Percentage of Net Product and Engineering Revenue from Major Customers (Detail) - Sales Revenue, Net - Largest customers |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
Apr. 30, 2017 |
Apr. 30, 2016 |
|
| Concentration Risk [Line Items] | ||||
| Percentage of net product and engineering revenue | 61.00% | 62.00% | 63.00% | 62.00% |
| Philips | ||||
| Concentration Risk [Line Items] | ||||
| Percentage of net product and engineering revenue | 14.00% | 14.00% | 14.00% | 13.00% |
| Siemens AG | ||||
| Concentration Risk [Line Items] | ||||
| Percentage of net product and engineering revenue | 11.00% | 11.00% | 12.00% | 13.00% |
| L-3 | ||||
| Concentration Risk [Line Items] | ||||
| Percentage of net product and engineering revenue | 11.00% | 10.00% | 10.00% | |
| Toshiba | ||||
| Concentration Risk [Line Items] | ||||
| Percentage of net product and engineering revenue | 11.00% | |||