UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018
Statement of Cash Flows [Abstract]
Net income	[1]	$ 3,694	$ 3,352
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		352	317
Provision for uncollectible accounts		108	108
Deferred income tax expense (benefit)		39	(26)
Net unrealized gains on marketable equity securities		(419)	(107)
Stock-based compensation expense and other stock-based payments		245	226
Operating lease amortization		127	0
Amortization of debt discount and debt issuance costs		43	45
Unrealized foreign currency transaction gains on Euro-denominated debt		(54)	0
Contingent consideration fair value adjustment		9	8
Changes in assets and liabilities, net of effects of acquisitions:
Accounts receivable		(442)	(450)
Prepaid expenses and other current assets		(247)	(201)
Accounts payable, accrued expenses and other current liabilities		794	1,005
Other long-term assets and liabilities		(461)	(23)
Net cash provided by operating activities		3,788	4,254
INVESTING ACTIVITIES:
Purchase of investments		(696)	(2,195)
Proceeds from sale and maturity of investments		7,940	4,496
Additions to property and equipment		(281)	(356)
Acquisitions and other investments, net of cash acquired		(9)	(139)
Net cash provided by investing activities		6,954	1,806
FINANCING ACTIVITIES:
Proceeds from revolving credit facility and short-term borrowings		400	4
Repayments of revolving credit facility and short-term borrowings		(425)	0
Payments for conversion of senior notes		0	(1,487)
Payments for repurchase of common stock		(6,840)	(4,110)
Other financing activities		(11)	1
Net cash used in financing activities		(6,876)	(5,592)
Effect of exchange rate changes on cash and cash equivalents and restricted cash and cash equivalents		(26)	(37)
Net increase in cash and cash equivalents and restricted cash and cash equivalents		3,840	431
Total cash and cash equivalents and restricted cash and cash equivalents, beginning of period		2,645	2,563
Total cash and cash equivalents and restricted cash and cash equivalents, end of period		6,485	2,994
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid during the period for income taxes		986	1,044
Cash paid during the period for interest		171	155
Non-cash operating and financing activity for an acquisition		0	51
Non-cash investing and financing activity for an acquisition		$ 0	$ 59

[1] The Company reclassified from accumulated other comprehensive income a net gain of $10 million ($11 million before tax) and a net loss of $1 million ($1 million before tax) for the nine months ended September 30, 2019 and 2018, respectively, from sales of investments in debt securities.
In addition, for both the three and nine months ended September 30, 2019, the Company reclassified from accumulated other comprehensive income a tax charge of $21 million related to the maturity in August 2019 of the Company's investment of $500 million in Trip.com Group (formerly known as Ctrip.com International Ltd.) convertible notes (see Note 5).
The reclassified net gain and loss before tax are included in "Foreign currency transactions and other" and the reclassified tax charges are included in "Income tax expense" in the Unaudited Consolidated Statements of Operations.