CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Cash flows relating to operating activities
Net income	$ 365,306	$ 254,061	$ 228,724
Less: Income from discontinued operations, net of income taxes	0	0	1,506
Income from continuing operations, net of income taxes	365,306	254,061	227,218
Adjustments to reconcile net income from continuing operations to net cash provided by operating activities:
Depreciation and amortization	234,924	198,095	161,779
Stock-based compensation	56,341	57,271	47,346
Deferred income taxes	(133)	(21,895)	(9,702)
Gain on venture capital and strategic equity investments, net	(100,861)	(20,706)	(15,928)
Other, net	17,273	7,931	15,613
Changes in assets and liabilities:
Trade receivables, net	(85,627)	(8,323)	(21,196)
Inventories	(18,379)	(21,399)	(13,338)
Accounts payable	748	29,775	(12,732)
Accrued compensation	40,481	3,394	31,616
Deferred revenue	28,647	(3,620)	36,072
Customer contract deposits	8,955	(10,898)	28,115
Other assets and liabilities, net	(1,100)	17,250	(33,723)
Net cash provided by operating activities	546,575	480,936	441,140
Cash flows relating to investing activities
Acquisition of businesses and assets, net of cash acquired	(418,628)	(515,701)	(824,868)
Capital expenditures	(166,560)	(140,514)	(140,054)
Purchases of investments and contributions to venture capital investments	(26,692)	(22,341)	(25,125)
Proceeds from sale of investments	11,401	942	35,849
Other, net	(1,065)	(3,888)	(805)
Net cash used in investing activities	(601,544)	(681,502)	(955,003)
Cash flows relating to financing activities
Proceeds from long-term debt and revolving credit facility	2,230,988	3,358,461	2,755,028
Proceeds from exercises of stock options	46,586	34,546	37,657
Payments on long-term debt, revolving credit facility, and finance lease obligations	(2,200,400)	(3,124,588)	(2,201,003)
Payments on debt financing costs	0	(6,593)	(18,337)
Purchase of treasury stock	(23,979)	(18,087)	(13,846)
Other, net	(5,947)	(11,802)	(1,440)
Net cash provided by financing activities	47,248	231,937	558,059
Discontinued operations
Net cash used in operating activities from discontinued operations	0	0	(3,735)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	794	11,357	(9,474)
Net change in cash, cash equivalents, and restricted cash	(6,927)	42,728	30,987
Cash, cash equivalents, and restricted cash, beginning of period	240,046	197,318	166,331
Cash, cash equivalents, and restricted cash, end of period	233,119	240,046	197,318
Supplemental cash flow information:
Cash, cash equivalents, and restricted cash, end of period	233,119	197,318	197,318
Cash paid for income taxes	60,059	54,060	67,600
Cash paid for interest	72,461	67,813	47,540
Non-cash investing and financing activities:
Additions to property, plant and equipment, net	25,614	21,447	18,212
Assets acquired under finance leases	$ 1,571	$ 4,819	$ 1,473