Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Oct. 02, 2015
Cash flows from operating activities:
Net income	$ 37,092	$ 33,749
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and leasehold improvements	4,509	4,034
Amortization of premiums and accretion of discounts on short-term investments	7	515
Deferred rent	(330)	(80)
Provision for contract losses and doubtful accounts	1,688	785
Stock-based compensation	10,659	10,536
Deferred income tax provision	(1,284)	(869)
Excess tax benefit from equity incentive plans	0	(4,983)
Changes in operating assets and liabilities:
Accounts receivable	(7,403)	(8,585)
Prepaid expenses and other assets	(342)	1,206
Accounts payable and accrued liabilities	(1,059)	4,236
Accrued payroll and employee benefits	(4,091)	(3,900)
Deferred revenues	(2,212)	(2,334)
Net cash provided by operating activities	37,234	34,310
Cash flows from investing activities:
Capital expenditures	(13,063)	(4,355)
Purchase of short-term investments	(36,000)	(16,000)
Maturity of short-term investments	29,950	13,555
Net cash used in investing activities	(19,113)	(6,800)
Cash flows from financing activities:
Excess tax benefit from equity incentive plans	0	4,983
Payroll taxes for restricted stock units	(7,685)	(7,365)
Repurchase of common stock	(24,456)	(19,814)
Exercise of share-based payment awards	1,499	1,547
Dividends and dividend equivalents rights	(14,174)	(11,780)
Net cash used in financing activities	(44,816)	(32,429)
Effect of foreign currency exchange rates on cash and cash equivalents	(631)	(114)
Net decrease in cash and cash equivalents	(27,326)	(5,033)
Cash and cash equivalents at beginning of period	125,751	129,490
Cash and cash equivalents at end of period	$ 98,425	$ 124,457