Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 26, 2015	Sep. 27, 2014
OPERATING ACTIVITIES
Net income	$ 109,834	$ 100,318
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property	21,253	20,419
Non-cash interest charges	164	164
Provisions for losses on trade and other accounts receivable	4,667	3,823
Gains on sales/disposals of operating property	(278)	(1,955)
Deferred income taxes, net	957	(3,346)
Stock-based compensation	4,939	4,218
Changes in operating assets and liabilities:
Decrease (increase) in trade and other accounts receivable	23,262	(19,021)
Decrease (increase) in other assets	5,830	(2,427)
(Decrease) increase in accounts payable	(14,563)	45,407
Decrease in other liabilities	(3,849)	(10,998)
Decrease in insurance claims	(4,132)	(64,005)
NET CASH PROVIDED BY OPERATING ACTIVITIES	148,084	72,597
INVESTING ACTIVITIES
Net change in other short-term investments		(4,979)
Sales and maturities of investments	29,545	25,027
Purchases of investments	(34,751)	(26,425)
Purchases of operating property	(3,798)	(9,131)
Proceeds from sales of operating property	1,567	6,160
NET CASH USED BY INVESTING ACTIVITIES	(7,437)	(9,348)
FINANCING ACTIVITIES
(Decrease) increase in cash overdraft	(4,963)	4,452
Dividends paid	(54,467)	(24,472)
Proceeds from exercises of stock options	1,076	2,974
Taxes paid in lieu of shares issued related to stock-based compensation plans	(2,176)	(2,419)
Excess tax benefits from stock-based awards	652	1,327
Purchases of common stock	(107,214)	(56,393)
Principal payments on long-term debt and capital lease obligations	(26,972)	(28,111)
NET CASH USED BY FINANCING ACTIVITIES	(194,064)	(102,642)
Effect of exchange rate changes on cash and cash equivalents	(1,628)	(318)
Decrease in cash and cash equivalents	(55,045)	(39,711)
Cash and cash equivalents at beginning of period	163,944	180,302
Cash and cash equivalents at end of period	$ 108,899	$ 140,591