Contingencies	6 Months Ended
Jun. 30, 2012
Contingencies [Abstract]
Commitments and Contingencies Disclosure [Text Block]	12. CONTINGENCIES In February 2012, the International UAW filed suit in the United States District Court for the Eastern District of Michigan, alleging that AAM violated certain provisions of the collective bargaining agreement covering represented hourly associates at the Detroit Manufacturing Complex and Cheektowaga Manufacturing Facility related to pension and postretirement benefits. As a result of the potential impact from the enactment of MAP-21 on this litigation, we recorded an actuarially determined expense of $28.1 million in cost of goods sold in the second quarter of 2012. This charge represents our actuarial estimate of the cost of the pension and postretirement benefits that would have to be provided to eligible UAW associates if the International UAW were to prevail in this litigation. AAM disputes these claims and continues to defend the lawsuit vigorously. Additional facts and circumstances may continue to develop in the future that could have a significant impact on our estimates, including changes in discount rates and other actuarial assumptions.

Contingencies

6 Months Ended

Jun. 30, 2012

Commitments and Contingencies Disclosure [Text Block]

12. CONTINGENCIES

In February 2012, the International UAW filed suit in the United States District Court for the Eastern District of Michigan, alleging that AAM violated certain provisions of the collective bargaining agreement covering represented hourly associates at the Detroit Manufacturing Complex and Cheektowaga Manufacturing Facility related to pension and postretirement benefits. As a result of the potential impact from the enactment of MAP-21 on this litigation, we recorded an actuarially determined expense of $28.1 million in cost of goods sold in the second quarter of 2012. This charge represents our actuarial estimate of the cost of the pension and postretirement benefits that would have to be provided to eligible UAW associates if the International UAW were to prevail in this litigation.

AAM disputes these claims and continues to defend the lawsuit vigorously. Additional facts and circumstances may continue to develop in the future that could have a significant impact on our estimates, including changes in discount rates and other actuarial assumptions.