Leasing Activities (Income Recognized From Cross-border Energy Lease Investments) (Details) (USD $) In Millions	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Leasing Activities
Pre-tax income from PHI's cross-border energy lease investments (included in "Other Revenue")	$ 14	$ 13	$ 28	$ 26
Income tax expense related to cross-border energy lease investments	7	3	10	7
Net income from PHI's cross-border energy lease investments	$ 7	$ 10	$ 18	$ 19

- Details

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

- Definition

Pretax lease income allocated in proportionate amounts from unearned income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 47

+ Details

Name:	us-gaap_LeveragedLeasesIncomeStatementIncomeFromLeveragedLeases
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The tax effect from the current year income from arrangements meeting the criteria for classification as a leveraged lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 47

+ Details

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

- Definition

The total recognized during the period for income on leases meeting the criteria for classification as leveraged leases.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 13
-Paragraph 47

+ Details

Name:	us-gaap_LeveragedLeasesIncomeStatementNetIncomeFromLeveragedLeases
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration