CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 696	$ 753	$ 592
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	249	304	314
Provision for doubtful accounts	308	297	296
Deferred income tax provision	37	112	23
Stock-based compensation expense	69	52	51
Gain on disposition of business	(118)	(334)	0
Other, net	(6)	6	(12)
Changes in operating assets and liabilities:
Accounts receivable	(343)	(262)	(312)
Accounts payable and accrued expenses	56	(24)	74
Income taxes payable	42	(41)	(84)
Termination of interest rate swap agreements	54	0	0
Other assets and liabilities, net	25	(42)	2
Net cash provided by operating activities	1,069	821	944
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(139)	(67)	(728)
Proceeds from sale of businesses	270	0	0
Capital expenditures	(293)	(263)	(308)
Investment in equity method investee	0	(33)	0
Decrease in investments and other assets	10	1	11
Net cash used in investing activities	(152)	(362)	(1,025)
Cash flows from financing activities:
Proceeds from borrowings	1,869	2,453	2,018
Repayments of debt	(1,724)	(2,537)	(1,647)
Purchases of treasury stock	(590)	(224)	(132)
Exercise of stock options	73	60	78
Employee payroll tax withholdings on stock issued under stock-based compensation plans	(10)	(7)	(6)
Dividends paid	(223)	(212)	(187)
Distributions to noncontrolling interests	(41)	(42)	(31)
Sale of noncontrolling interest in subsidiary	0	63	0
Payment of deferred business acquisition consideration	0	(51)	0
Other financing activities, net	(45)	(21)	(7)
Net cash (used in) provided by financing activities	(691)	(518)	86
Net change in cash and cash equivalents	226	(59)	5
Cash and cash equivalents, beginning of year	133	192	187
Cash and cash equivalents, end of year	$ 359	$ 133	$ 192