Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 393,745	$ 1,036,455
Marketable securities	1,143,249	855,650
Accounts receivable, net of reserves of $1,880 and $1,534 at December 31, 2019 and 2018, respectively	551,943	479,889
Prepaid expenses and other current assets	142,676	163,360
Total current assets	2,231,613	2,535,354
Marketable securities	835,384	209,066
Property and equipment, net	1,152,153	910,618
Operating lease right-of-use assets	758,450
Acquired intangible assets, net	179,431	168,348
Goodwill	1,600,265	1,487,404
Deferred income tax assets	76,528	34,913
Other assets	173,062	116,067
Total assets	7,006,886	5,461,770
Current liabilities:
Accounts payable	138,946	99,089
Accrued expenses	334,861	328,304
Deferred revenue	71,223	69,083
Convertible senior notes	0	686,552
Operating lease liabilities	139,463
Other current liabilities	8,843	27,681
Total current liabilities	693,336	1,210,709
Deferred revenue	4,368	4,557
Deferred income tax liabilities	29,187	19,624
Convertible senior notes	1,839,791	874,080
Operating lease liabilities	692,181
Other liabilities	90,065	160,940
Total liabilities	3,348,928	2,269,910
Commitments and contingencies (Note 13)
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; 162,000,843 and 162,904,550 shares issued and outstanding at December 31, 2019 and 2018, respectively	1,620	1,629
Additional paid-in capital	3,653,486	3,670,033
Accumulated other comprehensive loss	(45,144)	(48,912)
Retained earnings (accumulated deficit)	47,996	(430,890)
Total stockholders’ equity	3,657,958	3,191,860
Total liabilities and stockholders’ equity	$ 7,006,886	$ 5,461,770