Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 24, 2011	Sep. 25, 2010
OPERATING ACTIVITIES
Net income	$ 80,313	$ 62,703
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property and intangible assets	19,336	18,444
Non-cash interest charges	164	164
Provisions for losses on trade and other accounts receivable	4,308	3,539
Losses (gains) on sales/disposals of operating property	(253)	570
Deferred income taxes, net	(4,205)	(1,592)
Stock-based compensation	3,783	3,567
Changes in operating assets and liabilities:
Increase in trade and other accounts receivable	(114,765)	(49,502)
Decrease in other assets	3,957	323
Increase in accounts payable	43,191	25,677
Increase in other liabilities	14,401	10,582
Increase (decrease) in insurance claims	34,164	(6,192)
NET CASH PROVIDED BY OPERATING ACTIVITIES	84,394	68,283
INVESTING ACTIVITIES
Net change in other short-term investments		149
Sales and maturities of investments	65,646	31,145
Purchases of investments	(58,279)	(60,865)
Purchases of operating property	(3,460)	(25,474)
Proceeds from sales of operating property	2,463	948
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES	6,370	(54,097)
FINANCING ACTIVITIES
Decrease in cash overdraft	(1,816)	(6,422)
Dividends paid	(7,407)	(7,003)
Proceeds from exercises of stock options	656	1,527
Excess (shortfall) tax effect on stock option exercises	(122)	1,556
Borrowings on revolving credit facility	10,000	40,000
Purchases of common stock	(41,966)	(54,647)
Principal payments on capital lease obligations	(17,575)	(19,912)
Purchase of noncontrolling interest	(8,000)
NET CASH USED BY FINANCING ACTIVITIES	(66,230)	(44,901)
Effect of exchange rate changes on cash and cash equivalents	169	71
Increase (decrease) in cash and cash equivalents	24,703	(30,644)
Cash and cash equivalents at beginning of period	44,706	85,719
Cash and cash equivalents at end of period	$ 69,409	$ 55,075