Statutory Information - Narrative (Details) $ in Millions	1 Months Ended
	Mar. 31, 2023 USD ($) state	Dec. 31, 2022 USD ($)
Statutory Accounting Practices [Line Items]
Risk to capital ratio, regulatory maximum	25
Consolidated insurance subsidiaries
Statutory Accounting Practices [Line Items]
Restricted net assets held by consolidated subsidiaries	$ 4,400.0
Radian Guaranty
Statutory Accounting Practices [Line Items]
Risk to capital ratio	10.6	10.7
Statutory positive unassigned surplus	$ 221.0	$ 258.0
Payments of ordinary dividends	$ 100.0
State Insurance Regulations
Statutory Accounting Practices [Line Items]
Number of states that have a statutory or regulatory risk based capital requirement | state	16