Restructuring Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Annualized savings from reduction of workforce	$ 29.0
Reduction in workforce	10.00%
Restructuring and Other Charges [Abstract]
Impairment of assets	$ 34.2	$ 23.7	$ 0.0
Severance and other employee costs	11.0	18.8
Total restructuring and other charges	45.2	43.2	$ 0.0
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning of period	14.6
Additional provisions	11.0	18.8
Cash payments	(14.0)
Other adjustments	(3.7)
Restructuring liability, end of period	7.9	14.6
Specialty Minerals [Member]
Restructuring and Other Charges [Abstract]
Severance and other employee costs	0.0	3.0
Restructuring Reserve [Roll Forward]
Additional provisions	0.0	3.0
Refractories [Member]
Restructuring and Other Charges [Abstract]
Severance and other employee costs	2.0	0.7
Restructuring Reserve [Roll Forward]
Additional provisions	2.0	0.7
Performance Materials [Member]
Restructuring and Other Charges [Abstract]
Impairment of assets	0.0	0.4
Severance and other employee costs	0.0	5.6
Other	0.0	0.7
Restructuring Reserve [Roll Forward]
Additional provisions	0.0	5.6
Construction Technologies [Member]
Restructuring and Other Charges [Abstract]
Impairment of assets	0.0	11.7
Severance and other employee costs	0.0	5.8
Restructuring Reserve [Roll Forward]
Additional provisions	0.0	5.8
Energy Services [Member]
Restructuring and Other Charges [Abstract]
Impairment of assets	33.0	11.6
Severance and other employee costs	9.0	3.7
Restructuring Reserve [Roll Forward]
Additional provisions	9.0	3.7
Corporate [Member]
Restructuring and Other Charges [Abstract]
Impairment of assets	$ 1.2	$ 0.0