Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 18,663	$ 91,679
Receivables, net of allowance for doubtful accounts of $8,700 and $8,100 in 2011 and 2010, respectively	165,876	141,166
Prepaid expenses	59,063	40,046
Deferred income tax assets	9,539	9,241
Other current assets	26,731	27,277
Total current assets	279,872	309,409
Property, plant and equipment	2,827,552	2,796,935
Less accumulated depreciation and amortization	(1,597,426)	(1,539,484)
Net property, plant and equipment	1,230,126	1,257,451
Goodwill	1,426,826	1,426,135
Intangible assets	521,537	569,723
Deferred financing costs, net of accumulated amortization	39,020	43,170
Other assets	40,868	43,073
Total assets	3,538,249	3,648,961
Current liabilities:
Trade accounts payable	12,610	13,208
Current maturities of long-term debt	713	5,694
Accrued expenses	89,726	96,542
Deferred income	50,943	38,136
Total current liabilities	153,992	153,580
Long-term debt	2,285,008	2,403,446
Deferred income tax liabilities	86,544	87,234
Asset retirement obligation	177,467	173,673
Other liabilities	14,327	12,505
Total liabilities	2,717,338	2,830,438
Stockholders' equity:
Additional paid-in capital	2,396,588	2,389,125
Accumulated comprehensive income	6,511	6,110
Accumulated deficit	(693,780)	(691,784)
Cost of shares held in treasury, 17,082,652 and 16,998,850 shares in 2011 and 2010, respectively	(888,518)	(885,037)
Stockholders' equity	820,911	818,523
Total liabilities and stockholders' equity	3,538,249	3,648,961
Subsidiaries [Member]
Current assets:
Cash and cash equivalents	18,354	88,565
Receivables, net of allowance for doubtful accounts of $8,700 and $8,100 in 2011 and 2010, respectively	165,876	141,166
Prepaid expenses	59,063	40,046
Deferred income tax assets	9,539	9,241
Other current assets	17,394	20,391
Total current assets	270,226	299,409
Property, plant and equipment	2,827,552	2,796,935
Less accumulated depreciation and amortization	(1,597,426)	(1,539,484)
Net property, plant and equipment	1,230,126	1,257,451
Goodwill	1,416,674	1,415,983
Intangible assets	521,018	569,189
Deferred financing costs, net of accumulated amortization	37,066	41,218
Other assets	35,583	37,787
Total assets	3,510,693	3,621,037
Current liabilities:
Trade accounts payable	12,610	13,208
Current maturities of long-term debt	713	5,694
Accrued expenses	78,988	85,803
Deferred income	50,943	38,136
Total current liabilities	143,254	142,841
Long-term debt	2,285,008	2,403,446
Deferred income tax liabilities	119,494	120,083
Asset retirement obligation	177,467	173,673
Other liabilities	14,327	12,505
Total liabilities	2,739,550	2,852,548
Stockholders' equity:
Common Stock, Value	0	0
Additional paid-in capital	2,570,227	2,562,765
Accumulated comprehensive income	6,511	6,110
Accumulated deficit	(1,805,595)	(1,800,386)
Stockholders' equity	771,143	768,489
Total liabilities and stockholders' equity	3,510,693	3,621,037
Common Class A [Member]
Stockholders' equity:
Common Stock, Value	95	94
Common Class B
Stockholders' equity:
Common Stock, Value	15	15
Preferred Class A
Stockholders' equity:
Preferred Stock, Value	0	0
Series AA Preferred Stock
Stockholders' equity:
Preferred Stock, Value	$ 0	$ 0