Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Initial Public Offering	Private Placement	Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock Initial Public Offering	Common Stock	Common Stock Initial Public Offering	Class A and Class B Common Stock	Common Class A Initial Public Offering	Common Class A Private Placement	Common Class B	Additional Paid-in Capital	Additional Paid-in Capital Initial Public Offering	Additional Paid-in Capital Private Placement	Accumulated Deficit
Redeemable convertible preferred stock, Beginning balance at Dec. 31, 2017				$ 166,777
Redeemable convertible preferred stock, Beginning balance, Shares at Dec. 31, 2017				5,654,000
Beginning balance at Dec. 31, 2017	$ (31,753)					$ 157						$ 54,281			$ (86,191)
Beginning balance, Shares at Dec. 31, 2017						78,483,000
Stock options exercised	3,349					$ 11						3,338
Stock options exercised, Shares						5,285,000
Vesting of restricted stock awards, Shares						94,000
Redeemable convertible preferred stock, Conversion of redeemable convertible preferred stock to common stock				$ (166,777)
Redeemable convertible preferred stock, Conversion of redeemable convertible preferred stock to common stock, Shares				(5,654,000)
Conversion of redeemable convertible preferred stock to common stock	166,777					$ 283						166,494
Conversion of redeemable convertible preferred stock to common stock, Shares						141,339,000
Preferred stock issuance, net of issuance costs				$ 737,009
Preferred stock issuance, net of issuance costs, Shares				126,046,000
Stock-based compensation	1,762											1,762
Dividends paid ($152.25 per preferred share, $5.91 per common share)	(1,346,355)											(225,875)			(1,120,480)
Net income (loss)	43,793														43,793
Redeemable convertible preferred stock, Ending balance at Dec. 31, 2018				$ 737,009
Redeemable convertible preferred stock, Ending balance, Shares at Dec. 31, 2018				126,046,000
Ending balance at Dec. 31, 2018	(1,162,427)					$ 451									(1,162,878)
Ending balance, Shares at Dec. 31, 2018						225,201,000
Stock options exercised	3,042					$ 5						3,037
Stock options exercised, Shares						2,397,000
Issuance of common stock	1,623					$ 1						1,622
Issuance of common stock, Shares						273,000
Restricted stock issuance						$ 3						(3)
Restricted stock issuance, Shares						1,879,000
Stock-based compensation	4,132											4,132
Net income (loss)	66,048														66,048
Redeemable convertible preferred stock, Ending balance at Dec. 31, 2019	$ 737,009			$ 737,009
Redeemable convertible preferred stock, Ending balance, Shares at Dec. 31, 2019	126,046,000			126,046,000
Ending balance at Dec. 31, 2019	$ (1,087,582)					$ 460						8,788			(1,096,830)
Ending balance, Shares at Dec. 31, 2019						229,750,000
Stock options exercised	10,831					$ 3						10,828
Stock options exercised, Shares						1,469,000		2,300,000
Vesting of restricted stock awards, Shares								1,252,000
Redeemable convertible preferred stock, Conversion of redeemable convertible preferred stock to common stock					$ (737,009)
Redeemable convertible preferred stock, Conversion of redeemable convertible preferred stock to common stock, Shares					(126,046,000)
Conversion of redeemable convertible preferred stock to common stock		$ 737,009					$ 252						$ 736,757
Conversion of redeemable convertible preferred stock to common stock, Shares							126,046,000
Issuance of common stock		$ 886,856	$ 100,000						$ 3				$ 886,853	$ 100,000
Issuance of common stock, Shares									28,615,000	3,030,000
Stock-based compensation	399,722											399,722
Conversion of common stock into Class B common stock in connection with initial public offering						$ (715)					$ 36	679
Conversion of common stock into Class B common stock in connection with initial public offering, Shares						(357,265,000)					357,265,000
Common stock withheld for tax obligations and net settlement	(83,575)											(83,575)
Common stock withheld for tax obligations and net settlement, Shares								(1,877,000)
Charitable stock donation	41,721											41,721
Charitable stock donation, Shares								1,075,000
Net income (loss)	$ (293,623)														(293,623)
Redeemable convertible preferred stock, Ending balance, Shares at Dec. 31, 2020	0
Ending balance at Dec. 31, 2020	$ 711,359							$ 39				$ 2,101,773			$ (1,390,453)
Ending balance, Shares at Dec. 31, 2020								391,660,000