Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
OPERATING ACTIVITIES
Net income	$ 177,655	$ 186,913
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of operating property and intangible assets	33,045	32,520
Non-cash interest charges	190	190
Provisions for losses on trade and other accounts receivable	6,942	5,360
Gains on sales/disposals of operating property	(1,188)	(1,025)
Deferred income taxes, net	7,151	7,459
Stock-based compensation	4,470	13,003
Changes in operating assets and liabilities:
Decrease (increase) in trade and other accounts receivable	84,607	(60,785)
Increase in other assets	(21,129)	(9,779)
(Decrease) increase in accounts payable	(28,692)	22,121
(Decrease) increase in other liabilities	(16,076)	3,245
Increase in insurance claims	13,739	4,983
NET CASH PROVIDED BY OPERATING ACTIVITIES	260,714	204,205
INVESTING ACTIVITIES
Sales and maturities of investments	56,467	34,259
Purchases of investments	(58,829)	(36,296)
Purchases of operating property	(15,199)	(7,325)
Proceeds from sales of operating property	3,621	3,542
NET CASH USED BY INVESTING ACTIVITIES	(13,940)	(5,820)
FINANCING ACTIVITIES
Decrease in cash overdraft	(10,714)	(2,483)
Dividends paid	(20,589)	(82,261)
Proceeds from exercises of stock options	629	1,397
Taxes paid in lieu of shares issued related to stock-based compensation plans	(8,449)	(3,936)
Purchases of common stock	(88,578)	(105,488)
Principal payments on finance lease obligations	(34,141)	(32,663)
Purchase of noncontrolling interest	(600)
Payment of contingent consideration		(985)
NET CASH USED BY FINANCING ACTIVITIES	(162,442)	(226,419)
Effect of exchange rate changes on cash and cash equivalents	366	(408)
Increase (decrease) in cash and cash equivalents	84,698	(28,442)
Cash and cash equivalents at beginning of period	199,736	242,416
Cash and cash equivalents at end of period	$ 284,434	$ 213,974