XML 49 R32.htm IDEA: XBRL DOCUMENT v3.19.1
Summary of Significant Accounting Policies Accounts Receivable (Details) - USD ($)
$ in Millions
Mar. 31, 2019
Dec. 31, 2018
Accounting Policies [Abstract]    
Trade receivables $ 7,158 $ 6,896
Vendor and manufacturer receivables 8,901 7,655
Premiums receivables 2,582 2,259
Other receivables 868 821
Total accounts receivable, net $ 19,509 $ 17,631