Other Liabilities (Details 1) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Carrying amount of deferred charge card and other fees
Deferred card and other fees	$ 1,996	$ 1,767
Deferred direct acquisition costs	(280)	(204)
Reserves for membership cancellations	(162)	(152)
Total	$ 1,554	$ 1,411