Segment and Related Information, Sales By Product Category (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013
Revenue from External Customer [Line Items]
Total net sales	$ 543.5	$ 254.2	$ 1,209.0	$ 761.5
Paper PCC [Member]
Revenue from External Customer [Line Items]
Total net sales	113.4	119.3	341.3	357.9
Specialty PCC [Member]
Revenue from External Customer [Line Items]
Total net sales	16.5	16.6	50.7	50.8
Talc [Member]
Revenue from External Customer [Line Items]
Total net sales	13.8	12.8	41.7	38.2
Ground Calcium Carbonate [Member]
Revenue from External Customer [Line Items]
Total net sales	19.3	18.7	56.8	55.6
Refractory Products [Member]
Revenue from External Customer [Line Items]
Total net sales	69.7	66.3	201.4	195.9
Metallurgical Products [Member]
Revenue from External Customer [Line Items]
Total net sales	20.7	20.5	65.4	63.1
Metalcasting [Member]
Revenue from External Customer [Line Items]
Total net sales	70.0	0	109.4	0
Household, Personal Care and Specialty Products [Member]
Revenue from External Customer [Line Items]
Total net sales	42.8	0	66.2	0
Basic Minerals and Other Products [Member]
Revenue from External Customer [Line Items]
Total net sales	22.8	0	35.8	0
Environmental Products [Member]
Revenue from External Customer [Line Items]
Total net sales	34.5	0	51.8	0
Building Materials and Other Products [Member]
Revenue from External Customer [Line Items]
Total net sales	34.6	0	54.5	0
Energy Services [Member]
Revenue from External Customer [Line Items]
Total net sales	$ 85.4	$ 0	$ 134.0	$ 0