Changes in Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016
Component of accumulated other comprehensive loss [Roll Forward]
Balance at the beginning of the period	$ 21,739
Other comprehensive income (loss) for the period	702	$ (2,416)
Balance at the end of the period	20,254	21,739
Accumulated Other Comprehensive Loss [Member]
Component of accumulated other comprehensive loss [Roll Forward]
Balance at the beginning of the period	(13,420)	(11,004)
Balance at the end of the period	(12,718)	(13,420)
Foreign Currency Items [Member]
Component of accumulated other comprehensive loss [Roll Forward]
Balance at the beginning of the period	(2,270)	(1,274)
Other comprehensive income (loss) for the period	635	(996)
Balance at the end of the period	(1,635)	(2,270)
Defined Benefit Pension Plans [Member]
Component of accumulated other comprehensive loss [Roll Forward]
Balance at the beginning of the period	(11,150)	(9,730)
Other comprehensive income (loss) for the period	67	(1,420)
Balance at the end of the period	$ (11,083)	$ (11,150)