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Revenue Recognition - Net Sales Disaggregated by Product Line and Geographic Area (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2020 | Mar. 31, 2019 | Mar. 31, 2018
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales | $ 23,082 | $ 25,286 | $ 21,643 | $ 20,593 | $ 23,641 | $ 17,198 | $ 21,441 | $ 29,551 | $ 90,604 | $ 91,831 | $ 77,534
Asia [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | 5,517 | 10,292 | 10,200
Canada [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | 8,907 | 16,602 | 8,888
Middle East [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | 13,112 | 2,610 | 3,785
South America [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | 3,783 | 324 | 1,560
U.S. [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | 58,042 | 59,441 | 51,950
All Other [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | 1,243 | 2,562 | 1,151
Heat Transfer Equipment [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | 31,986 | 24,785 | 27,023
Vacuum Equipment [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | 33,354 | 34,461 | 22,175
All Other [Member] |  |  |  |  |  |  |  |  |  |  |
Disaggregation Of Revenue [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net sales |  |  |  |  |  |  |  |  | $ 25,264 | $ 32,585 | $ 28,336

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