Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Oct. 01, 2021	Oct. 02, 2020
Cash flows from operating activities:
Net income	$ 80,822	$ 60,712
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and leasehold improvements	4,943	5,176
Amortization of premiums and accretion of discounts on short-term investments	(11)	(150)
Provision for contract losses and doubtful accounts	1,197	2,890
Stock-based compensation	15,239	13,326
Deferred income tax provision	(2,020)	(2,505)
Changes in operating assets and liabilities:
Accounts receivable	(33,671)	7,284
Prepaid expenses and other current assets	(4,878)	(8,439)
Change in operating leases	(472)	(331)
Accounts payable and accrued liabilities	5,784	311
Accrued payroll and employee benefits	3,053	(12,507)
Deferred revenues	392	(3,320)
Net cash provided by operating activities	70,378	62,447
Cash flows from investing activities:
Capital expenditures	(5,437)	(4,144)
Purchase of short-term investments	(34,994)
Maturity of short-term investments	55,000	35,000
Net cash provided by investing activities	14,569	30,856
Cash flows from financing activities:
Payroll taxes for restricted stock units	(15,666)	(15,263)
Repurchase of common stock	(7,000)	(40,049)
Exercise of stock-based payment awards	2,675	3,013
Dividends and dividend equivalents rights	(32,775)	(29,936)
Net cash used in financing activities	(52,766)	(82,235)
Effect of foreign currency exchange rates on cash and cash equivalents	79	128
Net change in cash and cash equivalents	32,260	11,196
Cash and cash equivalents at beginning of period	197,525	176,436
Cash and cash equivalents at end of period	$ 229,785	$ 187,632