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Earnings Per Share - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2013 | Jun. 30, 2012 | Jun. 30, 2013 | Jun. 30, 2012
Maximum [Member] |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |
Participating securities outstanding | 0 | 1 | 0 | 1
Stock and Performance Awards [Member] |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |
Participating securities outstanding, nonforfeitable | 17 | 12 | 17 | 12
Convertible Notes [Member] |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |
Shares that would have been included in diluted earnings per share calculation | 89 | 89 |  |
Number of anti-dilutive securities | 89 | 89 | 89 | 89
Stock Awards [Member] |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |
Shares that would have been included in diluted earnings per share calculation | 17 | 12 |  |
Number of anti-dilutive securities | 8 | 6 |  |
Stock Option [Member] |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |
Shares that would have been included in diluted earnings per share calculation | 9 | 19 |  |
Number of anti-dilutive securities | 1 | 4 |  |
Weighted average exercise price of options |  |  | 10.77 | 15.44
Equity Unit Purchase Agreements [Member] |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |
Number of anti-dilutive securities |  |  | 48 | 28

X
- Definition This element represents the number of outstanding nonvested stock awards that contain forfeitable rights to dividends or dividend equivalents (whether paid or unpaid). + References No definition available. + Details
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- Definition This element represents the number of outstanding nonvested stock awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid). + References No definition available. + Details
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- Definition Shares that would have been included in diluted earnings per share calculation. + References No definition available. + Details
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- Definition The weighted average exercise price of stock options whose individual exercise prices were greater than the average market price of an entity's common stock during the period. + References No definition available. + Details
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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 + Details
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