Derivatives and Fair Value of Financial Instruments (Details) (USD $)	6 Months Ended
	Jun. 29, 2013	Jun. 29, 2013 Commodities	Dec. 31, 2012 Commodities	Jun. 29, 2013 Money market funds	Dec. 31, 2012 Money market funds	Jun. 29, 2013 Corporate bonds	Dec. 31, 2012 Corporate bonds	Jun. 29, 2013 Enhanced cash mutual fund	Jun. 29, 2013 U.S. Government agency securities	Dec. 31, 2012 U.S. Government agency securities	Jun. 29, 2013 Emerging markets debt mutual fund	Dec. 31, 2012 Emerging markets debt mutual fund	Jun. 29, 2013 U.S. Treasury securities	Dec. 31, 2012 U.S. Treasury securities	Jun. 29, 2013 Collateralized mortgage obligations	Dec. 31, 2012 Collateralized mortgage obligations	Jun. 29, 2013 Asset backed debt securities	Dec. 31, 2012 Asset backed debt securities	Jun. 29, 2013 High yield trading debt securities	Dec. 31, 2012 High yield trading debt securities	Jun. 29, 2013 Emerging markets trading debt mutual fund	Dec. 31, 2012 Emerging markets trading debt mutual fund	Jun. 29, 2013 Emerging markets trading debt securities	Dec. 31, 2012 Emerging markets trading debt securities	Jun. 29, 2013 Recurring basis Balance at period end	Dec. 31, 2012 Recurring basis Balance at period end	Jun. 29, 2013 Recurring basis Balance at period end Commodities	Dec. 31, 2012 Recurring basis Balance at period end Commodities	Jun. 29, 2013 Recurring basis Balance at period end Interest rate swaps	Dec. 31, 2012 Recurring basis Balance at period end Interest rate swaps	Jun. 29, 2013 Recurring basis Balance at period end Foreign currencies	Dec. 31, 2012 Recurring basis Balance at period end Foreign currencies	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 2013 Recurring basis Balance at period end Enhanced cash mutual fund Short-term investments	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 2013 Recurring basis Balance at period end Other Other current assets	Dec. 31, 2012 Recurring basis Balance at period end Other Other current assets	Jun. 29, 2013 Recurring basis Level 1	Dec. 31, 2012 Recurring basis Level 1	Jun. 29, 2013 Recurring basis Level 1 Commodities	Dec. 31, 2012 Recurring basis Level 1 Commodities	Jun. 29, 2013 Recurring basis Level 1 Money market funds Short-term investments	Dec. 31, 2012 Recurring basis Level 1 Money market funds Short-term investments	Jun. 29, 2013 Recurring basis Level 1 Money market funds Other current assets	Dec. 31, 2012 Recurring basis Level 1 Money market funds Other current assets	Jun. 29, 2013 Recurring basis Level 1 Enhanced cash mutual fund Short-term investments	Jun. 29, 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	Jun. 29, 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	Jun. 29, 2013 Recurring basis Level 1 Other trading investments Short-term investments	Dec. 31, 2012 Recurring basis Level 1 Other trading investments Short-term investments	Jun. 29, 2013 Recurring basis Level 1 Domestic equity securities Other current assets	Dec. 31, 2012 Recurring basis Level 1 Domestic equity securities Other current assets	Jun. 29, 2013 Recurring basis Level 1 Foreign equity securities Other current assets	Dec. 31, 2012 Recurring basis Level 1 Foreign equity securities Other current assets	Jun. 29, 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	Jun. 29, 2013 Recurring basis Level 1 Other Other current assets	Dec. 31, 2012 Recurring basis Level 1 Other Other current assets	Jun. 29, 2013 Recurring basis Level 2	Dec. 31, 2012 Recurring basis Level 2	Dec. 31, 2012 Recurring basis Level 2 Commodities	Jun. 29, 2013 Recurring basis Level 2 Interest rate swaps	Dec. 31, 2012 Recurring basis Level 2 Interest rate swaps	Jun. 29, 2013 Recurring basis Level 2 Foreign currencies	Dec. 31, 2012 Recurring basis Level 2 Foreign currencies	Jun. 29, 2013 Recurring basis Level 2 Corporate bonds Short-term investments	Dec. 31, 2012 Recurring basis Level 2 Corporate bonds Short-term investments	Jun. 29, 2013 Recurring basis Level 2 Corporate bonds Other current assets	Dec. 31, 2012 Recurring basis Level 2 Corporate bonds Other current assets	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 2013 Recurring basis Level 2 Collateralized mortgage obligations Short-term investments	Dec. 31, 2012 Recurring basis Level 2 Collateralized mortgage obligations Short-term investments	Jun. 29, 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	Jun. 29, 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	Jun. 29, 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	Jun. 29, 2013 Recurring basis Level 2 Other trading investments Short-term investments	Dec. 31, 2012 Recurring basis Level 2 Other trading investments Short-term investments	Jun. 29, 2013 Recurring basis Level 2 Foreign equity securities Other current assets	Dec. 31, 2012 Recurring basis Level 2 Foreign equity securities Other current assets	Jun. 29, 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				148,983,000	126,537,000	70,098,000	69,214,000	24,978,000	23,271,000	23,775,000	17,278,000	18,734,000	16,935,000	17,169,000	15,315,000	15,162,000	11,423,000	12,238,000															148,983,000	126,537,000			70,098,000	69,214,000			24,978,000	23,271,000	23,775,000			17,278,000	18,734,000	16,935,000	17,169,000			15,315,000	15,162,000	11,423,000	12,238,000																					148,983,000	126,537,000			24,978,000	17,278,000	18,734,000																				70,098,000	69,214,000			23,271,000	23,775,000			16,935,000	17,169,000			15,315,000	15,162,000	11,423,000	12,238,000
Trading securities																			24,214,000	23,406,000	2,929,000	3,237,000	2,034,000	2,600,000											1,586,000	3,157,000			83,000	60,000				1,106,000	2,117,000					1,623,000	1,567,000					24,214,000	23,406,000	2,929,000	3,237,000	2,034,000	2,600,000	1,048,000	1,307,000	21,437,000	15,864,000	8,587,000	6,831,000	5,725,000	7,153,000	290,000	239,000							1,586,000	3,157,000				2,929,000	3,237,000	512,000	822,000	21,437,000	15,864,000	5,323,000	4,218,000	5,725,000	7,153,000	239,000	187,000										83,000	60,000			1,106,000	2,117,000			1,623,000	1,567,000					24,214,000	23,406,000	2,034,000	2,600,000	536,000	485,000	3,264,000	2,613,000	51,000	52,000
Derivatives																											6,581,000	6,916,000			4,309,000																																											6,581,000	6,699,000																						217,000			4,309,000
Margin account		22,188,000	14,063,000																								22,188,000	14,063,000
Derivative assets and liabilities, net basis																											15,133,000	13,867,000
Total Assets																									409,833,000	357,283,000																																														235,571,000	186,608,000																						174,262,000	170,675,000
Liabilities:
Derivatives																											13,636,000	7,112,000	5,297,000	9,810,000	184,000	4,157,000																																										13,636,000	7,112,000																							5,297,000	9,810,000	184,000	4,157,000
Total Liabilities																									$ 19,117,000	$ 21,079,000																																														$ 13,636,000	$ 7,112,000																						$ 5,481,000	$ 13,967,000