Segment and Related Information, Sales By Product Category (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013
Revenue from External Customer [Line Items]
Total net sales	$ 421.1	$ 256.8	$ 665.5	$ 507.4
Paper PCC [Member]
Revenue from External Customer [Line Items]
Total net sales	115.2	118.3	227.9	238.8
Specialty PCC [Member]
Revenue from External Customer [Line Items]
Total net sales	17.9	17.3	34.2	34.2
Talc [Member]
Revenue from External Customer [Line Items]
Total net sales	14.4	13.0	27.9	25.4
Ground Calcium Carbonate [Member]
Revenue from External Customer [Line Items]
Total net sales	20.4	19.7	37.5	36.9
Refractory Products [Member]
Revenue from External Customer [Line Items]
Total net sales	68.5	67.2	131.7	129.6
Metallurgical Products [Member]
Revenue from External Customer [Line Items]
Total net sales	23.1	21.3	44.7	42.5
Metalcasting [Member]
Revenue from External Customer [Line Items]
Total net sales	39.4	0	39.4	0
Household, Personal Care and Specialty Products [Member]
Revenue from External Customer [Line Items]
Total net sales	23.4	0	23.4	0
Basic Minerals and Other Products [Member]
Revenue from External Customer [Line Items]
Total net sales	13.0	0	13.0	0
Environmental Products [Member]
Revenue from External Customer [Line Items]
Total net sales	17.3	0	17.3	0
Building Materials and Other Products [Member]
Revenue from External Customer [Line Items]
Total net sales	19.9	0	19.9	0
Energy Services [Member]
Revenue from External Customer [Line Items]
Total net sales	$ 48.6	$ 0	$ 48.6	$ 0