Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 10,811,026	$ 10,927,981	$ 10,679,874
Charged To Income	2,259,690	3,236,138	1,990,692
Business Acquisitions	0
Deductions (a)	2,448,442	3,353,093	1,742,585
Balance at end of Year	10,622,274	10,811,026	10,927,981
Tax valuation allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	183,911,843	176,766,238	231,270,010
Charged To Income	13,812,211	2,843,723
Charged to Equity		4,301,882
Deductions (a)	169,453,483		54,503,772
Balance at end of Year	28,270,571	183,911,843	176,766,238
Lower of cost or market inventory reserve [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year			10,237,000
Deductions (a)			$ 10,237,000