Reorganization and Fresh Start Accounting - Reorganization Adjustments to Common Stock and Additional Paid in Capital (Details) - USD ($) shares in Thousands, $ in Thousands		1 Months Ended
	Feb. 05, 2021	Feb. 05, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Reorganization, Chapter 11 [Line Items]
Par value of 50 million shares of new common stock issued	$ 1	$ 1	$ 1		$ 2,511
Additional paid-in capital	1,018,767	1,018,767	1,388,388		814,796
Total shareholders’ equity	$ 1,018,768	$ 1,018,768	1,366,668	$ 1,385,724	(311,388)	$ 2,509,034	$ 2,556,970	$ 3,658,972
Shares
Reorganization, Chapter 11 [Line Items]
Issuance of common stock (in shares)	50,000	50,000
Total shareholders’ equity	$ 1	$ 1	$ 1	$ 1	$ 2,511	$ 2,510	$ 2,510	$ 2,492
Ordinary Shares
Reorganization, Chapter 11 [Line Items]
Additional paid-in capital	875,931	875,931
Warrant
Reorganization, Chapter 11 [Line Items]
Additional paid-in capital	$ 142,836	$ 142,836