Debt Costs (Detail) - USD ($) $ in Thousands	4 Months Ended	5 Months Ended	12 Months Ended
	Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Interest and debt costs incurred, net of interest capitalized	$ 11,179	$ 13,009	$ 29,068	$ 30,439
Interest costs capitalized	601	101		521
Total interest and debt costs	$ 11,780	$ 13,110	$ 29,068	$ 30,960