Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jul. 01, 2017	Jun. 25, 2016
OPERATING ACTIVITIES
Net income	$ 69,893	$ 61,498
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property	19,831	17,093
Non-cash interest charges	127	112
Provisions for losses on trade and other accounts receivable	3,601	2,951
Gains on sales/disposals of operating property	(701)	(1,761)
Deferred income taxes, net	1,766	6,043
Stock-based compensation	2,237	2,066
Changes in operating assets and liabilities:
(Increase) decrease in trade and other accounts receivable	(22,917)	57,274
Increase in other assets	(12,658)	(2,939)
Increase (decrease) in accounts payable	8,829	(36,238)
Increase (decrease) in other liabilities	3,316	(8,907)
Increase in insurance claims	6,475	7,943
NET CASH PROVIDED BY OPERATING ACTIVITIES	79,799	105,135
INVESTING ACTIVITIES
Sales and maturities of investments	33,486	23,454
Purchases of investments	(34,360)	(24,377)
Purchases of operating property	(6,628)	(8,955)
Proceeds from sales of operating property	2,793	4,791
NET CASH USED BY INVESTING ACTIVITIES	(4,709)	(5,087)
FINANCING ACTIVITIES
Decrease in cash overdraft	(2,106)	(5,254)
Dividends paid	(7,544)	(6,782)
Proceeds from exercises of stock options	1,962	900
Taxes paid in lieu of shares issued related to stock-based compensation plans	(365)	(1,690)
Excess tax benefits from stock-based awards		277
Purchases of common stock		(26,485)
Principal payments on capital lease obligations	(24,417)	(23,001)
NET CASH USED BY FINANCING ACTIVITIES	(32,470)	(62,035)
Effect of exchange rate changes on cash and cash equivalents	585	837
Increase in cash and cash equivalents	43,205	38,850
Cash and cash equivalents at beginning of period	178,897	114,520
Cash and cash equivalents at end of period	$ 222,102	$ 153,370