Commitments And Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		3 Months Ended							3 Months Ended		3 Months Ended		0 Months Ended
	Mar. 31, 2012	Dec. 21, 2001	Mar. 31, 2012 Contingent Promissory Note [Member] Y	Mar. 31, 2012 Minimum [Member] Y	Mar. 31, 2012 Maximum [Member] Y	Mar. 31, 2012 Tennessee And Mississippi Dairy Farmer Actions [Member]	Jun. 30, 2011 Tennessee And Mississippi Dairy Farmer Actions [Member]	Dec. 31, 2008 Tennessee And Mississippi Dairy Farmer Actions [Member]	Jul. 05, 2007 Tennessee And Mississippi Dairy Farmer Actions [Member]	Mar. 31, 2012 Tennessee Dairy Farmer Actions [Member]	Feb. 21, 2012 Tennessee Dairy Farmer Actions [Member]	Mar. 31, 2012 Tennessee Dairy Farmer Actions [Member] Minimum [Member] Y	Mar. 31, 2012 Tennessee Dairy Farmer Actions [Member] Maximum [Member] Y	Feb. 21, 2012 Receivables Securitization Facility [Member] Receivables-Backed Facility [Member]	Feb. 21, 2012 Receivables Securitization Facility [Member] Receivables-Backed Facility [Member] Standby Letters Of Credit [Member]
Commitments And Contingencies [Line Items]
Acquired interest percentage		33.80%
Principal amount of contingent promissory note			$ 40
Promissory note, term (years)			20
Contingent promissory note, maximum amount including interest			96
Insurance deductible for casualty claims	2.0
Lease term, (years)				1	20
Number of pending cases						6		4	2
Name of the settlement agreement preliminary approval court						United States District Court for the Middle District of Tennessee
Preliminary approval of the settlement agreement										July 14, 2011
Amount of settlement agreement										140
Time period for distribution of funds for settlement, in years												4	5
Initial payment into an escrow account											60
Issuance of standby letter of credit														80	80
Payments for legal settlements													20
Present value of litigation settlement							$ 131.3
Discount rate used to determine present value of litigation settlement							4.77%