Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Net sales	$ 1,412.9	$ 1,276.9	$ 1,463.8
Cost of sales	1,178.3	1,073.9	1,228.6
Gross profit	234.6	203.0	235.2
Selling, general and administrative expenses	147.7	129.8	135.1
Litigation (settlement gains) judgment costs	(3.3)	0.0	2.2
Asset impairment charge	0.0	4.0	0.0
Operating income	90.2	69.2	97.9
Interest expense	31.5	28.2	27.9
Loss on extinguishment of debt	11.0	0.0	0.0
Income before income taxes	47.7	41.0	70.0
Income tax expense	18.2	8.8	21.3
Net income	29.5	32.2	48.7
Net income attributable to noncontrolling interest	(0.9)	(0.5)	(0.6)
Net income attributable to ParkOhio common shareholders	$ 28.6	$ 31.7	$ 48.1
Earnings per common share attributable to ParkOhio common shareholders:
Basic (in dollars per share)	$ 2.34	$ 2.62	$ 3.94
Diluted (in dollars per share)	$ 2.30	$ 2.58	$ 3.88
Weighted-average shares used to compute earnings per share:
Basic (in shares)	12,211,978	12,126,264	12,215,425
Diluted (in shares)	12,455,941	12,274,452	12,382,951
Cash dividends per common share (in dollars per share)	$ 0.5	$ 0.5	$ 0.5