Stock-Based Compensation - Additional Information (Details) - USD ($)										1 Months Ended	12 Months Ended
	Dec. 11, 2020	Nov. 23, 2020	Oct. 15, 2020	Aug. 25, 2020	Mar. 10, 2020	Jan. 28, 2020	Dec. 03, 2019	Nov. 18, 2019	May 01, 2019	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	482,000		388,292				5,556	2,549,556			872,003	2,555,109	0
Granted (in dollars per share)	$ 10.35		$ 13.82				$ 16.20	$ 16.20			$ 11.90	$ 16.20
Option, cost not yet recognized, amount											$ 15,500,000	$ 17,200,000
Options, outstanding, fair value												60,200,000
Options, vested, fair value												43,000,000.0
Proceeds from stock options exercised											11,200,000	400,000	$ 0
Exercise of option, tax benefit											1,700,000	400,000
Stock based compensation benefit												3,600,000	$ 10,000,000.0
Treasury stock reissued at lower than repurchase price				$ 800,000
Private placement, loss recorded in additional paid-in-capital											444,000
Purchase of treasury stock (in shares)					800,000	1,000,000.0			24,000,000.0	800,000
Purchase of treasury stock					$ 9,200,000	$ 12,600,000			$ 438,000,000.0	$ 8,800,000	30,626,000	437,962,000
Payments for stock options exercised									$ 33,900,000
Warrants outstanding											$ 10,500,000	$ 10,500,000
Number of shares of common stock to be issued for upon exercise of warrants (in shares)											5,800,000	5,800,000
Warrant, exercise price (in usd per share)											$ 24.39	$ 24.39
Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued (in shares)				68,857
Price per share (in dollars per share)				$ 10.17
Total value raised, net of expenses				$ 400,000
Affiliated Entity
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options settled in period (in shares)									2,300,000
Affiliated Entity | Mudrick Capital Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase of treasury stock (in shares)									11,100,000
Purchase of treasury stock									$ 202,600,000
Affiliated Entity | Paulson and Co
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase of treasury stock (in shares)									5,600,000
Purchase of treasury stock									$ 102,200,000
Affiliated Entity | GoldenTree Asset Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase of treasury stock (in shares)									4,200,000
Purchase of treasury stock									$ 75,800,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period											3 years
Award expiration period											10 years
Plan modification, number of shares affected (in shares)		2,377,886
Plan modification, original exercise price (in dollars per share)		$ 16.20
Plan modification, repriced exercise price (in dollars per share)		$ 13.82
Plan modification, incremental cost		$ 1,500,000
Cost not yet recognized, period for recognition											2 years 6 months	3 years
Minimum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period											3 years
Maximum | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period											4 years
2016 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)														6,166,667
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for future issuance (in shares)											1,000,000