Restructuring and Separation Costs (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring And Related Activities [Abstract]
Separation costs		$ 7,900	$ 2,600
Restructuring and separation expenses	$ 3,800	8,441	3,397
Restructuring and separation costs paid		6,800
Restructuring and separation costs payable over the next fiscal year		1,100
Restructuring costs related to exited of Canadian facility lease and write-off of associated leasehold improvements		$ 500	$ 800