Other Liabilities - Summary of Other Liabilities (Parenthetical) (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Future rents related to buy-back agreements	$ 822	$ 926

Amount at the balance sheet date that has been received by the entity that represents rents paid in advance.

No definition available.