Quarterly Financial Data (Unaudited) - Additional Information (Detail) (USD $)	3 Months Ended				12 Months Ended			3 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2014 Director [Member]	Sep. 30, 2013 SRI Litigation [Member]
Quarterly Financial Data [Line Items]
Impairment Loss on investment	$ 1,200,000				$ 1,184,000	$ 158,000	$ 804,000
Allocated share-based compensation expense					3,337,000	2,552,000	2,671,000	900,000
Gain on sale of strategic investment		700,000		1,200,000	842,000	1,430,000	228,000
Restructuring charges			500,000			476,000
Recovery of legal fees associated with litigation									$ 1,000,000