Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Activities:
Net income	$ 1,968	$ 1,539
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	60	56
Amortization expense	299	301
Stock-based compensation expense	143	220
Deferred income taxes	24	35
Other	(157)	49
Changes in operating assets and liabilities:
Accounts receivable, net	32	101
Inventories	(15)	(14)
Prepaid expenses and other	(43)	529
Accounts payable	(201)	(92)
Income taxes payable	(249)	(618)
Accrued liabilities and other	(417)	164
Net cash provided by operating activities	1,444	2,270
Investing Activities:
Purchases of marketable debt securities	(6,722)	(397)
Proceeds from sales of marketable debt securities	575	221
Proceeds from maturities of marketable debt securities	6,511	4,762
Capital expenditures	(237)	(212)
Other	238	20
Net cash provided by (used in) investing activities	(111)	4,354
Financing Activities:
Proceeds from issuances of common stock	103	111
Repurchases of common stock	(834)	(1,039)
Repayments of debt and other obligations	(750)	(4,500)
Payments of dividends	(817)	(753)
Other	(68)	(414)
Net cash used in financing activities	(2,366)	(6,595)
Effect of exchange rate changes on cash and cash equivalents	20	26
Net change in cash and cash equivalents	(1,013)	55
Cash and cash equivalents at beginning of period	17,940	7,588
Cash and cash equivalents at end of period	$ 16,927	$ 7,643