Employee Benefit Plans (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Pension plans	Dec. 31, 2011 Pension plans	Dec. 31, 2012 Pension plans Global equity securities: Capital equipment	Dec. 31, 2011 Pension plans Global equity securities: Capital equipment	Dec. 31, 2012 Pension plans Global equity securities: Consumer goods	Dec. 31, 2011 Pension plans Global equity securities: Consumer goods	Dec. 31, 2012 Pension plans Global equity securities: Energy	Dec. 31, 2011 Pension plans Global equity securities: Energy	Dec. 31, 2012 Pension plans Global equity securities: Finance	Dec. 31, 2011 Pension plans Global equity securities: Finance	Dec. 31, 2012 Pension plans Global equity securities: Materials	Dec. 31, 2011 Pension plans Global equity securities: Materials	Dec. 31, 2012 Pension plans Global equity securities: Services	Dec. 31, 2011 Pension plans Global equity securities: Services	Dec. 31, 2012 Pension plans Global equity securities: Miscellaneous	Dec. 31, 2011 Pension plans Global equity securities: Miscellaneous	Dec. 31, 2012 Pension plans Global Equity Common Trust Funds	Dec. 31, 2011 Pension plans Global Equity Common Trust Funds	Dec. 31, 2012 Pension plans Fixed Income Common Trust Funds	Dec. 31, 2011 Pension plans Fixed Income Common Trust Funds	Dec. 31, 2012 Pension plans Non-U.S. Government securities	Dec. 31, 2011 Pension plans Non-U.S. Government securities	Dec. 31, 2012 Pension plans Commingled Global Fund Allocations	Dec. 31, 2011 Pension plans Commingled Global Fund Allocations	Dec. 31, 2012 Pension plans Short term investments	Dec. 31, 2011 Pension plans Short term investments	Dec. 31, 2012 Pension plans Other	Dec. 31, 2011 Pension plans Other	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Capital equipment	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Capital equipment	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Consumer goods	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Consumer goods	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Energy	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Energy	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Finance	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Finance	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Materials	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Materials	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Services	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Services	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Miscellaneous	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global equity securities: Miscellaneous	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global Equity Common Trust Funds	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Global Equity Common Trust Funds	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Fixed Income Common Trust Funds	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Fixed Income Common Trust Funds	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Commingled Global Fund Allocations	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Commingled Global Fund Allocations	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Short term investments	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Short term investments	Dec. 31, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Other	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) Pension plans Other	Dec. 31, 2012 Significant Observable Inputs (Level 2) Securities collateralized	Dec. 31, 2011 Significant Observable Inputs (Level 2) Securities collateralized	Dec. 31, 2012 Significant Observable Inputs (Level 2) Pension plans	Dec. 31, 2011 Significant Observable Inputs (Level 2) Pension plans	Dec. 31, 2012 Significant Observable Inputs (Level 2) Pension plans Global Equity Common Trust Funds	Dec. 31, 2011 Significant Observable Inputs (Level 2) Pension plans Global Equity Common Trust Funds	Dec. 31, 2012 Significant Observable Inputs (Level 2) Pension plans Fixed Income Common Trust Funds	Dec. 31, 2011 Significant Observable Inputs (Level 2) Pension plans Fixed Income Common Trust Funds	Dec. 31, 2012 Significant Observable Inputs (Level 2) Pension plans Non-U.S. Government securities	Dec. 31, 2011 Significant Observable Inputs (Level 2) Pension plans Non-U.S. Government securities	Dec. 31, 2012 Significant Observable Inputs (Level 2) Pension plans Commingled Global Fund Allocations	Dec. 31, 2011 Significant Observable Inputs (Level 2) Pension plans Commingled Global Fund Allocations	Dec. 31, 2012 Significant Observable Inputs (Level 2) Pension plans Other	Dec. 31, 2012 Significant Unobservable Inputs (Level 3)	Dec. 31, 2011 Significant Unobservable Inputs (Level 3)	Dec. 31, 2010 Significant Unobservable Inputs (Level 3)	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Global Equity Common Trust Funds	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Global Equity Common Trust Funds	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Fixed Income Common Trust Funds	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Fixed Income Common Trust Funds	Dec. 31, 2010 Significant Unobservable Inputs (Level 3) Fixed Income Common Trust Funds	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Commingled Global Fund Allocations	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Commingled Global Fund Allocations	Dec. 31, 2010 Significant Unobservable Inputs (Level 3) Commingled Global Fund Allocations	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Other	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Other	Dec. 31, 2010 Significant Unobservable Inputs (Level 3) Other	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Pension plans	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Pension plans	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Pension plans Global Equity Common Trust Funds	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Pension plans Global Equity Common Trust Funds	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Pension plans Fixed Income Common Trust Funds	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Pension plans Fixed Income Common Trust Funds	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Pension plans Commingled Global Fund Allocations	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Pension plans Commingled Global Fund Allocations	Dec. 31, 2012 Significant Unobservable Inputs (Level 3) Pension plans Other	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) Pension plans Other
Employee Benefit Plans
Fair value of plan assets		$ 1,213,800,000	$ 1,115,200,000	$ 20,200,000	$ 27,100,000	$ 17,700,000	$ 16,500,000	$ 8,800,000	$ 12,300,000	$ 8,200,000	$ 10,100,000	$ 9,400,000	$ 17,200,000	$ 10,600,000	$ 12,700,000	$ 37,300,000	$ 39,400,000	$ 366,100,000	$ 328,900,000	$ 380,500,000	$ 331,900,000	$ 36,300,000	$ 36,000,000	$ 247,100,000	$ 231,900,000	$ 61,500,000	$ 43,500,000	$ 10,100,000	$ 7,700,000	$ 440,300,000	$ 432,800,000	$ 20,200,000	$ 27,100,000	$ 17,700,000	$ 16,500,000	$ 8,800,000	$ 12,300,000	$ 8,200,000	$ 10,100,000	$ 9,400,000	$ 17,200,000	$ 10,600,000	$ 12,700,000	$ 37,300,000	$ 39,400,000	$ 103,600,000	$ 91,600,000	$ 69,400,000	$ 64,000,000	$ 91,200,000	$ 96,700,000	$ 61,500,000	$ 43,500,000	$ 2,400,000	$ 1,700,000	$ 31,400,000	$ 47,400,000	$ 580,100,000	$ 520,700,000	$ 233,500,000	$ 212,900,000	$ 309,700,000	$ 266,500,000	$ 36,300,000	$ 36,000,000	$ 300,000	$ 5,300,000	$ 300,000	$ 193,400,000	$ 161,700,000	$ 131,900,000	$ 29,000,000	$ 24,400,000	$ 1,400,000	$ 1,400,000	$ 1,300,000	$ 155,600,000	$ 129,900,000	$ 122,400,000	$ 7,400,000	$ 6,000,000	$ 8,200,000	$ 193,400,000	$ 161,700,000	$ 29,000,000	$ 24,400,000	$ 1,400,000	$ 1,400,000	$ 155,600,000	$ 129,900,000	$ 7,400,000	$ 6,000,000
Value of Short term investments (in dollars per unit)	$ 1.00