CONSOLIDATED BALANCE SHEETS (Parentheticals) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts	$ 20,646,000	$ 21,084,000
Accumulated depreciation	232,412,000	229,196,000
Finite-Lived Intangible Assets, Accumulated Amortization	139,192	110,828
Debt discount	$ 171,547,000	$ 174,686,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury stock, shares (in shares)	18,550,758	18,250,178
Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	210,000,000	210,000,000
Common stock, shares, issued (in shares)	58,480,990	58,400,736
Common stock, shares outstanding (in shares)	44,269,663	44,489,989
Common Class B [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares, issued (in shares)	4,339,431	4,339,431
Common stock, shares outstanding (in shares)	0	0