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) Income	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)
Purchase of treasury stock	(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
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)	(10.4)
Ending balance (in shares) at Sep. 30, 2020		16,148,791
Ending balance at Sep. 30, 2020	334.0	$ 16.2	133.6	286.5	(79.0)	(36.9)	13.6
Beginning balance (in shares) at Mar. 31, 2020		15,707,398
Beginning 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]
Other comprehensive income (loss)	(13.7)			(16.6)		3.3	(0.4)
Stock-based compensation expense	1.3		1.3
Stock-based compensation activity (in shares)		283,993
Stock-based compensation activity	0.0	$ 0.3	(0.3)
Purchase of treasury stock	(2.4)				(2.4)
Payments of withholding taxes on share awards	(0.6)				(0.6)
Ending balance (in shares) at Jun. 30, 2020		15,991,391
Ending balance at Jun. 30, 2020	316.2	$ 16.0	132.2	281.2	(77.1)	(49.8)	13.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	18.1			5.3		12.9	(0.1)
Stock-based compensation expense	1.6		1.6
Stock-based compensation activity (in shares)		157,400
Stock-based compensation activity	0.0	$ 0.2	(0.2)
Purchase of treasury stock	(1.9)				(1.9)
Ending balance (in shares) at Sep. 30, 2020		16,148,791
Ending balance at Sep. 30, 2020	334.0	$ 16.2	133.6	286.5	(79.0)	(36.9)	13.6
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
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)	(15.1)
Ending balance (in shares) at Sep. 30, 2021		16,319,370
Ending balance at Sep. 30, 2021	337.7	$ 16.3	141.1	278.8	(84.9)	(25.7)	12.1
Beginning balance (in shares) at Mar. 31, 2021		16,142,124
Beginning 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]
Other comprehensive income (loss)	(3.7)			(5.3)		1.8	(0.2)
Stock-based compensation expense	1.4		1.4
Stock-based compensation activity (in shares)		174,746
Stock-based compensation activity	0.0	$ 0.2	(0.2)
Dividends	(1.5)			(1.5)
Payments of withholding taxes on share awards	(2.1)				(2.1)
Ending balance (in shares) at Jun. 30, 2021		16,316,870
Ending balance at Jun. 30, 2021	353.2	$ 16.3	139.4	287.6	(82.0)	(20.4)	12.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	(12.7)			(7.2)	0.0	(5.3)	(0.2)
Stock-based compensation expense	1.7		1.7
Stock-based compensation activity (in shares)		2,500
Dividends	(1.6)			(1.6)
Purchase of treasury stock	(2.5)				(2.5)
Payments of withholding taxes on share awards	(0.4)				(0.4)
Ending balance (in shares) at Sep. 30, 2021		16,319,370
Ending balance at Sep. 30, 2021	$ 337.7	$ 16.3	$ 141.1	$ 278.8	$ (84.9)	$ (25.7)	$ 12.1