Fair Value (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2016	Jun. 30, 2016	Jun. 30, 2017	Dec. 31, 2016
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents			$ 16.1	$ 19.2
Restricted cash			2.8	2.7
Short-term investments			4.8	2.3
Foreign currency hedges		$ 1.2		9.9
Foreign currency hedges		5.7		2.1
Assets Held-for-sale, Not Part of Disposal Group, Other		0.2
Impairment of Long-Lived Assets to be Disposed of		(0.2)
Assets Held-for-sale, Long Lived, Fair Value Disclosure		0.0
Long Lived Fixed Assets Held and Used at Carrying Value - Fair Value Disclosure		5.7
Impairment of Long-Lived Assets Held-for-use		(2.4)
Long Lived Assets Held and Used Fair Value		3.3
Land [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Assets Held-for-sale, Not Part of Disposal Group, Other	$ 0.2	0.2
Impairment of Long-Lived Assets to be Disposed of		(0.2)
Assets Held-for-sale, Long Lived, Fair Value Disclosure	0.0	0.0
Impairment of Long-Lived Assets Held-for-use	(0.2)
Altavista Bearing Plant [Member] [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Assets Held-for-sale, Long Lived, Fair Value Disclosure	3.3
Long Lived Fixed Assets Held and Used at Carrying Value - Fair Value Disclosure	5.7	5.7
Impairment of Long-Lived Assets Held-for-use	$ (2.4)	(2.4)
Long Lived Assets Held and Used Fair Value		$ 3.3
Level 1 [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents			0.0	0.0
Level 2 [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents			0.0
Short-term investments			0.0	0.0
Level 3 [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents			0.0
Fair Value, Measurements, Recurring [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents			429.0	129.6
Restricted cash			2.8	2.7
Short-term investments			14.5	9.4
Foreign currency hedges			1.2	9.9
Total Assets			468.4	173.1
Foreign currency hedges			5.7	2.1
Total Liabilities			5.7	2.1
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents			425.3	125.0
Restricted cash			2.8	2.7
Short-term investments			0.0	0.0
Foreign currency hedges			0.0	0.0
Total Assets			428.1	127.7
Foreign currency hedges			0.0	0.0
Total Liabilities			0.0	0.0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents			3.7	4.6
Restricted cash			0.0
Restricted Cash and Cash Equivalents				0.0
Short-term investments			14.5	9.4
Foreign currency hedges			1.2	9.9
Total Assets			19.4	23.9
Foreign currency hedges			5.7	2.1
Total Liabilities			5.7	2.1
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents			0.0	0.0
Restricted cash			0.0	0.0
Short-term investments			0.0	0.0
Foreign currency hedges			0.0	0.0
Total Assets			0.0	0.0
Foreign currency hedges			0.0	0.0
Total Liabilities			$ 0.0	$ 0.0