Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 192,850	$ 92,274
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	165,420	213,792
Gain on disposal of property and equipment—net	(891)	(221)
Amortization and write-off of deferred financing costs	4,710	2,358
Deferred tax provision	38,356	18,075
Share-based compensation expense	17,324	8,553
Provision for doubtful accounts	9,078	8,975
Changes in operating assets and liabilities, net of business acquisitions:
Increase in receivables	(98,191)	(188,565)
(Increase) decrease in inventories	(420)	4,179
Increase in prepaid expenses and other assets	(18,663)	(20,634)
Increase in accounts payable and bank checks outstanding	174,579	276,493
Decrease in accrued expenses and other liabilities	(173,498)	(46,807)
Net cash provided by operating activities	310,654	368,472
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of businesses—net of cash	(299)	(134,808)
Proceeds from sales of property and equipment	2,124	1,679
Purchases of property and equipment	(117,396)	(107,967)
Proceeds from redemption of industrial revenue bonds	0	22,139
Net cash used in investing activities	(115,571)	(218,957)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from debt borrowings	2,151,107	1,117,267
Principal payments on debt and capital leases	(2,382,384)	(1,212,792)
Redemption of industrial revenue bonds	0	(22,139)
Contingent consideration paid for business acquisitions	(1,560)	(5,000)
Payment for debt financing costs and fees	(823)	(426)
Proceeds from employee share purchase plan	10,116	7,729
Proceeds from exercise of stock options	15,605	10,944
Tax withholding payments for net share-settled equity awards	(5,646)	(25,693)
Common stock and share-based awards settled	(133)	(497)
Net cash used in financing activities	(213,718)	(130,607)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(18,635)	18,908
CASH, CASH EQUIVALENTS AND RESTRICTED CASH—Beginning of period	119,184	131,436
CASH, CASH EQUIVALENTS AND RESTRICTED CASH—End of period	100,549	150,344
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest (net of amounts capitalized)	87,701	79,135
Income taxes paid—net	41,530	2,862
NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases included in accounts payable	13,375	17,405
Capital lease additions	68,163	60,730
Cashless exercise of equity awards	1,221	25,535
Contingent consideration payable for business acquisitions	$ 0	$ 4,200