Debt (Long Term Debt) (Details) (USD $)							12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 $100 million revolving credit facility, LIBOR plus 2.25%-2.75%, due April 2015 [Member]	Dec. 31, 2010 $100 million revolving credit facility, LIBOR plus 2.25%-2.75%, due April 2015 [Member]	Dec. 31, 2011 Working Capital Facility Due January 2011 [Member] Subsidiaries [Member]	Dec. 31, 2010 Working Capital Facility Due January 2011 [Member] Subsidiaries [Member]	Dec. 31, 2011 Working Capital Facility Due January 2012 And April 2012 Member Subsidiaries [Member]	Dec. 31, 2010 Working Capital Facility Due January 2012 And April 2012 Member Subsidiaries [Member]	Dec. 31, 2011 Revolving Credit Facility 2.20% Due June 2012 [Member] Subsidiaries [Member]	Dec. 31, 2010 Revolving Credit Facility 2.20% Due June 2012 [Member] Subsidiaries [Member]	Dec. 31, 2011 Senior Notes Due June 2016 [Member]	Dec. 31, 2010 Senior Notes Due June 2016 [Member]	Dec. 31, 2011 Senior Notes Due May 2018 [Member]	Dec. 31, 2010 Senior Notes Due May 2018 [Member]	Dec. 31, 2011 Senior Notes Due 2021 [Member]	Dec. 31, 2010 Senior Notes Due 2021 [Member]	Dec. 31, 2011 Convertible Senior Subordinated Notes Due May 2011 [Member]	Dec. 31, 2010 Convertible Senior Subordinated Notes Due May 2011 [Member]	Dec. 31, 2010 Convertible Senior Subordinated Notes Due April 2014 [Member]	Apr. 30, 2009 Convertible Senior Subordinated Notes Due April 2014 [Member]	Dec. 31, 2011 Convertible Subordinated Notes Due December 2013 [Member] Related Party [Member]	Dec. 31, 2010 Convertible Subordinated Notes Due December 2013 [Member] Related Party [Member]	Dec. 31, 2011 Term Loan TIBOR Due July 2011 Member Subsidiaries [Member]	Dec. 31, 2010 Term Loan TIBOR Due July 2011 Member Subsidiaries [Member]	Dec. 31, 2011 Term Loan TIBOR Due September 2012 [Member] Subsidiaries [Member]	Dec. 31, 2010 Term Loan TIBOR Due September 2012 [Member] Subsidiaries [Member]	Dec. 31, 2011 Term Loan Due May 2013 [Member] Subsidiaries [Member]	Dec. 31, 2010 Term Loan Due May 2013 [Member] Subsidiaries [Member]	Dec. 31, 2011 Term Loan Due April 2014 [Member] Subsidiaries [Member]	Dec. 31, 2010 Term Loan Due April 2014 [Member] Subsidiaries [Member]	Dec. 31, 2011 Term Loan Due July 2014 [Member] Subsidiaries [Member]	Dec. 31, 2010 Term Loan Due July 2014 [Member] Subsidiaries [Member]	Dec. 31, 2011 Term Loan 90 Day Commercial Paper Due April 2015 [Member] Subsidiaries [Member]	Dec. 31, 2010 Term Loan 90 Day Commercial Paper Due April 2015 [Member] Subsidiaries [Member]	Dec. 31, 2011 Term Loan Bank Sinking Fund Due Mar 2016 [Member] Subsidiaries [Member]	Dec. 31, 2010 Term Loan Bank Sinking Fund Due Mar 2016 [Member] Subsidiaries [Member]	Dec. 31, 2011 Secured Equipment and Property Financing [Member] Subsidiaries [Member]	Dec. 31, 2010 Secured Equipment and Property Financing [Member] Subsidiaries [Member]
Debt Instrument [Line Items]
Borrowing under senior secured credit facility			$ 0	$ 0	$ 0	$ 15,000,000	$ 20,000,000	$ 0	$ 0	$ 0
Senior notes											0	264,283,000	345,000,000	345,000,000	400,000,000	0
Convertible subordinated notes																	0	42,579,000	250,000,000	250,000,000	0	100,000,000
Term Loan for subsidiaries																							0	2,680,000	9,495,000	19,848,000	103,000,000	123,000,000	107,140,000	149,996,000	50,000,000	0	49,504,000	51,042,000	12,512,000	0
Secured equipment and property financing																																					0	872,000
Debt, Long-term and Short-term, Combined Amount, Total	1,346,651,000	1,364,300,000
Less: Short-term borrowings and current portion of long-term debt	(59,395,000)	(150,081,000)
Long-term debt (including related party)	1,287,256,000	1,214,219,000
Debt Instrument, Description of Variable Rate Basis							LIBOR
Maturity profile:
2012	59,395,000
2013	138,885,000
2014	378,356,000
2015	23,972,000
2016	1,043,000
Thereafter	745,000,000
Total debt	$ 1,346,651,000	$ 1,364,300,000