Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended
	May 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
Goodwill And Intangible Assets [Line Items]
Goodwill		$ 524,000,000		$ 536,000,000
Goodwill annual impairment	0
Amortization expense estimated for year one		17,000,000
Amortization expense estimated for year two		17,000,000
Amortization expense estimated for year three		17,000,000
Amortization expense estimated for year four		17,000,000
Amortization expense estimated for year five		17,000,000
Asset impairment charges	0
Cost of Sales and Selling and Administrative Expenses [Member]
Goodwill And Intangible Assets [Line Items]
Amortization of intangible assets		$ 4,000,000	$ 4,000,000
Minimum [Member]
Goodwill And Intangible Assets [Line Items]
Useful life of intangible assets		16 years
Maximum [Member]
Goodwill And Intangible Assets [Line Items]
Useful life of intangible assets		20 years
Weighted Average [Member]
Goodwill And Intangible Assets [Line Items]
Useful life of intangible assets		19 years