v3.4.0.3
Activity in Allowance for Credit Losses for Device Installment Plan Receivables (Detail)
$ in Millions
3 Months Ended
Mar. 31, 2016
USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]  
Balance at January 1, 2016 $ 444
Bad debt expense 163
Write-offs (95)
Allowance related to receivables sold (2)
Other 3
Balance at March 31, 2016 $ 513