Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 110,277	$ 65,983
Short-term investments		42,882
Accounts receivable, net	58,506	54,095
Current portion of deferred income taxes	363	3,526
Prepaid expenses and other	6,965	7,945
Total current assets	176,111	174,431
Property and equipment, net	35,332	26,840
Deferred income taxes, net of current portion	1,496	30,238
Other assets, net	1,193	1,118
Goodwill	6,334	6,334
Total assets	220,466	238,961
Current liabilities:
Accounts payable	5,577	8,617
Accrued taxes	1,026	924
Accrued compensation and benefits	16,775	21,749
Other accrued liabilities	9,237	7,639
Obligations under capital leases	733	706
Total current liabilities	33,348	39,635
Obligations under capital leases, net of current portion	707	958
Other long-term liabilities	5,353	1,352
Total liabilities	39,408	41,945
Commitments and contingencies (Note 8)
Stockholders' equity:
Common stock; $0.0001 par value; 1,000,000 shares authorized; 75,650 shares issued and 75,529 shares outstanding as of September 30, 2012; 72,688 shares issued and 72,567 shares outstanding as of December 31, 2011	8	7
Treasury stock	(441)	(441)
Additional paid-in capital	203,667	177,796
Retained earnings (accumulated deficit)	(22,213)	19,416
Accumulated other comprehensive income	37	238
Total stockholders' equity	181,058	197,016
Total liabilities and stockholders' equity	$ 220,466	$ 238,961