Reinsurance - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Oct. 31, 2023 USD ($)
Ceded Credit Risk [Line Items]
Ceded to Other Companies	$ 110,137	$ 120,828	$ 72,923
Mortgage insurance-linked notes
Ceded Credit Risk [Line Items]
Fair Value	47,156	48,996
Mortgage insurance
Ceded Credit Risk [Line Items]
Direct primary mortgage insurance risk in force	72,100,000	69,700,000
Ceded to Other Companies	109,777	120,578	$ 72,419
Radian Guaranty
Ceded Credit Risk [Line Items]
Funds held under reinsurance agreements, asset	283,000	274,000
QSR Program | Radian Guaranty
Ceded Credit Risk [Line Items]
RIF ceded	$ 86,000	100,000
Excess-of-Loss Program | Radian Guaranty
Ceded Credit Risk [Line Items]
Reinsurance optional clean-up call, outstanding principal balance percentage threshold	0.10
Excess-of-Loss Program | Radian Guaranty | Mortgage insurance | 2023 XOL Agreement
Ceded Credit Risk [Line Items]
Direct primary mortgage insurance risk in force	$ 6,815,000	7,814,000		$ 8,002,000
2024 QSR Agreement [Member] | Radian Guaranty
Ceded Credit Risk [Line Items]
RIF ceded	$ 1,621,000	$ 0
Maximum | Radian Guaranty | Mortgage insurance
Ceded Credit Risk [Line Items]
Reinsurance retention policy, term of coverage, period	12 years 6 months
Maximum | Excess-of-Loss Program | Radian Guaranty
Ceded Credit Risk [Line Items]
Reinsurance right to terminate, optional call date, years after issuance	7 years
Maximum | 2024 QSR Agreement [Member]
Ceded Credit Risk [Line Items]
Direct primary mortgage insurance risk in force	$ 4,300,000
Minimum | Radian Guaranty | Mortgage insurance
Ceded Credit Risk [Line Items]
Reinsurance retention policy, term of coverage, period	10 years
Minimum | Excess-of-Loss Program | Radian Guaranty
Ceded Credit Risk [Line Items]
Reinsurance right to terminate, optional call date, years after issuance	5 years