Segment and Related Information, Sales By Product Category (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Revenue from External Customer [Line Items]
Total net sales	$ 451.0	$ 543.5	$ 1,367.6	$ 1,209.0
Paper PCC [Member]
Revenue from External Customer [Line Items]
Total net sales	106.1	113.4	315.9	341.3
Specialty PCC [Member]
Revenue from External Customer [Line Items]
Total net sales	15.8	16.5	48.5	50.7
Talc [Member]
Revenue from External Customer [Line Items]
Total net sales	13.9	13.8	41.9	41.7
Ground Calcium Carbonate [Member]
Revenue from External Customer [Line Items]
Total net sales	20.7	19.3	60.6	56.8
Refractory Products [Member]
Revenue from External Customer [Line Items]
Total net sales	60.5	69.7	178.3	201.4
Metallurgical Products [Member]
Revenue from External Customer [Line Items]
Total net sales	16.9	20.7	49.4	65.4
Metalcasting [Member]
Revenue from External Customer [Line Items]
Total net sales	63.4	70.0	200.3	109.4
Household, Personal Care and Specialty Products [Member]
Revenue from External Customer [Line Items]
Total net sales	43.0	42.8	126.6	66.2
Basic Minerals and Other Products [Member]
Revenue from External Customer [Line Items]
Total net sales	20.1	22.8	56.6	35.8
Environmental Products [Member]
Revenue from External Customer [Line Items]
Total net sales	21.7	34.5	55.2	51.8
Building Materials and Other Products [Member]
Revenue from External Customer [Line Items]
Total net sales	28.0	34.6	85.5	54.5
Energy Services [Member]
Revenue from External Customer [Line Items]
Total net sales	$ 40.9	$ 85.4	$ 148.8	$ 134.0