SUPPLEMENTAL CASH FLOW FINANCIAL INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash paid during the period for:
Interest	$ 16,902	$ 17,345
Income taxes (net of refunds)	22,106	12,319
Non-cash financing and investing activities:
Non-cash property, plant and equipment purchases	455	169
Earnouts payable on acquisitions	2,676	2,067
Issuance of notes in connection with acquisitions	7,625	3,850
Issuance of restricted shares of common stock	$ 5,452	$ 13,252