Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Disaggregation of Revenue [Abstract]
Total net sales	$ 417.5	$ 437.7
Metalcasting [Member]
Disaggregation of Revenue [Abstract]
Total net sales	61.7	73.2
Household, Personal Care & Specialty Products [Member]
Disaggregation of Revenue [Abstract]
Total net sales	96.2	94.8
Environmental Products [Member]
Disaggregation of Revenue [Abstract]
Total net sales	11.5	15.9
Building Materials [Member]
Disaggregation of Revenue [Abstract]
Total net sales	16.8	15.3
Paper PCC [Member]
Disaggregation of Revenue [Abstract]
Total net sales	85.1	91.5
Specialty PCC [Member]
Disaggregation of Revenue [Abstract]
Total net sales	17.5	18.1
Ground Calcium Carbonate [Member]
Disaggregation of Revenue [Abstract]
Total net sales	22.6	22.3
Talc [Member]
Disaggregation of Revenue [Abstract]
Total net sales	11.9	12.5
Refractory Products [Member]
Disaggregation of Revenue [Abstract]
Total net sales	55.8	62.0
Metallurgical Products [Member]
Disaggregation of Revenue [Abstract]
Total net sales	13.2	11.8
Performance Materials [Member]
Disaggregation of Revenue [Abstract]
Total net sales	186.2	199.2
Performance Materials [Member] | Metalcasting [Member]
Disaggregation of Revenue [Abstract]
Total net sales	61.7	73.2
Performance Materials [Member] | Household, Personal Care & Specialty Products [Member]
Disaggregation of Revenue [Abstract]
Total net sales	96.2	94.8
Performance Materials [Member] | Environmental Products [Member]
Disaggregation of Revenue [Abstract]
Total net sales	11.5	15.9
Performance Materials [Member] | Building Materials [Member]
Disaggregation of Revenue [Abstract]
Total net sales	16.8	15.3
Specialty Minerals [Member]
Disaggregation of Revenue [Abstract]
Total net sales	137.1	144.4
Specialty Minerals [Member] | Paper PCC [Member]
Disaggregation of Revenue [Abstract]
Total net sales	85.1	91.5
Specialty Minerals [Member] | Specialty PCC [Member]
Disaggregation of Revenue [Abstract]
Total net sales	17.5	18.1
Specialty Minerals [Member] | Ground Calcium Carbonate [Member]
Disaggregation of Revenue [Abstract]
Total net sales	22.6	22.3
Specialty Minerals [Member] | Talc [Member]
Disaggregation of Revenue [Abstract]
Total net sales	11.9	12.5
Refractories [Member]
Disaggregation of Revenue [Abstract]
Total net sales	69.0	73.8
Refractories [Member] | Refractory Products [Member]
Disaggregation of Revenue [Abstract]
Total net sales	55.8	62.0
Refractories [Member] | Metallurgical Products [Member]
Disaggregation of Revenue [Abstract]
Total net sales	13.2	11.8
Energy Services [Member]
Disaggregation of Revenue [Abstract]
Total net sales	$ 25.2	$ 20.3