Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Detail) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|||
| Basic and diluted earnings per share: | ||||||
| Net income (loss) from continuing operations available to common shareholders | $ (56) | $ (253) | $ (118) | $ (340) | ||
| Income (loss) from discontinued operations, net of income taxes | 0 | (2) | 0 | (1) | ||
| Less: Net income (loss) from discontinued operations attributable to noncontrolling interests | 0 | (1) | 0 | (1) | ||
| Net income (loss) from discontinued operations attributable to MBIA Inc. | 0 | (1) | 0 | 0 | ||
| Net income (loss) attributable to MBIA Inc. | $ (56) | $ (254) | $ (118) | $ (340) | ||
| Basic weighted average shares | [1] | 49,543,258 | 47,501,248 | 48,952,068 | 47,161,085 | |
| Diluted weighted average shares | [1] | 49,543,258 | 47,501,248 | 48,952,068 | 47,161,085 | |
| Continuing operations - Basic | $ (1.12) | $ (5.3) | $ (2.4) | $ (7.2) | ||
| Continuing operations - Diluted | (1.12) | (5.3) | (2.4) | (7.2) | ||
| Discontinued operations - Basic | 0 | (0.04) | 0 | (0.01) | ||
| Discontinued operations - Diluted | 0 | (0.04) | 0 | (0.01) | ||
| Net income (loss) per share - basic | (1.12) | (5.34) | (2.4) | (7.21) | ||
| Net income (loss) per share - diluted | $ (1.12) | $ (5.34) | $ (2.4) | $ (7.21) | ||
| Potentially dilutive securities excluded from the calculation of diluted EPS because of antidilutive affect | 900,000 | 3,400,000 | 900,000 | 3,400,000 | ||
| ||||||
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount after tax of income (loss) from a discontinued operation attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount after tax of income (loss) from a discontinued operation attributable to the parent. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Per basic share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Per diluted share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|