Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2020	Mar. 29, 2019
Cash flows from operating activities:
Net income	$ 26,282	$ 22,712
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization of property, equipment and leasehold improvements	1,786	1,590
Amortization of premiums and accretion of discounts on short-term investments	(60)	(132)
Provision for contract losses and doubtful accounts	2,383	788
Stock-based compensation	6,138	5,731
Deferred income tax provision	1,614	161
Changes in operating assets and liabilities:
Accounts receivable	(9,457)	(13,838)
Prepaid expenses and other current assets	(12,561)	(10,431)
Change in operating leases	(707)	(425)
Accounts payable and accrued liabilities	(4,110)	(333)
Accrued payroll and employee benefits	(24,117)	(16,477)
Deferred revenues	(1,026)	(1,599)
Net cash used in operating activities	(13,835)	(12,253)
Cash flows from investing activities:
Capital expenditures	(1,293)	(5,670)
Purchase of short-term investments		(23,848)
Maturity of short-term investments	9,000	13,000
Net cash provided by (used in) investing activities	7,707	(16,518)
Cash flows from financing activities:
Payroll taxes for restricted stock units	(15,112)	(11,194)
Repurchase of common stock	(40,049)
Exercise of stock-based payment awards	1,145	372
Dividends and dividend equivalents rights	(10,308)	(8,593)
Net cash used in financing activities	(64,324)	(19,415)
Effect of foreign currency exchange rates on cash and cash equivalents	(390)	207
Net decrease in cash and cash equivalents	(70,842)	(47,979)
Cash and cash equivalents at beginning of period	176,436	127,059
Cash and cash equivalents at end of period	$ 105,594	$ 79,080