Segment and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2019

Segments, Geographical Areas [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	Year Ended December 31, 2019
	Driveline		Metal Forming		Casting		Corporate and Eliminations		Total
	(in millions)
Sales	$	4,550.2	$	1,845.2	$	669.2	$	—	$	7,064.6
Less: Intersegment sales	100.5		391.7		41.5		—		533.7
Net external sales	$	4,449.7	$	1,453.5	$	627.7	$	—	$	6,530.9
Segment adjusted EBITDA	$	610.8	$	316.5	$	43.0	$	—	$	970.3
Depreciation and amortization	$	307.7	$	186.9	$	42.3	$	—	$	536.9
Capital expenditures	$	283.8	$	105.5	$	28.5	$	15.5	$	433.3
Total assets	$	3,778.8	$	1,900.0	$	—	$	965.8	$	6,644.6

	Year Ended December 31, 2018
	Driveline		Metal Forming		Casting		Corporate and Eliminations		Total
Sales	$	5,001.2	$	2,046.0	$	780.6	$	—	$	7,827.8
Less: Intersegment sales	89.8		428.3		39.3		—		557.4
Net external sales	$	4,911.4	$	1,617.7	$	741.3	$	—	$	7,270.4
Segment adjusted EBITDA	$	754.5	$	376.5	$	52.9	$	—	$	1,183.9
Depreciation and amortization	$	272.0	$	192.6	$	64.2	$	—	$	528.8
Capital expenditures	$	339.4	$	138.3	$	35.0	$	12.0	$	524.7
Total assets	$	3,796.6	$	2,607.2	$	521.5	$	585.4	$	7,510.7

	Year Ended December 31, 2017
	Driveline		Metal Forming		Casting		Corporate and Eliminations		Total
Sales	$	4,567.8	$	1,634.9	$	576.1	$	—	$	6,778.8
Less: Intersegment sales	65.9		417.7		29.2		—		512.8
Net external sales	$	4,501.9	$	1,217.2	$	546.9	$	—	$	6,266.0
Segment adjusted EBITDA	$	762.3	$	305.7	$	34.7	$	—	$	1,102.7
Depreciation and amortization	$	237.3	$	147.8	$	43.4	$	—	$	428.5
Capital expenditures	$	340.2	$	97.7	$	24.7	$	15.1	$	477.7
Total assets	$	3,507.0	$	2,731.1	$	926.0	$	718.7	$	7,882.8

Assets included in the Corporate and Eliminations column of the tables above represent AAM corporate assets, as well as eliminations of intercompany assets.

Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]

The following table represents a reconciliation of Segment Adjusted EBITDA to consolidated income (loss) before income taxes for the years ended December 31, 2019, 2018 and 2017:

	Year Ended December 31,
	2019			2018			2017
	(in millions)
Segment adjusted EBITDA	$	970.3		$	1,183.9		$	1,102.7
Interest expense	(217.3		)	(216.3		)	(195.6		)
Depreciation and amortization	(536.9		)	(528.8		)	(428.5		)
Impairment charges	(665.0		)	(485.5		)	—
Restructuring and acquisition-related costs	(57.8		)	(78.9		)	(110.7		)
Pension settlement	(9.8		)	—			(3.2		)
Gain (loss) on sale of business	(21.3		)	15.5			—
Gain on bargain purchase of business	10.8			—			—
Gain on settlement of capital lease	—			15.6			—
Acquisition-related fair value inventory adjustment	—			—			(24.9		)
Impact of change in accounting principle	—			—			3.7
Debt refinancing and redemption costs	(8.4		)	(19.4		)	(3.5		)
Other	2.4			—			—
Income (loss) before income taxes	$	(533.0	)	$	(113.9	)	$	340.0

Schedule of Disclosure on Geographic Areas, Revenue and Long-Lived Assets by Country [Table Text Block]

Financial information relating to our operations by geographic area is presented in the following table. Net sales are attributed to countries based upon location of production. Long-lived assets exclude deferred income taxes.

	December 31,
	2019		2018		2017
	(in millions)
Net sales
United States	$	2,894.0	$	3,293.2	$	2,742.7
Mexico	2,353.1		2,547.1		2,456.1
South America	105.3		129.7		133.2
China	315.4		373.4		318.6
All other Asia	255.8		304.9		193.9
Europe	607.3		622.1		421.5
Total net sales	$	6,530.9	$	7,270.4	$	6,266.0
Long-lived assets
United States	$	2,805.8	$	3,612.3	$	4,253.8
Mexico	1,117.4		1,117.9		993.8
South America	61.9		70.6		61.4
China	191.4		177.6		180.9
All other Asia	106.8		101.0		103.4
Europe	439.4		356.0		307.4
Total long-lived assets	$	4,722.7	$	5,435.4	$	5,900.7