CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Income tax expense (benefit) on unrealized gains (losses) on hedging instruments	$ (5)	$ (2)	$ (1)
Income tax (expense) on amortization of net loss and prior service cost previously recognized	(18)	(24)	(6)
Income tax expense (benefit) on net (loss) gain arising during the period	$ 69	49	$ (211)
Amount includes in other comprehensive income (loss), net actuarial gain (loss), before tax		9
Other comprehensive income (loss), net actuarial gain (loss), tax		$ 5