XML 67 R52.htm IDEA: XBRL DOCUMENT
v3.19.2

Loss Reserves (Details) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2019 USD ($) loan | Jun. 30, 2018 loan | Jun. 30, 2019 USD ($) loan | Jun. 30, 2018 USD ($) loan | Dec. 31, 2018 USD ($)
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |  |  |  |
Percentage of prior year delinquent inventory resolved (as a percent) |  |  | 49.00% | 51.00% |
Prior years |  |  | $ (33,164) | $ (97,966) |
Prior years |  |  | 109,420 | $ 173,313 |
Premium refund liability, expected claim payments | $ 34,000 |  | $ 34,000 |  | $ 40,000
Primary Delinquent Inventory [Roll Forward] |  |  |  |  |
Delinquent inventory at the beginning of period (in loans) | loan | 30,921 | 41,243 | 32,898 | 46,556 |
New notices (in loans) | loan | 12,915 | 12,159 | 26,526 | 26,782 |
Cures (in loans) | loan | (12,882) | (15,350) | (27,230) | (33,423) |
Paids (including those charged to a deductible or captive) (in loans) | loan | (1,112) | (1,501) | (2,300) | (3,072) |
Rescissions and denials (in loans) | loan | (47) | (76) | (99) | (144) |
Other items removed from inventory (in loans) | loan | 0 | (438) | 0 | (662) |
Delinquent inventory at end of period (in loans) | loan | 29,795 | 36,037 | 29,795 | 36,037 |
Probable loss on litigation claims paying practices |  |  |  |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |  |  |  |
Prior years |  |  | $ 23,500 |  |
Settlements for commutations of coverage, pools of nonperforming loans |  |  |  |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |  |  |  |
Prior years |  |  |  | $ 21,000 |
Decrease in estimated claim rate on primary defaults |  |  |  |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |  |  |  |
Prior years |  |  | (67,000) | (120,000) |
Increase in estimated severity on primary defaults |  |  |  |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |  |  |  |
Prior years |  |  | 3,000 | 19,000 |
Change in estimates related to pool reserves, LAE reserves, reinsurance, and other |  |  |  |  |
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items] |  |  |  |  |
Prior years |  |  | $ 31,000 | $ 3,000 |

X
- Definition The percentage of the prior year default inventory resolved, which is used in the calculation of the change in the severity and claim rates. + References No definition available. + Details
Name: | mtg_PercentageOfPriorYearDefaultInventoryResolved
Namespace Prefix: | mtg_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The carrying amount for the estimate of premiums to be refunded on expected claim payments. + References No definition available. + Details
Name: | mtg_PremiumRefundLiabilityExpectedClaimPayments
Namespace Prefix: | mtg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The number of loans in the primary default inventory. + References No definition available. + Details
Name: | mtg_PrimaryDefaultInventory
Namespace Prefix: | mtg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Deductions from the primary default inventory resulting from loans in default being brought current. + References No definition available. + Details
Name: | mtg_PrimaryDefaultInventoryCures
Namespace Prefix: | mtg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Additions to the primary default inventory resulting from new notices of defaulted loans. + References No definition available. + Details
Name: | mtg_PrimaryDefaultInventoryNewNotices
Namespace Prefix: | mtg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Other deductions from the primary default inventory, including items removed for settlements + References No definition available. + Details
Name: | mtg_PrimaryDefaultInventoryOtherItemsRemoved
Namespace Prefix: | mtg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Deductions from the primary default inventory resulting from claims being paid, including those charged to a deductible or captive. + References No definition available. + Details
Name: | mtg_PrimaryDefaultInventoryPaids
Namespace Prefix: | mtg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Deductions from the primary default inventory resulting from rescissions and denials. + References No definition available. + Details
Name: | mtg_PrimaryDefaultInventoryRescissionsAndDenials
Namespace Prefix: | mtg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | mtg_PrimaryDefaultInventoryRollForward
Namespace Prefix: | mtg_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_CausesOfIncreaseDecreaseInLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after effects of reinsurance, of payments to settle claims incurred in prior periods and related claims settlement costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437 + Details
Name: | us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred in prior reporting periods and related claims settlement costs. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=116884095&loc=d3e14764-158437 + Details
Name: | us-gaap_SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_NoncatastrophicEventAxis=mtg_ProbableLossOnLitigationClaimsPayingPracticesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_NoncatastrophicEventAxis=mtg_SettlementsForCommutationsOfCoveragePoolsOfNonperformingLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_NoncatastrophicEventAxis=mtg_IncreaseDecreaseInExpectedClaimRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_NoncatastrophicEventAxis=mtg_IncreaseDecreaseInEstimatedSeverityPrimaryDefaultsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_NoncatastrophicEventAxis=mtg_IncreaseDecreaseRelatedToPoolReservesLaeReservesAndReinsuranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |