Income Taxes (Details) (USD $)				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 State	Dec. 31, 2012 State Certain subsidiaries
Deferred tax assets:
Stock-based compensation expense	$ 48,098,000	$ 37,752,000
Accrued expenses	64,047,000	53,050,000
Deferred tax assets resulting from unrecognized tax benefits	10,839,000	12,231,000
Net operating losses	6,935,000	6,165,000	5,700,000
Accumulated other comprehensive loss	2,709,000	59,000
Gross deferred tax assets	132,628,000	109,257,000
Less valuation allowance	(3,221,000)	(3,160,000)
Net deferred tax assets	129,407,000	106,097,000
Deferred tax liabilities:
Property, plant and equipment	(174,285,000)	(123,525,000)
Intangibles	(131,686,000)	(117,842,000)
Net deferred tax liabilities	(305,971,000)	(241,367,000)
Net:	(176,564,000)	(135,270,000)
Reflected on consolidated balance sheets:
Current deferred tax assets, net	39,793,000	32,306,000
Non current deferred tax liabilities, net	(216,357,000)	(167,576,000)
Net:	(176,564,000)	(135,270,000)
Operating loss carryforwards
Net operating loss carryforwards			138,000,000
Tax benefit associated with net operating loss carryforwards	6,935,000	6,165,000	5,700,000
Valuation allowance recorded to reflect the net operating losses which are not presently expected to be realized			3,200,000
Gross state net operating loss carryforwards for which no benefit has been recorded as they are attributable to uncertain tax positions				953,400,000
Unrecognized tax benefits attributable to the net operating losses				59,500,000
Increase to equity in the event of any benefit from realization of net operating losses				$ 9,400,000