Restructuring Costs - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016
Restructuring Cost And Reserve [Line Items]
Restructuring costs	$ 7,502	$ 24
Global workforce elimination percentage under restructuring plan	11.00%
Minimum
Restructuring Cost And Reserve [Line Items]
Restructuring and related cost, expected cost remaining	$ 5,000		$ 5,000
Maximum
Restructuring Cost And Reserve [Line Items]
Restructuring and related cost, expected cost remaining	$ 7,000		7,000
December 2015 Restructuring
Restructuring Cost And Reserve [Line Items]
Accumulated Restructuring Costs			$ 18,000