Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Revenue	$ 4,132,981	$ 4,084,577	$ 4,615,144
Investment income	3,399	5,041	3,816
Costs and expenses:
Purchased transportation	3,192,850	3,127,474	3,569,961
Commissions to agents	340,780	342,226	378,002
Other operating costs, net of gains/losses on asset sales/dispositions	30,463	37,274	31,803
Insurance and claims	87,773	80,319	75,677
Selling, general and administrative	167,633	158,953	188,212
Depreciation and amortization	45,855	44,468	43,570
Impairment of intangible and other assets	2,582
Commission program termination costs	15,494
Total costs and expenses	3,883,430	3,790,714	4,287,225
Operating income	252,950	298,904	331,735
Interest and debt expense	3,953	3,141	3,354
Income before income taxes	248,997	295,763	328,381
Income taxes	56,891	68,060	73,168
Net income	192,106	227,703	255,213
Less: Net loss attributable to noncontrolling interest		(17)	(68)
Net income attributable to Landstar System, Inc. and subsidiary	$ 192,106	$ 227,720	$ 255,281
Earnings per common share attributable to Landstar System, Inc. and subsidiary	$ 4.98	$ 5.72	$ 6.19
Diluted earnings per share attributable to Landstar System, Inc. and subsidiary	$ 4.98	$ 5.72	$ 6.18
Average number of shares outstanding:
Earnings per common share	38,602,000	39,786,000	41,273,000
Diluted earnings per share	38,602,000	39,786,000	41,310,000
Dividends per common share	$ 2.79	$ 2.70	$ 0.63