Employee Benefits Plans (Details 9) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 5,988	$ 5,199	$ 5,256
Western Conference Teamsters [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	1,855	1,494	1,455
Pension Plan Number	91-6145047
Pension Protection Act Zone Status	Green	Green
FIP/RP Status Pending/ Implemented	No
Surcharge Imposed	No
Expiration Date of Collective Bargaining Agreement	12/31/2011 to 4/1/2016
IAM National [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	1,794	1,573	1,535
Pension Plan Number	51-6031295
Pension Protection Act Zone Status	Green	Green
FIP/RP Status Pending/ Implemented	No
Surcharge Imposed	No
Expiration Date of Collective Bargaining Agreement	11/30/2011 to 8/31/2014
Automobile Mechanics Local No. 701 [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	1,203	1,076	1,058
Pension Plan Number	36-6042061
Pension Protection Act Zone Status	Red	Red
FIP/RP Status Pending/ Implemented	FIP Adopted
Surcharge Imposed	No
Expiration Date of Collective Bargaining Agreement	10/31/2011 to 5/31/2013
International Association of Machinists Motor City [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	392	372	379
Pension Plan Number	38-6237143
Pension Protection Act Zone Status	Yellow	Yellow
FIP/RP Status Pending/ Implemented	RP adopted
Surcharge Imposed	No
Expiration Date of Collective Bargaining Agreement	11/30/2011 to 1/31/2014
Other Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions	$ 744	$ 684	$ 829