Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 28.1	$ 54.1	$ 82.0	$ 38.1	$ (6.9)	$ 34.0	$ 48.2	$ 65.8	$ 202.3	$ 141.1	$ 191.4
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments									47.1	(22.8)	(64.8)
Pension and postretirement liability adjustment									(1.8)	1.1	(2.4)
Change in fair value of derivative financial instruments									(3.3)	0.1	1.1
Other comprehensive income (loss), net of tax									42.0	(21.6)	(66.1)
Comprehensive Income, net of tax									244.3	119.5	125.3
Less: comprehensive income attributable to noncontrolling interest									1.3	2.0	0.7
Comprehensive Income Attributable to The Timken Company									$ 243.0	$ 117.5	$ 124.6