Accumulated Other Comprehensive Income - Changes in Each Component of Accumulated Other Comprehensive Income, Net of Tax (Parenthetical) (Detail) (Maximum [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2013
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Amounts reclassified from other comprehensive items	$ 1
Currency Translation Adjustment [Member]
Components Of Accumulated Other Comprehensive Income Loss [Line Items]
Amounts reclassified from other comprehensive items	$ 1