CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical)	Dec. 31, 2020	Jul. 01, 2020	May 31, 2020	May 29, 2020	May 18, 2020	Sep. 30, 2019	Mar. 31, 2018
Interest rate (as a percent)			3.50%
5.5% Convertible Senior Notes
Interest rate (as a percent)	5.50%		5.50%		5.50%		5.50%
3.75% Convertible Senior Notes
Interest rate (as a percent)	3.75%		3.75%	3.75%	3.75%
7.5% Convertible Senior Note
Interest rate (as a percent)	7.50%	7.50%				7.50%