Supplemental Financial Statement Information (Accrued Expenses and Other Current Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Components Disclosure [Abstract]
Accrued customer liabilities	$ 1,256	$ 908
Other accrued expenses and current liabilities	4,888	3,860
Accrued expenses and other current liabilities	$ 6,144	$ 4,768