Derivatives and Fair Value of Financial Instruments (Details) (USD $)	3 Months Ended
	Mar. 29, 2014	Mar. 29, 2014 Commodities	Dec. 31, 2013 Commodities	Mar. 29, 2014 Money market funds	Dec. 31, 2013 Money market funds	Mar. 29, 2014 Corporate bonds	Dec. 31, 2013 Corporate bonds	Mar. 29, 2014 U.S. Government agency securities	Dec. 31, 2013 U.S. Government agency securities	Mar. 29, 2014 Asset backed debt securities	Dec. 31, 2013 Asset backed debt securities	Mar. 29, 2014 Collateralized mortgage obligations	Dec. 31, 2013 Collateralized mortgage obligations	Mar. 29, 2014 U.S. Treasury securities	Dec. 31, 2013 U.S. Treasury securities	Dec. 31, 2013 Emerging markets debt mutual fund	Mar. 29, 2014 High yield debt securities	Dec. 31, 2013 High yield debt securities	Mar. 29, 2014 Emerging markets trading debt mutual fund	Dec. 31, 2013 Emerging markets trading debt mutual fund	Mar. 29, 2014 Money market funds held in trading accounts	Dec. 31, 2013 Money market funds held in trading accounts	Mar. 29, 2014 Emerging markets trading debt securities	Dec. 31, 2013 Emerging markets trading debt securities	Mar. 29, 2014 Recurring basis Balance at period end	Dec. 31, 2013 Recurring basis Balance at period end	Mar. 29, 2014 Recurring basis Balance at period end Commodities	Dec. 31, 2013 Recurring basis Balance at period end Commodities	Mar. 29, 2014 Recurring basis Balance at period end Interest rate swaps	Dec. 31, 2013 Recurring basis Balance at period end Interest rate swaps	Mar. 29, 2014 Recurring basis Balance at period end Foreign currencies	Dec. 31, 2013 Recurring basis Balance at period end Foreign currencies	Mar. 29, 2014 Recurring basis Balance at period end Other current assets Commodities	Dec. 31, 2013 Recurring basis Balance at period end Other current assets Commodities	Mar. 29, 2014 Recurring basis Balance at period end Other current liability Commodities	Dec. 31, 2013 Recurring basis Balance at period end Other current liability Commodities	Mar. 29, 2014 Recurring basis Balance at period end Money market funds Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Money market funds Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end Money market funds Other current assets	Dec. 31, 2013 Recurring basis Balance at period end Money market funds Other current assets	Mar. 29, 2014 Recurring basis Balance at period end Corporate bonds Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Corporate bonds Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end U.S. Government agency securities Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end U.S. Government agency securities Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end Asset backed debt securities Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Asset backed debt securities Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end Collateralized mortgage obligations Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Collateralized mortgage obligations Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end U.S. Treasury securities Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end U.S. Treasury securities Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Emerging markets debt mutual fund Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end High yield debt securities Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end High yield debt securities Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end Emerging markets trading debt mutual fund Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Emerging markets trading debt mutual fund Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end Money market funds held in trading accounts Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Money market funds held in trading accounts Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end Emerging markets trading debt securities Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Emerging markets trading debt securities Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end Other trading investments Short-term investments	Dec. 31, 2013 Recurring basis Balance at period end Other trading investments Short-term investments	Mar. 29, 2014 Recurring basis Balance at period end Domestic equity securities Other current assets	Dec. 31, 2013 Recurring basis Balance at period end Domestic equity securities Other current assets	Mar. 29, 2014 Recurring basis Balance at period end Foreign equity securities Other current assets	Dec. 31, 2013 Recurring basis Balance at period end Foreign equity securities Other current assets	Mar. 29, 2014 Recurring basis Balance at period end Fixed income mutual funds Other current assets	Dec. 31, 2013 Recurring basis Balance at period end Fixed income mutual funds Other current assets	Mar. 29, 2014 Recurring basis Balance at period end Other Other current assets	Dec. 31, 2013 Recurring basis Balance at period end Other Other current assets	Mar. 29, 2014 Recurring basis Level 1	Dec. 31, 2013 Recurring basis Level 1	Mar. 29, 2014 Recurring basis Level 1 Commodities	Dec. 31, 2013 Recurring basis Level 1 Commodities	Mar. 29, 2014 Recurring basis Level 1 Money market funds Short-term investments	Dec. 31, 2013 Recurring basis Level 1 Money market funds Short-term investments	Mar. 29, 2014 Recurring basis Level 1 Money market funds Other current assets	Dec. 31, 2013 Recurring basis Level 1 Money market funds Other current assets	Dec. 31, 2013 Recurring basis Level 1 Emerging markets debt mutual fund Short-term investments	Mar. 29, 2014 Recurring basis Level 1 Emerging markets trading debt mutual fund Short-term investments	Dec. 31, 2013 Recurring basis Level 1 Emerging markets trading debt mutual fund Short-term investments	Mar. 29, 2014 Recurring basis Level 1 Money market funds held in trading accounts Short-term investments	Dec. 31, 2013 Recurring basis Level 1 Money market funds held in trading accounts Short-term investments	Mar. 29, 2014 Recurring basis Level 1 Domestic equity securities Other current assets	Dec. 31, 2013 Recurring basis Level 1 Domestic equity securities Other current assets	Mar. 29, 2014 Recurring basis Level 1 Foreign equity securities Other current assets	Dec. 31, 2013 Recurring basis Level 1 Foreign equity securities Other current assets	Mar. 29, 2014 Recurring basis Level 1 Fixed income mutual funds Other current assets	Dec. 31, 2013 Recurring basis Level 1 Fixed income mutual funds Other current assets	Mar. 29, 2014 Recurring basis Level 1 Other Other current assets	Dec. 31, 2013 Recurring basis Level 1 Other Other current assets	Mar. 29, 2014 Recurring basis Level 2	Dec. 31, 2013 Recurring basis Level 2	Mar. 29, 2014 Recurring basis Level 2 Commodities	Dec. 31, 2013 Recurring basis Level 2 Commodities	Mar. 29, 2014 Recurring basis Level 2 Interest rate swaps	Dec. 31, 2013 Recurring basis Level 2 Interest rate swaps	Mar. 29, 2014 Recurring basis Level 2 Foreign currencies	Dec. 31, 2013 Recurring basis Level 2 Foreign currencies	Mar. 29, 2014 Recurring basis Level 2 Corporate bonds Short-term investments	Dec. 31, 2013 Recurring basis Level 2 Corporate bonds Short-term investments	Mar. 29, 2014 Recurring basis Level 2 U.S. Government agency securities Short-term investments	Dec. 31, 2013 Recurring basis Level 2 U.S. Government agency securities Short-term investments	Mar. 29, 2014 Recurring basis Level 2 Asset backed debt securities Short-term investments	Dec. 31, 2013 Recurring basis Level 2 Asset backed debt securities Short-term investments	Mar. 29, 2014 Recurring basis Level 2 Collateralized mortgage obligations Short-term investments	Dec. 31, 2013 Recurring basis Level 2 Collateralized mortgage obligations Short-term investments	Mar. 29, 2014 Recurring basis Level 2 U.S. Treasury securities Short-term investments	Dec. 31, 2013 Recurring basis Level 2 U.S. Treasury securities Short-term investments	Mar. 29, 2014 Recurring basis Level 2 High yield debt securities Short-term investments	Dec. 31, 2013 Recurring basis Level 2 High yield debt securities Short-term investments	Mar. 29, 2014 Recurring basis Level 2 Emerging markets trading debt securities Short-term investments	Dec. 31, 2013 Recurring basis Level 2 Emerging markets trading debt securities Short-term investments	Mar. 29, 2014 Recurring basis Level 2 Other trading investments Short-term investments	Dec. 31, 2013 Recurring basis Level 2 Other trading investments Short-term investments	Mar. 29, 2014 Recurring basis Level 2 Foreign equity securities Other current assets	Dec. 31, 2013 Recurring basis Level 2 Foreign equity securities Other current assets	Mar. 29, 2014 Recurring basis Level 2 Other Other current assets	Dec. 31, 2013 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				216,623,000	88,430,000	49,482,000	70,258,000	47,554,000	27,147,000	11,938,000	8,477,000	6,451,000	7,600,000	2,770,000	5,223,000	16,941,000																					216,623,000	88,430,000			49,482,000	70,258,000	47,554,000	27,147,000	11,938,000	8,477,000	6,451,000	7,600,000	2,770,000	5,223,000	16,941,000																							216,623,000	88,430,000			16,941,000																					49,482,000	70,258,000	47,554,000	27,147,000	11,938,000	8,477,000	6,451,000	7,600,000	2,770,000	5,223,000
Trading securities																	51,923,000	50,428,000	2,856,000	2,858,000	1,287,000	11,033,000	729,000	1,336,000															2,102,000	1,931,000												51,923,000	50,428,000	2,856,000	2,858,000	1,287,000	11,033,000	729,000	1,336,000	609,000	918,000	28,210,000	26,672,000	7,943,000	9,570,000	4,909,000	3,974,000	3,641,000	3,203,000							2,102,000	1,931,000		2,856,000	2,858,000	1,287,000	11,033,000	28,210,000	26,672,000	5,676,000	7,317,000	4,909,000	3,974,000	1,702,000	1,628,000																			51,923,000	50,428,000	729,000	1,336,000	609,000	918,000	2,267,000	2,253,000	1,939,000	1,575,000
Derivatives																											19,402,000	2,331,000	388,000		59,000	2,763,000																																								19,402,000	2,331,000																						388,000		59,000	2,763,000
Margin account		42,622,000	29,822,000																								42,622,000	29,822,000
Total Assets																									458,876,000	341,093,000																																												282,767,000	163,115,000																				176,109,000	177,978,000
Derivative assets and liabilities, net basis																																	19,638,000	16,731,000
Liabilities:
Derivatives																											43,271,000	16,014,000	4,551,000	4,103,000	2,043,000	101,000			885,000	592,000																																				42,386,000	15,422,000																				885,000	592,000	4,551,000	4,103,000	2,043,000	101,000
Total Liabilities																									$ 49,865,000	$ 20,218,000																																												$ 42,386,000	$ 15,422,000																				$ 7,479,000	$ 4,796,000