Commitments and Contingencies (Details Textuals) (USD $)	3 Months Ended		9 Months Ended
	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2011	Dec. 31, 2009	Sep. 14, 2006	Sep. 30, 2011 Minimum Range [Member]	Jun. 30, 2009 Minimum Range [Member]	Sep. 30, 2011 Maximum Range [Member]	Jun. 30, 2009 Maximum Range [Member]	Sep. 30, 2011 Messrs.Isenberg [Member]	Sep. 30, 2011 Petrello [Member]
Income Tax Examination [Line Items]
Aggregate potential tax assessments range						$ 90,000,000	$ 6,000,000	$ 95,000,000	$ 26,000,000
Commitments and Contingencies (Textuals) [Abstract]
Amount of payment due to death, disability or termination										100,000,000	50,000,000
Approximate amount of payment due to death, disability or termination											34,000,000
Assessed income tax amount of NDIL's Mexico branch					19,800,000
Potential tax assessments range			$6 million to $26 million per year for the period from 2005 to 2009
Unrecognized tax benefits reductions resulting from lapse of applicable statute of limitations		7,400,000
Alleged customs infractions amount				19,700,000
Amount of loss range, minimum				140,000
Amount of loss range, maximum				19,700,000
Payment of attorney's fees in full settlement			475,000
Possible Loss Relating to Foreign Currency Exchange Control	39,100,000
Payment of Contract Amount in Foreign Currency	7,500,000
Payment of Contract Amount in Domestic Currency	3,200,000
Potential judgment in excess of accrual	$ 31,100,000
Period within which payment received			30 days