INCOME TAXES - Net Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Investment in partnership	$ 65,851	$ 0
Asset retirement obligation	220	3,956
Net operating losses	495	48,024
Other	1,212	530
Total deferred tax assets	67,778	52,510
Valuation allowance	0	(8,177)
Net deferred tax assets	67,778	44,333
Deferred tax liabilities:
Property, plant and equipment	2,863	51,374
Net deferred tax assets	$ 64,915
Net deferred tax liabilities		$ (7,041)