Long-Term and Other Debt (Details 3)								12 Months Ended
	Sep. 30, 2012 USD ($)	May 02, 2012 CNY	Dec. 31, 2012 Base rate Minimum	Dec. 31, 2012 Base rate Maximum	Dec. 31, 2012 LIBOR Minimum	Dec. 31, 2012 LIBOR Maximum	Dec. 31, 2012 Secured Senior Term Loan and Revolving Credit Facility [Member] USD ($)	Dec. 31, 2011 Credit Agreement [Member] marginlevel	Dec. 31, 2012 Credit Agreement [Member] Federal funds effective rate	Dec. 31, 2012 Credit Agreement [Member] One month LIBOR	Dec. 31, 2011 Term Loan, varying interest rate USD ($)
Debt Instrument
Maximum revolving commitments		60,000,000					$ 250,000
Remaining outstanding amount	28,023,000										559,730,000
Outstanding letters of credit											43,823,000
Amount available for additional borrowings											$ 206,177,000
Base rate of interest on debt									Federal funds effective rate	One month LIBOR
Basis spread on variable interest rate (as a percent)			1.50%	2.50%	2.50%	3.50%			0.50%	1.00%
Number of lowest applicable margin levels that were eliminated								2