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Income Taxes - Summary of Deferred Income Taxes Provided on Temporary Differences (Detail) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Income Tax Disclosure [Abstract] |  |  |  |  |
Tax depreciation greater (less) than book depreciation |  |  | $ (23) | $ 13 | $ 51
Book amortization less than (in excess of) tax amortization |  |  | (57) | 16 | 0
Liabilities currently not deductible for tax |  |  | (48) | (29) | (28)
Net tax losses (benefited) utilized |  |  | 50 | (11) | (37)
Change in valuation allowance on deferred tax assets | (89) | (78) | (21) | (89) | (78)
Net tax credits utilized |  |  | 2 | 53 | 24
Other |  |  | (3) | 1 | (8)
Deferred income tax, Total |  |  | $ (100) | $ (46) | $ (76)

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- Definition Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I.7) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section I -Subsection 7 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Deferred Tax Expense (or Benefit) -URI http://asc.fasb.org/extlink&oid=6510177 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319 + Details
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