Restructuring Charge - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended	12 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2016	Mar. 31, 2015
Restructuring And Related Activities [Abstract]
Restructuring charge	$ 7,600,000	$ 4,100,000		$ 7,586,000	$ 4,052,000
Payments related to restructuring charges	$ 0		$ 7,400,000