Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended						2 Months Ended	3 Months Ended			6 Months Ended		9 Months Ended		12 Months Ended
	Feb. 28, 2021	Jan. 31, 2021	Nov. 30, 2020	Aug. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Feb. 28, 2021	Dec. 31, 2020	Mar. 31, 2020	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 31, 2020	May 29, 2020	May 18, 2020
Subsequent Events
Public offerings, common stock, net (in shares)			43,700,000	35,276,250	46,000,000	10,000,000		4,400,000							79,000,000.0
Net proceeds from shares of common stock sold			$ 927,300	$ 344,400	$ 120,400	$ 23,500				$ 23,498	$ (269)	$ 28,265	$ 344,398	$ 38,098	$ 1,271,714	$ 158,343	$ 7,195
Share Price			$ 22.25	$ 10.25	$ 2.75	$ 2.35				$ 2.35						$ 2.75
Conversion of preferred stock to common stock									$ 441		$ 441		$ 43,058	$ 1,883	$ 1,179	$ 28,392
Interest rate (as a percent)																		3.50%
Common stock, shares issued					318,637,560	244,537,235		473,977,469	322,220,469	244,537,235	348,201,792	246,975,173	406,123,816	253,982,578	473,977,469	318,637,560
3.75% Convertible Senior Notes
Subsequent Events
Share Price								$ 33.91							$ 33.91
Interest rate (as a percent)								3.75%							3.75%			3.75%	3.75%	3.75%
Conversion of notes through common stock issuance							3,000,000.0
Subsequent event
Subsequent Events
Public offerings, common stock, net (in shares)	54,966,188
Subsequent event | SK Holdings Co LTD
Subsequent Events
Public offerings, common stock, net (in shares)	54,996,188
Net proceeds from shares of common stock sold	$ 1,600,000
Common stock, shares issued	54,966,188						54,966,188
Per share price of shares of common stock	$ 29.2893						$ 29.2893
Subsequent event | 3.75% Convertible Senior Notes
Subsequent Events
Conversion of preferred stock to common stock	$ 15,200	$ 15,200					$ 15,200
Interest rate (as a percent)	3.75%	3.75%					3.75%
Conversion of notes through common stock issuance	3,000,000.0	3,000,000.0
Subsequent event | Public Offerings
Subsequent Events
Public offerings, common stock, net (in shares)	32,200,000	32,200,000
Net proceeds from shares of common stock sold	$ 1,800,000	$ 1,800,000
Share Price	$ 65.00	$ 65.00					$ 65.00