Pension and Other Postretirement Benefits - Schedule of Fair Value of Pension Plan Assets (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Sale Of Subsidiary [Abstract]
Net receivables which represents assets related to divested businesses to be transferred to the buyers	$ 2
Net payable which represents assets related to divested businesses to be transferred to the buyers		$ 116