Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020
OPERATING ACTIVITIES
Net income	$ 169,534	$ 65,149
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property and intangible assets	24,244	22,972
Non-cash interest charges	224	126
Provisions for losses on trade and other accounts receivable	1,393	6,528
Gains on sales/disposals of operating property	(766)	(1,812)
Impairment of intangible and other assets	0	2,582
Deferred income taxes, net	6,240	6,228
Stock-based compensation	10,893	1,201
Changes in operating assets and liabilities:
(Increase) decrease in trade and other accounts receivable	(55,236)	99,601
Increase in other assets	(24,704)	(24,809)
Increase (decrease) in accounts payable	101,206	(31)
Increase in other liabilities	7,882	10,231
(Decrease) increase in insurance claims	(103,734)	10,419
NET CASH PROVIDED BY OPERATING ACTIVITIES	137,176	198,385
INVESTING ACTIVITIES
Net changes in other short-term investments	0	131
Sales and maturities of investments	17,242	14,897
Purchases of investments	(68,366)	(16,382)
Purchases of operating property	(9,000)	(17,676)
Proceeds from sales of operating property	1,438	4,465
Consideration paid for acquisition	0	(2,701)
NET CASH USED BY INVESTING ACTIVITIES	(58,686)	(17,266)
FINANCING ACTIVITIES
Decrease in cash overdraft	(4,194)	(18,344)
Dividends paid	(92,905)	(93,382)
Proceeds from exercises of stock options	77	614
Taxes paid in lieu of shares issued related to stock-based compensation plans	(2,341)	(3,280)
Purchases of common stock	(23,837)	(115,962)
Principal payments on finance lease obligations	(19,143)	(21,958)
Payment of deferred consideration	(168)	0
NET CASH USED BY FINANCING ACTIVITIES	(142,511)	(252,312)
Effect of exchange rate changes on cash and cash equivalents	1,071	(2,851)
Decrease in cash and cash equivalents	(62,950)	(74,044)
Cash and cash equivalents at beginning of period	249,354	319,515
Cash and cash equivalents at end of period	$ 186,404	$ 245,471