CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Net earnings	$ 53,703	$ 45,882	$ 42,512
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	6,383	(1,462)	(6,297)
Amortization of prior service costs and actuarial gains (losses)	5,573	(5,250)	(6,961)
Net unrealized gain (loss) on derivative instruments	19	(33)	(94)
Total other comprehensive income (loss), net of tax	11,975	(6,745)	(13,352)
Comprehensive income	$ 65,678	$ 39,137	$ 29,160