Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 352,917	$ 393,745
Marketable securities	745,156	1,143,249
Accounts receivable, net of reserves of $1,822 and $1,880 at December 31, 2020 and 2019, respectively	660,052	551,943
Prepaid expenses and other current assets	171,406	142,676
Total current assets	1,929,531	2,231,613
Marketable securities	1,398,802	835,384
Property and equipment, net	1,478,272	1,152,153
Operating lease right-of-use assets	793,945	758,450
Acquired intangible assets, net	234,724	179,431
Goodwill	1,674,371	1,600,265
Deferred income tax assets	106,918	76,528
Other assets	147,567	173,062
Total assets	7,764,130	7,006,886
Current liabilities:
Accounts payable	118,546	138,946
Accrued expenses	380,468	334,861
Deferred revenue	76,600	71,223
Operating lease liabilities	154,801	139,463
Other current liabilities	27,755	8,843
Total current liabilities	758,170	693,336
Deferred revenue	5,262	4,368
Deferred income tax liabilities	37,458	29,187
Convertible senior notes	1,906,707	1,839,791
Operating lease liabilities	715,404	692,181
Other liabilities	89,833	90,065
Total liabilities	3,512,834	3,348,928
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; 162,709,720 and 162,000,843 shares issued and outstanding at December 31, 2020 and 2019, respectively	1,627	1,620
Additional paid-in capital	3,664,820	3,653,486
Accumulated other comprehensive loss	(20,201)	(45,144)
Retained earnings	605,050	47,996
Total stockholders’ equity	4,251,296	3,657,958
Total liabilities and stockholders’ equity	$ 7,764,130	$ 7,006,886