Derivatives and Fair Value of Financial Instruments (Details) (USD $)	9 Months Ended
	Sep. 28, 2013	Sep. 28, 2013 Commodities	Dec. 31, 2012 Commodities	Sep. 28, 2013 Money market funds	Dec. 31, 2012 Money market funds	Sep. 28, 2013 Corporate bonds	Dec. 31, 2012 Corporate bonds	Sep. 28, 2013 U.S. Government agency securities	Dec. 31, 2012 U.S. Government agency securities	Sep. 28, 2013 Emerging markets debt mutual fund	Dec. 31, 2012 Emerging markets debt mutual fund	Sep. 28, 2013 Collateralized mortgage obligations	Dec. 31, 2012 Collateralized mortgage obligations	Sep. 28, 2013 Asset backed debt securities	Dec. 31, 2012 Asset backed debt securities	Sep. 28, 2013 U.S. Treasury securities	Dec. 31, 2012 U.S. Treasury securities	Sep. 28, 2013 High yield trading debt securities	Dec. 31, 2012 High yield trading debt securities	Sep. 28, 2013 Emerging markets trading debt mutual fund	Dec. 31, 2012 Emerging markets trading debt mutual fund	Sep. 28, 2013 Emerging markets trading debt securities	Dec. 31, 2012 Emerging markets trading debt securities	Sep. 28, 2013 Recurring basis Balance at period end	Dec. 31, 2012 Recurring basis Balance at period end	Sep. 28, 2013 Recurring basis Balance at period end Commodities	Dec. 31, 2012 Recurring basis Balance at period end Commodities	Sep. 28, 2013 Recurring basis Balance at period end Interest rate swaps	Dec. 31, 2012 Recurring basis Balance at period end Interest rate swaps	Sep. 28, 2013 Recurring basis Balance at period end Foreign currencies	Dec. 31, 2012 Recurring basis Balance at period end Foreign currencies	Sep. 28, 2013 Recurring basis Balance at period end Money market funds Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end Money market funds Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end Money market funds Other current assets	Dec. 31, 2012 Recurring basis Balance at period end Money market funds Other current assets	Sep. 28, 2013 Recurring basis Balance at period end Corporate bonds Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end Corporate bonds Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end Corporate bonds Other current assets	Dec. 31, 2012 Recurring basis Balance at period end Corporate bonds Other current assets	Sep. 28, 2013 Recurring basis Balance at period end U.S. Government agency securities Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end U.S. Government agency securities Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end U.S. Government agency securities Other current assets	Dec. 31, 2012 Recurring basis Balance at period end U.S. Government agency securities Other current assets	Sep. 28, 2013 Recurring basis Balance at period end Emerging markets debt mutual fund Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end Emerging markets debt mutual fund Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end Collateralized mortgage obligations Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end Collateralized mortgage obligations Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end Asset backed debt securities Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end Asset backed debt securities Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end U.S. Treasury securities Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end U.S. Treasury securities Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end U.S. Treasury securities Other current assets	Dec. 31, 2012 Recurring basis Balance at period end U.S. Treasury securities Other current assets	Sep. 28, 2013 Recurring basis Balance at period end High yield trading debt securities Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end High yield trading debt securities Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end Emerging markets trading debt mutual fund Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end Emerging markets trading debt mutual fund Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end Emerging markets trading debt securities Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end Emerging markets trading debt securities Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end Other trading investments Short-term investments	Dec. 31, 2012 Recurring basis Balance at period end Other trading investments Short-term investments	Sep. 28, 2013 Recurring basis Balance at period end Domestic equity securities Other current assets	Dec. 31, 2012 Recurring basis Balance at period end Domestic equity securities Other current assets	Sep. 28, 2013 Recurring basis Balance at period end Foreign equity securities Other current assets	Dec. 31, 2012 Recurring basis Balance at period end Foreign equity securities Other current assets	Sep. 28, 2013 Recurring basis Balance at period end Fixed income mutual funds Other current assets	Dec. 31, 2012 Recurring basis Balance at period end Fixed income mutual funds Other current assets	Sep. 28, 2013 Recurring basis Balance at period end Other Other current assets	Dec. 31, 2012 Recurring basis Balance at period end Other Other current assets	Sep. 28, 2013 Recurring basis Level 1	Dec. 31, 2012 Recurring basis Level 1	Sep. 28, 2013 Recurring basis Level 1 Commodities	Dec. 31, 2012 Recurring basis Level 1 Commodities	Sep. 28, 2013 Recurring basis Level 1 Money market funds Short-term investments	Dec. 31, 2012 Recurring basis Level 1 Money market funds Short-term investments	Sep. 28, 2013 Recurring basis Level 1 Money market funds Other current assets	Dec. 31, 2012 Recurring basis Level 1 Money market funds Other current assets	Sep. 28, 2013 Recurring basis Level 1 Emerging markets debt mutual fund Short-term investments	Dec. 31, 2012 Recurring basis Level 1 Emerging markets debt mutual fund Short-term investments	Sep. 28, 2013 Recurring basis Level 1 Emerging markets trading debt mutual fund Short-term investments	Dec. 31, 2012 Recurring basis Level 1 Emerging markets trading debt mutual fund Short-term investments	Sep. 28, 2013 Recurring basis Level 1 Other trading investments Short-term investments	Dec. 31, 2012 Recurring basis Level 1 Other trading investments Short-term investments	Sep. 28, 2013 Recurring basis Level 1 Domestic equity securities Other current assets	Dec. 31, 2012 Recurring basis Level 1 Domestic equity securities Other current assets	Sep. 28, 2013 Recurring basis Level 1 Foreign equity securities Other current assets	Dec. 31, 2012 Recurring basis Level 1 Foreign equity securities Other current assets	Sep. 28, 2013 Recurring basis Level 1 Fixed income mutual funds Other current assets	Dec. 31, 2012 Recurring basis Level 1 Fixed income mutual funds Other current assets	Sep. 28, 2013 Recurring basis Level 1 Other Other current assets	Dec. 31, 2012 Recurring basis Level 1 Other Other current assets	Sep. 28, 2013 Recurring basis Level 2	Dec. 31, 2012 Recurring basis Level 2	Dec. 31, 2012 Recurring basis Level 2 Commodities	Sep. 28, 2013 Recurring basis Level 2 Interest rate swaps	Dec. 31, 2012 Recurring basis Level 2 Interest rate swaps	Sep. 28, 2013 Recurring basis Level 2 Foreign currencies	Dec. 31, 2012 Recurring basis Level 2 Foreign currencies	Sep. 28, 2013 Recurring basis Level 2 Corporate bonds Short-term investments	Dec. 31, 2012 Recurring basis Level 2 Corporate bonds Short-term investments	Sep. 28, 2013 Recurring basis Level 2 Corporate bonds Other current assets	Dec. 31, 2012 Recurring basis Level 2 Corporate bonds Other current assets	Sep. 28, 2013 Recurring basis Level 2 U.S. Government agency securities Short-term investments	Dec. 31, 2012 Recurring basis Level 2 U.S. Government agency securities Short-term investments	Sep. 28, 2013 Recurring basis Level 2 U.S. Government agency securities Other current assets	Dec. 31, 2012 Recurring basis Level 2 U.S. Government agency securities Other current assets	Sep. 28, 2013 Recurring basis Level 2 Collateralized mortgage obligations Short-term investments	Dec. 31, 2012 Recurring basis Level 2 Collateralized mortgage obligations Short-term investments	Sep. 28, 2013 Recurring basis Level 2 Asset backed debt securities Short-term investments	Dec. 31, 2012 Recurring basis Level 2 Asset backed debt securities Short-term investments	Sep. 28, 2013 Recurring basis Level 2 U.S. Treasury securities Short-term investments	Dec. 31, 2012 Recurring basis Level 2 U.S. Treasury securities Short-term investments	Sep. 28, 2013 Recurring basis Level 2 U.S. Treasury securities Other current assets	Dec. 31, 2012 Recurring basis Level 2 U.S. Treasury securities Other current assets	Sep. 28, 2013 Recurring basis Level 2 High yield trading debt securities Short-term investments	Dec. 31, 2012 Recurring basis Level 2 High yield trading debt securities Short-term investments	Sep. 28, 2013 Recurring basis Level 2 Emerging markets trading debt securities Short-term investments	Dec. 31, 2012 Recurring basis Level 2 Emerging markets trading debt securities Short-term investments	Sep. 28, 2013 Recurring basis Level 2 Other trading investments Short-term investments	Dec. 31, 2012 Recurring basis Level 2 Other trading investments Short-term investments	Sep. 28, 2013 Recurring basis Level 2 Foreign equity securities Other current assets	Dec. 31, 2012 Recurring basis Level 2 Foreign equity securities Other current assets	Sep. 28, 2013 Recurring basis Level 2 Other Other current assets	Dec. 31, 2012 Recurring basis Level 2 Other Other current assets
Derivatives and Fair Value of Financial Instruments
Transfers that occurred into or out of level 1	$ 0
Transfers that occurred into or out of level 2	0
Transfers that occurred into or out of level 3	0
Assets:
Available-for-sale securities				78,435,000	126,537,000	69,038,000	69,214,000	20,412,000	23,775,000	17,253,000	18,734,000	15,007,000	15,162,000	8,967,000	12,238,000	5,237,000	17,169,000															78,435,000	126,537,000			69,038,000	69,214,000			20,412,000	23,775,000			17,253,000	18,734,000	15,007,000	15,162,000	8,967,000	12,238,000	5,237,000	17,169,000																							78,435,000	126,537,000			17,253,000	18,734,000																				69,038,000	69,214,000			20,412,000	23,775,000			15,007,000	15,162,000	8,967,000	12,238,000	5,237,000	17,169,000
Trading securities																		25,195,000	23,406,000	2,900,000	3,237,000	1,535,000	2,600,000											2,046,000	3,157,000			81,000	60,000			958,000	2,117,000									1,506,000	1,567,000	25,195,000	23,406,000	2,900,000	3,237,000	1,535,000	2,600,000	1,016,000	1,307,000	22,881,000	15,864,000	9,380,000	6,831,000	5,954,000	7,153,000	313,000	239,000							2,046,000	3,157,000			2,900,000	3,237,000	507,000	822,000	22,881,000	15,864,000	5,614,000	4,218,000	5,954,000	7,153,000	271,000	187,000										81,000	60,000			958,000	2,117,000							1,506,000	1,567,000	25,195,000	23,406,000	1,535,000	2,600,000	509,000	485,000	3,766,000	2,613,000	42,000	52,000
Derivatives																										2,062,000	6,916,000			4,088,000																																										2,062,000	6,699,000																					217,000			4,088,000
Margin account		30,382,000	14,063,000																							30,382,000	14,063,000
Derivative assets and liabilities, net basis																										14,562,000	13,867,000
Total Assets																								294,264,000	357,283,000																																													137,923,000	186,608,000																					156,341,000	170,675,000
Liabilities:
Derivatives																										17,882,000	7,112,000	5,318,000	9,810,000	92,000	4,157,000																																									17,882,000	7,112,000																						5,318,000	9,810,000	92,000	4,157,000
Total Liabilities																								$ 23,292,000	$ 21,079,000																																													$ 17,882,000	$ 7,112,000																					$ 5,410,000	$ 13,967,000