Intangible Assets - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Goodwill And Intangible Assets [Line Items]
Intangible amortization expense	$ 20	$ 21	$ 40	$ 42
GenCell Biosystems [Member]
Goodwill And Intangible Assets [Line Items]
Increase in intangible assets					81
CRISI Medical Systems Inc [Member]
Goodwill And Intangible Assets [Line Items]
Increase in intangible assets	$ 49		$ 49