Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Operating activities:
Net income	$ 7,169	$ 6,140
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	4,441	4,284
Amortization	2,199	2,670
Property and equipment write-off	17	0
Excess tax benefit from stock options	(1,247)	(340)
Stock-based compensation expense	4,265	3,946
Deferred income tax expense, net	(4,986)	(2,271)
Provision for losses on accounts receivable	865	1,018
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(1,084)	1,137
Prepaid expenses and other current assets	148	719
Deposits and other assets	377	404
Accounts payable and other liabilities	2,662	2,718
Deferred revenue	458	274
Net cash provided by operating activities	15,284	20,699
Investing activities:
Sales of investments	233	8,141
Proceeds from sale of building, net	83,553	0
Purchases of property and equipment and other assets	(9,887)	(46,566)
Net cash provided by (used in) investing activities	73,899	(38,425)
Financing activities:
Excess tax benefit from stock options	1,247	340
Repurchase of restricted stock to satisfy tax withholding obligations	(1,777)	(1,012)
Proceeds from equity offering, net of transaction costs	247,924	0
Proceeds from exercise of stock options and ESPP	4,540	1,194
Net cash provided by financing activities	251,934	522
Effect of foreign currency exchange rates on cash and cash equivalents	95	(292)
Net increase (decrease) in cash and cash equivalents	341,212	(17,496)
Cash and cash equivalents at the beginning of period	206,405	205,786
Cash and cash equivalents at the end of period	$ 547,617	$ 188,290