SUPPLEMENTAL CASH FLOW FINANCIAL INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash paid during the period for:
Interest	$ 3,278	$ 3,789
Income taxes (net of refunds)	1,566	1,030
Non-cash financing and investing activities:
Non-cash property, plant and equipment purchases	1,028	2,628
Earnouts payable on acquisitions		321
Issuance of notes in connection with acquisitions		693
Issuance of restricted shares of common stock	$ 8,419	$ 11,566