Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Jun. 25, 2011	Dec. 25, 2010
Current Assets
Allowance on trade accounts receivable	$ 4,155	$ 5,324
Allowance on other receivables	4,987	5,511
Accumulated depreciation and amortization on operating property	$ 146,476	$ 137,830
Landstar System, Inc. and subsidiary shareholders' equity
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized shares	160,000,000	160,000,000
Common stock, issued shares	66,589,780	66,535,169
Treasury stock, shares	18,872,652	18,674,902