Note 7 - Reinsurance Single Premium QSR Program (Details) - USD ($) $ in Thousands			1 Months Ended	3 Months Ended		9 Months Ended
		Dec. 31, 2017	Oct. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Ceded Premiums Written	[1]			$ 15,455	$ 24,348	$ 39,900	$ 76,162
2016 Single Premium QSR | Radian Guaranty | Reinsurer Concentration Risk
Risk In Force				5,700,000	6,400,000	5,700,000	6,400,000
2018 Single Premium QSR | Radian Guaranty | Reinsurer Concentration Risk
Risk In Force				$ 2,900,000	$ 1,600,000	$ 2,900,000	$ 1,600,000
Concentration Risk, Percentage		65.00%
Ceded Premiums Written			$ 335,000

[1] Net of profit commission.