Restructuring and Other Items, net (Tables)

12 Months Ended

Dec. 31, 2018

Restructuring and Other Items, net [Abstract]

Schedule of restructuring charges

The following table outlines the amount of restructuring charges recorded within the Consolidated Statements of Income, and the segments they relate to:

Restructuring and Other Items, net	Year Ended December 31,
(millions of dollars)	2018		2017			2016
Impairment of assets
Specialty Minerals	$	0.7	$	5.3		$	—
Energy Services		—		—			18.5
Corporate		—		—			—
Total impairment of assets charges	$	0.7	$	5.3		$	18.5
Severance and other employee costs
Specialty Minerals	$	—	$	5.0		$	—
Energy Services		1.8		1.7			12.7
Corporate		—		4.1			—
Total severance and other employee costs	$	1.8	$	10.8		$	12.7
Other
Refractories	$	—	$	—		$	(2.0	)
Energy Services		—		(1.1	)		(0.9	)
Total restructuring and other items, net	$	2.5	$	15.0		$	28.3

Reconciliation of Restructuring Liability

The following table is a reconciliation of our restructuring liability balance:

(millions of dollars)
Restructuring liability, December 31, 2017	$	8.1
Additional provisions		1.7
Cash payments		(6.6	)
Other		(0.7	)
Restructuring liability, December 31, 2018	$	2.5