Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014
OPERATING ACTIVITIES
Net income	$ 70,486	$ 63,563
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property	14,068	13,333
Non-cash interest charges	109	109
Provisions for losses on trade and other accounts receivable	3,344	2,650
Gains on sales/disposals of operating property	(178)	(736)
Deferred income taxes, net	1,859	1,304
Stock-based compensation	3,243	2,799
Changes in operating assets and liabilities:
Decrease (increase) in trade and other accounts receivable	1,147	(64,709)
Decrease (increase) in other assets	1,596	(15,592)
(Decrease) increase in accounts payable	(3,270)	37,539
Decrease in other liabilities	(9,999)	(11,939)
Decrease in insurance claims	(388)	(14,721)
NET CASH PROVIDED BY OPERATING ACTIVITIES	82,017	13,600
INVESTING ACTIVITIES
Net change in other short-term investments		(3,225)
Sales and maturities of investments	16,656	20,830
Purchases of investments	(20,052)	(21,807)
Purchases of operating property	(3,050)	(1,354)
Proceeds from sales of operating property	1,281	2,410
NET CASH USED BY INVESTING ACTIVITIES	(5,165)	(3,146)
FINANCING ACTIVITIES
Decrease in cash overdraft	(2,912)	(578)
Dividends paid	(50,980)	(21,341)
Proceeds from exercises of stock options	534	2,111
Taxes paid in lieu of shares issued related to stock-based compensation plans	(2,083)	(1,724)
Excess tax benefits from stock-based awards	516	669
Purchases of common stock	(84,635)	(56,393)
Principal payments on long-term debt and capital lease obligations	(18,112)	(20,110)
NET CASH USED BY FINANCING ACTIVITIES	(157,672)	(97,366)
Effect of exchange rate changes on cash and cash equivalents	(698)	(257)
Decrease in cash and cash equivalents	(81,518)	(87,169)
Cash and cash equivalents at beginning of period	163,944	180,302
Cash and cash equivalents at end of period	$ 82,426	$ 93,133