Note 7 - Reinsurance Reinsurance Transactions (Details) - Reinsurer Concentration Risk [Member] - Radian Guaranty - USD ($) $ in Thousands			1 Months Ended	3 Months Ended		6 Months Ended		36 Months Ended
		Dec. 31, 2017	Oct. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Single Premium QSR Transaction [Member]
Ceded Credit Risk [Line Items]
Ceded Premiums Written	[1]			$ 28,107	$ 13,856	$ 43,898	$ 22,816
Ceded Premiums Earned	[1]			11,160	6,311	21,537	12,170
Ceding commissions written				9,880	5,134	16,501	8,846
Ceding Commissions Earned	[2]			5,643	3,248	10,911	6,185
Ceded losses, net				1,013	464	1,913	1,037
Quota Share Reinsurance Transactions [Member]
Ceded Credit Risk [Line Items]
Ceded Premiums Written	[1]			3,516	5,059	7,447	10,516
Ceded Premiums Earned	[1]			5,258	7,404	10,870	15,238
Ceding commissions written				1,012	1,446	2,140	3,005
Ceding Commissions Earned	[2]			2,896	3,379	6,444	7,273
Ceded losses, net				6	(310)	252	260
2016 Single Premium QSR Transaction [Member]
Ceded Credit Risk [Line Items]
Concentration Risk, Percentage								35.00%
Risk In Force				6,600,000	4,100,000	6,600,000	4,100,000
2018 Single Premium QSR [Member]
Ceded Credit Risk [Line Items]
Concentration Risk, Percentage		65.00%
Ceded Premiums Written			$ 335,000
Risk In Force				1,000,000		1,000,000
First Lien Mortgage Insurance Products [Member] | Quota Share Reinsurance Transactions [Member]
Ceded Credit Risk [Line Items]
Risk In Force				$ 1,000,000	$ 1,400,000	$ 1,000,000	$ 1,400,000

[1] Net of profit commission.

[2] Includes amounts reported in policy acquisition costs and other operating expenses.