Note 2 - Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 years group	Dec. 31, 2011	Dec. 31, 2010
Reserve for Losses and LAE [Abstract]
Under Our Master Insurance Policy Any Suit Or Action Arising From Any Right Of The Insured Under The Policy Must Be Commenced Within This Number Of Years After Such Right First Arose	2
Under Our Master Insurance Policy Any Suit Or Action Arising From Any Right Of Certain Other Policies Must Be Commenced Within This Number Of Years After Such Right First Arose	3
Deferred Policy Acquisition Costs Disclosures [Abstract]
Deferred Policy Acquisition Cost, Amortization Expense	$ 61,876,000	$ 52,763,000	$ 53,469,000
Investments [Abstract]
Number of Investment Categories	3
Criteria For Establishing Reserve For Losses [Member]
Reserve for Losses and LAE [Abstract]
Number of Groups of States Used in Reserve Modeling	3
Minimum [Member]
Basis of Presentation [Abstract]
Equity Method Investment, Ownership Percentage	20.00%
Minimum [Member] | Criteria For Establishing Reserve For Losses [Member]
Reserve for Losses and LAE [Abstract]
Number Of Payments Missed For Insured Loans	2
Maximum [Member]
Basis of Presentation [Abstract]
Equity Method Investment, Ownership Percentage	50.00%
Investments [Abstract]
Maximum Maturity Duration for Short Term Investment Grouping	3 months
Maximum [Member] | Criteria For Establishing Reserve For Losses [Member]
Reserve for Losses and LAE [Abstract]
Period of Time That Insured Has to Rebut Decision to Rescind Coverage	90 days
Period of Time Insureds Have After Foreclosure to Provide Documents to Perfect a Claim	1 year
Computer Equipment [Member]
Company-Owned Life Insurance
Property, Plant and Equipment, Useful Life, Maximum	3 years
Furniture, Fixtures and Office Equipment [Member]
Company-Owned Life Insurance
Property, Plant and Equipment, Useful Life, Maximum	7 years
Cash Surrender Value [Member]
Company-Owned Life Insurance
Life Insurance, Corporate or Bank Owned, Amount	76,500,000	73,700,000
Financial Guaranty Segment
Deferred Policy Acquisition Costs Disclosures [Abstract]
Deferred Policy Acquisition Cost, Amortization Expense	27,745,000	16,712,000	17,367,000
Mortgage Insurance Segment
Reserve for Losses and LAE [Abstract]
Weighted Average Default To Claim Rate Assumption Net Of Denials And Rescissions	47.00%	43.00%	40.00%
Weighted Average Default To Claim Rate Assumption Excluding Pending Claims Net Of Denials And Rescissions	39.00%
Default To Claim Rate Estimate Net Of Rescission And Denial Estimates For Insured Loans That Missed Two To Three Monthly Payments	20.00%
Default To Claim Estimate Net Of Rescission And Denial Estimates For Loans That Missed Twelve Or More Monthly Payments	46.00%
Percentage Of Defaults Related To Origination Years 2005 Through 2008	75.00%	76.20%
Number of Mortgage Insurance Product Categories	2
Deferred Policy Acquisition Costs Disclosures [Abstract]
Deferred Policy Acquisition Costs, Additions	20,500,000	46,200,000
Deferred Policy Acquisition Cost, Amortization Expense	34,131,000	36,051,000	36,102,000
Mortgage Insurance Segment | Default To Claim Rate Assumptions Twelve Or More Missed Payments [Member]
Reserve for Losses and LAE [Abstract]
Number Of Payments Missed For Insured Loans	12
Mortgage Insurance Segment | Default To Claim Rate Assumptions Two Missed Payments [Member]
Reserve for Losses and LAE [Abstract]
Number Of Payments Missed For Insured Loans	2
Mortgage Insurance Segment | Default To Claim Rate Assumptions Three Missed Payments [Member]
Reserve for Losses and LAE [Abstract]
Number Of Payments Missed For Insured Loans	3
Mortgage Insurance Segment | Previous Accounting Guidance [Member]
Deferred Policy Acquisition Costs Disclosures [Abstract]
Deferred Policy Acquisition Costs, Additions	$ 39,600,000
Mortgage Insurance Segment | Maximum [Member]
Reserve for Losses and LAE [Abstract]
Number of Years That We Cap Calculating Interest on Defaulted Loan Principal	2 years
Financial Guaranty Credit Derivatives [Member]
Reserve for Losses and LAE [Abstract]
Derivative, Remaining Maturity	5 years