v3.7.0.1
Wireless Device Payment Plans - Additional Information (Detail) - USD ($)
 3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Receivables transferred to ABS Entities $ 9,500,000,000   $ 9,500,000,000    
Number of customer tenure days     210 days    
Receivables derecognized under receivable securitization program 1,500,000,000 $ 8,400,000,000 $ 1,500,000,000 $ 8,400,000,000  
Total portfolio of device payment plan agreement receivables 16,000,000,000   16,000,000,000    
Device payment plan agreement receivables sold, net 0 700,000,000 0 3,300,000,000  
Cash proceeds received from new transfers       2,000,000,000  
Cash proceeds received from reinvested collections   $ 600,000,000   900,000,000  
Deferred purchase price recorded       $ 400,000,000  
Deferred purchase price receivable collected 300,000,000   600,000,000    
Finance receivables collected and remitted, net of fees     9,600,000,000    
Cash proceeds received, net of remittances     500,000,000    
Maximum exposure to loss related to involvement with sellers 1,100,000,000   1,100,000,000    
Other Assets          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Deferred purchase price receivable         $ 400,000,000
Prepaid Expenses and Other          
Accounts, Notes, Loans and Financing Receivable [Line Items]          
Deferred purchase price receivable $ 1,100,000,000   $ 1,100,000,000   $ 1,200,000,000