Note 15 - Statutory Information - Risk To Capital Calculation (Details) - Radian Guaranty $ in Thousands		6 Months Ended
		Jun. 30, 2020 USD ($)	Jan. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Risk to Capital Line Items [Line Items]
RIF, net	[1]	$ 46,879,100		$ 44,076,700
Common stock and paid-in capital		1,041,000		1,041,000
Surplus Note		300,000	$ 200,000	100,000
Unassigned earnings (deficit)		(861,300)		(503,300)
Statutory policyholders’ surplus		479,700		637,700
Contingency reserve		3,051,100		2,607,800
Statutory capital		$ 3,530,800		$ 3,245,500
Risk-to-capital		13.3		13.6
Increase (decrease) in Statutory Capital and Surplus		$ 285,300
Statutory Net Income (Loss)		103,200
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments		$ 0

[1] Excludes risk ceded through all reinsurance programs (including with affiliates, if any) and RIF on defaulted loans.