Fair Value of Financial Instruments - Recurring Basis (Details) - Assets and liabilities measured at fair value - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Assets
Current derivative assets	$ 1,761	$ 2,635
Noncurrent derivative assets	624	859
Total assets measured at fair value	2,385	3,494
Liabilities
Current derivative liabilities	4,365	529
Noncurrent derivative liabilities	13,342	228
Total liabilities measured at fair value	25,629	11,631
Deltenna
Liabilities
Contingent consideration to seller	2,806	1,787
Shield Aviation
Liabilities
Contingent consideration to seller	4,052	3,814
H4 Global
Liabilities
Contingent consideration to seller	564	1,073
Nuvotronics
Liabilities
Contingent consideration to seller		4,200
Delerrok Inc.
Liabilities
Contingent consideration to seller	500
Level 2
Assets
Current derivative assets	1,761	2,635
Noncurrent derivative assets	624	859
Total assets measured at fair value	2,385	3,494
Liabilities
Current derivative liabilities	4,365	529
Noncurrent derivative liabilities	13,342	228
Total liabilities measured at fair value	17,707	757
Level 3
Liabilities
Total liabilities measured at fair value	7,922	10,874
Level 3 \| Deltenna
Liabilities
Contingent consideration to seller	2,806	1,787
Level 3 \| Shield Aviation
Liabilities
Contingent consideration to seller	4,052	3,814
Level 3 \| H4 Global
Liabilities
Contingent consideration to seller	564	1,073
Level 3 \| Nuvotronics
Liabilities
Contingent consideration to seller		$ 4,200
Level 3 \| Delerrok Inc.
Liabilities
Contingent consideration to seller	$ 500

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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