CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 422	$ 382
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	151	128
Provision for doubtful accounts	0	4
Deferred income tax provision	39	79
Stock-based compensation expense	34	37
Other, net	18	(8)
Changes in operating assets and liabilities:
Accounts receivable	(127)	(24)
Accounts payable and accrued expenses	(64)	(93)
Income taxes payable	(7)	(3)
Other assets and liabilities, net	37	(12)
Net cash provided by operating activities	503	490
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(165)	(112)
Capital expenditures	(151)	(107)
(Increase) decrease in investments and other assets	(14)	2
Net cash used in investing activities	(330)	(217)
Cash flows from financing activities:
Proceeds from borrowings	1,520	0
Repayments of debt	(1,553)	(3)
Purchases of treasury stock	(50)	(300)
Exercise of stock options	71	97
Employee payroll tax withholdings on stock issued under stock-based compensation plans	(20)	(23)
Dividends paid	(129)	(124)
Distributions to noncontrolling interests	(28)	(20)
Sale of noncontrolling interest in subsidiaries	4	0
Other financing activities, net	7	30
Net cash used in financing activities	(178)	(343)
Net change in cash and cash equivalents and restricted cash	(5)	(70)
Cash and cash equivalents and restricted cash, beginning of period	137	384
Cash and cash equivalents and restricted cash, end of period	132	314
Cash and cash equivalents	137
Cash and cash equivalents and restricted cash, end of period	$ 137	$ 384