Income Taxes - Components of Net Deferred Income Tax Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	May 04, 2017
Deferred income tax assets:
Property, Plant & Equipment	$ 37,075	$ 2,208
Net operating loss carryforward	141,534	19,085
Disallowed interest expense	10,627	5,748
Accrued liabilities	1,431	1,387
Other	4,234	307
Total deferred income tax assets:	194,901	28,735
Valuation allowance	(189,941)	(23,934)
Net deferred income tax assets	4,960	4,801
Deferred income tax liabilities:
Derivatives	2,767	4,801
Other	2,193	0
Total deferred income tax liabilities	4,960	4,801
Net deferred income tax liabilities	$ 0	$ 0	$ 2,206