Condensed, Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income	$ 101,920	$ 92,036
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	41,386	33,387
Amortization of debt issue costs	1,169	461
Provision for uncollectible accounts	4,510	5,388
Debt retirement costs	2,764	2,550
Net (gain) loss on sale of assets	(43)	163
Share-based compensation	6,610	7,490
Deferred income taxes	14,649	10,992
Excess tax benefit from exercise of stock options	(963)	(370)
Other	(489)	(550)
Changes in operating assets and liabilities:
Trade accounts receivable	(7,018)	(7,533)
Inventory, prepaid expense and other assets	(9,806)	(1,754)
Accounts payable and other accrued liabilities	(8,328)	7,038
Accrued payroll and related liabilities	8,523	3,717
Income taxes	8,707	(9,545)
Net cash provided by operating activities	163,591	143,470
Cash flows from investing activities:
Business acquisitions, net of cash acquired	(190,363)	(44,126)
Real estate acquired in connection with business acquisitions	(1,900)	(5,834)
Property and equipment additions	(43,275)	(47,675)
Proceeds from sale of assets	447	15
Other	(723)	188
Net cash used in investing activities	(235,814)	(97,432)
Cash flows from financing activities:
Repayment of debt	(90,945)	(548,560)
Proceeds from issuance of long-term debt	150,000	500,000
Proceeds from revolving credit facility	50,000
Repayment of revolving credit facility	(50,000)
Payment of financing costs	(2,944)	(9,112)
Distributions to noncontrolling interest partners	(1,959)	(3,314)
Proceeds from issuance of common stock under stock option plans	2,596	4,781
Excess tax benefit from exercise of stock options	963	370
Stock repurchases	(2,663)	(2,292)
Other	(345)	(897)
Net cash provided by (used in) financing activities	54,703	(59,024)
Effect of currency exchange rate changes on cash and cash equivalents	(363)	38
Decrease in cash and cash equivalents	(17,883)	(12,948)
Cash and cash equivalents at beginning of period	97,126	145,181
Cash and cash equivalents at end of period	79,243	132,233
Supplemental disclosures of cash flow information:
Interest paid	12,214	9,207
Income taxes paid	40,601	62,018
Detail of acquisitions:
Fair value of assets acquired	241,688	104,251
Cash paid for acquisitions	(189,255)	(42,827)
Cash paid to bondholders/debt holders	(26,048)	(29,532)
Contingent consideration	(481)	(259)
Holdbacks	(800)
Liabilities assumed	$ 25,104	$ 31,633