Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:
Net income (loss)	$ (66)	$ 2,169
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	2,773	2,360
Amortization of intangible assets	539	559
Net (gains) losses from investments	(37)	200
Deferred income taxes	(132)	(1,519)
Stock-based compensation	1,947	1,860
Amortization of premium on investments	391	636
Foreign currency (gains) losses	245	(72)
Changes in assets and liabilities
Accounts receivable	28,310	25,186
Deferred commissions	(72)	(206)
Prepaid expenses and other current assets	(2,934)	1,156
Accounts payable	137	111
Accrued expenses and other liabilities	(4,871)	166
Deferred revenue	6,774	2,847
Net cash provided by operating activities	33,004	35,453
Cash flows from investing activities:
Purchases of property and equipment	(680)	(939)
Purchases of marketable investments	(20,046)	(4,125)
Proceeds from sales and maturities of marketable investments	23,934	17,750
Other investing activity	1,391	75
Net cash provided by investing activities	4,599	12,761
Cash flows from financing activities:
Dividend paid on common stock	(3,135)	(3,350)
Repurchases of common stock	(29,712)
Proceeds from issuance of common stock under employee equity incentive plans	1,556	1,447
Excess tax benefits from stock-based compensation	22	109
Net cash used in financing activities	(31,269)	(1,794)
Effect of exchange rate changes on cash and cash equivalents	35	(1,286)
Net increase in cash and cash equivalents	6,369	45,134
Cash and cash equivalents, beginning of period	74,132	98,810
Cash and cash equivalents, end of period	$ 80,501	$ 143,944