Statutory Information - Statutory Financial Statements (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) insuranceSubsidiary	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Statutory Accounting Practices [Line Items]
Number of insurance subsidiaries | insuranceSubsidiary	2
Radian Guaranty
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	$ 753,506	$ 441,947	$ 703,380
Statutory policyholders’ surplus	778,148	481,484	637,718
Radian Reinsurance
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	9,103	32,484	101,591
Statutory policyholders’ surplus	327,118	360,704	455,594
Other mortgage subsidiaries
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	1,669	1,086	144
Statutory policyholders’ surplus	14,524	41,327	45,672
Radian Title Insurance
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	6,862	2,126	331
Statutory policyholders’ surplus	$ 36,599	$ 28,849	$ 27,349