Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 28, 2019	Dec. 28, 2018
Current assets:
Cash and cash equivalents	$ 104,452	$ 127,059
Short-term investments	90,022	81,495
Accounts receivable, net of allowance for contract losses and doubtful accounts of $5,342 and $4,066 at June 28, 2019 and December 28, 2018, respectively	129,735	105,814
Prepaid expenses and other current assets	10,452	12,244
Total current assets	334,661	326,612
Property, equipment and leasehold improvements, net	56,112	46,103
Operating lease right-of-use assets	22,729
Goodwill	8,607	8,607
Deferred income taxes	34,099	34,090
Deferred compensation plan assets	63,484	52,286
Other assets	949	1,238
Total assets	520,641	468,936
Current liabilities:
Accounts payable and accrued liabilities	19,678	12,283
Accrued payroll and employee benefits	58,910	76,855
Deferred revenues	8,550	9,166
Operating lease liabilities	5,746
Total current liabilities	92,884	98,304
Other liabilities	2,846	2,548
Deferred compensation plan liabilities	63,391	52,708
Deferred rent		1,467
Operating lease liabilities	17,668
Total liabilities	176,789	155,027
Stockholders’ equity:
Common stock, $0.001 par value; 120,000 shares authorized; 65,707 shares issued at June 28, 2019 and December 28, 2018	66	66
Additional paid-in capital	240,930	227,283
Accumulated other comprehensive income (loss)
Investment securities, available-for-sale	358	(45)
Foreign currency translation adjustments	(2,932)	(2,808)
Accumulated other comprehensive income (loss)	(2,574)	(2,853)
Retained earnings	362,959	342,024
Treasury stock, at cost; 13,788 and 14,208 shares held at June 28, 2019 and December 28, 2018, respectively	(257,529)	(252,611)
Total stockholders’ equity	343,852	313,909
Total liabilities and stockholders’ equity	$ 520,641	$ 468,936