Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2020

Earnings Per Share [Abstract]

Reconciliation of Basic and Diluted Earnings Per Share Computations

The following table provides a reconciliation of basic and diluted earnings per share computations for the three and six months ended June 30, 2020 and 2019:

	Three Months Ended June 30,				Six Months Ended June 30,
(Millions of dollars, except share and per share amounts)	2020		2019		2020		2019
Earnings per common share:
Net income per share - basic
Net income attributable to common stockholders	$	168.9	$	32.7	$	258.2	$	38.0
Weighted average common shares outstanding (in thousands)	29,181		32,112		29,708		32,159
Earnings per common share	$	5.79	$	1.02	$	8.69	$	1.18

Earnings per common share - assuming dilution:
Net income per share - diluted
Net income attributable to common stockholders	$	168.9	$	32.7	$	258.2	$	38.0
Weighted average common shares outstanding (in thousands)	29,181		32,112		29,708		32,159
Common equivalent shares:
Dilutive share-based awards	314		216		310		213
Weighted average common shares outstanding - assuming dilution (in thousands)	29,495		32,328		30,018		32,372
Earnings per common share assuming dilution	$	5.73	$	1.01	$	8.60	$	1.18