XML 53 R41.htm IDEA: XBRL DOCUMENT
v3.20.2

Note 1 - Business Overview and Recent Developments (Details) $ in Thousands | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2020 USD ($) | Sep. 30, 2020 USD ($) segment | May 31, 2020 USD ($) | Dec. 31, 2019 USD ($)
Business Overview [Abstract] |  |  |  |
Number of Reportable Business Segments | segment |  | 2 |  |
Mortgage Insurance [Abstract] |  |  |  |
Reduction in Number of New Defaults from the Prior Quarter | (0.675) |  |  |
Senior Notes Due 2025 | Senior Notes |  |  |  |
Mortgage Insurance [Abstract] |  |  |  |
Debt Instrument, Face Amount |  |  | $ 525,000 |
Mortgage segment |  |  |  |
Mortgage Insurance [Abstract] |  |  |  |
Private Mortgage Insurance Protects Lenders For Loans Made With Less Than This Maximum Down Payment Percentage | 20.00% | 20.00% |  |
Private Mortgage Insurance Protects Lenders For Refinancings Made to Home Buyers With Less Than This Maximum Equity-Ownership Percentage | 20.00% | 20.00% |  |
Direct Primary Mortgage Insurance in Force | $ 245,500,000 | $ 245,500,000 |  | $ 240,600,000
Direct Primary Mortgage Insurance RIF | 61,000,000 | 61,000,000 |  | 60,900,000
Credit Risk Transfer Transactions | Mortgage segment |  |  |  |
Mortgage Insurance [Abstract] |  |  |  |
Direct Primary Mortgage Insurance RIF | $ 389,100 | $ 389,100 |  | $ 275,200

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

X
- Definition Mortgage Insurance [Abstract] + References No definition available. + Details
Name: | rdn_MortgageInsuranceAbstract
Namespace Prefix: | rdn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the maximum down payment percentage on a home's purchase price that is used to measure the need for private mortgage insurance. + References No definition available. + Details
Name: | rdn_PrivateMortgageInsuranceProtectsLendersForLoansMadeWithLessThanThisMaximumDownPaymentPercentage
Namespace Prefix: | rdn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition This element represents the maximum equity-ownership percentage on a home's value that is used to measure the need for private mortgage insurance for refinancings. + References No definition available. + Details
Name: | rdn_PrivateMortgageInsuranceProtectsLendersForRefinancingsMadetoHomeBuyersWithLessThanThisMaximumEquityOwnershipPercentage
Namespace Prefix: | rdn_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Reduction in Number of New Defaults from the Prior Quarter + References No definition available. + Details
Name: | rdn_ReductionInNumberOfNewDefaultsFromThePriorQuarter
Namespace Prefix: | rdn_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Risk In Force + References No definition available. + Details
Name: | rdn_RiskInForce
Namespace Prefix: | rdn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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 Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599 + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of participating insurance in force. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 50 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6483535&loc=d3e16392-158451 + Details
Name: | us-gaap_ParticipatingPoliciesAmountInForce
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=rdn_SeniorNotesDue2025Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
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: |

X
- Details
Name: | rdn_RiskinForceAxis=rdn_CreditRiskTransferTransactionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |