SUPPLEMENTAL CASH FLOW & OTHER DATA (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Supplemental Cash Flow Elements [Abstract]
Depreciation expense	$ 50,858	$ 51,943
Amortization expense	19,360	20,231
Interest paid	51,791	49,782
Income taxes paid	83,957	10,253
Assets acquired under capital leases	416	1,192
Fair value of assets acquired	151,543	50,800
Fair value of liabilities assumed	10,808	269
Fair value of net assets acquired	140,735	50,531
Merger consideration paid (payable)	(50,342)	25
Cash paid for business acquisitions	90,393	50,556
Less: Cash acquired	0	0
Business acquisitions, net of cash acquired	$ 90,393	$ 50,556