Stock-based Compensation (Time-Lapse Restricted Stock Units, EPS Performance Restricted Stock Units And Strategic Performance Restricted Stock Units And TSR Performance Restricted Stock Units) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended	12 Months Ended
May 03, 2015	Apr. 27, 2014	Aug. 03, 2014
Time-Lapse, EPS Performance, Strategic Performance And Special Performance Restricted Stock Units [Member]
Stock-based Compensation
Nonvested at beginning of period, Units	2,994
Granted, Units	1,080
Vested, Units	(1,257)
Forfeited, Units	(419)
Nonvested at end of period, Units	2,398
Nonvested at beginning of period, Weighted-Average Grant-Date Fair Value	$ 37.69
Granted, Weighted-Average Grant-Date Fair Value	$ 42.43	$ 39.83
Vested, Weighted-Average Grant-Date Fair Value	$ 35.62
Forfeited, Weighted Average Grant Date Fair Value	$ 36.53
Nonvested at end of period, Weighted-Average Grant-Date Fair Value	$ 41.11
TSR Performance Restricted Stock Units [Member]
Stock-based Compensation
Nonvested at beginning of period, Units	861
Granted, Units	874
Vested, Units	0
Forfeited, Units	(93)
Nonvested at end of period, Units	1,642		861
Nonvested at beginning of period, Weighted-Average Grant-Date Fair Value	$ 38.15
Granted, Weighted-Average Grant-Date Fair Value	$ 43.39		$ 36.26
Vested, Weighted-Average Grant-Date Fair Value	$ 0
Forfeited, Weighted Average Grant Date Fair Value	$ 40.90
Nonvested at end of period, Weighted-Average Grant-Date Fair Value	$ 40.78		$ 38.15

Stock-based Compensation (Time-Lapse Restricted Stock Units, EPS Performance Restricted Stock Units And Strategic Performance Restricted Stock Units And TSR Performance Restricted Stock Units) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified

9 Months Ended

12 Months Ended

May 03, 2015

Apr. 27, 2014

Aug. 03, 2014

Time-Lapse, EPS Performance, Strategic Performance And Special Performance Restricted Stock Units [Member]

Stock-based Compensation

Nonvested at beginning of period, Units

2,994us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Granted, Units

1,080us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Vested, Units

(1,257)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Forfeited, Units

(419)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Nonvested at end of period, Units

2,398us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Nonvested at beginning of period, Weighted-Average Grant-Date Fair Value

$ 37.69us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Granted, Weighted-Average Grant-Date Fair Value

$ 42.43us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

$ 39.83us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Vested, Weighted-Average Grant-Date Fair Value

$ 35.62us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Forfeited, Weighted Average Grant Date Fair Value

$ 36.53us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

Nonvested at end of period, Weighted-Average Grant-Date Fair Value

$ 41.11us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember

TSR Performance Restricted Stock Units [Member]

Stock-based Compensation

Nonvested at beginning of period, Units

861us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Granted, Units

874us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Vested, Units

0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Forfeited, Units

(93)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Nonvested at end of period, Units

1,642us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

861us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Nonvested at beginning of period, Weighted-Average Grant-Date Fair Value

$ 38.15us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Granted, Weighted-Average Grant-Date Fair Value

$ 43.39us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

$ 36.26us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Vested, Weighted-Average Grant-Date Fair Value

$ 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Forfeited, Weighted Average Grant Date Fair Value

$ 40.90us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

Nonvested at end of period, Weighted-Average Grant-Date Fair Value

$ 40.78us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= cpb_TSRPerformanceRestrictedStockUnitsMember

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iv)(3)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(3)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(2)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(2)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_AwardTypeAxis=cpb_TimeLapseEPSStrategicPerformanceAndSpecialPerformanceRestrictedStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=cpb_TSRPerformanceRestrictedStockUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: