Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Our condensed consolidated financial statements are prepared in accordance with GAAP and include the accounts of Radian Group and its subsidiaries. All intercompany accounts and transactions, and intercompany profits and losses, have been eliminated. Certain prior period amounts have been reclassified to conform to the current period presentation, including a reclassification for the three months ended March 31, 2023, of interest expense to net investment income for expenses associated with our securities lending transactions. We have condensed or omitted certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with GAAP pursuant to the instructions set forth in Article 10 of Regulation S-X of the SEC. We generally refer to our holding company alone, without its consolidated subsidiaries, as “Radian Group.” We refer to Radian Group together with its consolidated subsidiaries as “Radian,” the “Company,” “we,” “us” or “our,” unless the context requires otherwise. Unless otherwise defined in this report, certain terms and acronyms used throughout this report are defined in the Glossary of Abbreviations and Acronyms included as part of this report. The financial information presented for interim periods is unaudited; however, such information reflects all adjustments that are, in the opinion of management, necessary for the fair statement of the financial position, results of operations, comprehensive income (loss) and cash flows for the interim periods presented. Such adjustments are of a normal recurring nature. The year-end condensed consolidated balance sheet data was derived from our audited financial statements, but does not include all disclosures required by GAAP. To fully understand the basis of presentation, these interim financial statements and related notes contained herein should be read in conjunction with the audited financial statements and notes thereto included in our 2023 Form 10-K. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or for any other period.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of our contingent assets and liabilities at the dates of the financial statements, as well as the reported amounts of revenues and expenses during the reporting periods. While the amounts included in our condensed consolidated financial statements include our best estimates and assumptions, actual results may vary materially.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Standards Not Yet Adopted In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements—Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative. The amendments in this update modify disclosure and presentation requirements related to various topics and align codification with the SEC’s regulations. The effective date for each amendment will be the date on which the SEC’s removal of that related disclosure from Regulation S-X or Regulation S-K becomes effective. If by June 30, 2027, the SEC has not removed the applicable requirements, the pending content will be removed and not become effective. Early adoption is prohibited. We are currently evaluating the impact the new accounting guidance will have on our disclosures. In November 2023, the FASB issued ASU 2023-07, Segment Reporting—Improvements to Reportable Segment Disclosures. This update enhances disclosure requirements, primarily through enhanced disclosures about significant reportable segment expenses under ASC 280. This update is applicable to all public entities and is effective for fiscal years starting after December 15, 2023, and interim periods within fiscal periods commencing after December 15, 2024. Early adoption is permitted. The amendments in this update should be applied retrospectively for all periods presented in the financial statements. We are currently evaluating the impact the new accounting guidance will have on our disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes—Improvements to Income Tax Disclosures, an update which enhances income tax disclosures. This guidance requires disaggregated information about an entity’s effective tax rate reconciliation as well as information on income taxes paid. This update is applicable to all public entities and is effective for fiscal years starting after December 15, 2024. Early adoption is permitted. The amendments in this update should be applied prospectively; however, retrospective application is permitted. We are currently evaluating the impact the new accounting guidance will have on our disclosures.
Segment Reporting	In the first quarter of 2024, our Chief Executive Officer (Radian’s chief operating decision maker) made certain changes to the way that he organizes and assesses the performance of our operating segments, which resulted in updates to our quantitative and aggregation analyses in accordance with the accounting standard regarding segment reporting. Whereas previously we aggregated our Title, Real Estate Services and Real Estate Technology businesses and reported them as a single reportable segment named homegenius, effective this quarter, we are including the individual results of operations for these immaterial businesses, as well as the results of our Mortgage Conduit business (our other operating segment that does not meet the reportable segment materiality thresholds) in the All Other category, along with certain corporate and other activities. This reflects the way our Chief Executive Officer is currently managing and evaluating these businesses individually and is aligned with materiality considerations consistent with current accounting guidance. As a result of the change described above, we now have one reportable segment, Mortgage Insurance, which derives its revenue from mortgage insurance and other mortgage and risk services, including contract underwriting solutions provided to mortgage lending institutions and mortgage credit investors. In addition to this reportable segment, in All Other we report activities that include: (i) income (losses) from assets held by Radian Group, our holding company; (ii) related general corporate operating expenses not attributable or allocated to our reportable segment; and (iii) the operating results from certain other immaterial activities and operating segments, including our Mortgage Conduit, Title, Real Estate Services and Real Estate Technology businesses. We have reflected this change in our segment operating results for all periods presented, as shown below. We allocate corporate operating expenses to our Mortgage Insurance business and our immaterial operating businesses included in All Other based primarily on their respective forecasted annual percentage of total revenue, which approximates the estimated percentage of management time spent on each business. In addition, we allocate all corporate interest expense to our Mortgage Insurance segment, due to the capital-intensive nature of our mortgage insurance business. We do not manage assets by operating segments. See Note 1 for additional details about our Mortgage Insurance business.

Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2024

Our condensed consolidated financial statements are prepared in accordance with GAAP and include the accounts of Radian Group and its subsidiaries. All intercompany accounts and transactions, and intercompany profits and losses, have been eliminated. Certain prior period amounts have been reclassified to conform to the current period presentation, including a reclassification for the three months ended March 31, 2023, of interest expense to net investment income for expenses associated with our securities lending transactions. We have condensed or omitted certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with GAAP pursuant to the instructions set forth in Article 10 of Regulation S-X of the SEC.

We generally refer to our holding company alone, without its consolidated subsidiaries, as “Radian Group.” We refer to Radian Group together with its consolidated subsidiaries as “Radian,” the “Company,” “we,” “us” or “our,” unless the context requires otherwise. Unless otherwise defined in this report, certain terms and acronyms used throughout this report are defined in the Glossary of Abbreviations and Acronyms included as part of this report.

The financial information presented for interim periods is unaudited; however, such information reflects all adjustments that are, in the opinion of management, necessary for the fair statement of the financial position, results of operations,

comprehensive income (loss) and cash flows for the interim periods presented. Such adjustments are of a normal recurring nature. The year-end condensed consolidated balance sheet data was derived from our audited financial statements, but does not include all disclosures required by GAAP.

To fully understand the basis of presentation, these interim financial statements and related notes contained herein should be read in conjunction with the audited financial statements and notes thereto included in our 2023 Form 10-K. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year or for any other period.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of our contingent assets and liabilities at the dates of the financial statements, as well as the reported amounts of revenues and expenses during the reporting periods. While the amounts included in our condensed consolidated financial statements include our best estimates and assumptions, actual results may vary materially.

Recent Accounting Pronouncements

Accounting Standards Not Yet Adopted

In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements—Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative. The amendments in this update modify disclosure and presentation requirements related to various topics and align codification with the SEC’s regulations. The effective date for each amendment will be the date on which the SEC’s removal of that related disclosure from Regulation S-X or Regulation S-K becomes effective. If by June 30, 2027, the SEC has not removed the applicable requirements, the pending content will be removed and not become effective. Early adoption is prohibited. We are currently evaluating the impact the new accounting guidance will have on our disclosures.

In November 2023, the FASB issued ASU 2023-07, Segment Reporting—Improvements to Reportable Segment Disclosures. This update enhances disclosure requirements, primarily through enhanced disclosures about significant reportable segment expenses under ASC 280. This update is applicable to all public entities and is effective for fiscal years starting after December 15, 2023, and interim periods within fiscal periods commencing after December 15, 2024. Early adoption is permitted. The amendments in this update should be applied retrospectively for all periods presented in the financial statements. We are currently evaluating the impact the new accounting guidance will have on our disclosures.

In December 2023, the FASB issued ASU 2023-09, Income Taxes—Improvements to Income Tax Disclosures, an update which enhances income tax disclosures. This guidance requires disaggregated information about an entity’s effective tax rate reconciliation as well as information on income taxes paid. This update is applicable to all public entities and is effective for fiscal years starting after December 15, 2024. Early adoption is permitted. The amendments in this update should be applied prospectively; however, retrospective application is permitted. We are currently evaluating the impact the new accounting guidance will have on our disclosures.

Segment Reporting

In the first quarter of 2024, our Chief Executive Officer (Radian’s chief operating decision maker) made certain changes to the way that he organizes and assesses the performance of our operating segments, which resulted in updates to our quantitative and aggregation analyses in accordance with the accounting standard regarding segment reporting. Whereas previously we aggregated our Title, Real Estate Services and Real Estate Technology businesses and reported them as a single reportable segment named homegenius, effective this quarter, we are including the individual results of operations for these immaterial businesses, as well as the results of our Mortgage Conduit business (our other operating segment that does not meet the reportable segment materiality thresholds) in the All Other category, along with certain corporate and other activities. This reflects the way our Chief Executive Officer is currently managing and evaluating these businesses individually and is aligned with materiality considerations consistent with current accounting guidance.

As a result of the change described above, we now have one reportable segment, Mortgage Insurance, which derives its revenue from mortgage insurance and other mortgage and risk services, including contract underwriting solutions provided to mortgage lending institutions and mortgage credit investors. In addition to this reportable segment, in All Other we report activities that include: (i) income (losses) from assets held by Radian Group, our holding company; (ii) related general corporate operating expenses not attributable or allocated to our reportable segment; and (iii) the operating results from certain other immaterial activities and operating segments, including our Mortgage Conduit, Title, Real Estate Services and Real Estate Technology businesses. We have reflected this change in our segment operating results for all periods presented, as shown below.

We allocate corporate operating expenses to our Mortgage Insurance business and our immaterial operating businesses included in All Other based primarily on their respective forecasted annual percentage of total revenue, which approximates the estimated percentage of management time spent on each business. In addition, we allocate all corporate interest expense to our Mortgage Insurance segment, due to the capital-intensive nature of our mortgage insurance business. We do not manage assets by operating segments.

See Note 1 for additional details about our Mortgage Insurance business.