Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of cash and cash equivalent balances with financial institutions that exceeded 10% of cash and cash equivalents with individual financial institutions	25.00%	34.00%
Level 3 | Film Production
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charges	$ 115	$ 102
Carrying value of the asset prior to impairment	$ 143	$ 297