GOODWILL AND OTHER INTANGIBLE ASSETS (Amortizable Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Finite-lived intangible assets
Cost	$ 545,115	$ 543,439
Accumulated Amortization	93,717	86,142
Finite-Lived Intangible Assets, Net	451,398	457,297
Weighted Average Amortization Period (in years)	13 years 4 months 24 days	13 years 7 months 6 days
Intangible Assets, Gross (Excluding Goodwill)	660,627	658,959
Indefinite-Lived Intangible Assets (Excluding Goodwill)	115,512	115,520
Total permits and other intangible assets, Net	566,910	572,817
Permits
Finite-lived intangible assets
Cost	149,237	148,661
Accumulated Amortization	47,219	46,282
Finite-Lived Intangible Assets, Net	102,018	102,379
Weighted Average Amortization Period (in years)	20 years 1 month 6 days	21 years 9 months 18 days
Customer relationships
Finite-lived intangible assets
Cost	372,500	372,751
Accumulated Amortization	33,831	27,739
Finite-Lived Intangible Assets, Net	338,669	345,012
Weighted Average Amortization Period (in years)	13 years 2 months 12 days	13 years 2 months 12 days
Other intangible assets
Finite-lived intangible assets
Cost	23,378	22,027
Accumulated Amortization	12,667	12,121
Finite-Lived Intangible Assets, Net	$ 10,711	$ 9,906
Weighted Average Amortization Period (in years)	3 years 7 months 6 days	3 years 7 months 6 days