Note 1 - Condensed Consolidated Financial Statements - Business Overview and Significant Accounting Policies Business Overview and Significant Accounting Policies(Details) $ in Thousands, shares in Millions	1 Months Ended	3 Months Ended			6 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($) shares	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) segment	Jun. 30, 2015 USD ($)	Jun. 29, 2016 USD ($)	Dec. 31, 2015 USD ($)
Basis of Presentation and Business Overview [Line Items]
Proceeds from Sale and Maturity of Fixed-Maturity Investments Available-for-sale					$ 306,575	$ 3,621
Payments to Acquire Available-for-sale Securities					1,170,474	671,952
Net cash provided by (used in) operating activities, continuing operations					154,498	(66,804)
Net cash provided by (used in) operating activities, discontinued operations					0	(1,759)
Net cash provided by (used in) investing activities, discontinued operations					0	4,999
Net Cash Provided by (Used in) Discontinued Operations					$ 0	(421)
Business Overview [Abstract]
Number of Operating Segments | segment					2
Mortgage Insurance [Abstract]
Stock Repurchased During Period, Shares | shares			9.4
Payments for Repurchase of Common Stock			$ 100,200		$ 100,188	202,000
Loss on induced conversion and debt extinguishment (Note 11)		$ 2,108		$ 91,876	$ 57,678	91,876
Stock Repurchased During Period, Value							$ 125,000
Mortgage Insurance Segment
Mortgage Insurance [Abstract]
Private Mortgage Insurance Protects Lenders For Loans Made With Less Than This Maximum Down Payment Percentage	20.00%	20.00%			20.00%
Percentage Of Primary Insurance On Domestic First-Lien Mortgages To Total Risk In Force	97.70%	97.70%			97.70%
First Lien Primary Mortgage Insurance Risk In Force	$ 46,400,000	$ 46,400,000			$ 46,400,000
Percentage Of Pool Insurance On Domestic First-Lien Mortgages To Total Risk In Force	2.20%	2.20%			2.20%
Senior Notes Due 2017
Mortgage Insurance [Abstract]
Debt Instrument Repurchased, Authorized Amount							$ 195,500
Debt Instrument, Interest Rate, Stated Percentage	9.00%	9.00%			9.00%
Senior Notes Due 2021
Mortgage Insurance [Abstract]
Long-term debt, Gross	$ 350,000	$ 350,000	$ 350,000		$ 350,000
Debt Instrument, Interest Rate, Stated Percentage	7.00%	7.00%			7.00%
Convertible Senior Notes Due 2017
Mortgage Insurance [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.00%	3.00%			3.00%
Convertible Senior Notes Due 2019
Mortgage Insurance [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	2.25%	2.25%			2.25%
Scenario, Previously Reported [Member]
Basis of Presentation and Business Overview [Line Items]
Proceeds from Sale and Maturity of Fixed-Maturity Investments Available-for-sale						57,309
Payments to Acquire Available-for-sale Securities						$ 725,640
Convertible Debt
Mortgage Insurance [Abstract]
Loss on induced conversion and debt extinguishment (Note 11)					$ 57,700
Convertible Debt | Convertible Senior Notes Due 2017
Mortgage Insurance [Abstract]
Long-term debt, Gross	$ 22,233	$ 22,233			22,233			$ 52,370
Debt Instrument, Repurchase Amount	30,100	30,100			30,100
Convertible Debt | Convertible Senior Notes Due 2019
Mortgage Insurance [Abstract]
Long-term debt, Gross	89,194	89,194			89,194			$ 389,992
Debt Instrument, Repurchase Amount	300,800	$ 300,800			$ 300,800
Reportable Legal Entities [Member] | Radian Guaranty
Mortgage Insurance [Abstract]
Repayments of Notes Payable	325,000
Reportable Legal Entities [Member] | Parent Company
Mortgage Insurance [Abstract]
Repayment of Notes Receivable from Related Parties	$ 325,000