CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 382	$ 324
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	128	123
Provision for doubtful accounts	165	167
Deferred income tax provision	79	(4)
Stock-based compensation expense	37	36
Gain on disposition of business	0	(118)
Other, net	(8)	9
Changes in operating assets and liabilities:
Accounts receivable	(185)	(249)
Accounts payable and accrued expenses	(93)	23
Income taxes payable	(3)	141
Other assets and liabilities, net	(12)	12
Net cash provided by operating activities	490	464
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(112)	(135)
Disposition of businesses	1	275
Escrow proceeds associated with disposition of business	25	0
Capital expenditures	(107)	(104)
Decrease (increase) in investments and other assets	1	(9)
Net cash (used in) provided by investing activities	(192)	27
Cash flows from financing activities:
Proceeds from borrowings	0	1,869
Repayments of debt	(3)	(1,720)
Purchases of treasury stock	(300)	(390)
Exercise of stock options	97	38
Employee payroll tax withholdings on stock issued under stock-based compensation plans	(23)	(9)
Dividends paid	(124)	(111)
Distributions to noncontrolling interests	(20)	(19)
Other financing activities, net	30	1
Net cash used in financing activities	(343)	(341)
Net change in cash and cash equivalents	(45)	150
Cash and cash equivalents, beginning of period	359	133
Cash and cash equivalents, end of period	$ 314	$ 283