Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Components of Basic and Diluted Earnings Per Share

The components of basic and diluted earnings per share for the quarter and nine months ended September 30, 2017 and 2016 are as follows: 

	Quarter Ended    September 30,		Nine Months Ended   September 30,
	2017	2016	2017	2016
	(Thousands of dollars)
Weighted average outstanding shares of common stock, basic	15,799	15,683	15,750	15,655
Dilutive effect of unvested restricted stock units	—	—	—	—
Weighted average outstanding shares of common stock, diluted (1)	15,799	15,683	15,750	15,655

(1) For the three months ended September 30, 2017 and 2016, 0 and 52,126 unvested restricted stock units were excluded from the weighted average outstanding shares of common stock, diluted, respectively as they were anti-dilutive to earnings per share. For the nine months ended September 30, 2017 and 2016, 0 and 22,221 unvested restricted stock units were excluded from the weighted average outstanding shares of common stock, diluted, respectively as they were anti-dilutive to earnings per share.