SHARE-BASED COMPENSATION Stock-Based Compensation - SARs (Details) (USD $)	12 Months Ended
Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding	616,803
Sars Outstanding Weighted Average Exercise Price	$ 20.71
Exercised	(27,389)
Sars Exercised Weighted Average Exercise Price	$ 15.87
Forfeitures	(30,512)
Sars Forfeited Weighted Average Exercise Price	$ 27.41
Outstanding	558,902
Sars Outstanding Weighted Average Exercise Price	$ 20.58
SARs Exercisable	423,815
SARs Exercisable Weighted Average Exercise Price	$ 19.61

The number of stock appreciation rights currently exercisable.

No definition available.

Name:	pepl_SarsExercisable
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Data Type:	xbrli:sharesItemType
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Period Type:	instant

- Definition

The weighted average exercise price of stock appreciation rights exercisable.

+ References

No definition available.

+ Details

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Namespace Prefix:	pepl_
Data Type:	num:perShareItemType
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Period Type:	instant

- Definition

The weighted average exercise price of stock appreciation rights exercised during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	pepl_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average exercise price of stock appreciation rights forfeited during the period.

+ References

No definition available.

+ Details

Name:	pepl_Sarsforfeitedweightedaverageexerciseprice
Namespace Prefix:	pepl_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average exercise price of stock appreciation rights outstanding.

+ References

No definition available.

+ Details

Name:	pepl_Sarsoutstandingweightedaverageexerciseprice
Namespace Prefix:	pepl_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

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Balance Type:	na
Period Type:	duration

- Definition

Number of non-option equity instruments exercised by participants.

+ References

+ Details

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

- Definition

Number of shares under non-option equity instrument agreements that were either cancelled or expired.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Period Type:	duration

- Definition

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

+ 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)(i)

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(ii)

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

+ Details

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