Note 10 - Losses and LAE Rescissions And Denials (Details) - USD ($) $ in Thousands	Aug. 29, 2017	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Rescissions And Denials [Line Items]
Reserve for losses and loss adjustment expense (“LAE”) (Note 10)		$ 651,591	$ 760,269
Mortgage Insurance Segment
Rescissions And Denials [Line Items]
Default To Claim Rate Estimate, Gross, For New Defaults		11.00%	12.00%	12.50%
Decrease To Our Loss Reserves Due To Estimated Rescissions And Denials		$ 25,000	$ 39,000
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Claims, Amount		12,800	14,300
Reserve for losses and loss adjustment expense (“LAE”) (Note 10)		651,591	760,269	$ 848,379	$ 976,399
2013 Freddie Mac Agreement [Member]
Rescissions And Denials [Line Items]
Reserve for losses and loss adjustment expense (“LAE”) (Note 10)		57,400
2013 Freddie Mac Agreement [Member] | Radian Guaranty Inc [Member]
Rescissions And Denials [Line Items]
Marketable Securities, Restricted		$ 64,300	$ 63,900
2013 Freddie Mac Agreement [Member] | Radian Guaranty Inc [Member] | Scenario, Forecast [Member]
Rescissions And Denials [Line Items]
Not Final Loss Mitigation Activity (less than)	$ 61,000