Revenue from Contracts with Customers (Tables)

12 Months Ended

Dec. 31, 2018

Revenue from Contracts with Customers [Abstract]

Disaggregation of Revenue

The following table disaggregates our revenue by major source (product line) for the years ended December 31, 2018, 2017 and 2016:

	Year Ended December 31,
(millions of dollars)	2018		2017		2016
Net Sales
Metalcasting	$	328.9	$	294.3	$	258.0
Household, Personal Care and Specialty Products		248.8		169.6		171.2
Environmental Products		80.3		67.7		78.9
Building Materials		70.4		78.2		74.1
Basic Minerals		99.7		125.0		103.9
Performance Materials		828.1		734.8		686.1
Paper PCC		378.5		377.7		387.9
Specialty PCC		66.9		66.0		64.3
Ground Calcium Carbonate		91.0		87.3		83.6
Talc		52.9		53.8		55.7
Specialty Minerals		589.3		584.8		591.5
Refractory Products		261.1		226.9		219.0
Metallurgical Products		50.8		52.5		55.5
Refractories		311.9		279.4		274.5
Energy Services		78.3		76.7		85.9
Total	$	1,807.6	$	1,675.7	$	1,638.0