CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Dec. 25, 2010
OPERATING ACTIVITIES
Net income	$ 129,781	$ 112,945	$ 86,582
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property and intangible assets	27,456	25,814	24,804
Non-cash interest charges	218	218	219
Provisions for losses on trade and other accounts receivable	4,984	7,804	3,916
Losses (gains) on sales/disposals of operating property	(2,795)	(266)	1,058
Deferred income taxes, net	4,261	10,071	525
Stock-based compensation	6,149	5,012	4,769
Changes in operating assets and liabilities:
Increase in trade and other accounts receivable	(47,409)	(98,151)	(38,206)
Decrease (increase) in other assets	3,206	1,871	(1,752)
Increase in accounts payable	25,674	26,010	16,267
Increase (decrease) in other liabilities	(8,228)	(5,729)	11,200
Increase (decrease) in insurance claims	(17,713)	32,435	(624)
NET CASH PROVIDED BY OPERATING ACTIVITIES	125,584	118,034	108,758
INVESTING ACTIVITIES
Net change in other short-term investments			1,730
Sales and maturities of investments	33,028	67,174	39,187
Purchases of investments	(56,897)	(58,413)	(65,818)
Purchases of operating property	(7,072)	(4,337)	(27,505)
Proceeds from sales of operating property	9,730	4,385	1,686
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES	(21,211)	8,809	(50,720)
FINANCING ACTIVITIES
Increase (decrease) in cash overdraft	7,742	1,028	(4,042)
Dividends paid	(33,981)	(9,983)	(9,422)
Proceeds from exercises of stock options	1,360	923	1,660
Excess (shortfall) tax effect on stock option exercises	751	(683)	1,580
Borrowings on revolving credit facility	60,000	10,000	40,000
Purchases of common stock	(25,826)	(50,450)	(102,736)
Principal payments on long-term debt and capital lease obligations	(121,278)	(33,313)	(26,273)
Purchase of noncontrolling interest		(8,000)
NET CASH USED BY FINANCING ACTIVITIES	(111,232)	(90,478)	(99,233)
Effect of exchange rate changes on cash and cash equivalents	243	(171)	182
Increase (decrease) in cash and cash equivalents	(6,616)	36,194	(41,013)
Cash and cash equivalents at beginning of period	80,900	44,706	85,719
Cash and cash equivalents at end of period	$ 74,284	$ 80,900	$ 44,706