Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 914	$ 1,187	$ 1,246
Adjustment for discontinued operations	0	0	(14)
Adjustments to reconcile net income to net cash provided by operating activities from continuing operations:
Depreciation and other amortization	615	382	270
Amortization of acquisition-related intangible assets	1,036	163	159
Amortization of financing costs, debt discounts and other	127	11	15
Net foreign currency gain on financing activities	(50)	0	0
Share-based compensation	229	73	63
Deferred income taxes	47	133	(247)
Gain on sale of businesses	(15)	(227)	(10)
Income from investments in unconsolidated affiliates	(29)	(10)	(32)
Distributions from unconsolidated affiliates	23	2	45
Settlement of interest rate hedge contracts	(183)	0	0
Non-cash impairment charges	48	3	18
Other operating activities	(3)	4	(4)
Changes in assets and liabilities, net of effects from acquisitions and dispositions:
Trade accounts receivable	(7)	(108)	(75)
Prepaid expenses and other assets	(82)	(6)	(37)
Contract costs	(212)	(137)	(29)
Accounts payable and other liabilities	238	116	54
Contract liabilities	99	(34)	61
Net cash provided by operating activities from continuing operations	2,795	1,552	1,483
Cash flows from investing activities:
Capital expenditures, including capitalization of software costs	(721)	(360)	(287)
Proceeds from sale of businesses	51	419	17
Payments for acquisitions of businesses, net of cash acquired	(16,005)	(712)	(384)
Distributions from unconsolidated affiliates	113	0	0
Purchases of investments	(45)	(3)	(10)
Other investing activities	5	(7)	7
Net cash used in investing activities from continuing operations	(16,602)	(663)	(657)
Cash flows from financing activities:
Debt proceeds	20,030	5,039	2,310
Debt repayments	(5,043)	(4,005)	(1,985)
Payments of debt financing, redemption and other costs	(247)	0	0
Proceeds from issuance of treasury stock	156	75	78
Purchases of treasury stock, including employee shares withheld for tax obligations	(561)	(1,946)	(1,223)
Distributions paid to noncontrolling interests and redeemable noncontrolling interests	(118)	0	0
Other financing activities	(26)	(5)	0
Net cash provided by (used in) financing activities from continuing operations	14,191	(842)	(820)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	1	0	0
Net change in cash, cash equivalents and restricted cash from continuing operations	385	47	6
Net cash flows from discontinued operations	133	43	19
Cash, cash equivalents and restricted cash, beginning balance	415	325	300
Cash, cash equivalents and restricted cash, ending balance	933	415	325
Discontinued operations cash flow information:
Net cash (used in) provided by operating activities	0	(7)	19
Net cash provided by investing activities	133	50	0
Net cash flows from discontinued operations	$ 133	$ 43	$ 19