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

3 Months Ended

Mar. 31, 2018

Effect of Increase in Cost of Insurance and Claims

The following table summarizes the effect of the increase (decrease) in the cost of insurance claims resulting from unfavorable (favorable) 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 thirteen-week periods ended March 31, 2018 and April 1, 2017 (in thousands, except per share amounts):    

	Thirteen Weeks Ended
	March 31, 2018		April 1, 2017
Operating income	$	2,558	$	(104	)
Net income attributable to Landstar System, Inc. and subsidiary		1,931		(64	)
Earnings per share attributable to Landstar System, Inc. and subsidiary	$	0.05		—
Diluted earnings per share attributable to Landstar System, Inc. and subsidiary	$	0.05		—