Goodwill and Intangible Assets - Goodwill and Intangible Assets (Parenthetical) (Detail) (USD $)	1 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended
	Feb. 27, 2012 Customer relationships [Member]	Dec. 31, 2012 Customer relationships [Member]	Sep. 30, 2013 Patents [Member]	Dec. 31, 2012 Patents [Member]
Other Intangibles [Line Items]
Purchase price allocated to other intangible assets	$ 168,000	$ 168,000
Estimated useful lives of intangible assets acquired	5 years	5 years	20 years	20 years