Restructuring Charges - Additional Information (Detail) (USD $)	1 Months Ended		3 Months Ended			12 Months Ended
	Aug. 31, 2011	Oct. 31, 2010	Sep. 30, 2013	Dec. 31, 2011	Sep. 30, 2011	Sep. 30, 2013	Sep. 30, 2011
Restructuring And Related Activities [Abstract]
Restructuring costs related to SurModics			$ 500,000			$ 476,000	$ 1,616,000
Percentage of eliminated work force	10.00%	8.00%				6.00%
Pre-Tax Restructuring Charges				600,000	1,000,000	500,000
Cash payments for restructuring cost						300,000
Restructuring accrual balance expected to be paid within			$ 400,000			$ 400,000