Note 7 - Reinsurance Excess-of-Loss Program (Details) $ in Thousands		1 Months Ended			6 Months Ended
		Feb. 29, 2020 USD ($)	Apr. 30, 2019 USD ($)	Nov. 30, 2018 USD ($)	Jun. 30, 2020 USD ($) arrangements	Dec. 31, 2019 USD ($)
Mortgage segment
Risk In Force					$ 60,300,000
Radian Guaranty | Mortgage segment
Reinsurance Retention Policy, Term of Coverage, Period					10 years
Excess-of-Loss Program | Radian Guaranty | Mortgage segment
VIE, Non-consolidated, Carrying Amount, Assets	[1]				$ 1,148,705	$ 865,454
VIE, Non-consolidated, Carrying Amount, Liabilities					1,148,705	865,454
Excess-of-Loss Program | Radian Guaranty | Mortgage segment | Eagle Re 2020-1 (Primary)
VIE, Non-consolidated, Carrying Amount, Assets	[1]				488,385	0
VIE, Non-consolidated, Carrying Amount, Liabilities					488,385	0
Excess-of-Loss Program | Radian Guaranty | Mortgage segment | Eagle Re 2019-1 (Primary)
VIE, Non-consolidated, Carrying Amount, Assets	[1]				384,602	508,449
VIE, Non-consolidated, Carrying Amount, Liabilities					384,602	508,449
Excess-of-Loss Program | Radian Guaranty | Mortgage segment | Eagle Re 2018-1 (Primary)
VIE, Non-consolidated, Carrying Amount, Assets	[1]				275,718	357,005
VIE, Non-consolidated, Carrying Amount, Liabilities					$ 275,718	$ 357,005
Excess-of-Loss Program | Radian Guaranty | Reinsurer Concentration Risk
Number of Fully Collateralized Reinsurance Arrangements with the Eagle Re Issuers | arrangements					3
Excess-of-Loss Program | Radian Guaranty | Reinsurer Concentration Risk | Mortgage segment | Eagle Re 2020-1 (Primary)
Risk In Force		$ 9,866,000			$ 8,152,000
Reinsurance Retention Policy, Excess Retention, Amount Reinsured		488,000			488,000
Excess-of-Loss Program | Radian Guaranty | Reinsurer Concentration Risk | Mortgage segment | Eagle Re 2020-1 (Primary) | XOL First Layer
Reinsurance Retention Policy, Amount Retained		$ 202,000			202,000
Excess-of-Loss Program | Radian Guaranty | Reinsurer Concentration Risk | Mortgage segment | Eagle Re 2019-1 (Primary)
Risk In Force			$ 10,705,000		6,473,000
Reinsurance Retention Policy, Excess Retention, Amount Reinsured			562,000		385,000
Excess-of-Loss Program | Radian Guaranty | Reinsurer Concentration Risk | Mortgage segment | Eagle Re 2019-1 (Primary) | XOL First Layer
Reinsurance Retention Policy, Amount Retained			$ 268,000		267,000
Excess-of-Loss Program | Radian Guaranty | Reinsurer Concentration Risk | Mortgage segment | Eagle Re 2018-1 (Primary)
Risk In Force				$ 9,109,000	5,598,000
Reinsurance Retention Policy, Excess Retention, Amount Reinsured	[2]			434,000	276,000
Excess-of-Loss Program | Radian Guaranty | Reinsurer Concentration Risk | Mortgage segment | Eagle Re 2018-1 (Primary) | XOL First Layer
Reinsurance Retention Policy, Amount Retained				205,000	$ 202,000
Excess-of-Loss Program | Radian Guaranty | Reinsurer Concentration Risk | Mortgage segment | Separate Third-Party Reinsurer
Reinsurance Retention Policy, Excess Retention, Amount Reinsured				$ 21,400

[1] Assets held by the Eagle Re Issuers are required to be invested in U.S. government money market funds, cash or U.S. Treasury securities. Liabilities of the Eagle Re Issuers consist of their mortgage insurance-linked notes, described above.

[2] Excludes a separate excess-of-loss reinsurance agreement entered into by Radian Guaranty that initially provided up to $21.4 million of coverage.