XML 42 R31.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Earnings Per Share (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2016
Text Block [Abstract] |
Schedule Of Basic And Diluted Earnings Per Share |
|  |  | Three Months Ended June 30, |  | Six Months Ended June 30,
In millions except share and per share amounts |  | 2016 |  | 2015 |  | 2016 |  |  | 2015
Basic earnings per share: |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) |  | $ | (27) |  | $ | 64 |  | $ | (105) |  | $ | 133
Less: undistributed earnings allocated to participating securities |  |  | - |  |  | 2 |  |  | - |  |  | 4
Net income (loss) available to common shareholders |  |  | (27) |  |  | 62 |  |  | (105) |  |  | 129
Basic weighted average shares (1) |  |  | 132,677,066 |  |  | 172,146,651 |  |  | 134,245,952 |  |  | 176,914,777
Net income (loss) per basic common share: |  | $ | (0.20) |  | $ | 0.36 |  | $ | (0.78) |  | $ | 0.73
Diluted earnings per share: |  |  |  |  |  |  |  |  |  |  |  |
Net income (loss) |  |  | (27) |  |  | 64 |  |  | (105) |  |  | 133
Less: undistributed earnings allocated to participating securities |  |  | - |  |  | 2 |  |  | - |  |  | 4
Net income (loss) available to common shareholders |  |  | (27) |  |  | 62 |  |  | (105) |  |  | 129
Basic weighted average shares (1) |  |  | 132,677,066 |  |  | 172,146,651 |  |  | 134,245,952 |  |  | 176,914,777
Effect of common stock equivalents: |  |  |  |  |  |  |  |  |  |  |  |
| Stock options |  |  | - |  |  | 1,007,668 |  |  | - |  |  | 1,004,181
Diluted weighted average shares |  |  | 132,677,066 |  |  | 173,154,319 |  |  | 134,245,952 |  |  | 177,918,958
Net income (loss) per diluted common share: |  | $ | (0.20) |  | $ | 0.36 |  | $ | (0.78) |  | $ | 0.72
_________ |  |  |  |  |  |  |  |  |  |  |  |
(1) - Includes 932,355 and 581,102 of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend equivalents for the three months ended June 30, 2016 and 2015, respectively. Includes 822,642 and 629,569 of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend equivalents for the six months ended June 30, 2016 and 2015, respectively.

X
- Definition Schedule of Basic and Diluted Earnings Per Share [Table Text Block] + References No definition available. + Details
Name: | mbi_ScheduleOfBasicAndDilutedEarningsPerShareTableTextBlock
Namespace Prefix: | mbi_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_TextBlockAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration