Incentive Plans (Tables)

3 Months Ended

Mar. 31, 2021

Share-based Payment Arrangement [Abstract]

Share-Based Plans, Amounts Recognized in the Financial Statements

Amounts recognized in the financial statements with respect to share-based plans are shown in the following table:

	Three Months Ended March 31,
(Thousands of dollars)	2021		2020
Compensation charged against income before tax benefit	$	8,196	553
Related income tax (expense) benefit recognized in income	1,165		(592)