XML 86 R68.htm IDEA: XBRL DOCUMENT v3.10.0.1
Effect of Increase in Cost of Insurance and Claims (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 29, 2018
Sep. 29, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 30, 2017
Sep. 30, 2017
Jul. 01, 2017
Apr. 01, 2017
Dec. 29, 2018
Dec. 30, 2017
Dec. 31, 2016
Change in Accounting Estimate [Line Items]                      
Operating income $ 86,088 $ 87,068 $ 83,426 $ 75,153 $ 70,049 $ 60,567 $ 61,018 $ 52,334 $ 331,735 $ 243,968 $ 223,251
Net income attributable to Landstar System, Inc. and subsidiary $ 68,256 $ 66,985 $ 62,523 $ 57,517 $ 64,752 $ 42,443 $ 37,510 $ 32,383 $ 255,281 $ 177,088 $ 137,350
Earnings per share attributable to Landstar System, Inc. and subsidiary $ 1.69 [1] $ 1.63 [1] $ 1.51 [1] $ 1.37 [1] $ 1.54 [1] $ 1.01 [1] $ 0.89 [1] $ 0.77 [1] $ 6.19 $ 4.22 $ 3.26
Diluted earnings per share attributable to Landstar System, Inc. and subsidiary $ 1.68 [1] $ 1.63 [1] $ 1.51 [1] $ 1.37 [1] $ 1.54 [1] $ 1.01 [1] $ 0.89 [1] $ 0.77 [1] $ 6.18 $ 4.21 $ 3.25
Development of Prior Year Self Insured Claims Estimates                      
Change in Accounting Estimate [Line Items]                      
Operating income                 $ 13,960 $ 4,144 $ 1,079
Net income attributable to Landstar System, Inc. and subsidiary                 $ 10,582 $ 2,578 $ 667
Earnings per share attributable to Landstar System, Inc. and subsidiary                 $ 0.26 $ 0.06 $ 0.02
Diluted earnings per share attributable to Landstar System, Inc. and subsidiary                 $ 0.26 $ 0.06 $ 0.02
[1] Due to the changes in the number of average common shares and common stock equivalents outstanding during the year, the sum of earnings per share amounts for each quarter do not necessarily sum in the aggregate to the earnings per share amounts for the full year.