Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities
Net income	$ 1,805	$ 1,184
Adjustments to reconcile net income including non-controlling interests to net cash provided by operating activities:
Depreciation and amortization of property and equipment	4,515	2,529
Amortization of intangible assets	235	561
Stock-based compensation	993	206
Forgiveness of note receivable from stockholder		103
Excess tax benefits from stock-based compensation	(1,560)
Change in deferred income taxes		70
Changes in operating assets and liabilities:
Accounts receivable	(1,115)	73
Unbilled receivables	671	(227)
Prepaid expenses and other assets	1,242	940
Accounts payable	(312)	970
Accrued expenses and other liabilities	(3,122)	(2,604)
Deferred revenue	2,311	1,943
Net cash provided by operating activities	5,663	5,748
Cash flows from investing activities
Increase in restricted cash		(23)
Purchases of marketable securities available-for-sale	(41,170)
Purchases of property and equipment	(5,089)	(6,361)
Contractual payments related to business acquisition	(14)	(47)
Net cash used in investing activities	(46,273)	(6,431)
Cash flows from financing activities
Excess tax benefits from stock-based compensation	1,560
Proceeds from exercise of stock options	1,375	109
Payments of capital leases	(164)	(122)
Payments to non-controlling interests	(642)	(547)
Net cash provided by (used in) financing activities	2,129	(560)
Net decrease in cash and cash equivalents	(38,481)	(1,243)
Cash and cash equivalents at beginning of year	93,933	25,721
Cash and cash equivalents at end of year	55,452	24,478
Supplemental disclosure of cash flow information
Cash paid for taxes	279	937
Supplemental disclosure of non-cash investing and financing activities
Property and equipment and software maintenance costs in accounts payable, accrued expenses and other liabilities	3,648	2,154
IPO costs in accounts payable, accrued expenses and other liabilities		854
Accretion of convertible preferred stock		$ 1,195

Name:	us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.