CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Tax of actuarial loss	$ 63	$ 24	$ 82	$ 50
Tax of prior service credits	$ 1	$ 1	$ 1	$ 1