Fixed Charge Coverage Ratio

Name:	ntct_FixedChargeCoverageRatio
Namespace Prefix:	ntct
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Leverage Ratio

+ Details

Name:	ntct_LeverageRatio
Namespace Prefix:	ntct
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage Of Annual Excess Cash Flow To Be Used For Prepayment Of Credit Facility

+ Details

Name:	ntct_PercentageOfAnnualExcessCashFlowToBeUsedForPrepaymentOfCreditFacility
Namespace Prefix:	ntct
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of Net Proceeds From Issuance of Debt To Be Used For Prepayment Of Line Of Credit

+ Details

Name:	ntct_PercentageOfNetProceedsFromIssuanceOfDebtToBeUsedForPrepaymentOfLineOfCredit
Namespace Prefix:	ntct
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of Net Proceeds From Issuance of Equity To Be Used For Prepayment Of Line Of Credit

+ Details

Name:	ntct_PercentageOfNetProceedsFromIssuanceOfEquityToBeUsedForPrepaymentOfLineOfCredit
Namespace Prefix:	ntct
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of Net Proceeds From Issuance Recovery and Condemnation Events To Be Used For Prepayment Of Line Of Credit

+ Details

Name:	ntct_PercentageOfNetProceedsFromIssuanceRecoveryAndCondemnationEventsToBeUsedForPrepaymentOfLineOfCredit
Namespace Prefix:	ntct
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of Net Proceeds From Sale of Asset To Be Used For Prepayment Of Line Of Credit

+ Details

Name:	ntct_PercentageOfNetProceedsFromSaleOfAssetToBeUsedForPrepaymentOfLineOfCredit
Namespace Prefix:	ntct
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Spread Over Interest Rate

+ Details

Name:	ntct_SpreadOverInterestRate
Namespace Prefix:	ntct
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	instant

- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateDuringPeriod
Namespace Prefix:	us-gaap
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityAmountOutstanding
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 18

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 19

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfLongTermDebt
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Long-Term Debt (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
Long-Term Debt (Narrative) (Details) (USD $)	Dec. 31, 2007	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011
Debt Instrument [Line Items]
Percentage of net proceeds from sale of asset to be used for prepayment of credit facility				100.00%
Percentage of net proceeds from issuance of debt to be used for prepayment of credit facility				100.00%
Percentage of net proceeds from issuance of equity to be used for prepayment of credit facility				50.00%
Percentage of net proceeds from issuance recovery and condemnation events to be used for prepayment of credit facility				100.00%
Maximum [Member] \| Financial Covenants [Member]
Debt Instrument [Line Items]
Leverage ratio		3.00		3.00
Minimum [Member] \| Financial Covenants [Member]
Debt Instrument [Line Items]
Fixed charge coverage ratio		1.25		1.25
Term Loan [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity	$ 100,000,000
Proceeds from term loan	100,000,000
Interest rate at period end		2.50%	2.813%	2.30%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity	10,000,000
Credit facility outstanding amount		0		0
Maximum [Member]
Debt Instrument [Line Items]
Leverage ratio		1.00		1.00
Percentage of annual excess cash flow to be used for prepayment of credit facility				50.00%
Maximum [Member] \| Alternative Base Rate Loans [Member]
Debt Instrument [Line Items]
Margin over applicable interest rate (basis point)		75		75
Maximum [Member] \| Eurodollar Rate Loans [Member]
Debt Instrument [Line Items]
Margin over applicable interest rate (basis point)		200		200
Minimum [Member]
Debt Instrument [Line Items]
Leverage ratio		2.50		2.50
Percentage of annual excess cash flow to be used for prepayment of credit facility				25.00%
Minimum [Member] \| Alternative Base Rate Loans [Member]
Debt Instrument [Line Items]
Margin over applicable interest rate (basis point)		175		175
Minimum [Member] \| Eurodollar Rate Loans [Member]
Debt Instrument [Line Items]
Margin over applicable interest rate (basis point)		300		300