Note 7 - Reinsurance QSR Program (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Radian Guaranty | Reinsurer Concentration Risk | QSR Program
Risk In Force	$ 800.0	$ 1,100.0
Ceding Commissions Earned	2.9	3.5
Ceded losses	0.2
Mortgage Insurance Segment
Risk In Force	$ 57,400.0
Radian Guaranty | Radian Guaranty | Reinsurer Concentration Risk | QSR Program
Ceded losses		$ 0.2