Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 214,339	$ 333,891
Marketable securities	496,573	340,005
Accounts receivable, net of reserves of $5,866 and $3,703 at September 30, 2014 and December 31, 2013, respectively	326,747	271,988
Prepaid expenses and other current assets	90,173	62,096
Deferred income tax assets	24,844	21,734
Total current assets	1,152,676	1,029,714
Property and equipment, net	559,194	450,287
Marketable securities	850,847	573,026
Goodwill	1,049,047	757,368
Acquired intangible assets, net	140,815	77,429
Deferred income tax assets	2,530	2,325
Other assets	99,182	67,536
Total assets	3,854,291	2,957,685
Current liabilities:
Accounts payable	74,801	73,710
Accrued expenses	173,985	150,385
Deferred revenue	50,582	36,952
Other current liabilities	2,233	2,119
Total current liabilities	301,601	263,166
Deferred revenue	3,647	3,199
Deferred income tax liabilities	25,099	4,737
Convertible senior notes	600,098	0
Other liabilities	75,466	57,152
Total liabilities	1,005,911	328,254
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; 182,119,856 shares issued and 178,194,979 shares outstanding at September 30, 2014 and 178,580,696 shares issued and outstanding at December 31, 2013	1,851	1,808
Additional paid-in capital	4,777,961	4,561,929
Accumulated other comprehensive loss	(9,545)	(2,091)
Treasury stock, at cost, 3,924,877 shares at September 30, 2014 and no shares at December 31, 2013	(226,513)	0
Accumulated deficit	(1,695,374)	(1,932,215)
Total stockholders’ equity	2,848,380	2,629,431
Total liabilities and stockholders’ equity	$ 3,854,291	$ 2,957,685