CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) - USD ($)  $ in Thousands  | 
Total  | 
Common Stock  | 
Additional Paid-in Capital  | 
Retained Earnings  | 
Accumulated Other Comprehensive (Loss) Income  | 
Treasury Stock  | 
Non- controlling Interests  | 
| Beginning balance at Sep. 30, 2021 | 
$ 636,403
 | 
$ 36,334
 | 
$ 149,484
 | 
$ 834,208
 | 
$ (192,739)
 | 
$ (190,739)
 | 
$ (145)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income (loss) | 
(19,810)
 | 
 
 | 
 
 | 
(19,803)
 | 
 
 | 
 
 | 
(7)
 | 
| Minimum pension liability | 
34,133
 | 
 
 | 
 
 | 
 
 | 
34,133
 | 
 
 | 
 
 | 
| Translation adjustment | 
(1,985)
 | 
 
 | 
 
 | 
 
 | 
(1,989)
 | 
 
 | 
4
 | 
| Fair value of cash flow hedges | 
1,481
 | 
 
 | 
 
 | 
 
 | 
1,481
 | 
 
 | 
 
 | 
| Comprehensive income (loss) | 
13,819
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Stock-based compensation | 
3,709
 | 
 
 | 
3,709
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Purchase of treasury stock | 
(2,435)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
(2,435)
 | 
 
 | 
| Issuance of treasury stock | 
0
 | 
 
 | 
(6,859)
 | 
 
 | 
 
 | 
6,859
 | 
 
 | 
| Cancellations of treasury stock | 
0
 | 
 
 | 
2,091
 | 
 
 | 
 
 | 
(2,091)
 | 
 
 | 
| Dividends | 
(6,824)
 | 
 
 | 
 
 | 
(6,824)
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Dec. 31, 2021 | 
$ 644,672
 | 
36,334
 | 
148,425
 | 
807,581
 | 
(159,114)
 | 
(188,406)
 | 
(148)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Treasury Stock, Shares, Acquired | 
62,746
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Issuance of treasury stock (in shares) | 
174,107
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Sep. 30, 2021 | 
$ 636,403
 | 
36,334
 | 
149,484
 | 
834,208
 | 
(192,739)
 | 
(190,739)
 | 
(145)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income (loss) | 
(18,871)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Comprehensive income (loss) | 
(5,039)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Jun. 30, 2022 | 
590,603
 | 
36,334
 | 
156,942
 | 
794,581
 | 
(178,930)
 | 
(218,055)
 | 
(269)
 | 
| Beginning balance at Dec. 31, 2021 | 
644,672
 | 
36,334
 | 
148,425
 | 
807,581
 | 
(159,114)
 | 
(188,406)
 | 
(148)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income (loss) | 
(1,936)
 | 
 
 | 
 
 | 
(1,905)
 | 
 
 | 
 
 | 
(31)
 | 
| Minimum pension liability | 
(27)
 | 
 
 | 
 
 | 
 
 | 
(27)
 | 
 
 | 
 
 | 
| Translation adjustment | 
(6,177)
 | 
 
 | 
 
 | 
 
 | 
(6,181)
 | 
 
 | 
4
 | 
| Fair value of cash flow hedges | 
4,092
 | 
 
 | 
 
 | 
 
 | 
4,092
 | 
 
 | 
 
 | 
| Comprehensive income (loss) | 
(4,048)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Stock-based compensation | 
5,222
 | 
 
 | 
5,222
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Purchase of treasury stock | 
(9,703)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
(9,703)
 | 
 
 | 
| Issuance of treasury stock | 
0
 | 
 
 | 
(1,761)
 | 
 
 | 
 
 | 
1,761
 | 
 
 | 
| Cancellations of treasury stock | 
0
 | 
 
 | 
5
 | 
 
 | 
 
 | 
(5)
 | 
 
 | 
| Dividends | 
(7,128)
 | 
 
 | 
 
 | 
(7,128)
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Mar. 31, 2022 | 
$ 629,015
 | 
36,334
 | 
151,891
 | 
798,548
 | 
(161,230)
 | 
(196,353)
 | 
(175)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Treasury Stock, Shares, Acquired | 
289,184
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Issuance of treasury stock (in shares) | 
45,096
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income (loss) | 
$ 2,875
 | 
 
 | 
 
 | 
2,893
 | 
 
 | 
 
 | 
(18)
 | 
| Minimum pension liability | 
17
 | 
 
 | 
 
 | 
 
 | 
17
 | 
 
 | 
 
 | 
| Translation adjustment | 
(19,278)
 | 
 
 | 
 
 | 
 
 | 
(19,293)
 | 
 
 | 
15
 | 
| Fair value of cash flow hedges | 
1,576
 | 
 
 | 
 
 | 
 
 | 
1,576
 | 
 
 | 
 
 | 
| Comprehensive income (loss) | 
(14,810)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Stock-based compensation | 
5,197
 | 
 
 | 
5,197
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Purchase of treasury stock | 
(21,848)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
(21,848)
 | 
 
 | 
| Issuance of treasury stock | 
0
 | 
 
 | 
(146)
 | 
 
 | 
 
 | 
146
 | 
 
 | 
| Dividends | 
(6,860)
 | 
 
 | 
 
 | 
(6,860)
 | 
 
 | 
 
 | 
 
 | 
| Divestiture | 
(91)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
(91)
 | 
| Ending balance at Jun. 30, 2022 | 
$ 590,603
 | 
36,334
 | 
156,942
 | 
794,581
 | 
(178,930)
 | 
(218,055)
 | 
(269)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Treasury Stock, Shares, Acquired | 
704,531
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Issuance of treasury stock (in shares) | 
3,830
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Sep. 30, 2022 | 
$ 487,076
 | 
36,334
 | 
160,255
 | 
706,749
 | 
(190,191)
 | 
(225,795)
 | 
(276)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income (loss) | 
3,647
 | 
 
 | 
 
 | 
3,703
 | 
 
 | 
 
 | 
(56)
 | 
| Minimum pension liability | 
945
 | 
 
 | 
 
 | 
 
 | 
945
 | 
 
 | 
 
 | 
| Translation adjustment | 
20,564
 | 
 
 | 
 
 | 
 
 | 
20,560
 | 
 
 | 
4
 | 
| Fair value of cash flow hedges | 
(404)
 | 
 
 | 
 
 | 
 
 | 
(404)
 | 
 
 | 
 
 | 
| Comprehensive income (loss) | 
24,752
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Stock-based compensation | 
4,334
 | 
 
 | 
4,334
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Purchase of treasury stock | 
(2,451)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
(2,451)
 | 
 
 | 
| Issuance of treasury stock | 
0
 | 
 
 | 
(9,154)
 | 
 
 | 
 
 | 
9,154
 | 
 
 | 
| Cancellations of treasury stock | 
0
 | 
 
 | 
1,958
 | 
 
 | 
 
 | 
(1,958)
 | 
 
 | 
| Dividends | 
(8,794)
 | 
 
 | 
 
 | 
(8,794)
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Dec. 31, 2022 | 
$ 504,917
 | 
36,334
 | 
157,393
 | 
701,658
 | 
(169,090)
 | 
(221,050)
 | 
(328)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Treasury Stock, Shares, Acquired | 
89,025
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Issuance of treasury stock (in shares) | 
245,006
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Beginning balance at Sep. 30, 2022 | 
$ 487,076
 | 
36,334
 | 
160,255
 | 
706,749
 | 
(190,191)
 | 
(225,795)
 | 
(276)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income (loss) | 
21,443
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Comprehensive income (loss) | 
47,746
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Jun. 30, 2023 | 
521,821
 | 
36,334
 | 
164,640
 | 
704,366
 | 
(163,856)
 | 
(219,263)
 | 
(400)
 | 
| Beginning balance at Dec. 31, 2022 | 
504,917
 | 
36,334
 | 
157,393
 | 
701,658
 | 
(169,090)
 | 
(221,050)
 | 
(328)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income (loss) | 
9,125
 | 
 
 | 
 
 | 
9,127
 | 
 
 | 
 
 | 
(2)
 | 
| Minimum pension liability | 
(176)
 | 
 
 | 
 
 | 
 
 | 
(176)
 | 
 
 | 
 
 | 
| Translation adjustment | 
4,427
 | 
 
 | 
 
 | 
 
 | 
4,432
 | 
 
 | 
(5)
 | 
| Fair value of cash flow hedges | 
(2,242)
 | 
 
 | 
 
 | 
 
 | 
(2,242)
 | 
 
 | 
 
 | 
| Comprehensive income (loss) | 
11,134
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Stock-based compensation | 
4,278
 | 
 
 | 
4,278
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Purchase of treasury stock | 
(288)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
(288)
 | 
 
 | 
| Issuance of treasury stock | 
0
 | 
 
 | 
(1,723)
 | 
 
 | 
 
 | 
1,723
 | 
 
 | 
| Dividends | 
(7,683)
 | 
 
 | 
 
 | 
(7,683)
 | 
 
 | 
 
 | 
 
 | 
| Transactions with noncontrolling interests | 
33
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
33
 | 
| Ending balance at Mar. 31, 2023 | 
$ 512,391
 | 
36,334
 | 
159,948
 | 
703,102
 | 
(167,076)
 | 
(219,615)
 | 
(302)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Treasury Stock, Shares, Acquired | 
7,606
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Issuance of treasury stock (in shares) | 
46,069
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Net income (loss) | 
$ 8,671
 | 
 
 | 
 
 | 
8,738
 | 
 
 | 
 
 | 
(67)
 | 
| Minimum pension liability | 
(210)
 | 
 
 | 
 
 | 
 
 | 
(210)
 | 
 
 | 
 
 | 
| Translation adjustment | 
892
 | 
 
 | 
 
 | 
 
 | 
923
 | 
 
 | 
(31)
 | 
| Fair value of cash flow hedges | 
2,507
 | 
 
 | 
 
 | 
 
 | 
2,507
 | 
 
 | 
 
 | 
| Comprehensive income (loss) | 
11,860
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Stock-based compensation | 
5,023
 | 
 
 | 
5,023
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Purchase of treasury stock | 
(79)
 | 
 
 | 
 
 | 
 
 | 
 
 | 
(79)
 | 
 
 | 
| Issuance of treasury stock | 
100
 | 
 
 | 
(331)
 | 
 
 | 
 
 | 
431
 | 
 
 | 
| Dividends | 
(7,474)
 | 
 
 | 
 
 | 
(7,474)
 | 
 
 | 
 
 | 
 
 | 
| Ending balance at Jun. 30, 2023 | 
$ 521,821
 | 
$ 36,334
 | 
$ 164,640
 | 
$ 704,366
 | 
$ (163,856)
 | 
$ (219,263)
 | 
$ (400)
 | 
| Increase (Decrease) in Stockholders' Equity [Roll Forward] | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Treasury Stock, Shares, Acquired | 
2,068
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
| Issuance of treasury stock (in shares) | 
11,562
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 | 
 
 |