CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Net earnings	$ 92,136	$ 53,703	$ 45,882
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(2,254)	6,383	(1,462)
Amortization of prior service costs and actuarial (losses) gains	(2,003)	5,573	(5,250)
Net unrealized gain (loss) on derivative instruments	37	19	(33)
Total other comprehensive (loss) income, net of tax	(4,220)	11,975	(6,745)
Comprehensive income	$ 87,916	$ 65,678	$ 39,137