ACCOUNTS RECEIVABLE |
6 Months Ended |
|---|---|
Apr. 30, 2017 | |
| Receivables [Abstract] | |
| ACCOUNTS RECEIVABLE | ACCOUNTS RECEIVABLE As of April 30, 2017, no single customer accounted for greater than 10.0% of Ciena's net accounts receivable. As of October 31, 2016, one customer accounted for 10.4% of Ciena's net accounts receivable. Ciena has not historically experienced a significant amount of bad debt expense. The allowance for doubtful accounts was $4.5 million and $4.0 million as of April 30, 2017 and October 31, 2016, respectively. |