Note 8 - Losses and LAE Mortgage Insurance Loss Reserves Rollforward (Details) (USD $)			3 Months Ended				12 Months Ended					3 Months Ended			12 Months Ended	24 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Mortgage Insurance Segment		Mar. 31, 2012 Mortgage Insurance Segment		Dec. 31, 2012 Mortgage Insurance Segment		Mar. 31, 2013 Mortgage Insurance Segment Default To Claim Rate Assumptions Twelve Or More Missed Payments [Member] payment	Mar. 31, 2013 Mortgage Insurance Segment Default To Claim Rate Assumptions Two Missed Payments [Member] payment	Mar. 31, 2013 Mortgage Insurance Segment Default To Claim Rate Assumptions Three Missed Payments [Member] payment	Mar. 31, 2012 Mortgage Insurance Segment Smart Home [Member]	Mar. 31, 2013 Denials [Member] Mortgage Insurance Segment	Mar. 31, 2013 Rescissions [Member] Mortgage Insurance Segment	Mar. 31, 2013 Claims Denied in the Last Twelve Months [Member] Mortgage Insurance Segment	Mar. 31, 2013 Policies Rescinded in the Last Twenty Four Months [Member] Mortgage Insurance Segment
Liability For Unpaid Claims And Claims Adjustment Expense Activity In Liability [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Claims, Amount			$ 275,800,000				$ 323,000,000
Liability for Unpaid Claims and Claims Adjustment Expense, Reported and Incurred but Not Reported (IBNR) Claims													166,300,000	92,500,000
IBNR Reserve Estimate [Abstract]
Gross Exposure Related to Denied Claims From Previous Twelve Months															465,300,000
Gross Exposure Related to Rescinded Policies Within Twenty Four Months																767,900,000
Loss reserve [Roll Forward]
Balance at beginning of period			3,083,608,000		3,247,900,000		3,247,900,000
Less reinsurance recoverables	78,770,000	89,204,000	83,238,000	[1]	151,569,000	[1]	151,569,000	[1]
Balance at beginning of period, net of reinsurance recoverables			3,000,370,000		3,096,331,000		3,096,331,000
Add losses and LAE incurred in respect of default notices reported and unreported in [Abstract]
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims Current Year			182,534,000	[2]	218,345,000	[2]
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims, Prior Years			(50,578,000)		16,384,000
Total incurred			131,956,000		234,729,000
Deduct paid claims and LAE related to [Abstract]
Current year			0	[2]	0	[2]
Prior years			309,927,000		218,193,000
Paid losses and LAE			309,927,000		218,193,000
Balance at end of period, net of reinsurance recoverables			2,822,399,000		3,112,867,000		3,000,370,000
Add reinsurance recoverables	78,770,000	89,204,000	72,101,000	[1]	118,071,000	[1]	83,238,000	[1]
Balance at end of period			2,894,500,000		3,230,938,000		3,083,608,000
Default To Claim Rate Detail [Abstract]
Weighted Average Default To Claim Rate Assumption Net Of Denials Rescissions and Reinstatements			49.00%				47.00%
Weighted Average Default To Claim Rate Assumption Excluding Pending Claims Net Of Denials And Rescissions			40.00%
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%
Number Of Payments Missed For Insured Loans									12	2	3
Increase (Decrease) in Reinsurance Recoverable												27,000,000
Impact To Our Loss Reserves Due To Estimated Rescissions And Denials [Abstract]
Decrease To Our Loss Reserves Due To Estimated Rescissions And Denials			392,000,000				455,000,000
Increase To Our Loss Reserves Due To Estimated Future Reinstatements Of Previously Rescinded Policies And Denied Claims			259,000,000				303,000,000
Claim Severity Detail [Abstract]
Percentage Point Change In Severity For Assumption Shift Analysis			1.00%
First Lien Primary Claim Severity			27.00%
Impact To Loss Reserves Based On One Percentage Change In Primary Claim Severity			83,000,000
First Lien Pool Claim Severity			45.00%
Impact To Loss Reserves Based On One Percentage Change In Pool Claim Severity			4,000,000
Impact To Loss Reserves Based On One Percentage Increase In Default To Claim Rate			$ 50,000,000

[1] Related to ceded losses on captive reinsurance transactions, capital markets reinsurance transactions (“Smart Home”) and quota share reinsurance transactions.

[2] Related to underlying defaulted loans with a most recent date of default notice in the year indicated. For example, if a loan had defaulted in a prior year, but then subsequently cured and later re-defaulted in the current year, that default would be considered a current year default.