Retirement Benefit Obligations - Schedule of Change in Projected Benefit Obligation, Change in Fair Value of Plan Assets and Funded Status (Parenthetical) (Detail) - USD ($) $ in Millions	Jun. 30, 2016	Jun. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Increase in pension liability	$ 10	$ 12
Harlequin's Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Increase in pension liability		$ 15