Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 256,471	$ 238,650
Marketable securities	411,382	519,642
Accounts receivable, net of reserves of $9,007 and $9,023 at September 30, 2015, and December 31, 2014, respectively	365,957	329,578
Prepaid expenses and other current assets	115,601	128,981
Deferred income tax assets	61,574	45,704
Total current assets	1,210,985	1,262,555
Property and equipment, net	734,540	601,591
Marketable securities	837,020	869,992
Goodwill	1,135,500	1,051,294
Acquired intangible assets, net	158,978	132,412
Deferred income tax assets	1,888	1,955
Other assets	105,898	81,747
Total assets	4,184,809	4,001,546
Current liabilities:
Accounts payable	60,902	77,412
Accrued expenses	215,290	204,686
Deferred revenue	55,580	49,679
Other current liabilities	234	2,234
Total current liabilities	332,006	334,011
Deferred revenue	4,516	3,829
Deferred income tax liabilities	49,925	39,299
Convertible senior notes	619,365	604,851
Other liabilities	93,334	74,221
Total liabilities	$ 1,099,146	$ 1,056,211
Commitments and contingencies
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	$ 0	$ 0
Common stock, $0.01 par value; 700,000,000 shares authorized; 181,081,173 shares issued and 178,233,604 shares outstanding at September 30, 2015, and 178,300,603 shares issued and outstanding at December 31, 2014	1,811	1,783
Additional paid-in capital	4,685,078	4,559,430
Accumulated other comprehensive loss	(33,519)	(17,611)
Treasury stock, at cost, 2,847,569 shares at September 30, 2015, and no shares at December 31, 2014	(202,426)	0
Accumulated deficit	(1,365,281)	(1,598,267)
Total stockholders’ equity	3,085,663	2,945,335
Total liabilities and stockholders’ equity	$ 4,184,809	$ 4,001,546