Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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=64930785&loc=d3e28551-108399

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: 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_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Details

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- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=noc_October2017NotesDomain
Namespace Prefix:
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Balance Type:
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- Details

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- Details

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Subsequent Events (Unaudited) (Details) - Subsequent Event [Member] - USD ($) $ in Millions		14 Months Ended
	Oct. 13, 2017	Dec. 17, 2018
Senior Notes [Member] \| October 2017 Notes [Domain]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 8,250
Senior Notes [Member] \| 2020 Maturity [Domain]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 1,000
Debt Instrument, Interest Rate, Stated Percentage	2.08%
Senior Notes [Member] \| 2022 Maturity [Domain]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 1,500
Debt Instrument, Interest Rate, Stated Percentage	2.55%
Senior Notes [Member] \| 2025 Maturity [Domain]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 1,500
Debt Instrument, Interest Rate, Stated Percentage	2.93%
Senior Notes [Member] \| 2028 Maturity [Domain]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 2,000
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Senior Notes [Member] \| 2047 Maturity [Domain]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 2,250
Debt Instrument, Interest Rate, Stated Percentage	4.03%
General Redemption [Domain]
Subsequent Event [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Mandatory Redemption [Domain]
Subsequent Event [Line Items]
Debt Instrument, Redemption Price, Percentage		101.00%