Significant Accounting Policies - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Accounts Receivable, Net, Current	$ 438.0	$ 454.6
Other Assets, Noncurrent	34.9	49.1
Long-term Debt, Excluding Current Maturities	635.0	579.4
Short-term Investments	11.7	9.7
Foreign Currency Transaction Loss, before Tax	34.5	71.5
Foreign Currency Transaction Gain (Loss), before Tax	$ 5.6	$ 0.3	$ 9.9
Percent Inactive in US Pension Plan		95.00%
Updated Amortization Period of Actuarial Gain on U.S. Pension Plan		15 years 6 months
Amortization Period of Actuarial Gain in U.S. Pension Plan		10 years 1 month 6 days
Pension Expense		$ 5.7
Pension Expense Net of Tax		$ 3.6
Earnings per share effect of change in amortization period of actuarial gains and losses		$ 0.04
Minimum [Member]
Property, Plant and Equipment [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Maximum [Member]
Property, Plant and Equipment [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years
Building [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years
Software and Software Development Costs [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Accounting Standards Update - originally reported [Member]
Property, Plant and Equipment [Line Items]
Other Assets, Noncurrent		$ 50.3
Long-term Debt, Excluding Current Maturities		580.6
Accounting Standards Update 2015-03 [Member]
Property, Plant and Equipment [Line Items]
Other Assets, Noncurrent		49.1
Long-term Debt, Excluding Current Maturities		579.4
Adjustments for New Accounting Pronouncement [Member]
Property, Plant and Equipment [Line Items]
Other Assets, Noncurrent		1.2
Long-term Debt, Excluding Current Maturities		1.2
Contracts Accounted for under Percentage of Completion [Member]
Property, Plant and Equipment [Line Items]
Revenues	$ 68.0	66.0	$ 50.0
Timken Gears and Services [Member] | Contracts Accounted for under Percentage of Completion [Member]
Property, Plant and Equipment [Line Items]
Accounts Receivable, Net, Current	$ 63.5	$ 62.5