Segment and Related Information, Sales By Product Category (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 29, 2015	Mar. 30, 2014
Revenue from External Customer [Line Items]
Total net sales	$ 453.3	$ 244.4
Paper PCC [Member]
Revenue from External Customer [Line Items]
Total net sales	105.2	112.8
Specialty PCC [Member]
Revenue from External Customer [Line Items]
Total net sales	16.5	16.3
Talc [Member]
Revenue from External Customer [Line Items]
Total net sales	13.8	13.4
Ground Calcium Carbonate [Member]
Revenue from External Customer [Line Items]
Total net sales	18.5	17.2
Refractory Products [Member]
Revenue from External Customer [Line Items]
Total net sales	58.3	63.1
Metallurgical Products [Member]
Revenue from External Customer [Line Items]
Total net sales	15.6	21.6
Metalcasting [Member]
Revenue from External Customer [Line Items]
Total net sales	65.2	0
Household, Personal Care and Specialty Products [Member]
Revenue from External Customer [Line Items]
Total net sales	41.8	0
Basic Minerals and Other Products [Member]
Revenue from External Customer [Line Items]
Total net sales	20.9	0
Environmental Products [Member]
Revenue from External Customer [Line Items]
Total net sales	11.4	0
Building Materials and Other Products [Member]
Revenue from External Customer [Line Items]
Total net sales	27.5	0
Energy Services [Member]
Revenue from External Customer [Line Items]
Total net sales	$ 58.6	$ 0