INCOME TAXES - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
U.S. federal	$ 376	$ 292	$ 162
State and local	20	44	12
Total	396	336	174
Deferred
U.S. federal	(142)	159	225
State and local	6	(6)	24
Total	(136)	153	249
U.S. federal	234	451	387
State and local	26	38	36
Income tax expense	$ 260	$ 489	$ 423