Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net sales	$ 432.2	$ 350.9		$ 837.9	$ 694.7
Cost of sales	359.1	291.1		699.7	579.9
Gross profit	73.1	59.8		138.2	114.8
Selling, general and administrative expenses	47.6	37.0		90.4	74.7
Litigation settlement gain	0.0	0.0	$ (3.3)	0.0	(3.3)
Operating income (loss)	25.5	22.8		47.8	43.4
Other components of pension income and other postretirement benefits expense, net	2.1	1.5		4.4	3.1
Gain on sale of assets	1.9	0.0		1.9	0.0
Interest expense	(8.8)	(7.9)		(17.2)	(15.3)
Loss on extinguishment of debt	0.0	(11.0)		0.0	(11.0)
Income (loss) before income taxes	20.7	5.4		36.9	20.2
Income tax expense	(5.5)	(2.1)		(11.3)	(6.8)
Net income (loss)	15.2	3.3		25.6	13.4
Net income attributable to noncontrolling interests	(0.2)	(0.2)		(0.6)	(0.5)
Net income attributable to Park-Ohio Industries Inc. common shareholder	$ 15.0	$ 3.1		$ 25.0	$ 12.9