Amortizable Intangible Assets - Additional Information (Detail) (USD $)	Sep. 30, 2013
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense estimated, year one (2013)	$ 67,934,000
Amortization expense estimated, year two (2014)	70,652,000
Amortization expense estimated, year three (2015)	69,363,000
Amortization expense estimated, year four (2016)	64,782,000
Amortization expense estimated, year five (2017)	$ 62,070,000