Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 238,650	$ 333,891
Marketable securities	519,642	340,005
Accounts receivable, net of reserves of $9,023 and $3,703 at December 31, 2014 and 2013, respectively	329,578us-gaap_AccountsReceivableNetCurrent	271,988us-gaap_AccountsReceivableNetCurrent
Prepaid expenses and other current assets	128,981	62,096
Deferred income tax assets	45,704us-gaap_DeferredTaxAssetsNetCurrent	21,734us-gaap_DeferredTaxAssetsNetCurrent
Total current assets	1,262,555us-gaap_AssetsCurrent	1,029,714us-gaap_AssetsCurrent
Property and equipment, net	601,591	450,287
Marketable securities	869,992	573,026
Goodwill	1,051,294us-gaap_Goodwill	757,368us-gaap_Goodwill
Acquired intangible assets, net	132,412	77,429
Deferred income tax assets	1,955us-gaap_DeferredTaxAssetsNetNoncurrent	2,325us-gaap_DeferredTaxAssetsNetNoncurrent
Other assets	81,747us-gaap_OtherAssetsNoncurrent	67,536us-gaap_OtherAssetsNoncurrent
Total assets	4,001,546us-gaap_Assets	2,957,685us-gaap_Assets
Current liabilities:
Accounts payable	77,412us-gaap_AccountsPayableCurrent	73,710us-gaap_AccountsPayableCurrent
Accrued expenses	204,686us-gaap_AccruedLiabilitiesCurrent	150,385us-gaap_AccruedLiabilitiesCurrent
Deferred revenue	49,679us-gaap_DeferredRevenueCurrent	36,952us-gaap_DeferredRevenueCurrent
Other current liabilities	2,234us-gaap_OtherLiabilitiesCurrent	2,119us-gaap_OtherLiabilitiesCurrent
Total current liabilities	334,011us-gaap_LiabilitiesCurrent	263,166us-gaap_LiabilitiesCurrent
Deferred revenue	3,829us-gaap_DeferredRevenueNoncurrent	3,199us-gaap_DeferredRevenueNoncurrent
Deferred income tax liabilities	39,299	4,737
Convertible senior notes	604,851us-gaap_ConvertibleLongTermNotesPayable	0us-gaap_ConvertibleLongTermNotesPayable
Other liabilities	74,221us-gaap_OtherLiabilitiesNoncurrent	57,152us-gaap_OtherLiabilitiesNoncurrent
Total liabilities	1,056,211us-gaap_Liabilities	328,254us-gaap_Liabilities
Commitments and contingencies (Note 10)
Stockholders’ equity:
Preferred stock, $0.01 par value; 5,000,000 shares authorized; 700,000 shares designated as Series A Junior Participating Preferred Stock; no shares issued or outstanding	0us-gaap_PreferredStockValue	0us-gaap_PreferredStockValue
Common stock, $0.01 par value; 700,000,000 shares authorized; 178,300,603 and 178,580,696 shares issued and outstanding at December 31, 2014 and 2013, respectively.	1,783us-gaap_CommonStockValue	1,808us-gaap_CommonStockValue
Additional paid-in capital	4,559,430us-gaap_AdditionalPaidInCapital	4,561,929us-gaap_AdditionalPaidInCapital
Accumulated other comprehensive loss	(17,611)	(2,091)
Accumulated deficit	(1,598,267)	(1,932,215)
Total stockholders’ equity	2,945,335us-gaap_StockholdersEquity	2,629,431us-gaap_StockholdersEquity
Total liabilities and stockholders’ equity	$ 4,001,546	$ 2,957,685

Property, plant and equipment consists of tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment. Capitalized software consists of certain costs incurred in the development of internal-use software, including external direct costs of materials and services and payroll costs of employees devoted to specific software development.

No definition available.