Quarterly Financial Data (Details)		3 Months Ended									12 Months Ended
	Apr. 30, 2015 USD ($)	Dec. 31, 2017 USD ($) $ / shares	Sep. 30, 2017 USD ($) $ / shares	Jun. 30, 2017 USD ($) $ / shares	Mar. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares	Sep. 30, 2016 USD ($) $ / shares	Jun. 30, 2016 USD ($) $ / shares	Mar. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($)
Quarterly Financial Data
Net sales		$ 778,000,000.0	$ 771,400,000	$ 750,600,000	$ 703,800,000	$ 654,800,000	$ 657,400,000	$ 673,600,000	$ 684,000,000.0		$ 3,003,800,000	$ 2,669,800,000	$ 2,872,300,000	$ 20,600,000
Gross Profit		211,100,000	217,000,000.0	201,800,000	180,500,000	131,200,000	169,700,000	184,500,000	183,100,000		810,400,000	668,500,000	819,500,000
Selling, General and Administrative Expense		144,000,000.0	134,000,000.0	123,800,000	119,600,000	139,400,000	107,200,000	108,000,000.0	116,100,000		521,400,000	470,700,000	457,700,000
Impairment and restructuring charges		500,000	1,300,000	800,000	1,700,000	3,000,000.0	5,300,000	2,900,000	10,500,000		4,300,000	21,700,000	14,700,000
Gain (Loss) on Disposition of Business	$ (300,000)									$ (29,000,000.0)	0	0	(28,700,000)
Pension Settlement Charges											0	1,600,000	119,900,000
Net Income		28,100,000	54,100,000	82,000,000.0	38,100,000	(6,900,000)	34,000,000.0	48,200,000	65,800,000		202,300,000	141,100,000	191,400,000
Net (loss) income attributable to noncontrolling interest		(1,100,000)	600,000	(500,000)	(100,000)	0	400,000	0	(100,000)		(1,100,000)	300,000	2,800,000
Net Income (Loss) Attributable to The Timken Company		$ 29,200,000	$ 53,500,000	$ 82,500,000	$ 38,200,000	$ (6,900,000)	$ 33,600,000	$ 48,200,000	$ 65,900,000		$ 203,400,000	$ 140,800,000	$ 188,600,000
Earnings Per Share, Basic | $ / shares		$ 0.38	$ 0.69	$ 1.06	$ 0.49	$ (0.09)	$ 0.43	$ 0.61	$ 0.83		$ 2.62	$ 1.79	$ 2.23
Net income per share - Diluted:
Earnings Per Share, Diluted | $ / shares		0.37	0.68	1.04	0.48	(0.09)	0.43	0.61	0.82		2.58	1.78	2.21
Dividends per share (in dollars per share) | $ / shares		$ 0.27	$ 0.27	$ 0.27	$ 0.26	$ 0.26	$ 0.26	$ 0.26	$ 0.26		$ 1.07	$ 1.04	$ 1.03
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions				$ 34,000,000							$ 5,200,000	$ 7,800,000	$ 4,000,000.0
Other Tax Expense (Benefit)											35,300,000	0	$ 0
Fixed Asset Write-Off										9,700,000
After Tax Amount of Fixed Asset Write Off										6,100,000
Earnings per share effect of fixed asset write-off										$ 0.07
Number of U.S. Timken retirees													8,400
Quarterly Financial Data (Textual) [Abstract]
Severance expense and related benefit costs							$ 3,300,000		$ 7,700,000		3,500,000	15,300,000	$ 7,700,000
Impairment charges											100,000	3,900,000	3,300,000
Exit costs							800,000		200,000		700,000	2,500,000	3,700,000
Continued Dumping And Subsidy Offset Act Receipt Net Of Expenses						$ 6,000,000.0		$ 6,100,000	47,700,000		0	59,600,000	0
Other Asset Impairment Charges							$ 1,200,000		$ 2,600,000
Impairment charges											100,000	3,900,000	3,300,000
Restatement Adjustment [Member]
Quarterly Financial Data
Gross Profit						32,900,000					5,600,000	(26,300,000)	25,600,000
Selling, General and Administrative Expense						27,400,000					3,400,000	20,700,000	(36,600,000)
Pension Settlement Charges											(17,300,000)	(26,500,000)	(345,100,000)
Net Income						$ 31,000,000.0					13,000,000.0	(11,800,000)	259,400,000
Net Income (Loss) Attributable to The Timken Company											$ 13,000,000.0	$ (11,800,000)	$ 259,400,000
Earnings Per Share, Basic | $ / shares											$ 0.17	$ (0.15)	$ 3.07
Net income per share - Basic:
Basic earnings per share (in dollars per share) | $ / shares						$ 0.40
Net income per share - Diluted:
Earnings Per Share, Diluted | $ / shares											$ 0.17	$ (0.14)	$ 3.05
Cost of Sales [Member]
Net income per share - Diluted:
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit		$ 2,200,000				$ 35,600,000
Selling, General and Administrative Expenses [Member]
Net income per share - Diluted:
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit		$ 11,500,000				$ 29,800,000