Accounting Policies	6 Months Ended
Accounting Policies	Jun. 30, 2023
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 a Bermuda-based reinsurance company 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. 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, 2022 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, 2022 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 $8.8 million at June 30, 2023 and $9.2 million at December 31, 2022, 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 or expenses on share based compensation. For the three and six months ended June 30, 2023, our U.S. federal income tax expense was 23.6% and 23.9%, respectively, of the income before taxes (25.3% and 24.9% in the respective prior year periods). The effective rate exceeded the 21.0% U.S. statutory rate in all periods due to projected annual losses in Bermuda that do not provide a tax benefit and due to discrete items in the respective periods primarily related to excess tax expenses associated with vested restricted share units (“RSUs”). Adopted Accounting Standards There were no new accounting standards adopted in 2023 that materially impacted the Company's financial statements.