XML 79 R63.htm IDEA: XBRL DOCUMENT
v3.21.1

Note 11 - Losses and Loss Adjustment Expense - Reserve Activity (Details) | Mar. 31, 2021 | Mar. 31, 2020
--- | --- | ---
Primary Mortgage Product | Mortgage segment |  |
Default To Claim Rate Estimate, Gross, For New Defaults | 8.00% | 7.50%

X
- Definition This concept represents the rate at which newly reported defaulted loans are expected to result in a claim. + References No definition available. + Details
Name: | rdn_DefaultToClaimRateEstimateGrossForNewDefaults
Namespace Prefix: | rdn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | srt_ProductOrServiceAxis=rdn_PrimaryMortgageProductMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=rdn_MortgageInsuranceSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |