Revenue from Contracts with Customers (Tables)

12 Months Ended

Dec. 31, 2019

Revenue from Contract with Customers [Abstract]

Disaggregation of Revenue [Table Text Block]

Disaggregation of Net Sales

Net sales recognized from contracts with customers, disaggregated by segment and geographical location, are presented in the following table for the years ended December 31, 2019, December 31, 2018 and December 31, 2017. Net sales are attributed to regions based on the location of production. Intersegment sales have been excluded from the table.

In the first quarter of 2019, we reorganized our business to disaggregate our former Powertrain segment, with a portion moving to our Driveline segment and a portion moving to our Metal Forming segment. As a result, the Powertrain amounts previously reported for the years ended December 31, 2018 and December 31, 2017 have been reclassified to Driveline and Metal Forming.

Additionally, in the fourth quarter of 2019, we finalized the Casting Sale. The Casting Sale did not include the entities that conduct AAM's casting operations in El Carmen, Mexico, which are now included in our Driveline segment. The amounts previously reported in our Casting segment for the retained operations in El Carmen, Mexico have been reclassified to our Driveline segment for the years presented.

	Twelve Months Ended December 31, 2019
	Driveline		Metal Forming		Casting		Total
North America	$	3,466.3	$	1,153.1	$	627.7	$	5,247.1
Asia	533.6		37.6		—		571.2
Europe	351.0		256.3		—		607.3
South America	98.8		6.5		—		105.3
Total	$	4,449.7	$	1,453.5	$	627.7	$	6,530.9
	Twelve Months Ended December 31, 2018
	Driveline		Metal Forming		Casting		Total
North America	$	3,823.1	$	1,275.9	$	741.3	$	5,840.3
Asia	634.4		43.9		—		678.3
Europe	329.0		293.1		—		622.1
South America	124.9		4.8		—		129.7
Total	$	4,911.4	$	1,617.7	$	741.3	$	7,270.4
	Twelve Months Ended December 31, 2017
	Driveline		Metal Forming		Casting		Total
North America	$	3,676.1	$	975.8	$	546.9	$	5,198.8
Asia	472.5		40.0		—		512.5
Europe	220.6		200.9		—		421.5
South America	132.7		0.5		—		133.2
Total	$	4,501.9	$	1,217.2	$	546.9	$	6,266.0

Contract Assets and Liabilities

The following table summarizes our beginning and ending balances for accounts receivable and contract liabilities associated with our contracts with customers:

	Accounts Receivable, Net			Contract Liabilities (Current)			Contract Liabilities (Long-term)
December 31, 2018	$	966.5		$	44.3		$	77.6
December 31, 2019	815.4			18.9			83.7
Increase/(decrease)	$	(151.1	)	$	(25.4	)	$	6.1