Schedule of Losses Before Income Taxes Derived from United States and Non-U.S Operation (Detail) - USD ($) $ in Thousands	4 Months Ended	5 Months Ended	12 Months Ended
	Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	Mar. 31, 2017
Schedule Of Components Of Income Before Income Tax Expense Benefit [Line Items]
Losses before income taxes, Non-U.S		$ (5,137)	$ (99,607)
Losses before income taxes, Non-U.S		(31,550)	(53,912)
Total pre-tax amounts		$ (36,687)	$ (153,519)
Predecessor
Schedule Of Components Of Income Before Income Tax Expense Benefit [Line Items]
Losses before income taxes, Non-U.S	$ (1,603,788)			$ (498,931)
Losses before income taxes, Non-U.S	(44,355)			(144,683)
Total pre-tax amounts	$ (1,648,143)			$ (643,614)