Note 10 - Losses and Loss Adjustment Expense Reserve Activity (Details) - incident	Mar. 31, 2019	Mar. 31, 2018
Number of Natural Disasters	2
Mortgage Insurance Segment
Default To Claim Rate Estimate, Gross, For New Defaults		9.50%
Primary Mortgage Product | Mortgage Insurance Segment
Default To Claim Rate Estimate, Gross, For New Defaults	8.00%
Hurricanes Harvey and Irma | Primary Mortgage Product | Mortgage Insurance Segment
Default To Claim Rate Estimate, Gross, For New Defaults	3.00%