Commercial letters of credit outstanding amount

No definition available.

Name:	cmtl_CommercialLettersOfCreditOutstandingAmount
Namespace Prefix:	cmtl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Interest expense related to the credit facility for the period, including undrawn line fees and amortization of deferred financing costs.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Floor interest rate on debt instrument

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Represents the ratio calculated at period-end by total indebtedness less available cash (up to $50,000,000) divided by the trailing twelve months Consolidated EBITDA defined in the Secured Credit Facility.

+ References

No definition available.

+ Details

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Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum allowable leverage ratio included in financial covenants required by the lender, which is calculated based on (a) total indebtedness as of the date minus the lesser of (i) available cash on such date and (ii) $50.0 million divided by (b) Consolidated EBITDA (as defined in the Secured Credit Facility agreement) for the period of four consecutive fiscal quarters of the Borrower most recently ended prior to such date.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Represents a maximum amount of the available cash held by the Company at period end that can be used as a reduction to the total outstanding debt to determine a net balance of the outstanding debt in leverage ratio calculation for the purpose of the debt covenant.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
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-Publisher FASB
-Name Accounting Standards Codification
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-Section 45
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-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016

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-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

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-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

Name:	us-gaap_LongTermDebtCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

Name:	us-gaap_LongTermDebtNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
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-Glossary Financing Activities
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+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=cmtl_TermLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_FederalFundsEffectiveSwapRateMember
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Balance Type:
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- Details

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Secured Credit Facility (Details)	3 Months Ended			6 Months Ended
Secured Credit Facility (Details)	Jul. 31, 2017	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($)	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($)	Jul. 31, 2016 USD ($)	Feb. 23, 2016 USD ($)	Jul. 31, 2015 USD ($)
Line of Credit Facility [Line Items]
Current portion of long-term debt		$ 13,281,000		$ 13,281,000		$ 11,067,000
Non-current portion of long-term debt, net		229,834,000		229,834,000		239,969,000
Repayment of term loan facility				4,427,000	$ 0
Cash and cash equivalents		63,144,000	$ 163,466,000	63,144,000	163,466,000	66,805,000		$ 150,953,000
Secured Credit Facility
Line of Credit Facility [Line Items]
Long-term Debt		243,115,000		243,115,000		251,036,000
Current portion of long-term debt		13,281,000		13,281,000		11,067,000
Non-current portion of long-term debt, net		229,834,000		229,834,000		239,969,000
Secured credit facility, maximum borrowing capacity							$ 400,000,000
Interest expense related to Credit Facility		2,708,000	$ 0	5,883,000	$ 0
Outstanding standby letters of credit at period end		3,690,000		3,690,000
Outstanding commercial letters of credit at period end		0		0
Maximum amount of available cash on hand that can be used in leverage ratio calculation		$ 50,000,000		50,000,000
Leverage ratio		2.57
Maximum allowable leverage ratio included in financial covenants		3.00
Term Loan Facility \| Secured Credit Facility
Line of Credit Facility [Line Items]
Long-term Debt, Gross		$ 168,220,000		168,220,000		172,647,000
Unamortized deferred financing costs		4,909,000		4,909,000		5,515,000
Long-term Debt		163,311,000		163,311,000		167,132,000
Secured credit facility, maximum borrowing capacity							250,000,000
Repayment of term loan facility				4,427,000
Revolving Loan Facility \| Secured Credit Facility
Line of Credit Facility [Line Items]
Long-term Debt		$ 79,804,000		$ 79,804,000		$ 83,904,000
Secured credit facility, maximum borrowing capacity							150,000,000
Revolving Loan Facility \| Letter of Credit
Line of Credit Facility [Line Items]
Secured credit facility, maximum borrowing capacity							$ 25,000,000
Federal Funds Rate \| Revolving Loan Facility \| Secured Credit Facility
Line of Credit Facility [Line Items]
Variable interest rate (percent)				0.50%
Adjusted LIBO rate \| Revolving Loan Facility \| Secured Credit Facility
Line of Credit Facility [Line Items]
Variable interest rate (percent)				1.00%
Floor interest rate				1.00%
Minimum \| Secured Credit Facility
Line of Credit Facility [Line Items]
Blended interest rate (percent)		4.79%		4.79%
Minimum \| Revolving Loan Facility \| Secured Credit Facility
Line of Credit Facility [Line Items]
Long-term Debt		$ 56,904,000		$ 56,904,000
Maximum \| Secured Credit Facility
Line of Credit Facility [Line Items]
Blended interest rate (percent)		5.06%		5.06%
Maximum \| Revolving Loan Facility \| Secured Credit Facility
Line of Credit Facility [Line Items]
Long-term Debt		$ 84,904,000		$ 84,904,000
Subsequent Event \| Secured Credit Facility
Line of Credit Facility [Line Items]
Maximum allowable leverage ratio included in financial covenants	2.75