Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Assets
Currency contracts	$ 977	$ 150
Total assets	8,331	3,649
Liabilities
Currency contracts	114	551
Total liabilities	114	551
Level 1
Assets
Currency contracts	0	0
Total assets	0	0
Liabilities
Currency contracts	0	0
Total liabilities	0	0
Level 2
Assets
Currency contracts	977	150
Total assets	8,331	3,649
Liabilities
Currency contracts	114	551
Total liabilities	114	551
Level 3
Assets
Currency contracts	0	0
Total assets	0	0
Liabilities
Currency contracts	0	0
Total liabilities	0	0
Interest rate swaps
Assets
Interest rate swaps	7,354	3,499
Interest rate swaps | Level 1
Assets
Interest rate swaps	0	0
Interest rate swaps | Level 2
Assets
Interest rate swaps	7,354	3,499
Interest rate swaps | Level 3
Assets
Interest rate swaps	$ 0	$ 0