CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income	$ 70us-gaap_ProfitLoss	$ 111us-gaap_ProfitLoss
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	78	75
Provision for doubtful accounts	79us-gaap_ProvisionForDoubtfulAccounts	75us-gaap_ProvisionForDoubtfulAccounts
Deferred income tax provision (benefit)	14us-gaap_DeferredIncomeTaxExpenseBenefit	(10)us-gaap_DeferredIncomeTaxExpenseBenefit
Stock-based compensation expense	12us-gaap_ShareBasedCompensation	12us-gaap_ShareBasedCompensation
Excess tax benefits from stock-based compensation arrangements	(2)	0
Non-cash portion of loss on retirement of debt	1	0
Other, net	6us-gaap_OtherNoncashIncomeExpense	(2)us-gaap_OtherNoncashIncomeExpense
Changes in operating assets and liabilities:
Accounts receivable	(97)	(152)
Accounts payable and accrued expenses	(120)	(86)
Income taxes payable	10	70
Other assets and liabilities, net	1	(9)
Net cash provided by operating activities	52	84
Cash flows from investing activities:
Business acquisitions, net of cash acquired	0	(567)
Capital expenditures	(56)	(68)
Decrease (increase) in investments and other assets	1	(1)
Net cash used in investing activities	(55)	(636)
Cash flows from financing activities:
Proceeds from borrowings	1,389us-gaap_ProceedsFromIssuanceOfDebt	1,513us-gaap_ProceedsFromIssuanceOfDebt
Repayments of debt	(440)us-gaap_RepaymentsOfDebt	(923)us-gaap_RepaymentsOfDebt
Purchases of treasury stock	(110)	(32)
Exercise of stock options	35	12
Excess tax benefits from stock-based compensation arrangements	2	0
Dividends paid	(48)us-gaap_PaymentsOfDividendsCommonStock	(43)us-gaap_PaymentsOfDividendsCommonStock
Distributions to noncontrolling interests	(10)	(3)
Other financing activities, net	(33)	(15)
Net cash provided by financing activities	785	509
Net change in cash and cash equivalents	782	(43)
Cash and cash equivalents, beginning of period	192	187
Cash and cash equivalents, end of period	$ 974	$ 144

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