|
Schedule II - Valuation and Qualifying Accounts (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
|
|
Allowance for doubtful accounts receivable
|
|||
| Reserves and allowances deducted from asset accounts | |||
| Balance at the beginning of the period | $ 20 | $ 28 | $ 38 |
| Deductions | 6 | 8 | 10 |
| Balance at the end of the period | 14 | 20 | 28 |
|
Allowance for obsolete materials and supplies
|
|||
| Reserves and allowances deducted from asset accounts | |||
| Balance at the beginning of the period | 66 | 73 | 70 |
| Charge to cost and expenses | 17 | 8 | 5 |
| Deductions | 3 | 15 | 2 |
| Balance at the end of the period | 80 | 66 | 73 |
|
Valuation allowance on deferred tax assets
|
|||
| Reserves and allowances deducted from asset accounts | |||
| Balance at the beginning of the period | 210 | 183 | 164 |
| Charge to cost and expenses | 37 | 28 | 19 |
| Deductions | 1 | ||
| Balance at the end of the period | $ 247 | $ 210 | $ 183 |