v2.4.0.8
Valuation and Qualifying Accounts (Detail) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Allowance for Doubtful Accounts
      
Valuation and Qualifying Accounts Disclosure [Line Items]      
Balance at Beginning of Period $ 641 $ 802 $ 876
Charged to expenses 993 972 1,026
Charged to other Accounts 162 [1],[2] 113 [1],[2] 139 [1],[2]
Deductions 1,151 [3],[4] 1,246 [3],[4] 1,239 [3],[4]
Balance at End of Period 645 641 802
Valuation Allowance of Deferred Tax Assets
      
Valuation and Qualifying Accounts Disclosure [Line Items]      
Balance at Beginning of Period 2,041 2,376 3,421
Charged to expenses 235 120 108
Charged to other Accounts 30 [1],[2] 38 [1],[2] 25 [1],[2]
Deductions 710 [3],[4] 493 [3],[4] 1,178 [3],[4]
Balance at End of Period $ 1,596 $ 2,041 $ 2,376
[1] Allowance for Uncollectible Accounts Receivable primarily includes amounts previously written off which were credited directly to this account when recovered.
[2] Valuation Allowance for Deferred Tax Assets includes current year increase to valuation allowance charged to equity and reclassifications from other balance sheet accounts.
[3] Amounts written off as uncollectible or transferred to other accounts or utilized.
[4] Reductions to valuation allowances related to deferred tax assets.