Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities:
Net income	$ 8,381	$ 12,674
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	1,915	1,797
Amortization of intangible assets	1,219	1,810
Net gains from investments	(640)	(452)
Deferred income taxes	1,754	(660)
Stock-based compensation	1,681	2,529
Amortization of premium on investments	1,683	972
Foreign currency (gains) losses	1,011	(849)
Other non-cash items		99
Changes in assets and liabilities, net of acquisitions
Accounts receivable	27,160	26,220
Deferred commissions	1,834	526
Prepaid expenses and other current assets	(590)	(4,367)
Accounts payable	(1,044)	1,382
Accrued expenses	(2,699)	(2,927)
Deferred revenue	(3,522)	(6,404)
Net cash provided by operating activities	38,143	32,350
Cash flows from investing activities:
Acquisitions	(7,031)	(1,660)
Purchases of property and equipment	(26,100)	(2,442)
Purchases of marketable investments	(48,361)	(61,000)
Proceeds from sales and maturities of marketable investments	31,624	78,547
Decrease in restricted cash	11,175	1,893
Other investing activity	247	162
Net cash provided by (used in) investing activities	(38,446)	15,500
Cash flows from financing activities:
Proceeds from issuance of common stock under employee equity incentive plans	6,425	8,292
Excess tax benefits from stock-based compensation	332	260
Repurchases of common stock	(13,395)	(5,002)
Net cash provided by (used in) financing activities	(6,638)	3,550
Effect of exchange rate changes on cash and cash equivalents	3,199	(5,293)
Net increase (decrease) in cash and cash equivalents	(3,742)	46,107
Cash and cash equivalents, beginning of period	86,927	97,805
Cash and cash equivalents, end of period	$ 83,185	$ 143,912