Cash, Cash Equivalents, and Marketable Securities Reconciliation to Cash Flow (Tables)

12 Months Ended

Dec. 31, 2018

Cash and Cash Equivalents [Abstract]

Reconciliation of cash, cash equivalents, and restricted cash [Table Text Block]

The following table provides a reconciliation of the amount of cash, cash equivalents, and restricted cash reported within the consolidated balance sheets to the total of the same such amounts shown in the consolidated statements of cash flows (in millions):

	December 31, 2017		December 31, 2018
Cash and cash equivalents	$	20,522	$	31,750
Restricted cash included in accounts receivable, net and other	1,329		418
Restricted cash included in other assets	5		5
Total cash, cash equivalents, and restricted cash shown in the consolidated statements of cash flows	$	21,856	$	32,173