Return of capital	253	260
Redemptions	13,133	0
Short-term investments, net	85,867	(10,168)
Securities receivable or payable, net	(5,770)	14,643
Purchases of property and equipment	(342)	(144)
Net cash used in investing activities	(49,721)	(47,369)
Financing activities
Senior debt issuances	119,000	0
Senior debt repayments	0	(20,000)
Dividends paid	(9,468)	(9,244)
Issuance of common shares under equity incentive plans	0	2,632
Common share repurchases	(2,038)	(1,374)
Net cash provided by (used in) financing activities	107,494	(27,986)
Change in cash, cash equivalents, and restricted cash equivalents	(7,532)	(39,905)
Cash, cash equivalents, and restricted cash equivalents at beginning of period	1,406,076	172,457
Cash, cash equivalents, and restricted cash equivalents at end of period	1,398,544	132,552
Supplemental information
Interest paid	$ 3,248	$ 3,339

Accounting Policies

Accounting Policies	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Accounting Policies	Accounting Policies Organization James River Group Holdings, Ltd. (referred to as “JRG Holdings” or, with its subsidiaries, the “Company”) is an exempted holding company registered in Bermuda, organized for the purpose of acquiring and managing insurance and reinsurance entities. The Company owns five insurance companies based in the United States (“U.S.”) focused on specialty insurance niches and two Bermuda-based reinsurance companies as described below: • James River Group Holdings UK Limited (“James River UK”) is an insurance holding company formed in 2015 in the United Kingdom (“U.K.”). JRG Holdings contributed James River Group, Inc. (“James River Group”), a U.S. insurance holding company, to James River UK in 2015. • James River Group is a Delaware domiciled insurance holding company formed in 2002 which owns all of the Company’s U.S.-based subsidiaries, either directly or indirectly through one of its wholly-owned U.S. subsidiaries. James River Group oversees the Company’s U.S. insurance operations and maintains all of the outstanding debt in the U.S. • James River Insurance Company is an Ohio domiciled excess and surplus lines insurance company that, with its wholly-owned insurance subsidiary, James River Casualty Company, a Virginia domiciled company, is authorized to write business in every state and the District of Columbia. • Falls Lake National Insurance Company (“Falls Lake National”) is an Ohio domiciled insurance company which wholly owns Stonewood Insurance Company (“Stonewood Insurance”), a North Carolina domiciled company, and Falls Lake Fire and Casualty Company, a California domiciled company. Falls Lake National and its subsidiaries primarily write specialty admitted fronting and program business and individual risk workers' compensation insurance. • JRG Reinsurance Company Ltd. (“JRG Re”) was formed in 2007 and commenced operations in 2008. JRG Re, a Bermuda domiciled reinsurer, primarily provides non-catastrophe casualty reinsurance to U.S. third parties and, through December 31, 2017, to the Company’s U.S.-based insurance subsidiaries. • Carolina Re Ltd (“Carolina Re”) was formed in 2018 and as of January 1, 2018 provides reinsurance to the Company’s U.S.-based insurance subsidiaries. Carolina Re is also the cedent on a stop loss reinsurance treaty with JRG Re. Basis of Presentation The accompanying condensed consolidated financial statements and notes have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and do not contain all of the information and footnotes required by U.S. GAAP for complete financial statements. The condensed consolidated financial statements include the results of the Company and its subsidiaries from their respective dates of inception or acquisition, as applicable. Readers are urged to review the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 for a more complete description of the Company’s business and accounting policies. In the opinion of management, all adjustments necessary for a fair presentation of the condensed consolidated financial statements have been included. Such adjustments consist only of normal recurring items. Interim results are not necessarily indicative of results of operations for the full year. The consolidated balance sheet as of December 31, 2019 was derived from the Company’s audited annual consolidated financial statements. Intercompany transactions and balances have been eliminated. Estimates and Assumptions Preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying disclosures. Those estimates are inherently subject to change, and actual results may ultimately differ from those estimates. Variable Interest Entities Entities that do not have sufficient equity at risk to allow the entity to finance its activities without additional financial support or in which the equity investors, as a group, do not have the characteristic of a controlling financial interest are referred to as variable interest entities (“VIE”). A VIE is consolidated by the variable interest holder that is determined to have the controlling financial interest (primary beneficiary) as a result of having both the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance and the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE. The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE’s capital structure, contractual terms, nature of the VIE’s operations and purpose, and the Company’s relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE. The Company reassesses its VIE determination with respect to an entity on an ongoing basis. The Company holds interests in VIEs through certain equity method investments included in “other invested assets” in the accompanying condensed consolidated balance sheets. The Company has determined that it should not consolidate any of the VIEs as it is not the primary beneficiary in any of the relationships. Although the investments resulted in the Company holding variable interests in the entities, they did not empower the Company to direct the activities that most significantly impact the economic performance of the entities. The Company’s investments related to these VIEs totaled $31.3 million and $31.2 million as of March 31, 2020 and December 31, 2019 , respectively, representing the Company’s maximum exposure to loss. Income Tax Expense Our effective tax rate fluctuates from period to period based on the relative mix of income reported by country and the respective tax rates imposed by each tax jurisdiction. For U.S.-sourced income, the Company’s U.S. federal income tax expense differs from the amounts computed by applying the federal statutory income tax rate to income before taxes due primarily to interest income on tax-advantaged state and municipal securities, dividends received income, and excess tax benefits on share based compensation. The outbreak of the coronavirus pandemic in the first quarter of 2020 led to significant unrealized losses in our investment portfolio that were recognized in earnings. As a result, the Company had a pre-tax loss of $41.2 million for the three months ended March 31, 2020 and recorded a U.S. federal income tax benefit of $4.4 million . For the three months ended March 31, 2019 , our U.S. federal income tax expense was 10.8% of income before taxes. Adopted Accounting Standards On January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , using the modified retrospective approach, by which a cumulative-effect adjustment was made to retained earnings as of the date of adoption. This update requires financial assets measured at amortized cost, such as bank loan participations held for investment, to be presented at the net amount expected to be collected by means of an allowance for credit losses that is reflected in net income. Credit losses relating to available-for-sale debt securities are recorded through an allowance for credit losses, with the amount of the allowance limited to the amount by which fair value is below amortized cost. In connection with the adoption of this ASU, the Company elected the fair value option in accounting for bank loan participations effective January 1, 2020. The targeted transition relief offered by ASU 2019-05, Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief was applied to elect the fair value option to account for bank loan participations already held at the January 1, 2020 date of adoption. Under the fair value option, bank loan participations are measured at fair value, and changes in unrealized gains and losses in bank loan participations are reported in our income statement as net realized and unrealized (losses) gains on investments. At adoption on January 1, 2020, the Company reduced the carrying value of its bank loan portfolio to fair value through an $8.4 million adjustment with a $7.8 million (net of tax) cumulative effect adjustment to reduce retained earnings. Upon adoption of this ASU, the Company established an allowance for uncollectible reinsurance balances through a $265,000 (net of tax) cumulative effect adjustment to retained earnings. Because we purchase reinsurance from financially strong reinsurers or we have collateral securing the recoverables, the effect of adoption was not material to our financial position.

Investments

Investments	3 Months Ended
	Mar. 31, 2020
Investments [Abstract]
Investments	Investments The Company’s available-for-sale fixed maturity securities are summarized as follows: Cost or Gross Gross Fair (in thousands) March 31, 2020 Fixed maturity securities: State and municipal $ 173,919 $ 8,007 $ (551 ) $ 181,375 Residential mortgage-backed 298,904 9,366 (831 ) 307,439 Corporate 669,191 19,583 (3,753 ) 685,021 Commercial mortgage and asset-backed 274,448 3,790 (9,259 ) 268,979 U.S. Treasury securities and obligations guaranteed by the U.S. government 122,335 3,688 — 126,023 Redeemable preferred stock 2,025 — (257 ) 1,768 Total fixed maturity securities, available-for-sale $ 1,540,822 $ 44,434 $ (14,651 ) $ 1,570,605 December 31, 2019 Fixed maturity securities: State and municipal $ 159,894 $ 7,949 $ (742 ) $ 167,101 Residential mortgage-backed 261,524 3,244 (622 ) 264,146 Corporate 611,304 21,306 (389 ) 632,221 Commercial mortgage and asset-backed 249,309 3,954 (806 ) 252,457 U.S. Treasury securities and obligations guaranteed by the U.S. government 114,477 1,229 (39 ) 115,667 Redeemable preferred stock 2,025 9 — 2,034 Total fixed maturity securities, available-for-sale $ 1,398,533 $ 37,691 $ (2,598 ) $ 1,433,626 The amortized cost and fair value of available-for-sale investments in fixed maturity securities at March 31, 2020 are summarized, by contractual maturity, as follows: Cost or Fair (in thousands) One year or less $ 108,264 $ 108,823 After one year through five years 472,749 484,651 After five years through ten years 253,007 260,236 After ten years 131,425 138,709 Residential mortgage-backed 298,904 307,439 Commercial mortgage and asset-backed 274,448 268,979 Redeemable preferred stock 2,025 1,768 Total $ 1,540,822 $ 1,570,605 Actual maturities may differ for some securities because borrowers have the right to call or prepay obligations with or without penalties. The following table shows the Company’s gross unrealized losses and fair value for available-for-sale securities aggregated by investment category and the length of time that individual securities have been in a continuous unrealized loss position: Less Than 12 Months 12 Months or More Total Fair Gross Fair Gross Fair Gross (in thousands) March 31, 2020 Fixed maturity securities: State and municipal $ 33,372 $ (551 ) $ — $ — $ 33,372 $ (551 ) Residential mortgage-backed 27,670 (830 ) 27 (1 ) 27,697 (831 ) Corporate 157,118 (3,749 ) 1,251 (4 ) 158,369 (3,753 ) Commercial mortgage and asset-backed 109,143 (6,962 ) 37,859 (2,297 ) 147,002 (9,259 ) Redeemable preferred stock 1,768 (257 ) — — 1,768 (257 ) Total fixed maturity securities, available-for-sale $ 329,071 $ (12,349 ) $ 39,137 $ (2,302 ) $ 368,208 $ (14,651 ) December 31, 2019 Fixed maturity securities: State and municipal $ 30,028 $ (741 ) $ 667 $ (1 ) $ 30,695 $ (742 ) Residential mortgage-backed 23,632 (78 ) 37,363 (544 ) 60,995 (622 ) Corporate 45,550 (365 ) 9,933 (24 ) 55,483 (389 ) Commercial mortgage and asset-backed 46,434 (406 ) 56,720 (400 ) 103,154 (806 ) U.S. Treasury securities and obligations guaranteed by the U.S. government 8,474 (22 ) 7,168 (17 ) 15,642 (39 ) Total fixed maturity securities, available-for-sale $ 154,118 $ (1,612 ) $ 111,851 $ (986 ) $ 265,969 $ (2,598 ) The outbreak of the coronavirus pandemic in the first quarter of 2020 and uncertainty around the extent of its economic impact caused severe declines in financial markets which are reflected in the fair values of our investments. At March 31, 2020 , the Company held fixed maturity securities of 147 issuers that were in an unrealized loss position with a total fair value of $368.2 million and gross unrealized losses of $14.7 million . None of the fixed maturity securities with unrealized losses has ever missed, or been delinquent on, a scheduled principal or interest payment. At March 31, 2020 , 99.6% of the Company’s fixed maturity security portfolio was rated “BBB-” or better (“investment grade”) by Standard & Poor’s or received an equivalent rating from another nationally recognized rating agency. Fixed maturity securities with ratings below investment grade by Standard & Poor’s or another nationally recognized rating agency at March 31, 2020 had an aggregate fair value of $5.6 million and an aggregate net unrealized gain of $17,000 . The Company adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments on January 1, 2020. This update changed the impairment model for available-for-sale fixed maturities and requires the Company to determine whether unrealized losses on available-for-sale fixed maturities are due to credit-related factors. An allowance for credit losses is established for any credit-related impairments, limited to the amount by which fair value is below amortized cost. Changes in the allowance for credit losses are recognized in earnings and included in n et realized and unrealized (losses) gains on investments . Unrealized losses that are not credit-related will continue to be recognized in other comprehensive income. The Company considers the extent to which fair value is below amortized cost in determining whether a credit-related loss exists. The Company also considers the credit quality rating of the security, with a special emphasis on securities downgraded below investment grade. A comparison is made between the present value of expected future cash flows for a security and its amortized cost. If the present value of future expected cash flows is less than amortized cost, a credit loss is presumed to exist and an allowance for credit losses is established. Management may conclude that a qualitative analysis is sufficient to support its conclusion that the present value of the expected cash flows equals or exceeds a security’s amortized cost. As a result of this review, management concluded that there were no credit-related impairments of fixed maturity securities at March 31, 2020 . Management does not intend to sell the securities in an unrealized loss position, and it is not “more likely than not” that the Company will be required to sell these securities before a recovery in their value to their amortized cost basis occurs. Management concluded that none of the fixed maturity securities with an unrealized loss at December 31, 2019 had experienced an other-than-temporary impairment. At March 31, 2019, management concluded that three fixed maturity securities from one issuer that we intended to sell at a loss in the second quarter were impaired. The Company recorded impairment losses on these securities of $271,000 in the three months ended March 31, 2019. In connection with the adoption of ASU 2016-13, the Company elected the fair value option in accounting for bank loan participations effective January 1, 2020. The targeted transition relief offered by ASU 2019-05, Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief was applied to elect the fair value option to account for bank loan participations already held at the January 1, 2020 date of adoption. Under the fair value option, bank loan participations are measured at fair value, and changes in unrealized gains and losses in bank loan participations are reported in our income statement as net realized and unrealized gains (losses) on investments. At adoption on January 1, 2020, the Company applied the amendments on a modified retrospective basis, reducing the carrying value of its bank loan portfolio to fair value through an $8.4 million adjustment with a $7.8 million (net of tax) cumulative effect adjustment to reduce retained earnings. Applying the fair value option to the bank loan portfolio will increase volatility in the Company's financial statements, but management believes it is less subjective and less burdensome to implement and maintain than ASU 2016-13, which would have otherwise been required. At March 31, 2020 , the Company's bank loan portfolio had an aggregate fair value of $202.9 million and unpaid principal of $260.2 million . Interest income on bank loan participations included in net investment income was $4.1 million and $5.1 million for the three months ended March 31, 2020 and 2019 , respectively. Net realized and unrealized (losses) gains on investments includes losses of $43.9 million related to changes in unrealized gains and losses on bank loan participations in the three months ended March 31, 2020 and management concluded that $5.0 million of those losses were due to credit-related impairments. Losses due to credit-related impairments were determined based upon consultations and advice from the Company's specialized investment manager and consideration of any adverse situations that could affect the borrower's ability to repay, the estimated value of underlying collateral, and other relevant factors. Prior to the election of the fair value option on January 1, 2020, bank loan participations were classified as held-for-investment and carried at amortized cost net of any allowance for credit losses. Under the prior accounting method, management concluded that seven loans from six issuers in the Company's bank loan portfolio were impaired at December 31, 2019 . At December 31, 2019 , the impaired loans had a carrying value of $6.9 million , unpaid principal of $14.3 million , and an allowance for credit losses of $7.2 million , $5.1 million of which related to two loans from one issuer who was experiencing liquidity concerns resulting from revenue declines and poor growth prospects in its most profitable segment. Management concluded that two of the loans in the Company’s loan portfolio were impaired at March 31, 2019. At March 31, 2019, the impaired loans had a carrying value of $4.4 million , unpaid principal of $5.9 million , and an allowance for credit losses of $1.5 million . Bank loan participations generally provide a higher yield than our portfolio of fixed maturities and have a credit rating that is below investment grade (i.e. below “BBB-” for Standard & Poor’s) at the date of purchase. These bank loans are primarily senior, secured floating-rate debt rated “BB”, “B”, or “CCC” by Standard & Poor’s or an equivalent rating from another nationally recognized rating agency. These bank loans include assignments of, and participations in, performing and non-performing senior corporate debt generally acquired through primary bank syndications and in secondary markets. Bank loans consist of, but are not limited to, term loans, the funded and unfunded portions of revolving credit loans, and other similar loans and investments. Management believed that it was probable at the time that these loans were acquired that the Company would be able to collect all contractually required payments receivable. Interest income on bank loan participations is accrued on the unpaid principal balance, and discounts and premiums on bank loan participations are amortized to income using the interest method. Generally, the accrual of interest on a bank loan participation is discontinued when the contractual payment of principal or interest has become 90 days past due or management has serious doubts about further collectability of principal or interest. A bank loan participation may remain on accrual status if it is in the process of collection and is either guaranteed or well secured. Generally, bank loan participations are restored to accrual status when the obligation is brought current, has performed in accordance with the contractual terms for a reasonable period of time, and the ultimate collectability of the total contractual principal and interest is no longer in doubt. Interest received on nonaccrual loans generally is reported as investment income. There were no bank loans on nonaccrual status at March 31, 2020 or December 31, 2019 . The average recorded investment in impaired bank loans was $2.2 million during the three months ended March 31, 2019 . No investment income was recognized during the period that the loans were impaired and net realized investment losses of $1.5 million were recorded in the three months ended March 31, 2019 for changes in the fair value of impaired bank loans. The Company’s net realized and unrealized gains and losses on investments are summarized as follows: Three Months Ended 2020 2019 (in thousands) Fixed maturity securities: Gross realized gains $ 215 $ 177 Gross realized losses (1 ) (405 ) 214 (228 ) Bank loan participations: Gross realized gains 103 13 Gross realized losses (1,309 ) (1,692 ) Changes in fair values of bank loan participations (43,947 ) — (45,153 ) (1,679 ) Equity securities: Gross realized gains — — Gross realized losses (170 ) (18 ) Changes in fair values of equity securities (13,315 ) 3,549 (13,485 ) 3,531 Short-term investments and other: Gross realized gains 18 1 Gross realized losses (1 ) — 17 1 Total $ (58,407 ) $ 1,625 Realized investment gains or losses are determined on a specific identification basis. The Company invests selectively in private debt and equity opportunities. These investments, which together comprise the Company’s other invested assets, are primarily focused in renewable energy, limited partnerships, and bank holding companies. Carrying Value Investment Income March 31, December 31, Three Months Ended 2020 2019 2020 2019 (in thousands) Renewable energy LLCs (a) $ 31,305 $ 31,219 $ 834 $ 921 Renewable energy notes receivable ( b) 2,680 8,750 166 328 Limited partnerships (c) 9,212 16,741 (569 ) 2,069 Bank holding companies (d) 4,500 4,500 86 86 Total other invested assets $ 47,697 $ 61,210 $ 517 $ 3,404 (a) The Company’s Corporate and Other segment owns equity interests ranging from 2.6% to 32.2% in various LLCs whose principal objective is capital appreciation and income generation from owning and operating renewable energy production facilities (wind and solar). The LLCs are managed by an entity for which two former directors served as officers, and the Company’s Chairman and Chief Executive Officer ("CEO") has invested in certain of these LLCs. The equity method is used to account for the Company’s LLC investments. Income for the LLCs primarily reflects adjustments to the carrying values of investments in renewable energy projects to their determined fair values. The fair value adjustments are included in revenues for the LLCs. Expenses for the LLCs are not significant and are comprised of administrative and interest expenses. The Company received cash distributions from these investments totaling $747,000 and $253,000 in the three months ended March 31, 2020 and 2019 , respectively. (b) The Company's Corporate and Other segment has invested in notes receivable for renewable energy projects. At December 31, 2019 , the Company held an $8.8 million note issued by an entity for which two of our former directors serve as officers . During the three months ended March 31, 2020 , the Company received repayment of $6.1 million of the original note principal. Interest on the note, which matures in 2021, is fixed at 15.0% . Interest income on the note was $166,000 and $328,000 for the three months ended March 31, 2020 and 2019 , respectively. (c) The Company owns investments in limited partnerships that invest in concentrated portfolios including publicly-traded small cap equities, loans of middle market private equity sponsored companies, and tranches of distressed home loans. Income f rom the partnerships is recognized under the equity method of accounting. The Company’s Corporate and Other segment held an investment in a limited partnership with a carrying value of $2.7 million at March 31, 2020 . The Company recognized investment losses of $710,000 and investment income of $481,000 on the investment for the three months ended March 31, 2020 and 2019 , respectively. The Company’s Excess and Surplus Lines segment holds investments in limited partnerships of $6.5 million at March 31, 2020 . Investment income of $141,000 and $1.6 million was recognized on the investments for the three months ended March 31, 2020 and 2019 , respectively. (d) The Company's Corporate and Other segment holds $4.5 million of subordinated notes issued by a bank holding company for which the Company’s Chairman and CEO was previously the Lead Independent Director and an investor and for which one of the Company’s directors was an investor and is currently a holder of the subordinated notes (the "Bank Holding Company"). Interest on the notes, which mature on August 12, 2023, is fixed at 7.6% per annum. Interest income on the notes was $86,000 in both the three months ended March 31, 2020 and 2019 , respectively. At March 31, 2020 and December 31, 2019 , the Company held an investment in a CLO where one of the underlying loans was issued by the Bank Holding Company. The investment, with a carrying value of $2.3 million at March 31, 2020 , is classified as an available-for-sale fixed maturity.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets On December 11, 2007, the Company completed an acquisition of James River Group by acquiring 100% of the outstanding shares of James River Group common stock, referred to herein as the “Merger”. The transaction was accounted for under the purchase method of accounting, and goodwill and intangible assets were recognized by the Company as a result of the transaction. Goodwill resulting from the Merger was $181.8 million at March 31, 2020 and December 31, 2019 . The gross carrying amounts and accumulated amortization for each major specifically identifiable intangible asset class were as follows: March 31, 2020 December 31, 2019 Life Gross Accumulated Gross Accumulated ($ in thousands) Intangible Assets Trademarks Indefinite $ 22,200 $ — $ 22,200 $ — Insurance licenses and authorities Indefinite 8,964 — 8,964 — Identifiable intangibles not subject to amortization 31,164 — 31,164 — Broker relationships 24.6 11,611 5,984 11,611 5,835 Identifiable intangible assets subject to amortization 11,611 5,984 11,611 5,835 $ 42,775 $ 5,984 $ 42,775 $ 5,835

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following represents a reconciliation of the numerator and denominator of the basic and diluted earnings per share computations contained in the condensed consolidated financial statements: Three Months Ended 2020 2019 (in thousands, except share and per share amounts) Net (loss) income to shareholders $ (36,815 ) $ 22,728 Weighted average common shares outstanding: Basic 30,476,307 30,059,398 Common share equivalents — 412,906 Diluted 30,476,307 30,472,304 (Loss) earnings per share: Basic $ (1.21 ) $ 0.76 Common share equivalents — (0.01 ) Diluted $ (1.21 ) $ 0.75 For the three months ended March 31, 2020 and 2019 , common share equivalents of 309,443 and 171,509 shares, respectively, were excluded from the calculations of diluted earnings per share as their effects were anti-dilutive.

Reserve for Losses and Loss Adj

Reserve for Losses and Loss Adjustment Expenses	3 Months Ended
	Mar. 31, 2020
Liability for Claims and Claims Adjustment Expense [Abstract]
Reserve for Losses and Loss Adjustment Expenses	Reserve for Losses and Loss Adjustment Expenses The following table provides a reconciliation of the beginning and ending reserve balances for losses and loss adjustment expenses, net of reinsurance, to the gross amounts reported in the condensed consolidated balance sheets: Three Months Ended 2020 2019 (in thousands) Reserve for losses and loss adjustment expenses net of reinsurance recoverables at beginning of period $ 1,377,461 $ 1,194,088 Add: Incurred losses and loss adjustment expenses net of reinsurance: Current year 95,982 138,959 Prior years 874 968 Total incurred losses and loss and adjustment expenses 96,856 139,927 Deduct: Loss and loss adjustment expense payments net of reinsurance: Current year 4,271 4,679 Prior years 118,357 107,684 Total loss and loss adjustment expense payments 122,628 112,363 Reserve for losses and loss adjustment expenses net of reinsurance recoverables at end of period 1,351,689 1,221,652 Add: Reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period 691,669 508,655 Reserve for losses and loss adjustment expenses gross of reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period $ 2,043,358 $ 1,730,307 The Company experienced $874,000 of adverse reserve development in the three months ended March 31, 2020 on the reserve for losses and loss adjustment expenses held at December 31, 2019 . This reserve development included $3,000 of favorable development in the Excess and Surplus Lines segment, $1.0 million of favorable development in the Specialty Admitted Insurance segment due to favorable development in the workers' compensation business for prior accident years, and $1.9 million of adverse development in the Casualty Reinsurance segment. The Company experienced $1.0 million of adverse reserve development in the three months ended March 31, 2019 on the reserve for losses and loss adjustment expenses held at December 31, 2018 . This reserve development included $10,000 of favorable development in the Excess and Surplus Lines segment. The Specialty Admitted Insurance segment experienced $2.0 million of favorable development due to favorable development in the workers' compensation business for prior accident years. The Company also experienced $3.0 million of adverse development in the Casualty Reinsurance segment primarily related to losses from risk profiles and treaty structures that the Company no longer writes.

Other Comprehensive (Loss) Inco

Other Comprehensive (Loss) Income	3 Months Ended
	Mar. 31, 2020
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive (Loss) Income	Other Comprehensive (Loss) Income The following table summarizes the components of other comprehensive (loss) income: Three Months Ended 2020 2019 (in thousands) Unrealized (losses) gains arising during the period, before U.S. income taxes $ (5,096 ) $ 21,478 U.S. income taxes 1,378 (1,447 ) Unrealized (losses) gains arising during the period, net of U.S. income taxes (3,718 ) 20,031 Less reclassification adjustment: Net realized investment gains (losses) 214 (228 ) U.S. income taxes (13 ) (1 ) Reclassification adjustment for investment gains (losses) realized in net income 201 (229 ) Other comprehensive (loss) income $ (3,919 ) $ 20,260 In addition to the $214,000 of net realized investment gains and $228,000 of net realized investment losses on available-for-sale fixed maturities for the three months ended March 31, 2020 and 2019 , respectively, the Company also recognized $45.2 million and $1.7 million of net realized and unrealized investment losses in the respective periods on its investments in bank loan participations and $13.5 million of net realized and unrealized losses and $3.5 million of net realized and unrealized gains in the respective periods on its investments in equity securities.

Contingent Liabilities

Contingent Liabilities	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities	Contingent Liabilities The Company is a party to various lawsuits arising in the ordinary course of its operations. The Company believes that the ultimate resolution of these matters will not materially impact its financial position, cash flows, or results of operations. In response to the outbreak of the coronavirus pandemic in the first quarter of 2020, many state and local governments in the United States and around the world have instituted emergency restrictions that have substantially limited the operation of non-essential businesses and the activities of individuals. These restrictions could result in significant adverse effects on our policyholders and many different types of small and mid-sized businesses within the Company’s client base, particularly those in the retail, hospitality and food and beverage industries, among many others. The ultimate effect of COVID-19 on the economy is not known nor is the ultimate length of the restrictions and any accompanying effects. Moreover, the Federal Reserve has taken action to lower the Federal Funds rate and the U.S. equity markets have experienced substantial volatility in reaction to COVID-19, both of which have, along with other factors, placed pressure on net investment income and have resulted in material realized and unrealized losses in our investment portfolio. The effect of COVID-19 and related events could have a negative effect on the Company, including as a result of quarantines, market volatility, market downturns, actions of lawmakers and regulators, changes in consumer behavior, business closures, deterioration in the credit quality of policyholders or the inability of policyholders to pay their premium and deductible obligations to the Company, and deterioration in the credit quality of reinsurers or insurance entities with which we have a fronting arrangement or the inability of insurers or the insurance entities for which we are fronting to pay their obligations to the Company. At the federal and state level, there have been proposals by lawmakers to retroactively amend business interruption insurance policies to cover claims related to COVID-19 when such insurance policies otherwise would exclude such risks. In addition, a number of states have instituted, and other states are considering instituting, changes designed to effectively expand workers’ compensation coverage by creating presumptions of compensability of claims for certain types of workers. If these efforts are successful and enforceable, the Company may be forced to pay claims under policies for which it received inadequate premiums to cover such risks, and therefore the Company’s reserves may be inadequate to pay such claims. At the state level, insurance departments throughout the country have issued bulletins and regulations urging or requiring insurers to extend grace periods for the payment of policy premiums and to refrain from canceling or non-renewing policies for the non-payment of policy premiums for policyholders adversely affected by COVID-19. It is uncertain what impact these government mandates may have on our ability to recover unpaid premiums on the affected policies or what our obligations may be for the payment of claims made under policies for which we have not received premium payments. Further, demand for the insurance policies that the Company offers is highly dependent upon the business environment in the markets in which the Company operates. Given the ongoing and dynamic nature of the circumstances, it is not possible to predict the ultimate impact of the coronavirus outbreak, but it could have a material adverse impact on the business prospects, financial condition or results of operations of the Company. JRG Re has entered into three letter of credit facilities with banks as security to third-party reinsureds on reinsurance assumed by JRG Re. JRG Re has established custodial accounts to secure these letters of credit. Under a $75.0 million facility, $20.5 million of letters of credit were issued through March 31, 2020 which were secured by deposits of $36.7 million . Under a $102.5 million facility, $76.0 million of letters of credit were issued through March 31, 2020 which were secured by deposits of $95.5 million . Under a $100.0 million facility, $25.7 million of letters of credit were issued through March 31, 2020 which were secured by deposits of $52.0 million . JRG Re has also established trust accounts to secure its obligations to selected reinsureds. The total amount deposited in the trust accounts for the benefit of third-party reinsureds was $294.9 million at March 31, 2020 . The Company previously issued a set of insurance contracts to Rasier LLC and its affiliates (collectively, “Rasier”) under which the Company pays losses and loss adjustment expenses on the contracts. The Company has indemnity agreements with Rasier (non-insurance entities) and is contractually entitled to receive reimbursement for a significant portion of the losses and loss adjustment expenses paid on behalf of Rasier and other expenses incurred by the Company. Rasier is required to collateralize all amounts currently due to the Company and to provide additional collateral sufficient to cover the amounts that may be recoverable under the indemnity agreements, including, among other things, case loss and loss adjustment expense reserves, IBNR loss and loss adjustment expense reserves, extra contractual obligations and excess of policy limits liabilities. The collateral is provided through a collateral trust arrangement established in favor of the Company by a captive insurance company affiliate of Rasier. As permitted under our indemnification agreements with Rasier and the associated trust agreement, we have withdrawn the collateral posted to the trust account. At March 31, 2020 , the Company held collateral funds of $1,107.3 million . The funds withdrawn from the trust account, currently invested in short term securities and included in restricted cash equivalents on the Company's consolidated balance sheet, will be used to reimburse the Company for the losses and loss adjustment expenses paid on behalf of Rasier and other related expenses incurred by the Company to the extent not paid as required under the indemnity agreements. The Company has ongoing exposure to estimated losses and expenses on these contracts growing at a faster pace than growth in our collateral balances. In addition, we have credit exposure if our estimates of future losses and loss adjustment expenses and other amounts recoverable, which are the basis for establishing collateral balances, are lower than actual amounts paid or payable. The amount of our credit exposure in any of these instances could be material. To mitigate these risks, we closely and frequently monitor our exposure compared to our collateral held, and we request additional collateral when our analysis indicates that we have uncollateralized exposure.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Segment Information	Segment Information The Company has four reportable segments: the Excess and Surplus Lines segment, the Specialty Admitted Insurance segment, the Casualty Reinsurance segment, and the Corporate and Other segment. Segment profit (loss) is measured by underwriting profit (loss), which is generally defined as net earned premiums less loss and loss adjustment expenses and other operating expenses of the operating segments. Included in “other income” on the condensed consolidated statements of (loss) income and comprehensive (loss) income is gross fee income of $1.6 million and $2.7 million that is included in underwriting profit for the three months ended March 31, 2020 and 2019 , respectively. Segment results are reported prior to the effects of intercompany reinsurance agreements among the Company’s insurance subsidiaries. The following table summarizes the Company’s segment results: Excess and Specialty Casualty Corporate Total (in thousands) Three Months Ended March 31, 2020 Gross written premiums $ 136,197 $ 102,802 $ 44,842 $ — $ 283,841 Net earned premiums 99,739 13,283 32,896 — 145,918 Underwriting profit (loss) of insurance segments 8,112 (988 ) 207 — 7,331 Net investment income 7,941 928 11,604 363 20,836 Interest expense — — — 2,876 2,876 Segment revenues 83,829 12,673 13,280 502 110,284 Segment goodwill 181,831 — — — 181,831 Segment assets 2,293,444 829,699 1,824,729 48,938 4,996,810 Three Months Ended March 31, 2019 Gross written premiums $ 186,549 $ 102,953 $ 37,832 $ — $ 327,334 Net earned premiums 141,672 12,360 36,120 — 190,152 Underwriting profit of insurance segments 13,102 1,623 327 — 15,052 Net investment income 5,544 897 11,172 1,818 19,431 Interest expense — — — 2,808 2,808 Segment revenues 152,437 13,736 46,010 1,944 214,127 Segment goodwill 181,831 — — — 181,831 Segment assets 1,013,069 706,451 1,517,142 62,589 3,299,251 The following table reconciles the underwriting profit (loss) of the operating segments by individual segment to consolidated income before taxes: Three Months Ended 2020 2019 (in thousands) Underwriting profit (loss) of the insurance segments: Excess and Surplus Lines $ 8,112 $ 13,102 Specialty Admitted Insurance (988 ) 1,623 Casualty Reinsurance 207 327 Total underwriting profit of insurance segments 7,331 15,052 Other operating expenses of the Corporate and Other segment (8,279 ) (7,906 ) Underwriting (loss) profit (948 ) 7,146 Net investment income 20,836 19,431 Net realized and unrealized (losses) gains on investments (58,407 ) 1,625 Amortization of intangible assets (149 ) (149 ) Other income and expenses 326 246 Interest expense (2,876 ) (2,808 ) (Loss) income before taxes $ (41,218 ) $ 25,491

Other Operating Expenses

Other Operating Expenses	3 Months Ended
	Mar. 31, 2020
Other Operating Expenses [Abstract]
Other Operating Expenses	Other Operating Expenses Other operating expenses consist of the following: Three Months Ended 2020 2019 (in thousands) Amortization of policy acquisition costs $ 24,116 $ 18,621 Other underwriting expenses of the operating segments 19,226 19,225 Other operating expenses of the Corporate and Other segment 8,279 7,906 Total $ 51,621 $ 45,752

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Three levels of inputs are used to measure fair value of financial instruments: (1) Level 1: quoted price (unadjusted) in active markets for identical assets, (2) Level 2: inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the instrument, and (3) Level 3: inputs to the valuation methodology are unobservable for the asset or liability. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. To measure fair value, the Company obtains quoted market prices for its investment securities from its outside investment managers, who utilize independent pricing services. If a quoted market price is not available, the Company uses prices of similar securities. Values for U.S. Treasury and publicly-traded equity securities are generally based on Level 1 inputs which use the market approach valuation technique. The values for all other fixed maturity securities (including state and municipal securities and obligations of U.S. government corporations and agencies) and bank loan participations generally incorporate significant Level 2 inputs, and in some cases, Level 3 inputs, using the market approach and income approach valuation techniques. There have been no changes in the Company’s use of valuation techniques since December 31, 2018. The Company reviews fair value prices provided by its outside investment managers for reasonableness by comparing the fair values provided by the managers to those provided by its investment custodian or other alternative sources. The Company also reviews and monitors changes in unrealized gains and losses. The Company has not historically adjusted security prices. The Company obtains an understanding of the methods, models and inputs used by the investment managers and independent pricing services, and controls are in place to validate that prices provided represent fair values. The Company’s control process includes, but is not limited to, initial and ongoing evaluation of the methodologies used, a review of specific securities and an assessment for proper classification within the fair value hierarchy, and obtaining and reviewing internal control reports for our investment managers that obtain fair values from independent pricing services. Assets measured at fair value on a recurring basis as of March 31, 2020 are summarized below: Fair Value Measurements Using Quoted Prices Significant Significant Total (in thousands) Fixed maturity securities, available-for-sale: State and municipal $ — $ 181,375 $ — $ 181,375 Residential mortgage-backed — 307,439 — 307,439 Corporate — 685,021 — 685,021 Commercial mortgage and asset-backed — 268,979 — 268,979 U.S. Treasury securities and obligations guaranteed by the U.S. government 125,580 443 — 126,023 Redeemable preferred stock — 1,768 — 1,768 Total fixed maturity securities, available-for-sale $ 125,580 $ 1,445,025 $ — $ 1,570,605 Equity securities: Preferred stock — 60,861 — 60,861 Common stock 7,980 2,549 4 10,533 Total equity securities $ 7,980 $ 63,410 $ 4 $ 71,394 Bank loan participations $ — $ 201,860 $ 1,028 $ 202,888 Short-term investments $ — $ 71,058 $ — $ 71,058 Assets measured at fair value on a recurring basis as of December 31, 2019 are summarized below: Fair Value Measurements Using Quoted Prices Significant Significant Total (in thousands) Fixed maturity securities, available-for-sale: State and municipal $ — $ 167,101 $ — $ 167,101 Residential mortgage-backed — 264,146 — 264,146 Corporate — 632,221 — 632,221 Commercial mortgage and asset-backed — 252,457 — 252,457 U.S. Treasury securities and obligations guaranteed by the U.S. government 115,173 494 — 115,667 Redeemable preferred stock — 2,034 — 2,034 Total fixed maturity securities, available-for-sale $ 115,173 $ 1,318,453 $ — $ 1,433,626 Equity securities: Preferred stock — 62,747 — 62,747 Common stock 14,669 3,276 43 17,988 Total equity securities $ 14,669 $ 66,023 $ 43 $ 80,735 Short-term investments $ — $ 156,925 $ — $ 156,925 A reconciliation of the beginning and ending balances of available-for-sale fixed maturity securities, equity securities, and bank loan participations measured at fair value on a recurring basis (as a result of the fair value option effective January 1, 2020) using significant unobservable inputs (Level 3) is shown below: Three Months Ended March 31, 2020 March 31, 2019 (in thousands) Beginning balance $ 43 $ 4,442 Transfers out of Level 3 — (4,228 ) Transfers in to Level 3 358 — Purchases 703 — Sales — — Maturities, calls and paydowns (17 ) — Amortization of discount 3 — Total gains or losses (realized/unrealized): — Included in earnings (58 ) (37 ) Included in other comprehensive income — — Ending balance $ 1,032 $ 177 The Company held one available-for-sale fixed maturity security at December 31, 2018 for which the fair value was determined using significant unobservable inputs (Level 3). A market approach using prices in trades of comparable securities was utilized to determine a fair value of $4.2 million for the security at December 31, 2018. The Company was able to obtain a quoted price from a pricing vendor for the available-for-sale fixed maturity security at March 31, 2019 and it was transferred to Level 2. At March 31, 2020 , the Company held three bank loan participations and two equity securities for which the fair value was determined using significant unobservable inputs (Level 3). At December 31, 2019 , the Company held one equity security for which the fair value was determined using significant unobservable inputs (Level 3). A market approach using prices in trades of comparable securities was utilized to determine a fair value for the securities of $1.0 million at March 31, 2020 and $43,000 at December 31, 2019 . At March 31, 2019 and December 31, 2018, the Company held one equity security for which the fair value was determined using significant unobservable inputs (Level 3). A market approach using prices in trades of comparable securities was utilized to determine a fair value for the equity securities of $177,000 at March 31, 2019 and $214,000 at December 31, 2018. Transfers out of Level 3 occur when the Company is able to obtain reliable prices from pricing vendors for securities for which the Company was previously unable to obtain reliable prices. Transfers in to Level 3 occur when the Company is unable to obtain reliable prices for securities from pricing vendors and instead must use broker price quotes to value the securities. There were no transfers between Level 1 and Level 2 during the three months ended March 31, 2020 or 2019 . The Company recognizes transfers between levels at the beginning of the reporting period. In connection with the adoption of ASU 2016-13, the Company elected the fair value option in accounting for bank loan participations effective January 1, 2020. Prior to the election, bank loan participations were classified as held-for-investment and carried at amortized cost net of any allowance for credit losses. Prior to January 1, 2020, t he Company measured certain bank loan participations at fair value on a non-recurring basis as part of the Company’s impairment evaluation when loans were determined by management to be impaired. Bank loan participations held-for-investment that were determined to be impaired were written down to their fair value a t December 31, 2019 as shown below: Fair Value Measurements Using Quoted Prices Significant Significant Total (in thousands) December 31, 2019 Bank loan participations held-for-investment $ — $ — $ 6,949 $ 6,949 In the determination of the fair value for bank loan participations, the Company’s investment manager endeavors to obtain data from multiple external pricing sources. External pricing sources may include brokers, dealers and price data vendors that provide a composite price based on prices from multiple dealers. Such external pricing sources typically provide valuations for normal institutional size trading units of such securities using methods based on market transactions for comparable securities, and various relationships between securities, as generally recognized by institutional dealers. For investments in which the investment manager determines that only one external pricing source is appropriate or if only one external price is available, the relevant investment is generally recorded at fair value based on such price. Investments for which external sources are not available or are determined by the investment manager not to be representative of fair value are recorded at fair value as determined by the Company, with input from its investment managers and valuation specialists as considered necessary. In determining the fair value of such investments, the Company considers one or more of the following factors: type of security held, convertibility or exchangeability of the security, redeemability of the security (including the timing of redemptions), application of industry accepted valuation models, recent trading activity, liquidity, estimates of liquidation value, purchase cost, and prices received for securities with similar terms of the same issuer or similar issuers. At March 31, 2020 and December 31, 2019 , there were no investments for which external sources were unavailable to determine fair value. The carrying values and fair values of financial instruments are summarized below: March 31, 2020 December 31, 2019 Carrying Fair Value Carrying Fair Value (in thousands) Assets Fixed maturity securities, available-for-sale $ 1,570,605 $ 1,570,605 $ 1,433,626 $ 1,433,626 Equity securities 71,394 71,394 80,735 80,735 Bank loan participations 202,888 202,888 260,864 252,423 Cash and cash equivalents 291,223 291,223 206,912 206,912 Restricted cash equivalents 1,107,321 1,107,321 1,199,164 1,199,164 Short-term investments 71,058 71,058 156,925 156,925 Other invested assets – notes receivable 7,180 11,458 13,250 18,756 Liabilities Senior debt 277,300 257,965 158,300 158,043 Junior subordinated debt 104,055 106,618 104,055 122,193 The fair values of fixed maturity securities, equity securities, and bank loan participations have been determined by independent pricing services using quoted market prices for securities traded in the public market or prices using bid or closing prices for securities not traded in the public marketplace. The fair values of cash and cash equivalents and short-term investments approximate their carrying values due to their short-term maturity. The fair values of other invested assets-notes receivable, senior debt, and junior subordinated debt at March 31, 2020 and December 31, 2019 were determined by calculating the present value of expected future cash flows under the terms of the note agreements or debt agreements, as applicable, discounted at an estimated market rate of interest at March 31, 2020 and December 31, 2019 , respectively. The fair values of senior debt and junior subordinated debt at March 31, 2020 and December 31, 2019 were determined using inputs to the valuation methodology that are unobservable (Level 3).

Senior Debt

Senior Debt	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Senior Debt	Senior Debt ​ In the three months ended March 31, 2020 , the Company drew $60.0 million on the $212.5 million unsecured revolving facility in its $315.0 million senior revolving credit facility (as amended or amended and restated, the "2013 Facility”). The borrowing was a precautionary measure to increase the Company's cash position and preserve financial flexibility in light of current uncertainty in the global markets resulting from the coronavirus (COVID-19) outbreak. At March 31, 2020 , the Company had a drawn balance of $193.3 million outstanding on the unsecured revolver.​ The 2013 Facility contains certain financial and other covenants (including minimum net worth, maximum ratio of total adjusted debt outstanding to total capitalization, and financial strength ratings) with which the Company was in compliance, at March 31, 2020 . Also in the three months ended March 31, 2020 , the Company drew $59.0 million of unsecured capacity on a credit agreement (the "2017 Facility") that provides the Company with a revolving line of credit of up to $100 million , which may be used for loans and letters of credit made or issued, at the borrowers' option, on a secured or ​unsecured basis. The borrowing was a precautionary measure to increase the Company's cash position and preserve financial flexibility in light of current uncertainty in the global markets resulting from the coronavirus (COVID-19) outbreak. At March 31, 2020 , unsecured loans of $69.0 million and secured letters of credit totaling $25.7 million were outstanding under the facility. The 2017 Facility contains certain financial and other covenants which we are in compliance with at March 31, 2020 .

Capital Stock and Equity Awards

Capital Stock and Equity Awards	3 Months Ended
	Mar. 31, 2020
Stockholders' Equity Note [Abstract]
Capital Stock and Equity Awards	Capital Stock and Equity Awards The Company issued 96,037 common shares in the three months ended March 31, 2020 . The new shares were related to vesting restricted share units (“RSUs”). The total common shares outstanding increased from 30,424,391 at December 31, 2019 to 30,520,428 at March 31, 2020 . The Company declared the following dividends during the first three months of 2020 and 2019: Date of Declaration Dividend per Common Share Payable to Shareholders of Record on Payment Date Total Amount (thousands) 2020 February 19, 2020 $ 0.30 March 16, 2020 March 31, 2020 $ 9,269 2019 February 20, 2019 $ 0.30 March 11, 2019 March 29, 2019 $ 9,146 Included in the total dividends for the three months ended March 31, 2020 and 2019 are $113,000 and $107,000 , respectively, of dividend equivalents on unvested RSUs. The balance of dividends payable on unvested RSUs was $422,000 at March 31, 2020 and $623,000 at December 31, 2019 . Equity Incentive Plans The Company’s shareholders have approved various equity incentive plans, including the Amended and Restated 2009 Equity Incentive Plan (the “Legacy Plan”), the 2014 Long Term Incentive Plan (“2014 LTIP”), and the 2014 Non-Employee Director Incentive Plan (“2014 Director Plan”) (collectively, the “Plans”). All awards issued under the Plans are issued at the discretion of the Board of Directors. Under the Legacy Plan, employees received non-qualified stock options. Options are outstanding under the Legacy Plan; however, no additional awards may be granted. Employees are eligible to receive non-qualified stock options, incentive stock options, share appreciation rights, performance shares, restricted shares, RSUs, and other awards under the 2014 LTIP. The maximum number of shares available for issuance under the 2014 LTIP is 4,171,150 , and at March 31, 2020 , 1,404,379 shares are available for grant. Non-employee directors of the Company are eligible to receive non-qualified stock options, share appreciation rights, performance shares, restricted shares, RSUs, and other awards under the 2014 Director Plan. At the 2019 Annual General Meeting of Shareholders of the Company held on April 30, 2019, the Company's shareholders approved an amendment to the 2014 Director Plan. The Board of Directors of the Company had previously approved the amendment. The amendment increased the number of the Company's common shares authorized for issuance under the 2014 Director Plan by 100,000 shares. The maximum number of shares available for issuance under the 2014 Director Plan is 150,000 , and at March 31, 2020 , 101,746 shares are available for grant. Generally, awards issued under the 2014 LTIP and 2014 Director Plan vest immediately in the event that an award recipient is terminated without Cause (as defined in the applicable plans), and in the case of the 2014 LTIP for Good Reason (as defined in the applicable plans), at any time following a Change in Control (as defined in the applicable plans). Options The following table summarizes option activity: Three Months Ended March 31, 2020 2019 Shares Weighted- Shares Weighted- Outstanding: Beginning of period 643,851 $ 30.41 1,115,324 $ 29.02 Granted — $ — — $ — Exercised — $ — (125,349 ) $ 29.47 Forfeited — $ — (3,759 ) $ 36.37 End of period 643,851 $ 30.41 986,216 $ 28.94 Exercisable, end of period 640,606 $ 30.35 926,166 $ 28.07 All of the outstanding options vest over three to four years and have a contractual life of seven years from the original date of grant. All of the outstanding options have an exercise price equal to the fair value of the underlying shares at the date of grant. The weighted-average remaining contractual life of the options outstanding and options exercisable at March 31, 2020 was 2.7 years and 2.7 years , respectively. RSUs The following table summarizes RSU activity: Three Months Ended March 31, 2020 2019 Shares Weighted- Shares Weighted- Unvested, beginning of period 340,368 $ 41.50 300,142 $ 39.22 Granted 179,016 $ 43.55 167,295 $ 42.07 Vested (142,830 ) $ 41.16 (109,545 ) $ 39.93 Forfeited (1,188 ) $ 42.07 (1,398 ) $ 40.26 Unvested, end of period 375,366 $ 42.61 356,494 $ 40.33 The vesting period of RSUs granted to employees range from one to three years and vest ratably over the respective vesting period, and the majority vest in three years . All RSUs granted to date to non-employee directors had a one year vesting period. The holders of RSUs are entitled to dividend equivalents. The dividend equivalents are settled in cash at the same time that the underlying RSUs vest and are subject to the same risk of forfeiture as the underlying shares. The fair value of the RSUs granted is based on the market price of the underlying shares at the date of grant. Compensation Expense Share based compensation expense is recognized on a straight line basis over the vesting period. The amount of expense and related tax benefit is summarized below: Three Months Ended 2020 2019 (in thousands) Share based compensation expense $ 1,867 $ 1,674 U.S. tax benefit on share based compensation expense 250 200 As of March 31, 2020 , the Company had $14.5 million of unrecognized share based compensation expense expected to be charged to earnings over a weighted-average period of 2.2 years .

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On April 28, 2020 , the Board of Directors declared a cash dividend of $0.30 per common share. The dividend is payable on June 30, 2020 to shareholders of record on June 15, 2020 .

Accounting Policies (Policies)

Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements and notes have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and do not contain all of the information and footnotes required by U.S. GAAP for complete financial statements. The condensed consolidated financial statements include the results of the Company and its subsidiaries from their respective dates of inception or acquisition, as applicable. Readers are urged to review the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 for a more complete description of the Company’s business and accounting policies. In the opinion of management, all adjustments necessary for a fair presentation of the condensed consolidated financial statements have been included. Such adjustments consist only of normal recurring items. Interim results are not necessarily indicative of results of operations for the full year. The consolidated balance sheet as of December 31, 2019 was derived from the Company’s audited annual consolidated financial statements. Intercompany transactions and balances have been eliminated.
Estimates and Assumptions	Estimates and Assumptions Preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying disclosures. Those estimates are inherently subject to change, and actual results may ultimately differ from those estimates.
Variable Interest Entities	Variable Interest Entities Entities that do not have sufficient equity at risk to allow the entity to finance its activities without additional financial support or in which the equity investors, as a group, do not have the characteristic of a controlling financial interest are referred to as variable interest entities (“VIE”). A VIE is consolidated by the variable interest holder that is determined to have the controlling financial interest (primary beneficiary) as a result of having both the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance and the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE. The Company determines whether it is the primary beneficiary of an entity subject to consolidation based on a qualitative assessment of the VIE’s capital structure, contractual terms, nature of the VIE’s operations and purpose, and the Company’s relative exposure to the related risks of the VIE on the date it becomes initially involved in the VIE. The Company reassesses its VIE determination with respect to an entity on an ongoing basis.
Income Tax Expense	Income Tax Expense Our effective tax rate fluctuates from period to period based on the relative mix of income reported by country and the respective tax rates imposed by each tax jurisdiction. For U.S.-sourced income, the Company’s U.S. federal income tax expense differs from the amounts computed by applying the federal statutory income tax rate to income before taxes due primarily to interest income on tax-advantaged state and municipal securities, dividends received income, and excess tax benefits on share based compensation. The outbreak of the coronavirus pandemic in the first quarter of 2020 led to significant unrealized losses in our investment portfolio that were recognized in earnings. As a result, the Company had a pre-tax loss of $41.2 million for the three months ended March 31, 2020 and recorded a U.S. federal income tax benefit of $4.4 million . For the three months ended March 31, 2019 , our U.S. federal income tax expense was 10.8% of income before taxes.
Adopted and Prospective Accounting Standards	Adopted Accounting Standards On January 1, 2020, the Company adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , using the modified retrospective approach, by which a cumulative-effect adjustment was made to retained earnings as of the date of adoption. This update requires financial assets measured at amortized cost, such as bank loan participations held for investment, to be presented at the net amount expected to be collected by means of an allowance for credit losses that is reflected in net income. Credit losses relating to available-for-sale debt securities are recorded through an allowance for credit losses, with the amount of the allowance limited to the amount by which fair value is below amortized cost. In connection with the adoption of this ASU, the Company elected the fair value option in accounting for bank loan participations effective January 1, 2020. The targeted transition relief offered by ASU 2019-05, Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief was applied to elect the fair value option to account for bank loan participations already held at the January 1, 2020 date of adoption. Under the fair value option, bank loan participations are measured at fair value, and changes in unrealized gains and losses in bank loan participations are reported in our income statement as net realized and unrealized (losses) gains on investments. At adoption on January 1, 2020, the Company reduced the carrying value of its bank loan portfolio to fair value through an $8.4 million adjustment with a $7.8 million (net of tax) cumulative effect adjustment to reduce retained earnings. Upon adoption of this ASU, the Company established an allowance for uncollectible reinsurance balances through a $265,000 (net of tax) cumulative effect adjustment to retained earnings. Because we purchase reinsurance from financially strong reinsurers or we have collateral securing the recoverables, the effect of adoption was not material to our financial position.

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2020
Investments [Abstract]
Schedule of summary of available-for-sale investments	The Company’s available-for-sale fixed maturity securities are summarized as follows: Cost or Gross Gross Fair (in thousands) March 31, 2020 Fixed maturity securities: State and municipal $ 173,919 $ 8,007 $ (551 ) $ 181,375 Residential mortgage-backed 298,904 9,366 (831 ) 307,439 Corporate 669,191 19,583 (3,753 ) 685,021 Commercial mortgage and asset-backed 274,448 3,790 (9,259 ) 268,979 U.S. Treasury securities and obligations guaranteed by the U.S. government 122,335 3,688 — 126,023 Redeemable preferred stock 2,025 — (257 ) 1,768 Total fixed maturity securities, available-for-sale $ 1,540,822 $ 44,434 $ (14,651 ) $ 1,570,605 December 31, 2019 Fixed maturity securities: State and municipal $ 159,894 $ 7,949 $ (742 ) $ 167,101 Residential mortgage-backed 261,524 3,244 (622 ) 264,146 Corporate 611,304 21,306 (389 ) 632,221 Commercial mortgage and asset-backed 249,309 3,954 (806 ) 252,457 U.S. Treasury securities and obligations guaranteed by the U.S. government 114,477 1,229 (39 ) 115,667 Redeemable preferred stock 2,025 9 — 2,034 Total fixed maturity securities, available-for-sale $ 1,398,533 $ 37,691 $ (2,598 ) $ 1,433,626
Schedule of summary of available-for-sale investments by contractual maturity	The amortized cost and fair value of available-for-sale investments in fixed maturity securities at March 31, 2020 are summarized, by contractual maturity, as follows: Cost or Fair (in thousands) One year or less $ 108,264 $ 108,823 After one year through five years 472,749 484,651 After five years through ten years 253,007 260,236 After ten years 131,425 138,709 Residential mortgage-backed 298,904 307,439 Commercial mortgage and asset-backed 274,448 268,979 Redeemable preferred stock 2,025 1,768 Total $ 1,540,822 $ 1,570,605
Schedule of gross unrealized losses and fair value for available-for-sale securities	The following table shows the Company’s gross unrealized losses and fair value for available-for-sale securities aggregated by investment category and the length of time that individual securities have been in a continuous unrealized loss position: Less Than 12 Months 12 Months or More Total Fair Gross Fair Gross Fair Gross (in thousands) March 31, 2020 Fixed maturity securities: State and municipal $ 33,372 $ (551 ) $ — $ — $ 33,372 $ (551 ) Residential mortgage-backed 27,670 (830 ) 27 (1 ) 27,697 (831 ) Corporate 157,118 (3,749 ) 1,251 (4 ) 158,369 (3,753 ) Commercial mortgage and asset-backed 109,143 (6,962 ) 37,859 (2,297 ) 147,002 (9,259 ) Redeemable preferred stock 1,768 (257 ) — — 1,768 (257 ) Total fixed maturity securities, available-for-sale $ 329,071 $ (12,349 ) $ 39,137 $ (2,302 ) $ 368,208 $ (14,651 ) December 31, 2019 Fixed maturity securities: State and municipal $ 30,028 $ (741 ) $ 667 $ (1 ) $ 30,695 $ (742 ) Residential mortgage-backed 23,632 (78 ) 37,363 (544 ) 60,995 (622 ) Corporate 45,550 (365 ) 9,933 (24 ) 55,483 (389 ) Commercial mortgage and asset-backed 46,434 (406 ) 56,720 (400 ) 103,154 (806 ) U.S. Treasury securities and obligations guaranteed by the U.S. government 8,474 (22 ) 7,168 (17 ) 15,642 (39 ) Total fixed maturity securities, available-for-sale $ 154,118 $ (1,612 ) $ 111,851 $ (986 ) $ 265,969 $ (2,598 )
Schedule of summary of realized gains and losses	The Company’s net realized and unrealized gains and losses on investments are summarized as follows: Three Months Ended 2020 2019 (in thousands) Fixed maturity securities: Gross realized gains $ 215 $ 177 Gross realized losses (1 ) (405 ) 214 (228 ) Bank loan participations: Gross realized gains 103 13 Gross realized losses (1,309 ) (1,692 ) Changes in fair values of bank loan participations (43,947 ) — (45,153 ) (1,679 ) Equity securities: Gross realized gains — — Gross realized losses (170 ) (18 ) Changes in fair values of equity securities (13,315 ) 3,549 (13,485 ) 3,531 Short-term investments and other: Gross realized gains 18 1 Gross realized losses (1 ) — 17 1 Total $ (58,407 ) $ 1,625
Schedule of other invested assets	The Company invests selectively in private debt and equity opportunities. These investments, which together comprise the Company’s other invested assets, are primarily focused in renewable energy, limited partnerships, and bank holding companies. Carrying Value Investment Income March 31, December 31, Three Months Ended 2020 2019 2020 2019 (in thousands) Renewable energy LLCs (a) $ 31,305 $ 31,219 $ 834 $ 921 Renewable energy notes receivable ( b) 2,680 8,750 166 328 Limited partnerships (c) 9,212 16,741 (569 ) 2,069 Bank holding companies (d) 4,500 4,500 86 86 Total other invested assets $ 47,697 $ 61,210 $ 517 $ 3,404 (a) The Company’s Corporate and Other segment owns equity interests ranging from 2.6% to 32.2% in various LLCs whose principal objective is capital appreciation and income generation from owning and operating renewable energy production facilities (wind and solar). The LLCs are managed by an entity for which two former directors served as officers, and the Company’s Chairman and Chief Executive Officer ("CEO") has invested in certain of these LLCs. The equity method is used to account for the Company’s LLC investments. Income for the LLCs primarily reflects adjustments to the carrying values of investments in renewable energy projects to their determined fair values. The fair value adjustments are included in revenues for the LLCs. Expenses for the LLCs are not significant and are comprised of administrative and interest expenses. The Company received cash distributions from these investments totaling $747,000 and $253,000 in the three months ended March 31, 2020 and 2019 , respectively. (b) The Company's Corporate and Other segment has invested in notes receivable for renewable energy projects. At December 31, 2019 , the Company held an $8.8 million note issued by an entity for which two of our former directors serve as officers . During the three months ended March 31, 2020 , the Company received repayment of $6.1 million of the original note principal. Interest on the note, which matures in 2021, is fixed at 15.0% . Interest income on the note was $166,000 and $328,000 for the three months ended March 31, 2020 and 2019 , respectively. (c) The Company owns investments in limited partnerships that invest in concentrated portfolios including publicly-traded small cap equities, loans of middle market private equity sponsored companies, and tranches of distressed home loans. Income f rom the partnerships is recognized under the equity method of accounting. The Company’s Corporate and Other segment held an investment in a limited partnership with a carrying value of $2.7 million at March 31, 2020 . The Company recognized investment losses of $710,000 and investment income of $481,000 on the investment for the three months ended March 31, 2020 and 2019 , respectively. The Company’s Excess and Surplus Lines segment holds investments in limited partnerships of $6.5 million at March 31, 2020 . Investment income of $141,000 and $1.6 million was recognized on the investments for the three months ended March 31, 2020 and 2019 , respectively. (d) The Company's Corporate and Other segment holds $4.5 million of subordinated notes issued by a bank holding company for which the Company’s Chairman and CEO was previously the Lead Independent Director and an investor and for which one of the Company’s directors was an investor and is currently a holder of the subordinated notes (the "Bank Holding Company"). Interest on the notes, which mature on August 12, 2023, is fixed at 7.6% per annum. Interest income on the notes was $86,000 in both the three months ended March 31, 2020 and 2019 , respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of gross carrying amounts and accumulated amortization	The gross carrying amounts and accumulated amortization for each major specifically identifiable intangible asset class were as follows: March 31, 2020 December 31, 2019 Life Gross Accumulated Gross Accumulated ($ in thousands) Intangible Assets Trademarks Indefinite $ 22,200 $ — $ 22,200 $ — Insurance licenses and authorities Indefinite 8,964 — 8,964 — Identifiable intangibles not subject to amortization 31,164 — 31,164 — Broker relationships 24.6 11,611 5,984 11,611 5,835 Identifiable intangible assets subject to amortization 11,611 5,984 11,611 5,835 $ 42,775 $ 5,984 $ 42,775 $ 5,835

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Schedule of reconciliation of numerator and denominator of basic and diluted earnings per share	The following represents a reconciliation of the numerator and denominator of the basic and diluted earnings per share computations contained in the condensed consolidated financial statements: Three Months Ended 2020 2019 (in thousands, except share and per share amounts) Net (loss) income to shareholders $ (36,815 ) $ 22,728 Weighted average common shares outstanding: Basic 30,476,307 30,059,398 Common share equivalents — 412,906 Diluted 30,476,307 30,472,304 (Loss) earnings per share: Basic $ (1.21 ) $ 0.76 Common share equivalents — (0.01 ) Diluted $ (1.21 ) $ 0.75

Reserve for Losses and Loss A_2

Reserve for Losses and Loss Adjustment Expenses (Tables)	3 Months Ended
	Mar. 31, 2020
Liability for Claims and Claims Adjustment Expense [Abstract]
Schedule of reconciliation of beginning and ending reserve balances for losses and loss adjustment expenses	The following table provides a reconciliation of the beginning and ending reserve balances for losses and loss adjustment expenses, net of reinsurance, to the gross amounts reported in the condensed consolidated balance sheets: Three Months Ended 2020 2019 (in thousands) Reserve for losses and loss adjustment expenses net of reinsurance recoverables at beginning of period $ 1,377,461 $ 1,194,088 Add: Incurred losses and loss adjustment expenses net of reinsurance: Current year 95,982 138,959 Prior years 874 968 Total incurred losses and loss and adjustment expenses 96,856 139,927 Deduct: Loss and loss adjustment expense payments net of reinsurance: Current year 4,271 4,679 Prior years 118,357 107,684 Total loss and loss adjustment expense payments 122,628 112,363 Reserve for losses and loss adjustment expenses net of reinsurance recoverables at end of period 1,351,689 1,221,652 Add: Reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period 691,669 508,655 Reserve for losses and loss adjustment expenses gross of reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period $ 2,043,358 $ 1,730,307

Other Comprehensive (Loss) In_2

Other Comprehensive (Loss) Income (Tables)	3 Months Ended
	Mar. 31, 2020
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of components of comprehensive income (loss)	The following table summarizes the components of other comprehensive (loss) income: Three Months Ended 2020 2019 (in thousands) Unrealized (losses) gains arising during the period, before U.S. income taxes $ (5,096 ) $ 21,478 U.S. income taxes 1,378 (1,447 ) Unrealized (losses) gains arising during the period, net of U.S. income taxes (3,718 ) 20,031 Less reclassification adjustment: Net realized investment gains (losses) 214 (228 ) U.S. income taxes (13 ) (1 ) Reclassification adjustment for investment gains (losses) realized in net income 201 (229 ) Other comprehensive (loss) income $ (3,919 ) $ 20,260

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Schedule of summary of company's segment results	The following table summarizes the Company’s segment results: Excess and Specialty Casualty Corporate Total (in thousands) Three Months Ended March 31, 2020 Gross written premiums $ 136,197 $ 102,802 $ 44,842 $ — $ 283,841 Net earned premiums 99,739 13,283 32,896 — 145,918 Underwriting profit (loss) of insurance segments 8,112 (988 ) 207 — 7,331 Net investment income 7,941 928 11,604 363 20,836 Interest expense — — — 2,876 2,876 Segment revenues 83,829 12,673 13,280 502 110,284 Segment goodwill 181,831 — — — 181,831 Segment assets 2,293,444 829,699 1,824,729 48,938 4,996,810 Three Months Ended March 31, 2019 Gross written premiums $ 186,549 $ 102,953 $ 37,832 $ — $ 327,334 Net earned premiums 141,672 12,360 36,120 — 190,152 Underwriting profit of insurance segments 13,102 1,623 327 — 15,052 Net investment income 5,544 897 11,172 1,818 19,431 Interest expense — — — 2,808 2,808 Segment revenues 152,437 13,736 46,010 1,944 214,127 Segment goodwill 181,831 — — — 181,831 Segment assets 1,013,069 706,451 1,517,142 62,589 3,299,251
Schedule of underwriting profit of operating segments by individual segment and reconciliation to consolidated income before taxes	The following table reconciles the underwriting profit (loss) of the operating segments by individual segment to consolidated income before taxes: Three Months Ended 2020 2019 (in thousands) Underwriting profit (loss) of the insurance segments: Excess and Surplus Lines $ 8,112 $ 13,102 Specialty Admitted Insurance (988 ) 1,623 Casualty Reinsurance 207 327 Total underwriting profit of insurance segments 7,331 15,052 Other operating expenses of the Corporate and Other segment (8,279 ) (7,906 ) Underwriting (loss) profit (948 ) 7,146 Net investment income 20,836 19,431 Net realized and unrealized (losses) gains on investments (58,407 ) 1,625 Amortization of intangible assets (149 ) (149 ) Other income and expenses 326 246 Interest expense (2,876 ) (2,808 ) (Loss) income before taxes $ (41,218 ) $ 25,491

Other Operating Expenses (Table

Other Operating Expenses (Tables)	3 Months Ended
	Mar. 31, 2020
Other Operating Expenses [Abstract]
Schedule of other operating expenses	Other operating expenses consist of the following: Three Months Ended 2020 2019 (in thousands) Amortization of policy acquisition costs $ 24,116 $ 18,621 Other underwriting expenses of the operating segments 19,226 19,225 Other operating expenses of the Corporate and Other segment 8,279 7,906 Total $ 51,621 $ 45,752

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of assets measured at fair value on a recurring basis	Assets measured at fair value on a recurring basis as of March 31, 2020 are summarized below: Fair Value Measurements Using Quoted Prices Significant Significant Total (in thousands) Fixed maturity securities, available-for-sale: State and municipal $ — $ 181,375 $ — $ 181,375 Residential mortgage-backed — 307,439 — 307,439 Corporate — 685,021 — 685,021 Commercial mortgage and asset-backed — 268,979 — 268,979 U.S. Treasury securities and obligations guaranteed by the U.S. government 125,580 443 — 126,023 Redeemable preferred stock — 1,768 — 1,768 Total fixed maturity securities, available-for-sale $ 125,580 $ 1,445,025 $ — $ 1,570,605 Equity securities: Preferred stock — 60,861 — 60,861 Common stock 7,980 2,549 4 10,533 Total equity securities $ 7,980 $ 63,410 $ 4 $ 71,394 Bank loan participations $ — $ 201,860 $ 1,028 $ 202,888 Short-term investments $ — $ 71,058 $ — $ 71,058 Assets measured at fair value on a recurring basis as of December 31, 2019 are summarized below: Fair Value Measurements Using Quoted Prices Significant Significant Total (in thousands) Fixed maturity securities, available-for-sale: State and municipal $ — $ 167,101 $ — $ 167,101 Residential mortgage-backed — 264,146 — 264,146 Corporate — 632,221 — 632,221 Commercial mortgage and asset-backed — 252,457 — 252,457 U.S. Treasury securities and obligations guaranteed by the U.S. government 115,173 494 — 115,667 Redeemable preferred stock — 2,034 — 2,034 Total fixed maturity securities, available-for-sale $ 115,173 $ 1,318,453 $ — $ 1,433,626 Equity securities: Preferred stock — 62,747 — 62,747 Common stock 14,669 3,276 43 17,988 Total equity securities $ 14,669 $ 66,023 $ 43 $ 80,735 Short-term investments $ — $ 156,925 $ — $ 156,925
Reconciliation of securities measured at fair value on a recurring basis	A reconciliation of the beginning and ending balances of available-for-sale fixed maturity securities, equity securities, and bank loan participations measured at fair value on a recurring basis (as a result of the fair value option effective January 1, 2020) using significant unobservable inputs (Level 3) is shown below: Three Months Ended March 31, 2020 March 31, 2019 (in thousands) Beginning balance $ 43 $ 4,442 Transfers out of Level 3 — (4,228 ) Transfers in to Level 3 358 — Purchases 703 — Sales — — Maturities, calls and paydowns (17 ) — Amortization of discount 3 — Total gains or losses (realized/unrealized): — Included in earnings (58 ) (37 ) Included in other comprehensive income — — Ending balance $ 1,032 $ 177
Schedule of assets measured at fair value on a nonrecurring basis	Fair Value Measurements Using Quoted Prices Significant Significant Total (in thousands) December 31, 2019 Bank loan participations held-for-investment $ — $ — $ 6,949 $ 6,949
Schedule of carrying value and fair value	The carrying values and fair values of financial instruments are summarized below: March 31, 2020 December 31, 2019 Carrying Fair Value Carrying Fair Value (in thousands) Assets Fixed maturity securities, available-for-sale $ 1,570,605 $ 1,570,605 $ 1,433,626 $ 1,433,626 Equity securities 71,394 71,394 80,735 80,735 Bank loan participations 202,888 202,888 260,864 252,423 Cash and cash equivalents 291,223 291,223 206,912 206,912 Restricted cash equivalents 1,107,321 1,107,321 1,199,164 1,199,164 Short-term investments 71,058 71,058 156,925 156,925 Other invested assets – notes receivable 7,180 11,458 13,250 18,756 Liabilities Senior debt 277,300 257,965 158,300 158,043 Junior subordinated debt 104,055 106,618 104,055 122,193

Capital Stock and Equity Awar_2

Capital Stock and Equity Awards (Tables)	3 Months Ended
	Mar. 31, 2020
Stockholders' Equity Note [Abstract]
Schedule of dividends	The Company declared the following dividends during the first three months of 2020 and 2019: Date of Declaration Dividend per Common Share Payable to Shareholders of Record on Payment Date Total Amount (thousands) 2020 February 19, 2020 $ 0.30 March 16, 2020 March 31, 2020 $ 9,269 2019 February 20, 2019 $ 0.30 March 11, 2019 March 29, 2019 $ 9,146
Schedule of summary of option activity	The following table summarizes option activity: Three Months Ended March 31, 2020 2019 Shares Weighted- Shares Weighted- Outstanding: Beginning of period 643,851 $ 30.41 1,115,324 $ 29.02 Granted — $ — — $ — Exercised — $ — (125,349 ) $ 29.47 Forfeited — $ — (3,759 ) $ 36.37 End of period 643,851 $ 30.41 986,216 $ 28.94 Exercisable, end of period 640,606 $ 30.35 926,166 $ 28.07
Schedule of summary of RSU activity	The following table summarizes RSU activity: Three Months Ended March 31, 2020 2019 Shares Weighted- Shares Weighted- Unvested, beginning of period 340,368 $ 41.50 300,142 $ 39.22 Granted 179,016 $ 43.55 167,295 $ 42.07 Vested (142,830 ) $ 41.16 (109,545 ) $ 39.93 Forfeited (1,188 ) $ 42.07 (1,398 ) $ 40.26 Unvested, end of period 375,366 $ 42.61 356,494 $ 40.33
Schedule of summary of amount of expense and related tax benefit	Share based compensation expense is recognized on a straight line basis over the vesting period. The amount of expense and related tax benefit is summarized below: Three Months Ended 2020 2019 (in thousands) Share based compensation expense $ 1,867 $ 1,674 U.S. tax benefit on share based compensation expense 250 200

Accounting Policies - Narrative

Accounting Policies - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)company	Mar. 31, 2019USD ($)	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Pre-tax loss	$ 41,218	$ (25,491)
Income tax benefit	$ (4,403)	$ 2,763
Effective U.S. federal income tax expense rate		10.80%
UNITED STATES
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of insurance companies | company	5
BERMUDA
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of insurance companies | company	2
ASU 2019-05
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Bank loan participations			$ (8,400)
Cumulative effect of adoption of ASU			7,827
ASU 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of adoption of ASU			265
Retained Earnings | ASU 2019-05
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of adoption of ASU			7,827
Retained Earnings | ASU 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of adoption of ASU			$ 265
VIE, not primary beneficiary
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Investment in variable interest entities	$ 31,300			$ 31,200

Investments - Narrative (Detail

Investments - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)issuer	Mar. 31, 2019USD ($)securityloan	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)issuerloan
Gain (Loss) on Securities [Line Items]
Number of issuers | issuer	147
Total fair value	$ 368,208
Gross unrealized losses	14,651
Fixed maturity securities, available-for-sale	1,570,605			$ 1,433,626
Bank loan participations				$ 260,864
Bank loan participations	202,888
Unpaid principal balance	260,200
Net investment income	20,836	$ 19,431
Net realized and unrealized losses on investments	58,407	$ (1,625)
Losses due to credit-related impairments	5,000
Number of impaired loans | loan		2		7
Carrying value of impaired loans		$ 4,400		$ 6,900
Unpaid principal on impaired loans		5,900		14,300
Allowance for credit losses on impaired loans		1,500		7,200
Average recorded investment in impaired bank loans		2,200
Net realized gain (loss) on changes in fair value of impaired bank loans		$ 1,500
Fixed maturity securities
Gain (Loss) on Securities [Line Items]
Total fair value				265,969
Gross unrealized losses				2,598
Fixed maturity securities, available-for-sale	1,570,605			1,433,626
Aggregate net unrealized gain (loss)	$ 44,434			$ 37,691
Number of impaired fixed maturities | security		3
Impairment losses		$ 271
Bank Loan Portfolio
Gain (Loss) on Securities [Line Items]
Number of issuers with impaired loans | issuer				6
Loans from Issuer Experiencing Liquidity Concerns
Gain (Loss) on Securities [Line Items]
Number of impaired loans | loan				2
Number of issuers with impaired loans | issuer				1
Allowance for credit losses on impaired loans				$ 5,100
BBB- or better | Fixed maturity securities
Gain (Loss) on Securities [Line Items]
Percentage of available for sale securities	99.60%
Below BBB-
Gain (Loss) on Securities [Line Items]
Fixed maturity securities, available-for-sale	$ 5,600
Aggregate net unrealized gain (loss)	17
ASU 2019-05
Gain (Loss) on Securities [Line Items]
Bank loan participations			$ (8,400)
Cumulative effect of adoption of ASU			7,827
ASU 2019-05 | Retained Earnings
Gain (Loss) on Securities [Line Items]
Cumulative effect of adoption of ASU			$ 7,827
Bank Holding Company
Gain (Loss) on Securities [Line Items]
Carrying value of collateralized loan obligation held	2,300
Bank Loan Participations
Gain (Loss) on Securities [Line Items]
Net investment income	4,100
Net realized and unrealized losses on investments	$ 43,900

Investments - Schedule of Avail

Investments - Schedule of Available-for-Sale Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities, Cost or Amortized Cost	$ 1,540,822	$ 1,398,533
Fixed maturity securities, available-for-sale	1,570,605	1,433,626
Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities, Cost or Amortized Cost	1,540,822	1,398,533
Total investments available-for-sale, Gross Unrealized Gains	44,434	37,691
Total investments available-for-sale, Gross Unrealized Losses	(14,651)	(2,598)
Fixed maturity securities, available-for-sale	1,570,605	1,433,626
State and municipal
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities, Cost or Amortized Cost	173,919	159,894
Total investments available-for-sale, Gross Unrealized Gains	8,007	7,949
Total investments available-for-sale, Gross Unrealized Losses	(551)	(742)
Fixed maturity securities, available-for-sale	181,375	167,101
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities, Cost or Amortized Cost	298,904	261,524
Total investments available-for-sale, Gross Unrealized Gains	9,366	3,244
Total investments available-for-sale, Gross Unrealized Losses	(831)	(622)
Fixed maturity securities, available-for-sale	307,439	264,146
Corporate
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities, Cost or Amortized Cost	669,191	611,304
Total investments available-for-sale, Gross Unrealized Gains	19,583	21,306
Total investments available-for-sale, Gross Unrealized Losses	(3,753)	(389)
Fixed maturity securities, available-for-sale	685,021	632,221
Commercial mortgage and asset-backed
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities, Cost or Amortized Cost	274,448	249,309
Total investments available-for-sale, Gross Unrealized Gains	3,790	3,954
Total investments available-for-sale, Gross Unrealized Losses	(9,259)	(806)
Fixed maturity securities, available-for-sale	268,979	252,457
U.S. Treasury securities and obligations guaranteed by the U.S. government
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities, Cost or Amortized Cost	122,335	114,477
Total investments available-for-sale, Gross Unrealized Gains	3,688	1,229
Total investments available-for-sale, Gross Unrealized Losses	0	(39)
Fixed maturity securities, available-for-sale	126,023	115,667
Redeemable preferred stock
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities, Cost or Amortized Cost	2,025	2,025
Total investments available-for-sale, Gross Unrealized Gains	0	9
Total investments available-for-sale, Gross Unrealized Losses	(257)	0
Fixed maturity securities, available-for-sale	$ 1,768	$ 2,034

Investments - Schedule of Contr

Investments - Schedule of Contract Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Cost or Amortized Cost
One year or less	$ 108,264
After one year through five years	472,749
After five years through ten years	253,007
After ten years	131,425
Residential mortgage-backed	298,904
Commercial mortgage and asset-backed	274,448
Redeemable preferred stock	2,025
Total fixed maturity securities, Cost or Amortized Cost	1,540,822	$ 1,398,533
Fair Value
One year or less	108,823
After one year through five years	484,651
After five years through ten years	260,236
After ten years	138,709
Residential mortgage-backed	307,439
Commercial mortgage and asset-backed	268,979
Redeemable preferred stock	1,768
Total investments available-for-sale, Fair Value	$ 1,570,605	$ 1,433,626

Investments - Schedule of Gross

Investments - Schedule of Gross Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, fair value	$ 368,208
Fixed maturity securities, gross unrealized losses	(14,651)
Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, less than 12 months, fair value	329,071	$ 154,118
Fixed maturity securities, less than 12 months, gross unrealized losses	(12,349)	(1,612)
Fixed maturity securities, 12 months or more, fair value	39,137	111,851
Fixed maturity securities, 12 months or more, gross unrealized losses	(2,302)	(986)
Fixed maturity securities, fair value		265,969
Fixed maturity securities, gross unrealized losses		(2,598)
State and municipal
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, less than 12 months, fair value	33,372	30,028
Fixed maturity securities, less than 12 months, gross unrealized losses	(551)	(741)
Fixed maturity securities, 12 months or more, fair value	0	667
Fixed maturity securities, 12 months or more, gross unrealized losses	0	(1)
Fixed maturity securities, fair value	33,372	30,695
Fixed maturity securities, gross unrealized losses	(551)	(742)
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, less than 12 months, fair value	27,670	23,632
Fixed maturity securities, less than 12 months, gross unrealized losses	(830)	(78)
Fixed maturity securities, 12 months or more, fair value	27	37,363
Fixed maturity securities, 12 months or more, gross unrealized losses	(1)	(544)
Fixed maturity securities, fair value	27,697	60,995
Fixed maturity securities, gross unrealized losses	(831)	(622)
Corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, less than 12 months, fair value	157,118	45,550
Fixed maturity securities, less than 12 months, gross unrealized losses	(3,749)	(365)
Fixed maturity securities, 12 months or more, fair value	1,251	9,933
Fixed maturity securities, 12 months or more, gross unrealized losses	(4)	(24)
Fixed maturity securities, fair value	158,369	55,483
Fixed maturity securities, gross unrealized losses	(3,753)	(389)
Commercial mortgage and asset-backed
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, less than 12 months, fair value	109,143	46,434
Fixed maturity securities, less than 12 months, gross unrealized losses	(6,962)	(406)
Fixed maturity securities, 12 months or more, fair value	37,859	56,720
Fixed maturity securities, 12 months or more, gross unrealized losses	(2,297)	(400)
Fixed maturity securities, fair value	147,002	103,154
Fixed maturity securities, gross unrealized losses	(9,259)	(806)
U.S. Treasury securities and obligations guaranteed by the U.S. government
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, less than 12 months, fair value		8,474
Fixed maturity securities, less than 12 months, gross unrealized losses		(22)
Fixed maturity securities, 12 months or more, fair value		7,168
Fixed maturity securities, 12 months or more, gross unrealized losses		(17)
Fixed maturity securities, fair value		15,642
Fixed maturity securities, gross unrealized losses		$ (39)
Redeemable preferred stock
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, less than 12 months, fair value	1,768
Fixed maturity securities, less than 12 months, gross unrealized losses	(257)
Fixed maturity securities, 12 months or more, fair value	0
Fixed maturity securities, 12 months or more, gross unrealized losses	0
Fixed maturity securities, fair value	1,768
Fixed maturity securities, gross unrealized losses	$ (257)

Investments - Summary of Realiz

Investments - Summary of Realized Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Investments [Abstract]
Fixed maturity securities, gross realized gains	$ 215	$ 177
Fixed maturity securities, gross realized losses	(1)	(405)
Fixed maturity securities	214	(228)
Bank loan participations, gross realized gains	103	13
Bank loan participations, gross realized losses	(1,309)	(1,692)
Changes in fair values of bank loan participations	(43,947)	0
Bank loan participations	(45,153)	(1,679)
Equity securities, gross realized gain	0	0
Equity securities, gross realized losses	(170)	(18)
Equity securities, changes in fair values of equity securities	(13,315)	3,549
Equity securities	(13,485)	3,531
Short-term investments and other, gross realized gains	18	1
Short-term investments and other, gross realized losses	(1)	0
Short-term investments and other	17	1
Total	$ (58,407)	$ 1,625

Investments - Summary of Privat

Investments - Summary of Private Debt and Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Net Investment Income [Line Items]
Total other invested assets	$ 47,697		$ 61,210
Investment income	517	$ 3,404
Interest income		5,100
Renewable energy LLCs
Net Investment Income [Line Items]
Total other invested assets	31,305		31,219
Investment income	834	921
Renewable energy notes receivable
Net Investment Income [Line Items]
Total other invested assets	2,680		8,750
Investment income	166	328
Repayment received	$ 6,100
Rate of interest	15.00%
Limited partnerships
Net Investment Income [Line Items]
Total other invested assets	$ 9,212		16,741
Investment income	(569)	2,069
Bank holding companies
Net Investment Income [Line Items]
Total other invested assets	4,500		$ 4,500
Investment income	86	86
Interest income	$ 86	86
Bank Holding Company
Net Investment Income [Line Items]
Rate of interest	7.60%
Corporate and Other | Limited partnerships
Net Investment Income [Line Items]
Carrying values of limited partnerships held	$ 2,700
Investment income (loss)	710	481
Corporate and Other | Investment in LLC
Net Investment Income [Line Items]
Cash distributions from LLCs	747	253
Corporate and Other | Bank Holding Company
Net Investment Income [Line Items]
Investment in private subordinated notes	4,500
Excess and Surplus Lines | Limited partnerships
Net Investment Income [Line Items]
Carrying values of limited partnerships held	6,500
Investment income (loss)	$ 141	$ 1,600
Minimum | Corporate and Other | Investment in LLC
Net Investment Income [Line Items]
Ownership percentage	2.60%
Maximum | Corporate and Other | Investment in LLC
Net Investment Income [Line Items]
Ownership percentage	32.20%

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 11, 2007
Business Acquisition [Line Items]
Goodwill	$ 181,831	$ 181,831	$ 181,831
James River Group, Inc.
Business Acquisition [Line Items]
Percentage of outstanding shares				100.00%

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Acquired Intangible Assets [Line Items]
Identifiable intangibles not subject to amortization	$ 31,164	$ 31,164
Identifiable intangible assets subject to amortization
Gross Carrying Amount	11,611	11,611
Accumulated Amortization	5,984	5,835
Total Intangible Assets, Gross	42,775	42,775
Broker relationships
Identifiable intangible assets subject to amortization
Gross Carrying Amount	11,611	11,611
Accumulated Amortization	$ 5,984	5,835
Life	24 years 7 months 6 days
Trademarks
Acquired Intangible Assets [Line Items]
Identifiable intangibles not subject to amortization	$ 22,200	22,200
Insurance licenses and authorities
Acquired Intangible Assets [Line Items]
Identifiable intangibles not subject to amortization	$ 8,964	$ 8,964

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Stock options and restricted share units ("RSU's")
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of securities excluded from the calculations of diluted earnings per share	309,443	171,509

Earnings Per Share - Basic and

Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net (loss) income to shareholders	$ (36,815)	$ 22,728
Weighted average common shares outstanding:
Basic (in shares)	30,476,307	30,059,398
Common share equivalents (in shares)	0	412,906
Diluted (in shares)	30,476,307	30,472,304
(Loss) earnings per share:
Basic (in dollars per share)	$ (1.21)	$ 0.76
Common share equivalents (in dollars per share)	0	(0.01)
Diluted (in dollars per share)	$ (1.21)	$ 0.75

Reserve for Losses and Loss A_3

Reserve for Losses and Loss Adjustment Expenses - Reconciliation of Losses and Loss Adjustment Balances (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense, Period Increase (Decrease) [Abstract]
Reserve for losses and loss adjustment expenses net of reinsurance recoverables at beginning of period	$ 1,377,461	$ 1,194,088
Add: Incurred losses and loss adjustment expenses net of reinsurance:
Current year	95,982	138,959
Prior years	874	968
Total incurred losses and loss and adjustment expenses	96,856	139,927
Deduct: Loss and loss adjustment expense payments net of reinsurance:
Current year	4,271	4,679
Prior years	118,357	107,684
Total loss and loss adjustment expense payments	122,628	112,363
Reserve for losses and loss adjustment expenses net of reinsurance recoverables at end of period	$ 1,377,461	$ 1,194,088	$ 1,351,689	$ 1,377,461	$ 1,221,652
Add: Reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period			691,669	668,045	508,655
Reserve for losses and loss adjustment expenses gross of reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period			$ 2,043,358	$ 2,045,506	$ 1,730,307

Reserve for Losses and Loss A_4

Reserve for Losses and Loss Adjustment Expenses - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Favorable development on prior year loss reserves
Reserve for losses and loss adjustment expenses	$ (874)	$ (968)
Excess and Surplus Lines
Favorable development on prior year loss reserves
Reserve for losses and loss adjustment expenses	3	10
Specialty Admitted Insurance
Favorable development on prior year loss reserves
Reserve for losses and loss adjustment expenses	1,000	2,000
Casualty Reinsurance
Favorable development on prior year loss reserves
Reserve for losses and loss adjustment expenses	$ (1,900)	$ (3,000)

Other Comprehensive (Loss) In_3

Other Comprehensive (Loss) Income - Summary of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized (losses) gains arising during the period, before U.S. income taxes	$ (5,096)	$ 21,478
U.S. income taxes	1,378	(1,447)
Unrealized (losses) gains arising during the period, net of U.S. income taxes	(3,718)	20,031
Less reclassification adjustment:
Net realized investment gains (losses)	214	(228)
U.S. income taxes	(13)	(1)
Reclassification adjustment for investment gains (losses) realized in net income	201	(229)
Other comprehensive (loss) income	$ (3,919)	$ 20,260

Other Comprehensive (Loss) In_4

Other Comprehensive (Loss) Income - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Fixed maturity securities	$ 214	$ (228)
Bank loan participations	(45,153)	(1,679)
Net realized and unrealized gains (losses) on investments in equity securities	$ (13,500)	$ 3,500

Contingent Liabilities - Narrat

Contingent Liabilities - Narrative (Details)	Mar. 31, 2020USD ($)credit_facility	Dec. 31, 2019USD ($)
Contingent Liabilities [Line Items]
Amount of collateral held	$ 1,107,321,000	$ 1,199,164,000
JRG Reinsurance Company, Ltd.
Contingent Liabilities [Line Items]
Number of credit facilities | credit_facility	3
JRG Reinsurance Company, Ltd. | Letter of credit 75 Million
Contingent Liabilities [Line Items]
Letters of credit facility, amount	$ 75,000,000
Amount of letters of credit issued	20,500,000
Assets deposited for securing letters of credit	36,700,000
JRG Reinsurance Company, Ltd. | Letter of credit 102.5 Million
Contingent Liabilities [Line Items]
Letters of credit facility, amount	102,500,000
Amount of letters of credit issued	76,000,000
Assets deposited for securing letters of credit	95,500,000
JRG Reinsurance Company, Ltd. | Letter of credit 100 Million
Contingent Liabilities [Line Items]
Amount of letters of credit issued	25,700,000
Assets deposited for securing letters of credit	52,000,000
Line of credit (up to)	100,000,000
Third-party Reinsureds | JRG Reinsurance Company, Ltd.
Contingent Liabilities [Line Items]
Collateral trust arrangement amount	294,900,000
Raiser
Contingent Liabilities [Line Items]
Amount of collateral held	$ 1,107,300,000

Segment Information - Narrative

Segment Information - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)segment	Mar. 31, 2019USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	4
Fee income in Excess and Surplus Lines segment | $	$ 1.6	$ 2.7

Segment Information - Summary o

Segment Information - Summary of Segment Results (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Gross written premiums	$ 283,841	$ 327,334
Net earned premiums	145,918	190,152
Underwriting profit of insurance segments	7,331	15,052
Net investment income	20,836	19,431
Interest expense	2,876	2,808
Segment revenues	110,284	214,127
Segment goodwill	181,831	181,831	$ 181,831
Segment assets	4,996,810	3,299,251	$ 5,024,405
Excess and Surplus Lines
Segment Reporting Information [Line Items]
Gross written premiums	136,197	186,549
Net earned premiums	99,739	141,672
Underwriting profit of insurance segments	8,112	13,102
Net investment income	7,941	5,544
Interest expense	0	0
Segment revenues	83,829	152,437
Segment goodwill	181,831	181,831
Segment assets	2,293,444	1,013,069
Specialty Admitted Insurance
Segment Reporting Information [Line Items]
Gross written premiums	102,802	102,953
Net earned premiums	13,283	12,360
Underwriting profit of insurance segments	(988)	1,623
Net investment income	928	897
Interest expense	0	0
Segment revenues	12,673	13,736
Segment goodwill	0	0
Segment assets	829,699	706,451
Casualty Reinsurance
Segment Reporting Information [Line Items]
Gross written premiums	44,842	37,832
Net earned premiums	32,896	36,120
Underwriting profit of insurance segments	207	327
Net investment income	11,604	11,172
Interest expense	0	0
Segment revenues	13,280	46,010
Segment goodwill	0	0
Segment assets	1,824,729	1,517,142
Corporate and Other
Segment Reporting Information [Line Items]
Gross written premiums	0	0
Net earned premiums	0	0
Underwriting profit of insurance segments	0	0
Net investment income	363	1,818
Interest expense	2,876	2,808
Segment revenues	502	1,944
Segment goodwill	0	0
Segment assets	$ 48,938	$ 62,589

Segment Information - Reconcili

Segment Information - Reconciliation of Operating Segments by Individual Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Total underwriting profit of insurance segments	$ 7,331	$ 15,052
Other operating expenses of the Corporate and Other segment	(8,279)	(7,906)
Underwriting (loss) profit	(948)	7,146
Net investment income	20,836	19,431
Net realized and unrealized (losses) gains on investments	(58,407)	1,625
Amortization of intangible assets	(149)	(149)
Other income and expenses	326	246
Interest expense	(2,876)	(2,808)
(Loss) income before taxes	(41,218)	25,491
Excess and Surplus Lines
Segment Reporting Information [Line Items]
Total underwriting profit of insurance segments	8,112	13,102
Net investment income	7,941	5,544
Interest expense	0	0
Specialty Admitted Insurance
Segment Reporting Information [Line Items]
Total underwriting profit of insurance segments	(988)	1,623
Net investment income	928	897
Interest expense	0	0
Casualty Reinsurance
Segment Reporting Information [Line Items]
Total underwriting profit of insurance segments	207	327
Net investment income	11,604	11,172
Interest expense	$ 0	$ 0

Other Operating Expenses (Detai

Other Operating Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Operating Expenses [Abstract]
Amortization of policy acquisition costs	$ 24,116	$ 18,621
Other underwriting expenses of the operating segments	19,226	19,225
Other operating expenses of the Corporate and Other segment	8,279	7,906
Total	$ 51,621	$ 45,752

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	$ 1,570,605	$ 1,433,626
Equity securities:
Total equity securities	71,394	80,735
Bank loan participations	202,888
Fixed maturity securities
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	1,570,605	1,433,626
State and municipal
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	181,375	167,101
Residential mortgage-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	307,439	264,146
Corporate
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	685,021	632,221
Commercial mortgage and asset-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	268,979	252,457
U.S. Treasury securities and obligations guaranteed by the U.S. government
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	126,023	115,667
Redeemable preferred stock
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	1,768	2,034
Recurring basis
Equity securities:
Bank loan participations	202,888
Short-term investments	71,058	156,925
Recurring basis | Fixed maturity securities
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	1,570,605	1,433,626
Recurring basis | State and municipal
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	181,375	167,101
Recurring basis | Residential mortgage-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	307,439	264,146
Recurring basis | Corporate
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	685,021	632,221
Recurring basis | Commercial mortgage and asset-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	268,979	252,457
Recurring basis | U.S. Treasury securities and obligations guaranteed by the U.S. government
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	126,023	115,667
Recurring basis | Redeemable preferred stock
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	1,768	2,034
Recurring basis | Equity securities
Equity securities:
Total equity securities	71,394	80,735
Recurring basis | Preferred stock
Equity securities:
Total equity securities	60,861	62,747
Recurring basis | Common stock
Equity securities:
Total equity securities	10,533	17,988
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1
Equity securities:
Bank loan participations	0
Short-term investments	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | Fixed maturity securities
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	125,580	115,173
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | State and municipal
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | Residential mortgage-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | Corporate
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | Commercial mortgage and asset-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | U.S. Treasury securities and obligations guaranteed by the U.S. government
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	125,580	115,173
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | Redeemable preferred stock
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | Equity securities
Equity securities:
Total equity securities	7,980	14,669
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | Preferred stock
Equity securities:
Total equity securities	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets Level 1 | Common stock
Equity securities:
Total equity securities	7,980	14,669
Recurring basis | Significant Other Observable Inputs Level 2
Equity securities:
Bank loan participations	201,860
Short-term investments	71,058	156,925
Recurring basis | Significant Other Observable Inputs Level 2 | Fixed maturity securities
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	1,445,025	1,318,453
Recurring basis | Significant Other Observable Inputs Level 2 | State and municipal
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	181,375	167,101
Recurring basis | Significant Other Observable Inputs Level 2 | Residential mortgage-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	307,439	264,146
Recurring basis | Significant Other Observable Inputs Level 2 | Corporate
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	685,021	632,221
Recurring basis | Significant Other Observable Inputs Level 2 | Commercial mortgage and asset-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	268,979	252,457
Recurring basis | Significant Other Observable Inputs Level 2 | U.S. Treasury securities and obligations guaranteed by the U.S. government
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	443	494
Recurring basis | Significant Other Observable Inputs Level 2 | Redeemable preferred stock
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	1,768	2,034
Recurring basis | Significant Other Observable Inputs Level 2 | Equity securities
Equity securities:
Total equity securities	63,410	66,023
Recurring basis | Significant Other Observable Inputs Level 2 | Preferred stock
Equity securities:
Total equity securities	60,861	62,747
Recurring basis | Significant Other Observable Inputs Level 2 | Common stock
Equity securities:
Total equity securities	2,549	3,276
Recurring basis | Significant Unobservable Inputs Level 3
Equity securities:
Total equity securities	1,000		$ 177	$ 214
Bank loan participations	1,028
Short-term investments	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | Fixed maturity securities
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | State and municipal
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | Residential mortgage-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | Corporate
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | Commercial mortgage and asset-backed
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | U.S. Treasury securities and obligations guaranteed by the U.S. government
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | Redeemable preferred stock
Fixed maturity securities, available-for-sale:
Total fixed maturity securities, available-for-sale	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | Equity securities
Equity securities:
Total equity securities	4	43
Recurring basis | Significant Unobservable Inputs Level 3 | Preferred stock
Equity securities:
Total equity securities	0	0
Recurring basis | Significant Unobservable Inputs Level 3 | Common stock
Equity securities:
Total equity securities	$ 4	$ 43

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Securities Measured at Fair Value (Details) - Fair Value, Recurring - Available-for-sale fixed maturity securities and equity securities - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 43	$ 4,442
Transfers out of Level 3	0	(4,228)
Transfers in to Level 3	358	0
Purchases	703	0
Sales	0	0
Maturities, calls and paydowns	(17)	0
Amortization of discount	3	0
Total gains or losses (realized/unrealized)-Included in earnings	(58)	(37)
Total gains or losses (realized/unrealized)-Included in other comprehensive income	0	0
Ending balance	$ 1,032	$ 177

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total fixed maturity securities, available-for-sale	$ 1,570,605	$ 1,433,626
Equity securities	71,394	80,735
Recurring basis | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities	1,000		$ 177	$ 214
Nonrecurring basis
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired bank loan participations held for investment		6,949
Nonrecurring basis | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired bank loan participations held for investment		6,949
Common stock | Recurring basis
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities	10,533	17,988
Common stock | Recurring basis | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity securities	$ 4	$ 43
Market approach | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total fixed maturity securities, available-for-sale				$ 4,200

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Assets Fair Value on a Nonrecurring Basis (Details) - Nonrecurring basis $ in Thousands	Dec. 31, 2019USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Bank loan participations held-for-investment	$ 6,949
Quoted Prices in Active Markets for Identical Assets Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Bank loan participations held-for-investment	0
Significant Other Observable Inputs Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Bank loan participations held-for-investment	0
Significant Unobservable Inputs Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Bank loan participations held-for-investment	$ 6,949

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets
Fixed maturity securities, available-for-sale	$ 1,570,605	$ 1,433,626
Equity securities	71,394	80,735
Bank loan participations	202,888
Bank loan participations		260,864
Cash and cash equivalents	291,223	206,912
Restricted cash equivalents	1,107,321	1,199,164
Liabilities
Senior debt	277,300	158,300
Junior subordinated debt	104,055	104,055
Carrying Value
Assets
Fixed maturity securities, available-for-sale	1,570,605	1,433,626
Equity securities	71,394	80,735
Bank loan participations	202,888
Bank loan participations		260,864
Cash and cash equivalents	291,223	206,912
Restricted cash equivalents	1,107,321	1,199,164
Short-term investments	71,058	156,925
Other invested assets – notes receivable	7,180	13,250
Liabilities
Senior debt	277,300	158,300
Junior subordinated debt	104,055	104,055
Fair Value
Assets
Fixed maturity securities, available-for-sale	1,570,605	1,433,626
Equity securities	71,394	80,735
Bank loan participations	202,888
Bank loan participations		252,423
Cash and cash equivalents	291,223	206,912
Restricted cash equivalents	1,107,321	1,199,164
Short-term investments	71,058	156,925
Other invested assets – notes receivable	11,458	18,756
Liabilities
Senior debt	257,965	158,043
Junior subordinated debt	$ 106,618	$ 122,193

Senior Debt (Details)

Senior Debt (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Drawn balance outstanding	$ 277,300,000	$ 158,300,000
2013 Facility
Debt Instrument [Line Items]
Amount drawn	60,000,000
Unsecured Debt | 2013 Facility
Debt Instrument [Line Items]
Line of credit (up to)	212,500,000
Drawn balance outstanding	193,300,000
Line of Credit | 2013 Facility
Debt Instrument [Line Items]
Line of credit (up to)	315,000,000
JRG Reinsurance Company, Ltd. | 2013 Facility
Debt Instrument [Line Items]
Amount of letters of credit issued	76,000,000
JRG Reinsurance Company, Ltd. | 2017 Facility
Debt Instrument [Line Items]
Amount drawn	59,000,000
Line of credit (up to)	100,000,000
Amount of letters of credit issued	25,700,000
JRG Reinsurance Company, Ltd. | Unsecured Debt | 2017 Facility
Debt Instrument [Line Items]
Drawn balance outstanding	$ 69,000,000

Capital Stock and Equity Awar_3

Capital Stock and Equity Awards - Common Shares (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares outstanding (in shares)	30,520,428		30,424,391
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock unit dividend equivalents	$ 113	$ 107
Dividends payable	$ 422		$ 623
Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares issued during period (in shares)	96,037
Common stock, shares outstanding (in shares)	30,520,428	30,162,045	30,424,391	29,988,460

Capital Stock and Equity Awar_4

Capital Stock and Equity Awards - Schedule of Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2020	Feb. 19, 2020	Mar. 29, 2019	Feb. 20, 2019	Mar. 31, 2020	Mar. 31, 2019
Stockholders' Equity Note [Abstract]
Dividend declared per share (in dollars per share)		$ 0.30		$ 0.30	$ 0.30	$ 0.30
Total Amount (thousands)	$ 9,269		$ 9,146

Capital Stock and Equity Awar_5

Capital Stock and Equity Awards - Equity Incentive Plans (Details) - shares	Apr. 30, 2019	Mar. 31, 2020
2014 LTIP | Non-qualified stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for issuance		4,171,150
Number of shares available for grant		1,404,379
2014 Director Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for issuance		150,000
Number of shares available for grant		101,746
Increase in number of shares authorized for issuance (in shares)	100,000

Capital Stock and Equity Awar_6

Capital Stock and Equity Awards - Summary of Option Activity (Details) - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Weighted- Average Exercise Price
Weighted-average remaining contractual life of options outstanding	2 years 8 months 12 days
Weighted-average remaining contractual life of options exercisable	2 years 8 months 12 days
Options
Shares
Beginning of period (in shares)	643,851	1,115,324
Granted (in shares)	0	0
Exercised (in shares)	0	(125,349)
Forfeited (in shares)	0	(3,759)
End of period (in shares)	643,851	986,216
Exercisable, end of period (in shares)	640,606	926,166
Weighted- Average Exercise Price
Beginning of period (in dollars per share)	$ 30.41	$ 29.02
Granted (in dollars per share)	0	0
Exercised (in dollars per share)	0	29.47
Forfeited (in dollars per share)	0	36.37
End of period (in dollars per share)	30.41	28.94
Exercisable, end of period (in dollars per share)	$ 30.35	$ 28.07
Contractual life (in years)	7 years
Minimum | Options
Weighted- Average Exercise Price
Vesting period (in years)	3 years
Maximum | Options
Weighted- Average Exercise Price
Vesting period (in years)	4 years

Capital Stock and Equity Awar_7

Capital Stock and Equity Awards - Summary of RSU Activity (Details) - RSUs - $ / shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Shares
Unvested, beginning of period (in shares)	340,368	300,142
Granted (in shares)	179,016	167,295
Vested (in shares)	(142,830)	(109,545)
Forfeited (in shares)	(1,188)	(1,398)
Unvested, end of period (in shares)	375,366	356,494
Weighted- Average Grant Date Fair Value
Unvested, beginning of period (in dollars per share)	$ 41.50	$ 39.22
Granted (in dollars per share)	43.55	42.07
Vested (in dollars per share)	41.16	39.93
Forfeited (in dollars per share)	42.07	40.26
Unvested, end of period (in dollars per share)	$ 42.61	$ 40.33
Vesting period (in years)	3 years
Non-employee directors
Weighted- Average Grant Date Fair Value
Vesting period (in years)	1 year
Minimum
Weighted- Average Grant Date Fair Value
Vesting period (in years)	1 year
Maximum
Weighted- Average Grant Date Fair Value
Vesting period (in years)	3 years

Capital Stock and Equity Awar_8

Capital Stock and Equity Awards - Summary of Share Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Stockholders' Equity Note [Abstract]
Share based compensation expense	$ 1,867	$ 1,674
U.S. tax benefit on share based compensation expense	$ 250	$ 200

Capital Stock and Equity Awar_9

Capital Stock and Equity Awards - Compensation Expense (Details) - RSUs $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share based compensation expense	$ 14.5
Weighted-average period of unrecognized share based compensation expense	2 years 2 months 12 days

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - $ / shares	Jun. 30, 2020	Jun. 15, 2020	Apr. 28, 2020
Subsequent Event [Line Items]
Cash dividend declared (in dollars per share)			$ 0.30
Dividends payable, date to be paid	Jun. 30, 2020
Dividend payable, record date		Jun. 15, 2020

Uncategorized Items - jrvr03312

Label	Element	Value
Accounting Standards Update 2016-02 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 8,280,000
Accounting Standards Update 2016-02 [Member] | Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 8,280,000