CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 318,240	$ 354,988
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	142,014	144,029
Provision for doubtful accounts	139,449	147,183
Deferred income tax benefit	(10,991)	(11,305)
Stock-based compensation expense	16,515	34,178
Excess tax benefits from stock-based compensation arrangements	(2,736)	(3,929)
Other, net	(23,522)	264
Changes in operating assets and liabilities:
Accounts receivable	(213,312)	(181,918)
Accounts payable and accrued expenses	(68,198)	(87,698)
Income taxes payable	(34,547)	28,648
Other assets and liabilities, net	(7,588)	(12,306)
Net cash provided by operating activities	255,324	412,134
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(179,949)	(50,568)
Proceeds from sale of business	266,041	0
Capital expenditures	(104,718)	(77,408)
Increase in investments and other assets	(736)	(2,565)
Net cash used in investing activities	(19,362)	(130,541)
Cash flows from financing activities:
Proceeds from borrowings	578,082	685,000
Repayments of debt	(414,792)	(899,646)
Purchases of treasury stock	(511,630)	(100,000)
Exercise of stock options	63,257	90,579
Excess tax benefits from stock-based compensation arrangements	2,736	3,929
Dividends paid	(95,267)	(53,981)
Distributions to noncontrolling interests	(13,447)	(15,795)
Other financing activities, net	(9,379)	17,177
Net cash used in financing activities	(400,440)	(272,737)
Net change in cash and cash equivalents	(164,478)	8,856
Add: Decrease in cash and cash equivalents included in assets held for sale	17,234	0
Cash and cash equivalents, beginning of period	295,586	164,886
Cash and cash equivalents, end of period	$ 148,342	$ 173,742