XML 22 R48.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Earnings Per Share (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2013
Text Block [Abstract] |
Schedule Of Basic And Diluted Earnings Per Share |
|  |  | Years Ended December 31, |
$ in millions except share and per share amounts |  | 2013 |  | 2012 |  |  | 2011 |
Basic earnings per share: |  |  |  |  |  |  |  |  |  |
| Net income (loss) |  | $ | 250 |  | $ | 1,234 |  | $ | (1,319) |
| Less: undistributed earnings allocated to participating securities |  |  | 5 |  |  | 32 |  |  | 0 |
| Net income (loss) available to common shareholders |  |  | 245 |  |  | 1,202(1) |  |  | (1,319) |
| Basic weighted average shares (2) |  |  | 189,071,011 |  |  | 188,834,626(1) |  |  | 192,505,045(1) |
| Net income (loss) per basic common share |  | $ | 1.30 |  | $ | 6.36 |  | $ | (6.85)(1) |
Diluted earnings per share: |  |  |  |  |  |  |  |  |  |
| Net income (loss) |  |  | 250 |  |  | 1,234 |  |  | (1,319) |
| Less: undistributed earnings allocated to participating securities |  |  | 5 |  |  | 32 |  |  | 0 |
| Net income (loss) available to common shareholders |  |  | 245 |  |  | 1,202(1) |  |  | (1,319) |
| Basic weighted average shares (2) |  |  | 189,071,011 |  |  | 188,834,626 |  |  | 192,505,045 |
| Effect of common stock equivalents: |  |  |  |  |  |  |  |  |  |
| Stock options |  |  | 1,241,902 |  |  | 1,062,395 |  |  | 0 |
| Diluted weighted average shares |  |  | 190,312,913 |  |  | 189,897,021(1) |  |  | 192,505,045(1) |
| Net income (loss) per diluted common share |  | $ | 1.29 |  | $ | 6.33 |  | $ | (6.85)(1) |
| (1) Amounts shown are revised. |
| (2) Includes 629,896, 506,714 and 565,819 of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend |
| equivalents for the years ended December 31, 2013, 2012 and 2011, respectively. |
Schedule Of Revised Basic And Diluted Earnings Per Share |
|  |  | Years Ended December 31, |  | September 30, 2013 (unaudited) |  | June 30, 2013 (unaudited) |  | March 31, 2013 (unaudited)
$ in millions except share and per share amounts |  | 2012 |  |  | 2011 |  | Three Months Ended |  |  | Nine Months Ended |  | Three Months Ended |  |  | Six Months Ended |  | Three Months Ended
Numerator: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Net income (loss) - basic and diluted as reported |  |  | $ 1,234 |  |  | $ (1,319) |  |  | $ 132 |  |  | $ 118 |  |  | $ (178) |  |  | $ (14) |  | $ 164 |
| Net income (loss) - basic as revised |  |  | $ 1,202 |  |  | $ (1,319) |  |  | $ 129 |  |  | $ 115 |  |  | $ (178) |  |  | $ (14) |  | $ 159 |
| Net income (loss) -diluted as revised |  |  | $ 1,202 |  |  | $ (1,319) |  |  | $ 101 |  |  | $ 110 |  |  | $ (178) |  |  | $ (14) |  | $ 159 |
Denominator: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Weighted average shares - basic as reported |  |  | 193,842,435 |  |  | 197,019,968 |  |  | 192,711,608 |  |  | 193,440,078 |  |  | 193,104,610 |  |  | 193,810,351 |  | 194,523,933 |
| Weighted average shares - basic as revised |  |  | 188,834,626 |  |  | 192,505,045 |  |  | 188,931,800 |  |  | 189,094,678 |  |  | 189,163,527 |  |  | 189,135,587 |  | 189,111,170 |
| Weighted average shares - diluted as reported |  |  | 194,904,830 |  |  | 197,019,968 |  |  | 196,746,771 |  |  | 197,762,488 |  |  | 193,104,610 |  |  | 193,810,351 |  | 195,631,960 |
| Weighted average shares - diluted as revised |  |  | 189,897,021 |  |  | 192,505,045 |  |  | 192,581,064 |  |  | 193,031,189 |  |  | 189,163,527 |  |  | 189,135,587 |  | 190,219,197 |
Net income (loss) per common share: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Basic - as reported |  |  | $ 6.36 |  |  | $ (6.69) |  |  | $ 0.68 |  |  | $ 0.61 |  |  | $ (0.92) |  |  | $ (0.07) |  | $ 0.84 |
| Basic - as revised |  |  | $ 6.36 |  |  | $ (6.85) |  |  | $ 0.68 |  |  | $ 0.61 |  |  | $ (0.94) |  |  | $ (0.07) |  | $ 0.84 |
| Diluted - as reported |  |  | $ 6.33 |  |  | $ (6.69) |  |  | $ 0.67 |  |  | $ 0.60 |  |  | $ (0.92) |  |  | $ (0.07) |  | $ 0.84 |
| Diluted - as revised |  |  | $ 6.33 |  |  | $ (6.85) |  |  | $ 0.52 |  |  | $ 0.57 |  |  | $ (0.94) |  |  | $ (0.07) |  | $ 0.84 |

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

X
- Details
Name: | us-gaap_TextBlockAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration