Reinsurance - Narrative (Details) $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 01, 2022	Jul. 31, 2023	Jun. 30, 2023 USD ($) reinsuranceArrangement	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) reinsuranceArrangement	Jun. 30, 2022 USD ($)	Jun. 30, 2024 USD ($)	Jul. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Feb. 29, 2020 USD ($)	Apr. 30, 2019 USD ($)
Ceded Credit Risk [Line Items]
Mortgage-linked insurance notes tendered			$ 5,200,219		$ 5,200,219
Ceded premiums earned			45,885	$ 11,594	71,062	$ 26,193
Mortgage insurance-linked notes | Fixed-maturities available for sale
Ceded Credit Risk [Line Items]
Mortgage-linked insurance notes tendered			50,710		50,710				$ 53,019
Mortgage
Ceded Credit Risk [Line Items]
RIF ceded			68,300,000		68,300,000				66,100,000
Ceded premiums earned			45,785	$ 11,460	70,862	$ 25,913
Radian Guaranty
Ceded Credit Risk [Line Items]
Funds held under reinsurance agreements, asset			186,000		186,000				175,000
Radian Guaranty | Eagle Re 2019-1 Ltd. | Mortgage insurance-linked notes | Fixed-maturities available for sale
Ceded Credit Risk [Line Items]
Mortgage-linked insurance notes tendered			$ 455,000		$ 455,000
Mortgage-linked insurance notes tendered (as a percent)			100.00%		100.00%
Radian Guaranty | Eagle Re 2020-1 Ltd. | Mortgage insurance-linked notes | Fixed-maturities available for sale
Ceded Credit Risk [Line Items]
Mortgage-linked insurance notes tendered			$ 332,000		$ 332,000
Mortgage-linked insurance notes tendered (as a percent)			82.00%		82.00%
Radian Guaranty | Eagle Re 2019-1 Ltd. and Eagle Re 2020-1 Ltd.
Ceded Credit Risk [Line Items]
Ceded premiums earned			$ 21,000
One-time costs recovery period					1 year
Radian Guaranty | Eagle Re 2019-1 Ltd. and Eagle Re 2020-1 Ltd. | Forecast
Ceded Credit Risk [Line Items]
Ceded premiums saved							$ 58,000
Radian Guaranty | Eagle Re 2019-1 Ltd. and Eagle Re 2020-1 Ltd. | Tender Premiums
Ceded Credit Risk [Line Items]
Ceded premiums earned			16,000
Radian Guaranty | Eagle Re 2019-1 Ltd. and Eagle Re 2020-1 Ltd. | Deferred Costs
Ceded Credit Risk [Line Items]
Ceded premiums earned			$ 5,000
Radian Guaranty | Mortgage
Ceded Credit Risk [Line Items]
Number of fully collateralized reinsurance arrangements with Eagle Re Issuers | reinsuranceArrangement			6		6
Number of active fully collateralized reinsurance arrangements with Eagle Re Issuers | reinsuranceArrangement			4		4
Radian Guaranty | Maximum | Mortgage
Ceded Credit Risk [Line Items]
Reinsurance retention policy, term of coverage, period					12 years 6 months
Radian Guaranty | Minimum | Mortgage
Ceded Credit Risk [Line Items]
Reinsurance retention policy, term of coverage, period					10 years
Excess-of-Loss Program | Radian Guaranty
Ceded Credit Risk [Line Items]
Percent of reinsurance coverage threshold (in percent)					0.10
Excess-of-Loss Program | Radian Guaranty | Mortgage | Eagle Re 2019-1 Ltd.
Ceded Credit Risk [Line Items]
RIF ceded			$ 0		$ 0				1,769,000		$ 10,705,000
Excess-of-Loss Program | Radian Guaranty | Mortgage | Eagle Re 2020-1 Ltd.
Ceded Credit Risk [Line Items]
RIF ceded			2,206,000		$ 2,206,000				2,401,000	$ 9,866,000
Excess-of-Loss Program | Radian Guaranty | Maximum
Ceded Credit Risk [Line Items]
Right to termination on or after option call date, period after issuance of insurance-linked notes					7 years
Excess-of-Loss Program | Radian Guaranty | Minimum
Ceded Credit Risk [Line Items]
Right to termination on or after option call date, period after issuance of insurance-linked notes					5 years
2022 QSR Agreement | Maximum
Ceded Credit Risk [Line Items]
RIF ceded			8,500,000		$ 8,500,000
2022 QSR Agreement | Radian Guaranty
Ceded Credit Risk [Line Items]
RIF ceded			$ 4,611,000		$ 4,611,000				$ 3,307,000
Ceding commission %	20.00%
2022 QSR Agreement | Radian Guaranty | Maximum
Ceded Credit Risk [Line Items]
Profit commission %	59.00%
2023 QSR | Subsequent Event
Ceded Credit Risk [Line Items]
Percentage of policies ceded to reinsurer		0.225
2023 QSR | Maximum | Subsequent Event
Ceded Credit Risk [Line Items]
RIF ceded								$ 3,000,000
2023 QSR | Radian Guaranty | Subsequent Event
Ceded Credit Risk [Line Items]
Ceding commission %		20.00%
2023 QSR | Radian Guaranty | Maximum | Subsequent Event
Ceded Credit Risk [Line Items]
Profit commission %		55.00%