Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Jan. 01, 2021	Jan. 01, 2021	Jan. 03, 2020	Jan. 03, 2020
Cash flows from operating activities:
Net income	$ 101,202,000		$ 82,552,000	$ 82,460,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and leasehold improvements	6,487,000		6,871,000	6,806,000
Amortization of premiums and accretion of discounts on short-term investments	(11,000)		(163,000)	(516,000)
Provision for contract losses and doubtful accounts	1,958,000		1,849,000	2,224,000
Stock-based compensation	19,263,000	$ 17,278,000	17,278,000	17,466,000	$ 17,466,000
Deferred income tax provision	(6,005,000)		(3,639,000)	(2,845,000)
Changes in operating assets and liabilities:
Accounts receivable	(30,254,000)		6,724,000	(16,548,000)
Prepaid expenses and other current assets	(4,407,000)		(9,075,000)	(3,343,000)
Change in operating leases	(406,000)		(91,000)	205,000
Accounts payable and accrued liabilities	8,443,000		(2,646,000)	6,715,000
Accrued payroll and employee benefits	20,336,000		4,562,000	11,891,000
Deferred revenues	7,962,000		(910,000)	3,544,000
Net cash provided by operating activities	124,568,000		103,312,000	108,059,000
Cash flows from investing activities:
Capital expenditures	(6,826,000)		(4,987,000)	(23,038,000)
Purchase of short-term investments	(34,994,000)		(39,989,000)	(38,693,000)
Maturity of short-term investments	79,998,000		50,000,000	66,000,000
Net cash provided by investing activities	38,178,000		5,024,000	4,269,000
Cash flows from financing activities:
Payroll taxes for restricted stock units	(15,666,000)		(15,263,000)	(11,183,000)
Repurchase of common stock	(7,000,000)		(40,049,000)	(21,957,000)
Exercise of stock-based payment awards	3,111,000		6,732,000	3,229,000
Dividends and dividend equivalent rights	(43,198,000)		(39,775,000)	(33,503,000)
Net cash used in financing activities	(62,753,000)		(88,355,000)	(63,414,000)
Effect of foreign currency exchange rates on cash and cash equivalents	169,000		1,108,000	463,000
Net increase in cash and cash equivalents	100,162,000		21,089,000	49,377,000
Cash and cash equivalents at beginning of year	197,525,000		176,436,000	127,059,000
Cash and cash equivalents at end of year	$ 297,687,000	$ 197,525,000	$ 197,525,000	$ 176,436,000	$ 176,436,000