v2.4.0.8

Schedule II - Valuation and Qualifying Accounts | 12 Months Ended
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Dec. 31, 2013
Schedule II - Valuation and Qualifying Accounts |
Schedule II - Valuation and Qualifying Accounts | Schedule II - Valuation and Qualifying Accounts (In millions)
|  |  |  | Additions |  |  |  |  |
|  | Balance at beginning of period |  | Charge to cost and expenses |  | Charge to other accounts -describe |  | Deductions -describe |  | Balance at end of period |
Year ended December 31, 2011 |  |  |  |  |  |  |  |  |  |  |
Reserves and allowances deducted from asset accounts: |  |  |  |  |  |  |  |  |  |  |
Allowance for doubtful accounts receivable |  | $ | 38 |  | $ | — |  | $ | — |  | $ | 10 | (a) | $ | 28 |
Allowance for obsolete materials and supplies |  | 70 |  | 5 |  | — |  | 2 | (b) | 73 |
Valuation allowance on deferred tax assets |  | 164 |  | 19 |  | — |  | — |  | 183 |
Year ended December 31, 2012 |  |  |  |  |  |  |  |  |  |  |
Reserves and allowances deducted from asset accounts: |  |  |  |  |  |  |  |  |  |  |
Allowance for doubtful accounts receivable |  | $ | 28 |  | $ | — |  | $ | — |  | $ | 8 | (a) | $ | 20 |
Allowance for obsolete materials and supplies |  | 73 |  | 8 |  | — |  | 15 | (b) | 66 |
Valuation allowance on deferred tax assets |  | 183 |  | 28 |  | — |  | 1 | (c) | 210 |
Year ended December 31, 2013 |  |  |  |  |  |  |  |  |  |  |
Reserves and allowances deducted from asset accounts: |  |  |  |  |  |  |  |  |  |  |
Allowance for doubtful accounts receivable |  | $ | 20 |  | $ | — |  | $ | — |  | $ | 6 | (a) | $ | 14 |
Allowance for obsolete materials and supplies |  | 66 |  | 17 |  | — |  | 3 | (b) | 80 |
Valuation allowance on deferred tax assets |  | 210 |  | 37 |  | — |  | — |  | 247 |
(a) Uncollectible accounts receivable written off, net of recoveries. (b) Amount related to sale of rigs and related equipment. (c) Primarily due to reassessments of valuation allowances against future operations. Other schedules are omitted either because they are not required or are not applicable or because the required information is included in the financial statements or notes thereto.

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- Definition The entire disclosure for any allowance and reserve accounts (their beginning and ending balances, as well as a reconciliation by type of activity during the period). Alternatively, disclosure of the required information may be within the footnotes to the financial statements or a supplemental schedule to the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 09 -Article 12 + Details
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