Note 2 - Significant Accounting Policies - Level 4 (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) payment segment group	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($)
Losses and LAE Mortgage Insurance [Abstract]
Number Of Payments Missed For Insured Loans | payment	2
Second-Lien Reserve for Premium Deficiency	$ 100	$ 200
Percent of LTV at which HPA Must Be Canceled Automatically	0.78
Investments [Abstract]
Number of Investment Categories | group	3
Maximum Maturity Duration for Short Term Investment Grouping	12 months
Number of Reportable Segments | segment	2
Property, Plant and Equipment, Net [Abstract]
Depreciation, Depletion and Amortization	$ 18,300	20,800	$ 19,400
Property, Plant and Equipment, Gross	234,486	229,813
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(154,029)	(141,934)
Property and equipment	80,457	87,879
2018 Award Year | Timed-vested RSUs (Equity settled)
Property, Plant and Equipment, Net [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
Internal-use software
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Gross	136,033	131,854
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(81,724)	(73,498)
Property and equipment	54,309	58,356
Furniture and equipment
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Gross	65,478	65,087
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(56,697)	(55,027)
Property and equipment	8,781	10,060
Leasehold improvements
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Gross	32,975	32,872
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(15,608)	(13,409)
Property and equipment	$ 17,367	19,463
Real Estate Segment
Investments [Abstract]
Number of Reportable Segments | segment	1
Minimum
Losses and LAE Mortgage Insurance [Abstract]
Number Of Payments Missed For Insured Loans | payment	2
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Useful Life	3 years
Minimum | 2018 Award Year | Performance-based RSUs (Equity settled)
Property, Plant and Equipment, Net [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Post-Vesting Holding Period			1 year
Minimum | 2018 Award Year | Timed-vested RSUs (Equity settled)
Property, Plant and Equipment, Net [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			1 year
Maximum
Losses and LAE Mortgage Insurance [Abstract]
Lessee, Operating Lease, Term of Contract	12 months
Property, Plant and Equipment, Net [Abstract]
Property, Plant and Equipment, Useful Life	7 years
Mortgage segment
Losses and LAE Mortgage Insurance [Abstract]
Number of Mortgage Insurance Product Categories | group	2
Premium receivable for deferred monthly premiums	$ 29,700	17,400
Contractual deferred monthly premiums	$ 77,000	78,400
Increase in Net Premium Earned		$ 32,900
Increase in Net Premiums Earned Per Share | $ / shares		$ 0.12