Document_and_Entity_Informatio
| Document and Entity Information | 9 Months Ended | |
| Sep. 28, 2013 | Oct. 21, 2013 | |
| Document Information [Line Items] | ' | ' |
| Document Type | '10-Q | ' |
| Amendment Flag | 'false | ' |
| Document Period End Date | 28-Sep-13 | ' |
| Document Fiscal Year Focus | '2013 | ' |
| Document Fiscal Period Focus | 'Q3 | ' |
| Trading Symbol | 'LSTR | ' |
| Entity Registrant Name | 'LANDSTAR SYSTEM INC | ' |
| Entity Central Index Key | '0000853816 | ' |
| Current Fiscal Year End Date | '--12-28 | ' |
| Entity Filer Category | 'Large Accelerated Filer | ' |
| Entity Common Stock, Shares Outstanding | ' | 45,716,950 |
Consolidated_Balance_Sheets
| Consolidated Balance Sheets (USD $) | Sep. 28, 2013 | Dec. 29, 2012 |
| In Thousands, unless otherwise specified | ||
| Current Assets | ' | ' |
| Cash and cash equivalents | $97,552 | $74,284 |
| Short-term investments | 34,568 | 35,528 |
| Trade accounts receivable, less allowance of $8,252 and $8,650 | 394,796 | 408,787 |
| Other receivables, including advances to independent contractors, less allowance of $3,955 and $4,657 | 77,169 | 55,278 |
| Deferred income taxes and other current assets | 18,983 | 18,067 |
| Total current assets | 623,068 | 591,944 |
| Operating property, less accumulated depreciation and amortization of $157,901 and $158,999 | 184,441 | 158,953 |
| Goodwill | 57,470 | 57,470 |
| Other assets | 85,953 | 71,054 |
| Total assets | 950,932 | 879,421 |
| Current Liabilities | ' | ' |
| Cash overdraft | 26,894 | 33,647 |
| Accounts payable | 194,134 | 188,981 |
| Current maturities of long-term debt | 27,347 | 19,016 |
| Insurance claims | 89,877 | 64,509 |
| Other current liabilities | 32,922 | 38,186 |
| Total current liabilities | 371,174 | 344,339 |
| Long-term debt, excluding current maturities | 90,709 | 95,125 |
| Insurance claims | 23,119 | 21,896 |
| Deferred income taxes and other noncurrent liabilities | 42,669 | 38,607 |
| Shareholders' Equity | ' | ' |
| Common stock, $0.01 par value, authorized 160,000,000 shares, issued 67,013,297 and 66,859,864 shares | 670 | 669 |
| Additional paid-in capital | 178,952 | 173,976 |
| Retained earnings | 1,129,408 | 1,042,956 |
| Cost of 21,296,347 and 20,411,736 shares of common stock in treasury | -886,135 | -839,517 |
| Accumulated other comprehensive income | 366 | 1,370 |
| Total shareholders' equity | 423,261 | 379,454 |
| Total liabilities and shareholders' equity | $950,932 | $879,421 |
Consolidated_Balance_Sheets_Pa
| Consolidated Balance Sheets (Parenthetical) (USD $) | Sep. 28, 2013 | Dec. 29, 2012 |
| In Thousands, except Share data, unless otherwise specified | ||
| Allowance on trade accounts receivable | $8,252 | $8,650 |
| Allowance on other receivables | 3,955 | 4,657 |
| Accumulated depreciation and amortization on operating property | $157,901 | $158,999 |
| Common stock, par value | $0.01 | $0.01 |
| Common stock, authorized shares | 160,000,000 | 160,000,000 |
| Common stock, issued shares | 67,013,297 | 66,859,864 |
| Treasury stock, shares | 21,296,347 | 20,411,736 |
Consolidated_Statements_of_Inc
| Consolidated Statements of Income (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, except Share data, unless otherwise specified | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 |
| Revenue | $680,521 | $717,168 | $1,988,182 | $2,102,164 |
| Investment income | 366 | 393 | 1,111 | 1,185 |
| Costs and expenses: | ' | ' | ' | ' |
| Purchased transportation | 517,955 | 548,162 | 1,510,984 | 1,603,865 |
| Commissions to agents | 53,651 | 56,036 | 156,480 | 162,728 |
| Other operating costs, net of gains on asset dispositions | 6,031 | 6,447 | 15,557 | 17,635 |
| Insurance and claims | 13,386 | 8,010 | 37,040 | 28,411 |
| Selling, general and administrative | 34,244 | 37,455 | 105,220 | 113,916 |
| Depreciation and amortization | 7,840 | 7,072 | 22,833 | 20,476 |
| Total costs and expenses | 633,107 | 663,182 | 1,848,114 | 1,947,031 |
| Operating income | 47,780 | 54,379 | 141,179 | 156,318 |
| Interest and debt expense | 856 | 818 | 2,367 | 2,312 |
| Income before income taxes | 46,924 | 53,561 | 138,812 | 154,006 |
| Income taxes | 17,678 | 20,460 | 52,360 | 58,203 |
| Net income | $29,246 | $33,101 | $86,452 | $95,803 |
| Earnings per common share | $0.64 | $0.71 | $1.87 | $2.05 |
| Diluted earnings per share | $0.64 | $0.71 | $1.87 | $2.04 |
| Average number of shares outstanding: | ' | ' | ' | ' |
| Earnings per common share | 45,708,000 | 46,614,000 | 46,156,000 | 46,775,000 |
| Diluted earnings per share | 45,856,000 | 46,732,000 | 46,323,000 | 46,964,000 |
| Dividends paid per common share | ' | $0.06 | ' | $0.17 |
Consolidated_Statements_of_Com
| Consolidated Statements of Comprehensive Income (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 |
| Net income | $29,246 | $33,101 | $86,452 | $95,803 |
| Other comprehensive income (loss): | ' | ' | ' | ' |
| Unrealized holding (losses) gains on available-for-sale investments, net of tax benefit (expense) of $341, ($273), $(98) and ($136) | 179 | 247 | -620 | 495 |
| Foreign currency translation gains (losses) | 126 | 421 | -384 | 357 |
| Other comprehensive (loss) income | 305 | 668 | -1,004 | 852 |
| Comprehensive income | $29,551 | $33,769 | $85,448 | $96,655 |
Consolidated_Statements_of_Com1
| Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 |
| Unrealized holding (losses) gains on available-for-sale investments, tax benefit (expense) | ($98) | ($136) | $341 | ($273) |
Consolidated_Statements_of_Cas
| Consolidated Statements of Cash Flows (USD $) | 9 Months Ended | |
| In Thousands, unless otherwise specified | Sep. 28, 2013 | Sep. 29, 2012 |
| OPERATING ACTIVITIES | ' | ' |
| Net income | $86,452 | $95,803 |
| Adjustments to reconcile net income to net cash provided by operating activities: | ' | ' |
| Depreciation and amortization of operating property and intangible assets | 22,833 | 20,476 |
| Non-cash interest charges | 164 | 164 |
| Provisions for losses on trade and other accounts receivable | 2,455 | 3,436 |
| Gains on sales/disposals of operating property | -2,894 | -2,728 |
| Deferred income taxes, net | 4,730 | 6,223 |
| Stock-based compensation | 4,133 | 4,613 |
| Changes in operating assets and liabilities: | ' | ' |
| Increase in trade and other accounts receivable | -10,355 | -63,246 |
| Decrease (increase) in other assets | -2,328 | 603 |
| Increase in accounts payable | 5,153 | 49,346 |
| Decrease in other liabilities | -5,127 | -1,083 |
| Increase (decrease) in insurance claims | 26,591 | -10,322 |
| NET CASH PROVIDED BY OPERATING ACTIVITIES | 131,807 | 103,285 |
| INVESTING ACTIVITIES | ' | ' |
| Net change in other short-term investments | -4,091 | ' |
| Sales and maturities of investments | 33,265 | 20,889 |
| Purchases of investments | -44,596 | -44,261 |
| Purchases of operating property | -4,866 | -4,428 |
| Proceeds from sales of operating property | 8,662 | 8,997 |
| NET CASH USED BY INVESTING ACTIVITIES | -11,626 | -18,803 |
| FINANCING ACTIVITIES | ' | ' |
| Increase (decrease) in cash overdraft | -6,753 | 814 |
| Dividends paid | ' | -7,956 |
| Proceeds from exercises of stock options | 2,253 | 4,310 |
| Taxes paid in lieu of shares issued related to stock-based compensation plans | -1,767 | -3,023 |
| Excess tax effect on stock option exercises | 343 | 839 |
| Borrowings on revolving credit facility | ' | 60,000 |
| Purchases of common stock | -46,603 | -24,582 |
| Principal payments on long-term debt and capital lease obligations | -44,002 | -116,180 |
| NET CASH USED BY FINANCING ACTIVITIES | -96,529 | -85,778 |
| Effect of exchange rate changes on cash and cash equivalents | -384 | 357 |
| Increase (decrease) in cash and cash equivalents | 23,268 | -939 |
| Cash and cash equivalents at beginning of period | 74,284 | 80,900 |
| Cash and cash equivalents at end of period | $97,552 | $79,961 |
Consolidated_Statement_of_Chan
| Consolidated Statement of Changes in Shareholders' Equity (USD $) | Total | Common Stock | Additional Paid-In Capital | Retained Earnings | Treasury Stock at Cost | Accumulated Other Comprehensive Income (loss) |
| In Thousands, except Share data | ||||||
| Balance at Dec. 29, 2012 | $379,454 | $669 | $173,976 | $1,042,956 | ($839,517) | $1,370 |
| Balance (in shares) at Dec. 29, 2012 | ' | 66,859,864 | ' | ' | 20,411,736 | ' |
| Net income | 86,452 | ' | ' | 86,452 | ' | ' |
| Purchases of common stock (in shares) | ' | ' | ' | ' | 884,327 | ' |
| Purchases of common stock | -46,603 | ' | ' | ' | -46,603 | ' |
| Issuance of stock related to stock-based compensation plans, including excess tax effect (in shares) | ' | 153,433 | ' | ' | 284 | ' |
| Issuance of stock related to stock-based compensation plans, including excess tax effect | 829 | 1 | 843 | ' | -15 | ' |
| Stock-based compensation | 4,133 | ' | 4,133 | ' | ' | ' |
| Other comprehensive loss | -1,004 | ' | ' | ' | ' | -1,004 |
| Balance at Sep. 28, 2013 | $423,261 | $670 | $178,952 | $1,129,408 | ($886,135) | $366 |
| Balance (in shares) at Sep. 28, 2013 | ' | 67,013,297 | ' | ' | 21,296,347 | ' |
Sharebased_Payment_Arrangement
| Share-based Payment Arrangements | 9 Months Ended | ||||||||||||||||
| Sep. 28, 2013 | |||||||||||||||||
| Share-based Payment Arrangements | ' | ||||||||||||||||
| -1 | Share-based Payment Arrangements | ||||||||||||||||
| As of September 28, 2013, the Company had two employee equity incentive plans, the 2002 employee stock option and stock incentive plan (the “ESOSIP”) and the 2011 equity incentive plan (the “2011 EIP”). No further grants can be made under the ESOSIP. The Company also has two stock compensation plans for members of its Board of Directors, the 2003 Directors Stock Compensation Plan (the “2003 DSCP”) and the 2013 Directors Stock Compensation Plan (the “2013 DSCP”). In May 2013, the Company’s stockholders approved the 2013 DSCP. The provisions of the 2013 DSCP are substantially similar to the provisions of the 2003 DSCP. 115,000 shares of the Company’s common stock were authorized for issuance under the 2013 DSCP. No further grants can be made under the 2003 DSCP, including 113,704 shares of the Company’s common stock previously reserved for issuance, but not issued, under the 2003 DSCP. The ESOSIP, 2011 EIP, 2003 DSCP and 2013 DSCP are each referred to herein as a “Plan,” and, collectively, as the “Plans.” Amounts recognized in the financial statements with respect to these Plans are as follows (in thousands): | |||||||||||||||||
| Thirty Nine Weeks Ended | Thirteen Weeks Ended | ||||||||||||||||
| September 28, | September 29, | September 28, | September 29, | ||||||||||||||
| 2013 | 2012 | 2013 | 2012 | ||||||||||||||
| Total cost of the Plans during the period | $ | 4,133 | $ | 4,613 | $ | 1,141 | $ | 1,427 | |||||||||
| Amount of related income tax benefit recognized during the period | 1,294 | 2,001 | 315 | 669 | |||||||||||||
| Net cost of the Plans during the period | $ | 2,839 | $ | 2,612 | $ | 826 | $ | 758 | |||||||||
| Included in income tax benefits recognized in the thirty-nine-week periods ended September 28, 2013 and September 29, 2012 were income tax benefits of $478,000 and $750,000, respectively, recognized on disqualifying dispositions of the Company’s common stock by employees who obtained shares of common stock through exercises of incentive stock options. | |||||||||||||||||
| As of September 28, 2013, there were 102,655 shares of the Company’s common stock reserved for issuance under the 2013 DSCP and 6,695,537 shares of the Company’s common stock reserved for issuance in the aggregate under the ESOSIP and 2011 EIP. | |||||||||||||||||
| Stock Options | |||||||||||||||||
| The fair value of each option grant on its grant date was calculated using the Black-Scholes option pricing model with the following weighted average assumptions for grants made in the 2013 and 2012 thirty-nine-week periods: | |||||||||||||||||
| 2013 | 2012 | ||||||||||||||||
| Expected volatility | 32 | % | 34 | % | |||||||||||||
| Expected dividend yield | 0.41 | % | 0.42 | % | |||||||||||||
| Risk-free interest rate | 0.75 | % | 0.9 | % | |||||||||||||
| Expected lives (in years) | 4 | 4 | |||||||||||||||
| The Company utilizes historical data, including exercise patterns and employee departure behavior, in estimating the term that options will be outstanding. Expected volatility was based on historical volatility and other factors, such as expected changes in volatility arising from planned changes to the Company’s business, if any. The risk-free interest rate was based on the yield of zero coupon U.S. Treasury bonds for terms that approximated the terms of the options granted. The weighted average grant date fair value of stock options granted during the thirty-nine-week periods ended September 28, 2013 and September 29, 2012 was $14.21 per share and $13.99 per share, respectively. | |||||||||||||||||
| The following table summarizes information regarding the Company’s outstanding stock options under the Plans: | |||||||||||||||||
| Weighted Average | |||||||||||||||||
| Number of | Weighted Average | Remaining | Aggregate Intrinsic | ||||||||||||||
| Exercise Price | Contractual | ||||||||||||||||
| Options | per Share | Term (years) | Value (000s) | ||||||||||||||
| Options outstanding at December 29, 2012 | 1,781,182 | $ | 42.56 | ||||||||||||||
| Granted | 152,500 | $ | 56.4 | ||||||||||||||
| Exercised | (416,466 | ) | $ | 40.52 | |||||||||||||
| Forfeited | (47,300 | ) | $ | 41.88 | |||||||||||||
| Options outstanding at September 28, 2013 | 1,469,916 | $ | 44.6 | 6 | $ | 16,026 | |||||||||||
| Options exercisable at September 28, 2013 | 695,416 | $ | 42.27 | 4.3 | $ | 9,197 | |||||||||||
| The total intrinsic value of stock options exercised during the thirty-nine-week periods ended September 28, 2013 and September 29, 2012 was $6,021,000 and $12,350,000, respectively. | |||||||||||||||||
| As of September 28, 2013, there was $6,151,000 of total unrecognized compensation cost related to non-vested stock options granted under the Plans. The unrecognized compensation cost related to these non-vested options is expected to be recognized over a weighted average period of 3.1 years. | |||||||||||||||||
| Non-vested Restricted Stock | |||||||||||||||||
| The fair value of each share of non-vested restricted stock issued under the Plans is based on the fair value of a share of the Company’s common stock on the date of grant. | |||||||||||||||||
| The following table summarizes information regarding the Company’s outstanding non-vested restricted stock under the Plans: | |||||||||||||||||
| Number of | Weighted Average | ||||||||||||||||
| Grant Date | |||||||||||||||||
| Shares | Fair Value | ||||||||||||||||
| Outstanding at December 29, 2012 | 34,719 | $ | 42.75 | ||||||||||||||
| Granted | 13,449 | $ | 54.56 | ||||||||||||||
| Vested | (11,975 | ) | $ | 45.61 | |||||||||||||
| Outstanding at September 28, 2013 | 36,193 | $ | 46.19 | ||||||||||||||
| As of September 28, 2013, there was $1,041,000 of total unrecognized compensation cost related to non-vested shares of restricted stock granted under the Plans. The unrecognized compensation cost related to these non-vested shares of restricted stock is expected to be recognized over a weighted average period of 2.2 years. | |||||||||||||||||
| Restricted Stock Units | |||||||||||||||||
| The fair value of a restricted stock unit (“RSU”) is determined based on the market value of the Company’s common stock on the date of grant, discounted for lack of marketability for a minimum post-vesting holding requirement. The discount rate due to lack of marketability used for RSU award grants during both thirty-nine-week periods ended September 28, 2013 and September 29, 2012 was 7%. | |||||||||||||||||
| The following table summarizes information regarding the Company’s outstanding RSU awards under the Plans: | |||||||||||||||||
| Number of | Weighted Average | ||||||||||||||||
| Grant Date | |||||||||||||||||
| Units | Fair Value | ||||||||||||||||
| Outstanding at December 29, 2012 | 113,000 | $ | 44.78 | ||||||||||||||
| Granted | 244,500 | $ | 51.19 | ||||||||||||||
| Vested | (21,901 | ) | $ | 44.78 | |||||||||||||
| Forfeited | (7,046 | ) | $ | 45.45 | |||||||||||||
| Outstanding at September 28, 2013 | 328,553 | $ | 49.54 | ||||||||||||||
| The Company reports compensation expense over the life of the award based on an estimated number of shares that will vest over the life of the award, multiplied by the fair value of an RSU. RSU awards have contractual lives of three or five years from the date of grant. For RSUs with five-year contractual lives, the number of RSUs that vest is determined annually, for each year in the five-year period from date of grant, by multiplying the number of RSUs granted by the sum of (a) the average of the percentage change (positive or negative) in operating income and diluted earnings per share in each of the 5 years as compared to operating income and diluted earnings per share reported in the base year (base year being the year immediately preceding the year in which the RSUs were granted), plus (b) 5%, rounded to the nearest whole number, less (c) the number of RSUs from that grant that have previously vested. On January 23, 2013, the Company granted 100,000 RSUs to the Company’s Chairman, President and Chief Executive Officer. These 100,000 RSUs have three-year contractual lives and will vest on January 31 of 2014, 2015, and 2016, with the number of RSUs that vest on each vesting date determined by multiplying 100,000 by the sum of (1) the percentage increase in operating income in the most recently completed fiscal year as compared to the results from the immediately preceding fiscal year, plus (2) the percentage increase in diluted earnings per share in the most recently completed fiscal year as compared to the results from the preceding fiscal year. The Company recognized approximately $1,332,000 and $632,000 of share-based compensation expense related to RSU awards in the thirty-nine-week periods ended September 28, 2013 and September 29, 2012, respectively. As of September 28, 2013, there was a maximum of $15.0 million of total unrecognized compensation cost related to RSU awards granted under the Plans with an expected average remaining life of approximately 3.4 years. The amount of future compensation expense to be recognized will be determined based on future operating results. | |||||||||||||||||
Income_Taxes
| Income Taxes | 9 Months Ended | |
| Sep. 28, 2013 | ||
| Income Taxes | ' | |
| -2 | Income Taxes | |
| The provisions for income taxes for both the 2013 and 2012 thirty-nine-week periods were based on estimated full year combined effective income tax rates of 38.2% adjusted for discrete events recognized during the period, which generally relate to benefits resulting from disqualifying dispositions of the Company’s common stock by employees who obtained the stock through exercises of incentive stock options. The effective income tax rates for the 2013 and 2012 thirty-nine-week periods were 37.7% and 37.8%, respectively, which were higher than the statutory federal income tax rate primarily as a result of state taxes, the meals and entertainment exclusion and non-deductible stock-based compensation. | ||
Earnings_Per_Share
| Earnings Per Share | 9 Months Ended | ||||||||||||||||
| Sep. 28, 2013 | |||||||||||||||||
| Earnings Per Share | ' | ||||||||||||||||
| -3 | Earnings Per Share | ||||||||||||||||
| Earnings per common share are based on the weighted average number of shares outstanding, including outstanding non-vested restricted stock. Diluted earnings per share are based on the weighted average number of common shares outstanding plus the incremental shares that would have been outstanding upon the assumed exercise of all dilutive stock options. | |||||||||||||||||
| The following table provides a reconciliation of the average number of common shares outstanding used to calculate earnings per common share to the average number of common shares and common share equivalents outstanding used to calculate diluted earnings per share (in thousands): | |||||||||||||||||
| Thirty Nine Weeks Ended | Thirteen Weeks Ended | ||||||||||||||||
| September 28, | September 29, | September 28, | September 29, | ||||||||||||||
| 2013 | 2012 | 2013 | 2012 | ||||||||||||||
| Average number of common shares outstanding | 46,156 | 46,775 | 45,708 | 46,614 | |||||||||||||
| Incremental shares from assumed exercises of stock options | 167 | 189 | 148 | 118 | |||||||||||||
| Average number of common shares and common share equivalents outstanding | 46,323 | 46,964 | 45,856 | 46,732 | |||||||||||||
| For each of the thirty-nine-week and thirteen-week periods ended September 28, 2013, 149,000 options outstanding to purchase shares of common stock were excluded from the calculation of diluted earnings per share because they were antidilutive. For the thirty-nine-week and thirteen-week periods ended September 29, 2012, 2,000 and 323,000, respectively, options outstanding to purchase shares of common stock were excluded from the calculation of diluted earnings per share because they were antidilutive. For the thirty-nine-week and thirteen-week periods ended September 28, 2013 and September 29, 2012, outstanding RSUs were excluded from the calculation of diluted earnings per share because the performance metric requirements for vesting had not been satisfied. | |||||||||||||||||
Additional_Cash_Flow_Informati
| Additional Cash Flow Information | 9 Months Ended | |
| Sep. 28, 2013 | ||
| Additional Cash Flow Information | ' | |
| -4 | Additional Cash Flow Information | |
| During the 2013 thirty-nine-week period, Landstar paid income taxes and interest of $44,966,000 and $2,347,000, respectively. During the 2012 thirty-nine-week period, Landstar paid income taxes and interest of $48,528,000 and $2,331,000, respectively. Landstar acquired operating property by entering into capital leases in the amount of $47,917,000 and $42,952,000 in the 2013 and 2012 thirty-nine-week periods, respectively. | ||
Segment_Information
| Segment Information | 9 Months Ended | ||||||||||||||||||||||||
| Sep. 28, 2013 | |||||||||||||||||||||||||
| Segment Information | ' | ||||||||||||||||||||||||
| -5 | Segment Information | ||||||||||||||||||||||||
| The following table summarizes information about the Company’s reportable business segments as of and for the thirty-nine-week and thirteen-week periods ended September 28, 2013 and September 29, 2012 (in thousands): | |||||||||||||||||||||||||
| Thirty Nine Weeks Ended | |||||||||||||||||||||||||
| September 28, 2013 | September 29, 2012 | ||||||||||||||||||||||||
| Transportation | Insurance | Total | Transportation | Insurance | Total | ||||||||||||||||||||
| Logistics | Logistics | ||||||||||||||||||||||||
| External revenue | $ | 1,960,949 | $ | 27,233 | $ | 1,988,182 | $ | 2,075,475 | $ | 26,689 | $ | 2,102,164 | |||||||||||||
| Investment income | 1,111 | 1,111 | 1,185 | 1,185 | |||||||||||||||||||||
| Internal revenue | 22,808 | 22,808 | 22,457 | 22,457 | |||||||||||||||||||||
| Operating income | 121,191 | 19,988 | 141,179 | 130,009 | 26,309 | 156,318 | |||||||||||||||||||
| Expenditures on long-lived assets | 4,866 | 4,866 | 4,428 | 4,428 | |||||||||||||||||||||
| Goodwill | 57,470 | 57,470 | 57,470 | 57,470 | |||||||||||||||||||||
| Thirteen Weeks Ended | |||||||||||||||||||||||||
| September 28, 2013 | September 29, 2012 | ||||||||||||||||||||||||
| Transportation | Insurance | Total | Transportation | Insurance | Total | ||||||||||||||||||||
| Logistics | Logistics | ||||||||||||||||||||||||
| External revenue | $ | 671,390 | $ | 9,131 | $ | 680,521 | $ | 708,081 | $ | 9,087 | $ | 717,168 | |||||||||||||
| Investment income | 366 | 366 | 393 | 393 | |||||||||||||||||||||
| Internal revenue | 5,999 | 5,999 | 5,990 | 5,990 | |||||||||||||||||||||
| Operating income | 42,206 | 5,574 | 47,780 | 43,881 | 10,498 | 54,379 | |||||||||||||||||||
| Expenditures on long-lived assets | 2,117 | 2,117 | 1,446 | 1,446 | |||||||||||||||||||||
| In the thirty-nine-week and thirteen-week periods ended September 28, 2013 and September 29, 2012, there were no customers who accounted for 10 percent or more of the Company’s consolidated revenue. | |||||||||||||||||||||||||
Other_Comprehensive_Income
| Other Comprehensive Income | 9 Months Ended | ||||||||||||
| Sep. 28, 2013 | |||||||||||||
| Other Comprehensive Income | ' | ||||||||||||
| -6 | Other Comprehensive Income | ||||||||||||
| The following table presents the components of and changes in accumulated other comprehensive income, net of related income taxes, as of and for the thirty-nine-week period ended September 28, 2013 (in thousands): | |||||||||||||
| Unrealized Gains | Foreign Currency | Total | |||||||||||
| (Losses) on | Translation | ||||||||||||
| Available-for-Sale | |||||||||||||
| Securities | |||||||||||||
| Balance as of December 29, 2012 | $ | 908 | $ | 462 | $ | 1,370 | |||||||
| Other comprehensive loss | (620 | ) | (384 | ) | (1,004 | ) | |||||||
| Balance as of September 28, 2013 | $ | 288 | $ | 78 | $ | 366 | |||||||
| Amounts reclassified from accumulated other comprehensive income to investment income in the accompanying consolidated statements of income were not significant for the thirty-nine-week period ended September 28, 2013. | |||||||||||||
Investments
| Investments | 9 Months Ended | ||||||||||||||||||||||||
| Sep. 28, 2013 | |||||||||||||||||||||||||
| Investments | ' | ||||||||||||||||||||||||
| -7 | Investments | ||||||||||||||||||||||||
| Investments include primarily investment-grade corporate bonds and U.S. Treasury obligations having maturities of up to five years (the “bond portfolio”). Investments in the bond portfolio are reported as available-for-sale and are carried at fair value. Investments maturing less than one year from the balance sheet date are included in short-term investments and investments maturing more than one year from the balance sheet date are included in other assets in the consolidated balance sheets. Management performs an analysis of the nature of the unrealized losses on available-for-sale investments to determine whether such losses are other-than-temporary. Unrealized losses, representing the excess of the purchase price of an investment over its fair value as of the end of a period, considered to be other-than-temporary, are to be included as a charge in the statement of income, while unrealized losses considered to be temporary are to be included as a component of shareholders’ equity. Investments whose values are based on quoted market prices in active markets are classified within Level 1. Investments that trade in markets that are not considered to be active, but are valued based on quoted market prices, are classified within Level 2. As Level 2 investments include positions that are not traded in active markets, valuations may be adjusted to reflect illiquidity and/or non-transferability, which are generally based on available market information. Any transfers between levels are recognized as of the beginning of any reporting period. Fair value of the bond portfolio was determined using Level 1 inputs related to U.S. Treasury obligations and money market investments and Level 2 inputs related to investment-grade corporate bonds, asset-backed securities and direct obligations of government agencies. Unrealized gains, net of unrealized losses, on the investments in the bond portfolio were $446,000 and $1,407,000 at September 28, 2013 and December 29, 2012, respectively. | |||||||||||||||||||||||||
| The amortized cost and fair values of available-for-sale investments are as follows at September 28, 2013 and December 29, 2012 (in thousands): | |||||||||||||||||||||||||
| Gross | Gross | ||||||||||||||||||||||||
| Amortized | Unrealized | Unrealized | Fair | ||||||||||||||||||||||
| Cost | Gains | Losses | Value | ||||||||||||||||||||||
| September 28, 2013 | |||||||||||||||||||||||||
| Money market investments | $ | 1,172 | $ | — | $ | — | $ | 1,172 | |||||||||||||||||
| Asset-backed securities | 4,436 | 25 | 73 | 4,388 | |||||||||||||||||||||
| Corporate bonds and direct obligations of government agencies | 77,439 | 798 | 332 | 77,905 | |||||||||||||||||||||
| U.S. Treasury obligations | 18,790 | 38 | 10 | 18,818 | |||||||||||||||||||||
| Total | $ | 101,837 | $ | 861 | $ | 415 | $ | 102,283 | |||||||||||||||||
| December 29, 2012 | |||||||||||||||||||||||||
| Money market investments | $ | 2,865 | $ | — | $ | — | $ | 2,865 | |||||||||||||||||
| Asset-backed securities | 2,175 | 73 | — | 2,248 | |||||||||||||||||||||
| Corporate bonds and direct obligations of government agencies | 69,173 | 1,294 | 6 | 70,461 | |||||||||||||||||||||
| U.S. Treasury obligations | 16,782 | 47 | 1 | 16,828 | |||||||||||||||||||||
| Total | $ | 90,995 | $ | 1,414 | $ | 7 | $ | 92,402 | |||||||||||||||||
| For those available-for-sale investments with unrealized losses at September 28, 2013 and December 29, 2012, the following table summarizes the duration of the unrealized loss (in thousands): | |||||||||||||||||||||||||
| Less than 12 months | 12 months or longer | Total | |||||||||||||||||||||||
| Fair | Unrealized | Fair | Unrealized | Fair | Unrealized | ||||||||||||||||||||
| Value | Loss | Value | Loss | Value | Loss | ||||||||||||||||||||
| September 28, 2013 | |||||||||||||||||||||||||
| Asset -backed securities | $ | 3,456 | $ | 73 | $ | — | $ | — | $ | 3,456 | $ | 73 | |||||||||||||
| Corporate bonds and direct obligations of government agencies | 24,792 | 332 | — | — | 24,792 | 332 | |||||||||||||||||||
| U.S. Treasury obligations | 759 | 10 | — | — | 759 | 10 | |||||||||||||||||||
| Total | $ | 29,007 | $ | 415 | $ | — | $ | — | $ | 29,007 | $ | 415 | |||||||||||||
| December 29, 2012 | |||||||||||||||||||||||||
| Corporate bonds and direct obligations of government agencies | $ | 3,387 | $ | 6 | $ | — | $ | — | $ | 3,387 | $ | 6 | |||||||||||||
| U.S. Treasury obligations | 770 | 1 | — | — | 770 | 1 | |||||||||||||||||||
| Total | $ | 4,157 | $ | 7 | $ | — | $ | — | $ | 4,157 | $ | 7 | |||||||||||||
| The Company believes that unrealized losses on investments were primarily caused by rising interest rates rather than changes in credit quality. The Company expects to recover the amortized cost basis of these securities as it does not intend to sell and does not anticipate being required to sell these securities before recovery of the cost basis. For these reasons, the Company does not consider the unrealized losses on these securities to be other-than-temporary at September 28, 2013. | |||||||||||||||||||||||||
Commitments_and_Contingencies
| Commitments and Contingencies | 9 Months Ended | |
| Sep. 28, 2013 | ||
| Commitments and Contingencies | ' | |
| -8 | Commitments and Contingencies | |
| Short-term investments include $30,477,000 in current maturities of investments and $4,091,000 of cash equivalents held by the Company’s insurance segment at September 28, 2013. The non-current portion of the bond portfolio of $71,806,000 is included in other assets. The short-term investments, together with $31,251,000 of non-current investments, provide collateral for the $59,646,000 of letters of credit issued to guarantee payment of insurance claims. As of September 28, 2013, Landstar also had $34,751,000 of additional letters of credit outstanding under the Company’s Credit Agreement. | ||
| As further described in periodic and current reports previously filed by the Company with the Securities and Exchange Commission (the “SEC”), on September 23, 2011, a jury sitting in a state court in Cobb County, Georgia, entered a damage award of approximately $40.2 million (such amount, plus pre-judgment interest, attorney fees and post-judgment interest awarded to the plaintiffs are collectively referred to herein as the “Damage Award”) against Landstar Ranger, Inc., Landstar System Holdings, Inc. and Landstar System, Inc. (the “Landstar Defendants”). The Damage Award arises out of an accident that occurred in February 2007 involving a BCO Independent Contractor leased to Landstar Ranger, Inc. On May 28, 2013, the trial court issued an order denying post-trial motions for directed verdict and a new trial filed by the Landstar Defendants and entered an amended judgment that revised the Damage Award to include approximately $1.0 million of pre-judgment interest, $14.0 million of attorney fees and post-judgment interest at the rate of 6.25% per annum from and after September 23, 2011 on the aggregate sum of approximately $55.2 million awarded to the plaintiffs. Under the terms of the commercial trucking insurance program that Landstar had in place in 2007, Landstar retained liability for up to $5 million with respect to the accident giving rise to the Damage Award. Landstar has third party insurance and/or reinsurance policies in place that are expected to provide coverage for all amounts of the Damage Award in excess of such retention, including all related out-of-pocket expenses, such as the costs of an appeal bond, interest and attorney fees comprising the Damage Award that may be entered by the trial court or an appellate court in the future. The Company recorded a $5 million charge representing its self-insured retention in respect of this accident in the consolidated financial results of the Company in the 2007 first quarter. Accordingly, that portion of the Damage Award has been previously recorded by the Company and therefore did not reduce consolidated operating income or net income for the Company’s 2011 or 2012 fiscal years. Under the terms of the Company’s insurance policies, the Company is the primary obligor of the amount of the Damage Award, and as such, the Company has reported a $60.7 million receivable from the third party insurance providers in other receivables and a corresponding liability of the same amount in insurance claims in the unaudited consolidated balance sheets at September 28, 2013. The Landstar Defendants have filed an appeal of the Damage Award in the Court of Appeals for the State of Georgia and have posted the requisite supersedeas bond. No assurances can be given regarding the outcome of any such appeal, including as to the impact of the Damage Award on the premiums charged by the Company’s third party insurers from time to time for commercial trucking insurance. | ||
| The Company is involved in certain claims and pending litigation, including those described herein, arising from the normal conduct of business. Many of these claims are covered in whole or in part by insurance. Based on knowledge of the facts and, in certain cases, opinions of outside counsel, management believes that adequate provisions have been made for probable losses with respect to the resolution of all such claims and pending litigation and that the ultimate outcome, after provisions therefor, will not have a material adverse effect on the financial condition of the Company, but could have a material effect on the results of operations in a given quarter or year. | ||
Sharebased_Payment_Arrangement1
| Share-based Payment Arrangements (Tables) | 9 Months Ended | ||||||||||||||||
| Sep. 28, 2013 | |||||||||||||||||
| Amounts Recognized in Financial Statements with Respect to Plans | ' | ||||||||||||||||
| Amounts recognized in the financial statements with respect to these Plans are as follows (in thousands): | |||||||||||||||||
| Thirty Nine Weeks Ended | Thirteen Weeks Ended | ||||||||||||||||
| September 28, | September 29, | September 28, | September 29, | ||||||||||||||
| 2013 | 2012 | 2013 | 2012 | ||||||||||||||
| Total cost of the Plans during the period | $ | 4,133 | $ | 4,613 | $ | 1,141 | $ | 1,427 | |||||||||
| Amount of related income tax benefit recognized during the period | 1,294 | 2,001 | 315 | 669 | |||||||||||||
| Net cost of the Plans during the period | $ | 2,839 | $ | 2,612 | $ | 826 | $ | 758 | |||||||||
| Weighted Average Assumptions for Option Grants | ' | ||||||||||||||||
| The fair value of each option grant on its grant date was calculated using the Black-Scholes option pricing model with the following weighted average assumptions for grants made in the 2013 and 2012 thirty-nine-week periods: | |||||||||||||||||
| 2013 | 2012 | ||||||||||||||||
| Expected volatility | 32 | % | 34 | % | |||||||||||||
| Expected dividend yield | 0.41 | % | 0.42 | % | |||||||||||||
| Risk-free interest rate | 0.75 | % | 0.9 | % | |||||||||||||
| Expected lives (in years) | 4 | 4 | |||||||||||||||
| Summary of Information Regarding Stock Options | ' | ||||||||||||||||
| The following table summarizes information regarding the Company’s outstanding stock options under the Plans: | |||||||||||||||||
| Weighted Average | |||||||||||||||||
| Number of | Weighted Average | Remaining | Aggregate Intrinsic | ||||||||||||||
| Exercise Price | Contractual | ||||||||||||||||
| Options | per Share | Term (years) | Value (000s) | ||||||||||||||
| Options outstanding at December 29, 2012 | 1,781,182 | $ | 42.56 | ||||||||||||||
| Granted | 152,500 | $ | 56.4 | ||||||||||||||
| Exercised | (416,466 | ) | $ | 40.52 | |||||||||||||
| Forfeited | (47,300 | ) | $ | 41.88 | |||||||||||||
| Options outstanding at September 28, 2013 | 1,469,916 | $ | 44.6 | 6 | $ | 16,026 | |||||||||||
| Options exercisable at September 28, 2013 | 695,416 | $ | 42.27 | 4.3 | $ | 9,197 | |||||||||||
| Non-vested Restricted Stock | ' | ||||||||||||||||
| Schedule of Information on Non-Vested Restricted Stock | ' | ||||||||||||||||
| The following table summarizes information regarding the Company’s outstanding non-vested restricted stock under the Plans: | |||||||||||||||||
| Number of | Weighted Average | ||||||||||||||||
| Grant Date | |||||||||||||||||
| Shares | Fair Value | ||||||||||||||||
| Outstanding at December 29, 2012 | 34,719 | $ | 42.75 | ||||||||||||||
| Granted | 13,449 | $ | 54.56 | ||||||||||||||
| Vested | (11,975 | ) | $ | 45.61 | |||||||||||||
| Outstanding at September 28, 2013 | 36,193 | $ | 46.19 | ||||||||||||||
| Restricted Stock Units (RSUs) | ' | ||||||||||||||||
| Schedule of Information on Restricted Stock Units | ' | ||||||||||||||||
| The following table summarizes information regarding the Company’s outstanding RSU awards under the Plans: | |||||||||||||||||
| Number of | Weighted Average | ||||||||||||||||
| Grant Date | |||||||||||||||||
| Units | Fair Value | ||||||||||||||||
| Outstanding at December 29, 2012 | 113,000 | $ | 44.78 | ||||||||||||||
| Granted | 244,500 | $ | 51.19 | ||||||||||||||
| Vested | (21,901 | ) | $ | 44.78 | |||||||||||||
| Forfeited | (7,046 | ) | $ | 45.45 | |||||||||||||
| Outstanding at September 28, 2013 | 328,553 | $ | 49.54 | ||||||||||||||
Earnings_Per_Share_Tables
| Earnings Per Share (Tables) | 9 Months Ended | ||||||||||||||||
| Sep. 28, 2013 | |||||||||||||||||
| Reconciliation of Average Number of Common Shares Outstanding to Average Number of Diluted Shares Outstanding | ' | ||||||||||||||||
| The following table provides a reconciliation of the average number of common shares outstanding used to calculate earnings per common share to the average number of common shares and common share equivalents outstanding used to calculate diluted earnings per share (in thousands): | |||||||||||||||||
| Thirty Nine Weeks Ended | Thirteen Weeks Ended | ||||||||||||||||
| September 28, | September 29, | September 28, | September 29, | ||||||||||||||
| 2013 | 2012 | 2013 | 2012 | ||||||||||||||
| Average number of common shares outstanding | 46,156 | 46,775 | 45,708 | 46,614 | |||||||||||||
| Incremental shares from assumed exercises of stock options | 167 | 189 | 148 | 118 | |||||||||||||
| Average number of common shares and common share equivalents outstanding | 46,323 | 46,964 | 45,856 | 46,732 | |||||||||||||
Segment_Information_Tables
| Segment Information (Tables) | 9 Months Ended | ||||||||||||||||||||||||
| Sep. 28, 2013 | |||||||||||||||||||||||||
| Information Regarding Reportable Business Segments | ' | ||||||||||||||||||||||||
| The following table summarizes information about the Company’s reportable business segments as of and for the thirty-nine-week and thirteen-week periods ended September 28, 2013 and September 29, 2012 (in thousands): | |||||||||||||||||||||||||
| Thirty Nine Weeks Ended | |||||||||||||||||||||||||
| September 28, 2013 | September 29, 2012 | ||||||||||||||||||||||||
| Transportation | Insurance | Total | Transportation | Insurance | Total | ||||||||||||||||||||
| Logistics | Logistics | ||||||||||||||||||||||||
| External revenue | $ | 1,960,949 | $ | 27,233 | $ | 1,988,182 | $ | 2,075,475 | $ | 26,689 | $ | 2,102,164 | |||||||||||||
| Investment income | 1,111 | 1,111 | 1,185 | 1,185 | |||||||||||||||||||||
| Internal revenue | 22,808 | 22,808 | 22,457 | 22,457 | |||||||||||||||||||||
| Operating income | 121,191 | 19,988 | 141,179 | 130,009 | 26,309 | 156,318 | |||||||||||||||||||
| Expenditures on long-lived assets | 4,866 | 4,866 | 4,428 | 4,428 | |||||||||||||||||||||
| Goodwill | 57,470 | 57,470 | 57,470 | 57,470 | |||||||||||||||||||||
| Thirteen Weeks Ended | |||||||||||||||||||||||||
| September 28, 2013 | September 29, 2012 | ||||||||||||||||||||||||
| Transportation | Insurance | Total | Transportation | Insurance | Total | ||||||||||||||||||||
| Logistics | Logistics | ||||||||||||||||||||||||
| External revenue | $ | 671,390 | $ | 9,131 | $ | 680,521 | $ | 708,081 | $ | 9,087 | $ | 717,168 | |||||||||||||
| Investment income | 366 | 366 | 393 | 393 | |||||||||||||||||||||
| Internal revenue | 5,999 | 5,999 | 5,990 | 5,990 | |||||||||||||||||||||
| Operating income | 42,206 | 5,574 | 47,780 | 43,881 | 10,498 | 54,379 | |||||||||||||||||||
| Expenditures on long-lived assets | 2,117 | 2,117 | 1,446 | 1,446 | |||||||||||||||||||||
Other_Comprehensive_Income_Tab
| Other Comprehensive Income (Tables) | 9 Months Ended | ||||||||||||
| Sep. 28, 2013 | |||||||||||||
| Components of and Changes in Accumulated Other Comprehensive Income, Net of Related Income Taxes | ' | ||||||||||||
| The following table presents the components of and changes in accumulated other comprehensive income, net of related income taxes, as of and for the thirty-nine-week period ended September 28, 2013 (in thousands): | |||||||||||||
| Unrealized Gains | Foreign Currency | Total | |||||||||||
| (Losses) on | Translation | ||||||||||||
| Available-for-Sale | |||||||||||||
| Securities | |||||||||||||
| Balance as of December 29, 2012 | $ | 908 | $ | 462 | $ | 1,370 | |||||||
| Other comprehensive loss | (620 | ) | (384 | ) | (1,004 | ) | |||||||
| Balance as of September 28, 2013 | $ | 288 | $ | 78 | $ | 366 | |||||||
Investments_Tables
| Investments (Tables) | 9 Months Ended | ||||||||||||||||||||||||
| Sep. 28, 2013 | |||||||||||||||||||||||||
| Amortized Cost and Fair Value of Available for Sale Investments | ' | ||||||||||||||||||||||||
| The amortized cost and fair values of available-for-sale investments are as follows at September 28, 2013 and December 29, 2012 (in thousands): | |||||||||||||||||||||||||
| Gross | Gross | ||||||||||||||||||||||||
| Amortized | Unrealized | Unrealized | Fair | ||||||||||||||||||||||
| Cost | Gains | Losses | Value | ||||||||||||||||||||||
| September 28, 2013 | |||||||||||||||||||||||||
| Money market investments | $ | 1,172 | $ | — | $ | — | $ | 1,172 | |||||||||||||||||
| Asset-backed securities | 4,436 | 25 | 73 | 4,388 | |||||||||||||||||||||
| Corporate bonds and direct obligations of government agencies | 77,439 | 798 | 332 | 77,905 | |||||||||||||||||||||
| U.S. Treasury obligations | 18,790 | 38 | 10 | 18,818 | |||||||||||||||||||||
| Total | $ | 101,837 | $ | 861 | $ | 415 | $ | 102,283 | |||||||||||||||||
| December 29, 2012 | |||||||||||||||||||||||||
| Money market investments | $ | 2,865 | $ | — | $ | — | $ | 2,865 | |||||||||||||||||
| Asset-backed securities | 2,175 | 73 | — | 2,248 | |||||||||||||||||||||
| Corporate bonds and direct obligations of government agencies | 69,173 | 1,294 | 6 | 70,461 | |||||||||||||||||||||
| U.S. Treasury obligations | 16,782 | 47 | 1 | 16,828 | |||||||||||||||||||||
| Total | $ | 90,995 | $ | 1,414 | $ | 7 | $ | 92,402 | |||||||||||||||||
| Schedule of Unrealized Loss on Available for Sale Investments | ' | ||||||||||||||||||||||||
| For those available-for-sale investments with unrealized losses at September 28, 2013 and December 29, 2012, the following table summarizes the duration of the unrealized loss (in thousands): | |||||||||||||||||||||||||
| Less than 12 months | 12 months or longer | Total | |||||||||||||||||||||||
| Fair | Unrealized | Fair | Unrealized | Fair | Unrealized | ||||||||||||||||||||
| Value | Loss | Value | Loss | Value | Loss | ||||||||||||||||||||
| September 28, 2013 | |||||||||||||||||||||||||
| Asset -backed securities | $ | 3,456 | $ | 73 | $ | — | $ | — | $ | 3,456 | $ | 73 | |||||||||||||
| Corporate bonds and direct obligations of government agencies | 24,792 | 332 | — | — | 24,792 | 332 | |||||||||||||||||||
| U.S. Treasury obligations | 759 | 10 | — | — | 759 | 10 | |||||||||||||||||||
| Total | $ | 29,007 | $ | 415 | $ | — | $ | — | $ | 29,007 | $ | 415 | |||||||||||||
| December 29, 2012 | |||||||||||||||||||||||||
| Corporate bonds and direct obligations of government agencies | $ | 3,387 | $ | 6 | $ | — | $ | — | $ | 3,387 | $ | 6 | |||||||||||||
| U.S. Treasury obligations | 770 | 1 | — | — | 770 | 1 | |||||||||||||||||||
| Total | $ | 4,157 | $ | 7 | $ | — | $ | — | $ | 4,157 | $ | 7 | |||||||||||||
Share_Based_Payment_Arrangemen
| Share Based Payment Arrangements - Additional Information (Detail) (USD $) | 3 Months Ended | 9 Months Ended | 9 Months Ended | 1 Months Ended | 9 Months Ended | ||||||||||
| Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 28, 2013 | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Jan. 23, 2013 | Jan. 23, 2013 | Sep. 28, 2013 | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | |
| EquityPlan | 2013 Directors Stock Compensation Plan | 2003 Directors Stock Compensation Plan | Restricted Stock Units (RSUs) | Restricted Stock Units (RSUs) | Restricted Stock Units (RSUs) | Restricted Stock Units (RSUs) | Restricted Stock Units (RSUs) | Other Stock Compensation Plan | Employee Stock Option | Employee Stock Option | Non-Vested Restricted Stock | ||||
| CompensationPlan | Maximum | Chairman, President and Chief Executive Officer | Chairman, President and Chief Executive Officer | ||||||||||||
| Maximum | |||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Number of employee equity incentive plans | ' | ' | 2 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Number of board of director stock compensation plans | ' | ' | 2 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Common stock authorized for issuance | ' | ' | ' | ' | 115,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Common stock previously reserved for issuance | ' | ' | ' | ' | ' | 113,704 | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Income tax benefit realized on disqualifying dispositions of stock acquired by exercise of incentive stock options | ' | ' | $478,000 | $750,000 | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Common stock reserved for issuance | ' | ' | ' | ' | 102,655 | ' | ' | ' | ' | ' | ' | 6,695,537 | ' | ' | ' |
| The weighted average grant date fair value of stock options granted | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $14.21 | $13.99 | ' |
| Total intrinsic value of stock options exercised during periods | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 6,021,000 | 12,350,000 | ' |
| Unrecognized compensation cost | ' | ' | ' | ' | ' | ' | ' | ' | 15,000,000 | ' | ' | ' | 6,151,000 | ' | 1,041,000 |
| Unrecognized compensation cost expected to be recognized over period, years | ' | ' | ' | ' | ' | ' | '3 years 4 months 24 days | ' | ' | ' | ' | ' | '3 years 1 month 6 days | ' | '2 years 2 months 12 days |
| Discount rate on stock awards | ' | ' | ' | ' | ' | ' | 7.00% | 7.00% | ' | ' | ' | ' | ' | ' | ' |
| RSU awards maximum vesting period | ' | ' | ' | ' | ' | ' | ' | ' | '5 years | ' | '3 years | ' | ' | ' | ' |
| Percentage used in calculation to determine vesting | ' | ' | ' | ' | ' | ' | 5.00% | ' | ' | ' | ' | ' | ' | ' | ' |
| Awards issued | ' | ' | ' | ' | ' | ' | 244,500 | ' | ' | 100,000 | ' | ' | ' | ' | 13,449 |
| Recognized share-based compensation expense | $1,141,000 | $1,427,000 | $4,133,000 | $4,613,000 | ' | ' | $1,332,000 | $632,000 | ' | ' | ' | ' | ' | ' | ' |
Amounts_Recognized_in_Financia
| Amounts Recognized in Financial Statements with Respect to Plans (Detail) (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 |
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ' | ' | ' | ' |
| Total cost of the Plans during the period | $1,141 | $1,427 | $4,133 | $4,613 |
| Amount of related income tax benefit recognized during the period | 315 | 669 | 1,294 | 2,001 |
| Net cost of the Plans during the period | $826 | $758 | $2,839 | $2,612 |
Weighted_Average_Assumptions_f
| Weighted Average Assumptions for Option Grants (Detail) | 9 Months Ended | |
| Sep. 28, 2013 | Sep. 29, 2012 | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' |
| Expected volatility | 32.00% | 34.00% |
| Expected dividend yield | 0.41% | 0.42% |
| Risk-free interest rate | 0.75% | 0.90% |
| Expected lives (in years) | '4 years | '4 years |
Summary_of_Information_Regardi
| Summary of Information Regarding Stock Options (Detail) (USD $) | 9 Months Ended |
| In Thousands, except Share data, unless otherwise specified | Sep. 28, 2013 |
| Number of Options | ' |
| Beginning Balance, number of options | 1,781,182 |
| Granted, number of options | 152,500 |
| Exercised, number of options | -416,466 |
| Forfeited, number of options | -47,300 |
| Ending Balance, number of options | 1,469,916 |
| Options exercisable at the ending, Number of Options | 695,416 |
| Weighted Average Exercise Price per Share | ' |
| Beginning Balance, Weighted Average Exercise Price per Share | $42.56 |
| Granted, Weighted Average Exercise Price per Share | $56.40 |
| Exercised, Weighted Average Exercise Price per Share | $40.52 |
| Forfeited, Weighted Average Exercise Price per Share | $41.88 |
| Ending Balance, Weighted Average Exercise Price per Share | $44.60 |
| Options exercisable at September 28, 2013 | $42.27 |
| Weighted Average Remaining Contractual Term (years) | ' |
| Options outstanding at September 28, 2013 | '6 years |
| Options exercisable at September 28, 2013 | '4 years 3 months 18 days |
| Aggregate Intrinsic Value | ' |
| Options outstanding at September 28, 2013 | $16,026 |
| Options exercisable at September 28, 2013 | $9,197 |
Schedule_of_Information_on_Non
| Schedule of Information on Non-Vested Restricted Stock (Detail) (Non-Vested Restricted Stock, USD $) | 9 Months Ended |
| Sep. 28, 2013 | |
| Non-Vested Restricted Stock | ' |
| Number of Shares | ' |
| Beginning Balance | 34,719 |
| Granted | 13,449 |
| Vested | -11,975 |
| Ending Balance | 36,193 |
| Weighted Average Grant Date Fair Value | ' |
| Beginning Balance | $42.75 |
| Granted | $54.56 |
| Vested | $45.61 |
| Ending Balance | $46.19 |
Information_Regarding_Outstand
| Information Regarding Outstanding Restricted Stock Units Awards (Detail) (Restricted Stock Units (RSUs), USD $) | 9 Months Ended |
| Sep. 28, 2013 | |
| Restricted Stock Units (RSUs) | ' |
| Number of Shares | ' |
| Beginning Balance | 113,000 |
| Granted | 244,500 |
| Vested | -21,901 |
| Forfeited | -7,046 |
| Ending Balance | 328,553 |
| Weighted Average Grant Date Fair Value | ' |
| Beginning Balance | $44.78 |
| Granted | $51.19 |
| Vested | $44.78 |
| Forfeited | $45.45 |
| Ending Balance | $49.54 |
Income_Taxes_Additional_Inform
| Income Taxes - Additional Information (Detail) | 9 Months Ended | 12 Months Ended | |
| Sep. 28, 2013 | Sep. 29, 2012 | Dec. 28, 2013 | |
| Scenario, Forecast | |||
| Income Taxes [Line Items] | ' | ' | ' |
| Effective income tax rate | 37.70% | 37.80% | 38.20% |
Reconciliation_of_Average_Numb
| Reconciliation of Average Number of Common Shares Outstanding to Average Number of Diluted Shares Outstanding (Detail) | 3 Months Ended | 9 Months Ended | ||
| Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 | |
| Earnings Per Share Disclosure [Line Items] | ' | ' | ' | ' |
| Average number of common shares outstanding | 45,708,000 | 46,614,000 | 46,156,000 | 46,775,000 |
| Incremental shares from assumed exercises of stock options | 148,000 | 118,000 | 167,000 | 189,000 |
| Average number of common shares and common share equivalents outstanding | 45,856,000 | 46,732,000 | 46,323,000 | 46,964,000 |
Earnings_Per_Share_Additional_
| Earnings Per Share - Additional Information (Detail) | 3 Months Ended | 9 Months Ended | ||
| Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 | |
| Earnings Per Share Disclosure [Line Items] | ' | ' | ' | ' |
| Stock options to purchase share of common stock excluded from calculation of diluted earnings per share because they were antidilutive | 149,000 | 323,000 | 149,000 | 2,000 |
Additional_Cash_Flow_Informati1
| Additional Cash Flow Information - Additional Information (Detail) (USD $) | 9 Months Ended | |
| Sep. 28, 2013 | Sep. 29, 2012 | |
| Schedule of Cash Flow, Supplemental [Line Items] | ' | ' |
| Income taxes paid | $44,966,000 | $48,528,000 |
| Interest paid | 2,347,000 | 2,331,000 |
| Acquired operating property by capital leases | $47,917,000 | $42,952,000 |
Information_Regarding_Reportab
| Information Regarding Reportable Business Segments (Detail) (USD $) | 3 Months Ended | 9 Months Ended | |||
| In Thousands, unless otherwise specified | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 | Dec. 29, 2012 |
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ' |
| External revenue | $680,521 | $717,168 | $1,988,182 | $2,102,164 | ' |
| Investment income | 366 | 393 | 1,111 | 1,185 | ' |
| Internal revenue | 5,999 | 5,990 | 22,808 | 22,457 | ' |
| Operating income | 47,780 | 54,379 | 141,179 | 156,318 | ' |
| Expenditures on long-lived assets | 2,117 | 1,446 | 4,866 | 4,428 | ' |
| Goodwill | 57,470 | 57,470 | 57,470 | 57,470 | 57,470 |
| Transportation Logistics | ' | ' | ' | ' | ' |
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ' |
| External revenue | 671,390 | 708,081 | 1,960,949 | 2,075,475 | ' |
| Operating income | 42,206 | 43,881 | 121,191 | 130,009 | ' |
| Expenditures on long-lived assets | 2,117 | 1,446 | 4,866 | 4,428 | ' |
| Goodwill | 57,470 | 57,470 | 57,470 | 57,470 | ' |
| Insurance | ' | ' | ' | ' | ' |
| Segment Reporting Information [Line Items] | ' | ' | ' | ' | ' |
| External revenue | 9,131 | 9,087 | 27,233 | 26,689 | ' |
| Investment income | 366 | 393 | 1,111 | 1,185 | ' |
| Internal revenue | 5,999 | 5,990 | 22,808 | 22,457 | ' |
| Operating income | $5,574 | $10,498 | $19,988 | $26,309 | ' |
Segment_Information_Additional
| Segment Information - Additional Information (Detail) | 3 Months Ended | 9 Months Ended |
| Sep. 29, 2012 | Sep. 28, 2013 | |
| Customer | Customer | |
| Segment Reporting Information [Line Items] | ' | ' |
| Number of customers accounting for 10 percent or more of total revenue | 0 | 0 |
| No single customer accounted for benchmark percentage to be considered major customer | 10.00% | 10.00% |
Components_of_and_Changes_in_A
| Components of and Changes in Accumulated Other Comprehensive Income, Net of Related Income Taxes (Detail) (USD $) | 3 Months Ended | 9 Months Ended | ||
| In Thousands, unless otherwise specified | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 |
| Accumulated Other Comprehensive Income (Loss) [Line Items] | ' | ' | ' | ' |
| Beginning Balance | ' | ' | $1,370 | ' |
| Other comprehensive loss | 305 | 668 | -1,004 | 852 |
| Ending Balance | 366 | ' | 366 | ' |
| Unrealized Gains (Losses) on Available-for-Sale Securities | ' | ' | ' | ' |
| Accumulated Other Comprehensive Income (Loss) [Line Items] | ' | ' | ' | ' |
| Beginning Balance | ' | ' | 908 | ' |
| Other comprehensive loss | ' | ' | -620 | ' |
| Ending Balance | 288 | ' | 288 | ' |
| Foreign Currency Translation | ' | ' | ' | ' |
| Accumulated Other Comprehensive Income (Loss) [Line Items] | ' | ' | ' | ' |
| Beginning Balance | ' | ' | 462 | ' |
| Other comprehensive loss | ' | ' | -384 | ' |
| Ending Balance | $78 | ' | $78 | ' |
Investments_Additional_Informa
| Investments - Additional Information (Detail) (USD $) | 3 Months Ended | 9 Months Ended |
| Dec. 29, 2012 | Sep. 28, 2013 | |
| Y | Y | |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Investments, maximum maturity period, years | 5 | 5 |
| Unrealized gains, net of unrealized losses, on the investments in the bond portfolio | $1,407,000 | $446,000 |
Amortized_Cost_and_Fair_Value_
| Amortized Cost and Fair Value of Available for Sale Investments (Detail) (USD $) | Sep. 28, 2013 | Dec. 29, 2012 |
| In Thousands, unless otherwise specified | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Amortized Cost | $101,837 | $90,995 |
| Gross Unrealized Gains | 861 | 1,414 |
| Gross Unrealized Losses | 415 | 7 |
| Fair Value | 102,283 | 92,402 |
| Money market investments | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Amortized Cost | 1,172 | 2,865 |
| Fair Value | 1,172 | 2,865 |
| Asset-backed securities | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Amortized Cost | 4,436 | 2,175 |
| Gross Unrealized Gains | 25 | 73 |
| Gross Unrealized Losses | 73 | ' |
| Fair Value | 4,388 | 2,248 |
| Corporate bonds and direct obligations of government agencies | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Amortized Cost | 77,439 | 69,173 |
| Gross Unrealized Gains | 798 | 1,294 |
| Gross Unrealized Losses | 332 | 6 |
| Fair Value | 77,905 | 70,461 |
| U.S. Treasury Obligations | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Amortized Cost | 18,790 | 16,782 |
| Gross Unrealized Gains | 38 | 47 |
| Gross Unrealized Losses | 10 | 1 |
| Fair Value | $18,818 | $16,828 |
Schedule_of_Unrealized_Loss_on
| Schedule of Unrealized Loss on Available for Sale Investments (Detail) (USD $) | Sep. 28, 2013 | Dec. 29, 2012 |
| In Thousands, unless otherwise specified | ||
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value | $29,007 | $4,157 |
| Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss | 415 | 7 |
| Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value | ' | ' |
| Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss | ' | ' |
| Available-for-sale investments with unrealized losses, Fair Value, Total | 29,007 | 4,157 |
| Available-for-sale investments with unrealized losses, Unrealized Loss, Total | 415 | 7 |
| Asset-backed securities | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value | 3,456 | ' |
| Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss | 73 | ' |
| Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value | ' | ' |
| Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss | ' | ' |
| Available-for-sale investments with unrealized losses, Fair Value, Total | 3,456 | ' |
| Available-for-sale investments with unrealized losses, Unrealized Loss, Total | 73 | ' |
| Corporate bonds and direct obligations of government agencies | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value | 24,792 | 3,387 |
| Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss | 332 | 6 |
| Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value | ' | ' |
| Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss | ' | ' |
| Available-for-sale investments with unrealized losses, Fair Value, Total | 24,792 | 3,387 |
| Available-for-sale investments with unrealized losses, Unrealized Loss, Total | 332 | 6 |
| U.S. Treasury Obligations | ' | ' |
| Schedule of Available-for-sale Securities [Line Items] | ' | ' |
| Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value | 759 | 770 |
| Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss | 10 | 1 |
| Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value | ' | ' |
| Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss | ' | ' |
| Available-for-sale investments with unrealized losses, Fair Value, Total | 759 | 770 |
| Available-for-sale investments with unrealized losses, Unrealized Loss, Total | $10 | $1 |
Commitments_and_Contingencies_
| Commitments and Contingencies - Additional Information (Detail) (USD $) | 1 Months Ended | 3 Months Ended | 9 Months Ended | 1 Months Ended | 9 Months Ended | 12 Months Ended | 1 Months Ended | |||||||||
| 28-May-13 | Sep. 28, 2013 | Sep. 29, 2012 | Sep. 28, 2013 | Sep. 29, 2012 | Dec. 29, 2012 | Sep. 28, 2013 | 28-May-13 | Sep. 28, 2013 | Dec. 31, 2007 | Mar. 31, 2007 | 28-May-13 | 28-May-13 | Sep. 28, 2013 | Sep. 28, 2013 | Sep. 28, 2013 | |
| Credit Agreement | Damage Award | Damage Award | Damage Award | Damage Award | Prejudgment Interest | Attorney Fees and Post-judgment Interest | Guarantee Payment Of Insurance Claims | Current Investments | Non-Current Investments | |||||||
| Commitments and Contingencies Disclosure [Line Items] | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' |
| Investments providing collateral for letters of credit to guarantee insurance claims | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | $30,477,000 | $31,251,000 |
| Cash equivalents providing collateral for letters of credit to guarantee insurance claims | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 4,091,000 | ' |
| Total non-current investments | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 71,806,000 |
| Letters of credit outstanding | ' | ' | ' | ' | ' | ' | 34,751,000 | ' | ' | ' | ' | ' | ' | 59,646,000 | ' | ' |
| Aggregate damage awarded | 55,200,000 | ' | ' | ' | ' | ' | ' | 40,200,000 | 60,700,000 | ' | ' | 1,000,000 | 14,000,000 | ' | ' | ' |
| Post-judgment interest rate | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 6.25% | ' | ' | ' |
| Operating insurance and claims costs, production | ' | 13,386,000 | 8,010,000 | 37,040,000 | 28,411,000 | ' | ' | ' | ' | 5,000,000 | ' | ' | ' | ' | ' | ' |
| Retained liability of self-insurance program | ' | ' | ' | ' | ' | ' | ' | ' | ' | ' | 5,000,000 | ' | ' | ' | ' | ' |
| Other receivables | ' | $77,169,000 | ' | $77,169,000 | ' | $55,278,000 | ' | ' | $60,700,000 | ' | ' | ' | ' | ' | ' | ' |