Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 24, 2016	Sep. 30, 2017	Sep. 24, 2016
Net income attributable to Landstar System, Inc. and subsidiary	$ 42,443	$ 36,278	$ 112,336	$ 97,776
Other comprehensive income:
Unrealized holding gains (losses) on available-for-sale investments, net of tax expense (benefit) of $136, $198, $47 and ($19)	86	(34)	251	363
Foreign currency translation gains (losses)	545	(181)	1,130	656
Other comprehensive income (loss)	631	(215)	1,381	1,019
Comprehensive income attributable to Landstar System, Inc. and subsidiary	$ 43,074	$ 36,063	$ 113,717	$ 98,795