Debt (Narrative) (Details) (USD $)	12 Months Ended					0 Months Ended		12 Months Ended			12 Months Ended											12 Months Ended		12 Months Ended							12 Months Ended	3 Months Ended
	Dec. 31, 2011	Jan. 01, 2011	Jan. 02, 2010	Dec. 31, 2011 Notes [Member]	Dec. 31, 2011 Credit Agreement Term Loan [Member]	Dec. 17, 2010 Former Credit Agreement [Member]	Jan. 01, 2011 Credit Agreement and Notes [Member]	Dec. 31, 2011 Secured Debt [Member] Darling International Senior Secured Revolving Loan Facility [Member]	Mar. 24, 2011 Secured Debt [Member] Darling International Senior Secured Revolving Loan Facility [Member]	Jan. 01, 2011 Secured Debt [Member] Darling International Senior Secured Revolving Loan Facility [Member]	Dec. 31, 2011 Secured Debt [Member] Darling International Senior Unsecured Restricted Notes [Member]	Dec. 31, 2011 Secured Debt [Member] Credit Agreement Term Loan [Member]	Jan. 01, 2011 Secured Debt [Member] Credit Agreement Term Loan [Member]	Dec. 17, 2010 Secured Debt [Member] Credit Agreement Term Loan [Member]	Dec. 31, 2011 Unsecured Debt [Member] Darling International Senior Unsecured Restricted Notes [Member]	Jan. 01, 2011 Unsecured Debt [Member] Darling International Senior Unsecured Restricted Notes [Member]	Dec. 31, 2011 Unsecured Debt [Member] Darling International Senior Unsecured Exchange Notes [Member]	Dec. 31, 2011 Unsecured Debt [Member] Other Notes [Member]	Jan. 01, 2011 Unsecured Debt [Member] Other Notes [Member]	Dec. 31, 2011 Letter of Credit [Member] Darling International Senior Secured Letter of Credit Sub Facility [Member]	Jan. 01, 2011 Letter of Credit [Member] Darling International Senior Secured Letter of Credit Sub Facility [Member]	Jan. 01, 2011 Bridge Loan [Member]	Dec. 31, 2011 Bridge Loan [Member] Darling International Senior Secured Swingline Sub Facility [Member]	Dec. 31, 2011 Maximum [Member] Notes [Member]	Dec. 31, 2011 Minimum [Member] Notes [Member]	Dec. 31, 2011 Alternate Base Rate [Member] Credit Agreement Term Loan [Member]	Dec. 31, 2011 Alternate Base Rate [Member] Maximum [Member]	Dec. 31, 2011 Alternate Base Rate [Member] Minimum [Member]	Dec. 31, 2011 LIBOR Rate [Member]	Dec. 31, 2011 LIBOR Rate [Member] Credit Agreement Term Loan [Member]	Dec. 31, 2011 LIBOR Rate [Member] Secured Debt [Member] Credit Agreement Term Loan [Member]	Mar. 31, 2012 Repayment of Debt [Member] Secured Debt [Member] Credit Agreement Term Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Term								5 years				6 years
Line of Credit Facility, Maximum Borrowing Capacity								$ 415,000,000	$ 325,000,000	$ 325,000,000										$ 75,000,000		$ 250,000,000	$ 15,000,000
Company availability under revolving loan facility								391,560,000		141,617,000
Long-term Debt	280,030,000	710,039,000						0		160,000,000		30,000,000	300,000,000	300,000,000	250,000,000	250,000,000		30,000	39,000
Outstanding borrowings and letter of credit issued								0		160,000,000										23,440,000	23,383,000
Write-off of a portion of the senior term loan facilities deferred loan costs						900,000		4,900,000
Amount repaid of the original term loan issued	270,009,000	32,509,000	5,000,000									270,000,000																				30,000,000
Description of Variable Rate					Not less than 2.50% per annum, plus the term loan alternate base rate margin of 2.50% and not less than 1.50% per annum, plus the term loan LIBOR margin of 3.50%			The federal funds effective rate plus 1/2 to 1% and LIBOR for a month interest period plus 1%
Debt Instrument, Interest Rate Terms								Base rate plus a margin of 2.25% per annum			LIBOR plus a margin of 3.5% per annum
Debt Instrument, Basis Spread on Variable Rate												2.50%														2.50%	1.00%	0.50%	1.00%	3.50%
Debt Instrument, Interest Rate, Effective Percentage Rate Range, Minimum																										2.50%					1.50%
Debt Instrument, Interest Rate at Period End												5.75%
Face amount of debt insturment															250,000,000		250,000,000
Annual interest rate															8.50%		8.50%
Redemption Price Of Principal Amount Of Notes Redeemed	1
Debt Instrument, Notice Period																								60 days	30 days
Debt Instrument, Percentage of Origanal Principal Amount Eligible For Redemption																								35.00%
Debt Instrument, Redemption Price Of Principal Amount				108.50%
Debt Instrument, Redemption, Percentage of Principal Amount That Remains Outstanding After Redemption																									65.00%
Debt Instrument, Redemption Period				90 days
Default event, percent of principal held in order to declare notes due and payable immediately																									25.00%
Deferred Finance Costs, Gross							24,000,000
Pledge of stock	100.00%
Pledge of Capital stock	65.00%
Line of Credit Facility, Commitment Fee Amount																						$ 3,100,000