CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 26, 2021	Sep. 27, 2020
Cash flows from operating activities
Net income	$ 150,082	$ 90,094
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	43,529	46,368
Lease termination charge	3,831	0
Amortization of right of use asset	7,069	6,446
Stock-based compensation expense	14,387	10,744
Gain on non-marketable equity investment	(27,156)	(10,074)
Change in long-term retirement benefit obligations	(13,440)	(11,635)
Other – net	(256)	(5,505)
Changes in operating assets and liabilities:
Accounts receivable – net	19,072	88,065
Other assets	(13,192)	3,816
Accounts payable, accrued payroll and other liabilities	15,311	(23,366)
Unexpired subscriptions	10,320	11,730
Net cash provided by operating activities	209,557	206,683
Cash flows from investing activities
Purchases of marketable securities	(550,649)	(460,117)
Maturities of marketable securities	421,679	331,786
Business acquisitions	0	(33,085)
Sales of investments – net	20,569	1,000
Capital expenditures	(23,750)	(29,236)
Other-net	2,466	2,388
Net cash used in investing activities	(129,685)	(187,264)
Long-term obligations:
Dividends paid	(33,627)	(28,393)
Payment of contingent consideration	(862)	(862)
Capital shares:
Proceeds from stock option exercises	2,451	5,307
Share-based compensation tax withholding	(10,916)	(11,723)
Net cash used in financing activities	(42,954)	(35,671)
Net increase (decrease) in cash, cash equivalents and restricted cash	36,918	(16,252)
Effect of exchange rate changes on cash	(560)	349
Cash, cash equivalents and restricted cash at the beginning of the period	301,964	247,518
Cash, cash equivalents and restricted cash at the end of the period	$ 338,322	$ 231,615