Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash Flows from Operating Activities:
Net Income	$ 51,455	$ 42,070
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	40,588	35,437
Deferred income tax provision (benefit)	(5,494)	4,299
Gain on sales of property and equipment	(94)	(1,100)
Noncash compensation	4,089	2,810
Distributions from unconsolidated affiliates greater than earnings	2,968	1,050
Excluding the effects of acquisitions, increase (decrease) in cash from:
Accounts receivable	31,935	(18,253)
Inventory	(1,956)	(1,815)
Other operating assets	(72)	4,622
Currency translation effect on working capital	656	2,248
Current liabilities	19,802	(25,690)
Other long-term liabilities	2,562	3,207
Total adjustments to net income	94,984	6,815
Net Cash Provided by Operating Activities	146,439	48,885
Cash Flows from Investing Activities:
Purchases of property and equipment	(83,417)	(53,859)
Business acquisitions, net of cash acquired	(9,260)	(55,633)
Dispositions of property and equipment and equity investment	355	1,994
Net Cash Used in Investing Activities	(92,322)	(107,498)
Cash Flows from Financing Activities:
Net payments of revolving credit facility, including new loan costs	(21,045)	0
Excess tax benefits from stock-based compensation	4,523	255
Cash dividends	(16,245)	0
Net Cash Provided by (Used in) Financing Activities	(32,767)	255
Net Increase (Decrease) in Cash and Cash Equivalents	21,350	(58,358)
Cash and Cash Equivalents-Beginning of Period	106,142	245,219
Cash and Cash Equivalents-End of Period	$ 127,492	$ 186,861