INCOME TAXES - Reconciliation of Income Tax Expense Using Statutory Federal Income Tax Rate Compared with Actual Income Tax Expense (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective income tax reconciliation
Tax at Statutory U.S. Rate of 21% in 2019 and 2018 and 35% in 2017									$ (4)	$ 36	$ (13)
Increase resulting from:
Federal tax rate change									0	0	71
Allocation to Other comprehensive (income) loss related to pension benefits.									(1)	0	(2)
Other expenses									0	(1)	0
Net permanent differences									(1)	(1)	69
Valuation allowance									(115)	(4)	(63)
State income taxes (benefit)									3	(31)	0
Other									0	0	(1)
Total income tax (benefit) provision	$ (117)	$ (1)	$ 0	$ 1	$ 0	$ 0	$ 0	$ 0	$ (117)	$ 0	$ (8)
Federal statutory income tax rate, percent									21.00%	21.00%	35.00%