Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net income	$ 52.7	$ 151.3	$ 94.4	$ 240.8
Other comprehensive income (loss)
Defined benefit plans, net of tax (a)	1.1	12.2	1.8	13.5
Foreign currency translation adjustments	4.9	(81.0)	2.4	(43.1)
Changes in cash flow hedges, net of tax (b)	(15.8)	(7.9)	(18.3)	7.2
Other comprehensive loss	(9.8)	(76.7)	(14.1)	(22.4)
Comprehensive income	42.9	74.6	80.3	218.4
Net income attributable to noncontrolling interests	(0.2)	(0.2)	(0.3)	(0.3)
Comprehensive income attributable to AAM	$ 42.7	$ 74.4	$ 80.0	$ 218.1