XML 114 R49.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Note 1 - Description of Business and Recent Developments General (Details) | 12 Months Ended
--- | ---
Dec. 31, 2019 segment
Organization of Business [Abstract] |
Number of Reportable Segments | 2

X
- Definition Organization of Business [Abstract] + References No definition available. + Details
Name: | rdn_OrganizationofBusinessAbstract
Namespace Prefix: | rdn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration