Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Jan. 03, 2020	Dec. 28, 2018	Dec. 29, 2017
Cash flows from operating activities:
Net income	$ 82,460,000	$ 72,254,000	$ 41,305,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and leasehold improvements	6,806,000	6,292,000	6,285,000
Amortization of premiums and accretion of discounts on short-term investments	(516,000)	(114,000)
Deferred rent expense		175,000	(362,000)
Provision for contract losses and doubtful accounts	2,224,000	1,848,000	2,506,000
Stock-based compensation	17,466,000	16,993,000	16,155,000
Deferred income tax provision	(2,845,000)	(3,715,000)	11,786,000
Changes in operating assets and liabilities:
Accounts receivable	(16,548,000)	2,438,000	(25,197,000)
Prepaid expenses and other current assets	(3,343,000)	(11,047,000)	2,867,000
Change in operating leases	205,000
Accounts payable and accrued liabilities	6,715,000	(4,620,000)	5,984,000
Accrued payroll and employee benefits	11,891,000	9,820,000	5,831,000
Deferred revenues	3,544,000	864,000	678,000
Net cash provided by operating activities	108,059,000	91,188,000	67,838,000
Cash flows from investing activities:
Capital expenditures	(23,038,000)	(16,298,000)	(4,725,000)
Purchase of short-term investments	(38,693,000)	(52,522,000)	(28,997,000)
Maturity of short-term investments	66,000,000	43,000,000	16,000,000
Net cash provided by/(used in) investing activities	4,269,000	(25,820,000)	(17,722,000)
Cash flows from financing activities:
Payroll taxes for restricted stock units	(11,183,000)	(8,839,000)	(9,520,000)
Repurchase of common stock	(21,957,000)	(27,915,000)	(11,931,000)
Exercise of share-based payment awards	3,229,000	1,474,000	2,025,000
Dividends and dividend equivalent rights	(33,503,000)	(27,220,000)	(21,835,000)
Net cash used in financing activities	(63,414,000)	(62,500,000)	(41,261,000)
Effect of foreign currency exchange rates on cash and cash equivalents	463,000	(603,000)	972,000
Net increase in cash and cash equivalents	49,377,000	2,265,000	9,827,000
Cash and cash equivalents at beginning of year	127,059,000	124,794,000	114,967,000
Cash and cash equivalents at end of year	$ 176,436,000	$ 127,059,000	$ 124,794,000