CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 27, 2021	Jun. 28, 2020
Cash flows from operating activities
Net income	$ 95,426	$ 56,516
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	29,203	30,816
Lease termination charge	3,831	0
Amortization of right of use asset	4,442	4,645
Stock-based compensation expense	9,338	7,482
Gain on non-marketable equity investment	0	(10,074)
Long-term retirement benefit obligations	(8,866)	(8,524)
Other – net	(289)	475
Changes in operating assets and liabilities:
Accounts receivable – net	30,152	91,310
Other assets	(8,027)	(1,292)
Accounts payable, accrued payroll and other liabilities	(54,170)	(64,019)
Unexpired subscriptions	9,394	11,255
Net cash provided by operating activities	110,434	118,590
Cash flows from investing activities
Purchases of marketable securities	(326,996)	(278,773)
Maturities of marketable securities	293,053	228,938
Business acquisitions	0	(8,055)
Sales of investments – net	271	4,074
Capital expenditures	(14,677)	(21,510)
Other-net	2,017	2,388
Net cash used in investing activities	(46,332)	(72,938)
Long-term obligations:
Dividends paid	(21,825)	(18,359)
Capital shares:
Proceeds from stock option exercises	2,441	1,873
Share-based compensation tax withholding	(10,901)	(11,706)
Net cash used in financing activities	(30,285)	(28,192)
Net increase in cash, cash equivalents and restricted cash	33,817	17,460
Effect of exchange rate changes on cash	(280)	162
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	$ 335,501	$ 265,140