Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 25, 2016	Jun. 27, 2015
OPERATING ACTIVITIES
Net income	$ 61,498	$ 70,486
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property	17,093	14,068
Non-cash interest charges	112	109
Provisions for losses on trade and other accounts receivable	2,951	3,344
Gains on sales/disposals of operating property	(1,761)	(178)
Deferred income taxes, net	6,043	1,859
Stock-based compensation	2,066	3,243
Changes in operating assets and liabilities:
Decrease in trade and other accounts receivable	57,274	1,147
(Increase) decrease in other assets	(2,939)	1,596
Decrease in accounts payable	(36,238)	(3,270)
Decrease in other liabilities	(8,907)	(9,999)
Increase (decrease) in insurance claims	7,943	(388)
NET CASH PROVIDED BY OPERATING ACTIVITIES	105,135	82,017
INVESTING ACTIVITIES
Sales and maturities of investments	23,454	16,656
Purchases of investments	(24,377)	(20,052)
Purchases of operating property	(8,955)	(3,050)
Proceeds from sales of operating property	4,791	1,281
NET CASH USED BY INVESTING ACTIVITIES	(5,087)	(5,165)
FINANCING ACTIVITIES
Decrease in cash overdraft	(5,254)	(2,912)
Dividends paid	(6,782)	(50,980)
Proceeds from exercises of stock options	900	534
Taxes paid in lieu of shares issued related to stock-based compensation plans	(1,690)	(2,083)
Excess tax benefits from stock-based awards	277	516
Purchases of common stock	(26,485)	(84,635)
Principal payments on capital lease obligations	(23,001)	(18,112)
NET CASH USED BY FINANCING ACTIVITIES	(62,035)	(157,672)
Effect of exchange rate changes on cash and cash equivalents	837	(698)
Increase (decrease) in cash and cash equivalents	38,850	(81,518)
Cash and cash equivalents at beginning of period	114,520	163,944
Cash and cash equivalents at end of period	$ 153,370	$ 82,426