CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 1,140	$ 299
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	201	174
Provision for credit losses	2	13
Deferred income tax (benefit) provision	(89)	23
Stock-based compensation expense	39	31
Gain on disposition of investment	(314)	0
Other, net	1	3
Changes in operating assets and liabilities:
Accounts receivable	265	(75)
Accounts payable and accrued expenses	(199)	42
Income taxes payable	85	51
Termination of interest rate swap agreements	0	40
Other assets and liabilities, net	60	1
Net cash provided by operating activities	1,191	602
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(231)	(228)
Capital expenditures	(170)	(165)
Proceeds from disposition of investment	755	0
Increase in investments and other assets	(10)	(18)
Net cash provided by (used in) investing activities	344	(411)
Cash flows from financing activities:
Proceeds from borrowings	0	749
Repayments of debt	(1)	(1,001)
Purchases of treasury stock	(1,910)	(75)
Exercise of stock options	68	117
Employee payroll tax withholdings on stock issued under stock-based compensation plans	(22)	(13)
Dividends paid	(156)	(146)
Distributions to noncontrolling interest partners	(53)	(10)
Other financing activities, net	(59)	(16)
Net cash used in financing activities	(2,133)	(395)
Net change in cash and cash equivalents and restricted cash	(598)	(204)
Cash and cash equivalents and restricted cash, beginning of period	1,158	1,192
Cash and cash equivalents and restricted cash, end of period	$ 560	$ 988