Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 381,803	$ 289,473
Marketable securities	529,416	460,088
Accounts receivable, net of reserves of $8,789 and $7,364 at September 30, 2016, and December 31, 2015, respectively	357,997	380,399
Prepaid expenses and other current assets	117,748	123,228
Total current assets	1,386,964	1,253,188
Property and equipment, net	797,923	753,180
Marketable securities	767,691	774,674
Goodwill	1,151,216	1,150,244
Acquired intangible assets, net	138,870	156,095
Deferred income tax assets	21,156	4,700
Other assets	89,815	89,603
Total assets	4,353,635	4,181,684
Current liabilities:
Accounts payable	74,328	61,982
Accrued expenses	291,101	216,166
Deferred revenue	61,292	54,154
Other current liabilities	4,815	138
Total current liabilities	431,536	332,440
Deferred revenue	4,134	4,163
Deferred income tax liabilities	8,963	12,888
Convertible senior notes	634,504	618,047
Other liabilities	105,567	93,268
Total liabilities	1,184,704	1,060,806
Commitments and contingencies (Note 7)
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; 179,406,558 shares issued and 173,670,583 shares outstanding at September 30, 2016, and 177,212,181 shares issued and outstanding at December 31, 2015	1,794	1,772
Additional paid-in capital	4,547,834	4,437,420
Accumulated other comprehensive loss	(33,462)	(41,453)
Treasury stock, at cost, 5,735,975 shares at September 30, 2016, and no shares at December 31, 2015	(294,867)	0
Accumulated deficit	(1,052,368)	(1,276,861)
Total stockholders’ equity	3,168,931	3,120,878
Total liabilities and stockholders’ equity	$ 4,353,635	$ 4,181,684