Change in Accounting Estimate for Self-Insured Claims (Tables)

6 Months Ended

Jun. 30, 2018

Effect of Increase in Cost of Insurance and Claims

The following table summarizes the effect of the increase in the cost of insurance claims resulting from unfavorable development of prior year self-insured claims estimates on operating income, net income attributable to Landstar System, Inc. and subsidiary and earnings per share attributable to Landstar System, Inc. and subsidiary amounts in the consolidated statements of income for the twenty-six-week and thirteen-week periods ended June 30, 2018 and July 1, 2017 (in thousands, except per share amounts):    

	Twenty Six Weeks Ended				Thirteen Weeks Ended
	June 30, 2018		July 1, 2017		June 30, 2018		July 1, 2017
Operating income	$	8,244	$	203	$	5,686	$	307
Net income attributable to Landstar System, Inc. and subsidiary		6,224		125		4,293		189
Earnings per share attributable to Landstar System, Inc. and subsidiary	$	0.15		—	$	0.10		—
Diluted earnings per share attributable to Landstar System, Inc. and subsidiary	$	0.15		—	$	0.10		—