Condensed Consolidated Statement of Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2019		15,706,398
Beginning balance at Dec. 31, 2019	$ 349.6	$ 15.7	$ 129.8	$ 298.2	$ (71.1)	$ (37.0)	$ 14.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	(14.8)			1.2		(16.1)	0.1
Stock-based compensation expense	1.4		1.4
Stock-based compensation activity (in shares)		1,000
Dividends	(1.6)			(1.6)
Purchases of treasury stock (180,827 shares)	(2.9)				(2.9)
Payments of withholding taxes on share awards	(0.1)				(0.1)
Ending balance (in shares) at Mar. 31, 2020		15,707,398
Ending balance at Mar. 31, 2020	$ 331.6	$ 15.7	131.2	297.8	(74.1)	(53.1)	14.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends per common share (in dollars per share)	$ 0.125
Beginning balance (in shares) at Dec. 31, 2020		16,148,791
Beginning balance at Dec. 31, 2020	$ 357.9	$ 16.1	135.5	290.5	(79.8)	(18.1)	13.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	1.3			5.5		(4.1)	(0.1)
Stock-based compensation expense	1.6		1.6
Stock-based compensation activity (in shares)		(6,667)
Dividends	(1.6)			(1.6)
Increase in Park-Ohio ownership interest	0.0		1.1				(1.1)
Payments of withholding taxes on share awards	(0.1)				(0.1)
Ending balance (in shares) at Mar. 31, 2021		16,142,124
Ending balance at Mar. 31, 2021	$ 359.1	$ 16.1	$ 138.2	$ 294.4	$ (79.9)	$ (22.2)	$ 12.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends per common share (in dollars per share)	$ 0.125