Fair Value (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

The following tables present the fair value hierarchy for those assets and liabilities on the Consolidated Balance Sheets measured at fair value on a recurring basis as of December 31, 2017 and 2016:

	December 31, 2017
	Total		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	108.5	$	107.3	$	1.2	$	—
Cash and cash equivalents measured at net asset value	13.1
Restricted cash	3.8		3.8		—		—
Short-term investments	16.2		—		16.2		—
Short-term investments measured at net asset value	0.2
Foreign currency hedges	1.3		—		1.3		—
Total Assets	$	143.1	$	111.1	$	18.7	$	—
Liabilities:
Foreign currency hedges	$	7.1	$	—	$	7.1	$	—
Total Liabilities	$	7.1	$	—	$	7.1	$	—

	December 31, 2016
	Total		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	129.6	$	125.0	$	4.6	$	—
Cash and cash equivalents measured at net asset value	19.2
Restricted cash	2.7		2.7		—		—
Short-term investments	9.4		—		9.4		—
Short-term investments measured at net asset value	2.3
Foreign currency hedges	9.9		—		9.9		—
Total Assets	$	173.1	$	127.7	$	23.9	$	—
Liabilities:
Foreign currency hedges	$	2.1	$	—	$	2.1	$	—
Total Liabilities	$	2.1	$	—	$	2.1	$	—

Fair Value Measurements, Nonrecurring [Table Text Block]

The following table presents those assets measured at fair value on a nonrecurring basis during the year ended December 31, 2016, using Level 3 inputs:

	Carrying Value		Fair Value Adjustment			Fair Value
Long-lived assets held for sale:
Land	$	0.2	$	(0.2	)	$	—
Total long-lived assets held for sale	$	0.2	$	(0.2	)	$	—
Long-lived assets held and used:
Altavista bearing plant	$	5.6	$	(3.1	)	$	2.5
Equipment at Benoni bearing plant	0.5		(0.5		)	—
Total long-lived assets held and used	$	6.1	$	(3.6	)	$	2.5

The following table presents those assets measured at fair value on a nonrecurring basis during the year ended December 31, 2015, using Level 3 inputs:

	Carrying Value		Fair Value Adjustment			Fair Value
Long-lived assets held for sale:
Repair business	$	5.8	$	(3.0	)	$	2.8
Total long-lived assets held for sale	$	5.8	$	(3.0	)	$	2.8
Long-lived assets held and used:
Fixed assets	$	0.8	$	(0.3	)	$	0.5
Total long-lived assets held and used	$	0.8	$	(0.3	)	$	0.5