CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 1,264,590	$ 352,917
Marketable securities	652,695	745,156
Accounts receivable, net of reserves of $2,268 and $1,822 at September 30, 2021, and December 31, 2020, respectively	660,092	660,052
Prepaid expenses and other current assets	184,503	171,406
Total current assets	2,761,880	1,929,531
Marketable securities	835,074	1,398,802
Property and equipment, net	1,543,301	1,478,272
Operating lease right-of-use assets	821,033	793,945
Acquired intangible assets, net	203,596	234,724
Goodwill	1,680,496	1,674,371
Deferred income tax assets	136,305	106,918
Other assets	133,790	147,567
Total assets	8,115,475	7,764,130
Current liabilities:
Accounts payable	98,305	118,546
Accrued expenses	376,036	380,468
Deferred revenue	83,371	76,600
Operating lease liabilities	164,559	154,801
Other current liabilities	9,169	27,755
Total current liabilities	731,440	758,170
Deferred revenue	5,355	5,262
Deferred income tax liabilities	35,333	37,458
Convertible senior notes	1,958,558	1,906,707
Operating lease liabilities	722,294	715,404
Other liabilities	80,050	89,833
Total liabilities	3,533,030	3,512,834
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; 164,733,227 shares issued and 162,424,440 shares outstanding at September 30, 2021, and 162,709,720 shares issued and outstanding at December 31, 2020	1,647	1,627
Additional paid-in capital	3,789,623	3,664,820
Accumulated other comprehensive loss	(53,726)	(20,201)
Treasury stock, at cost, 2,308,787 shares at September 30, 2021, and no shares at December 31, 2020	(251,257)	0
Retained earnings	1,096,158	605,050
Total stockholders’ equity	4,582,445	4,251,296
Total liabilities and stockholders’ equity	$ 8,115,475	$ 7,764,130