Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 1,295.2	$ 1,618.3	$ 1,658.1
Cost of sales	1,126.6	1,358.0	1,386.6
Gross profit	168.6	260.3	271.5
Selling, general and administrative expenses	152.9	177.2	176.1
Gain on sale of assets	0.0	0.0	(1.9)
Operating income	15.7	83.1	97.3
Other components of pension income and other postretirement benefits expense, net	7.3	5.6	8.8
Interest expense, net	(30.3)	(33.8)	(34.3)
(Loss) income before income taxes	(7.3)	54.9	71.8
Income tax benefit (expense)	2.5	(15.2)	(16.6)
Net (loss) income	(4.8)	39.7	55.2
Net loss (income) attributable to noncontrolling interest	0.3	(1.1)	(1.6)
Net (loss) income attributable to ParkOhio common shareholders	$ (4.5)	$ 38.6	$ 53.6
(Loss) earnings per common share attributable to ParkOhio common shareholders:
Basic (in dollars per share)	$ (0.37)	$ 3.16	$ 4.37
Diluted (in dollars per share)	$ (0.37)	$ 3.12	$ 4.28
Weighted-average shares used to compute (loss) earnings per share:
Basic (in shares)	12,061,419	12,225,481	12,255,490
Diluted (in shares)	12,061,419	12,379,089	12,508,513