Pension Plans, Retirement Benefits and Savings Plans (details) - Miscellaneous Fair Value Disclosures	12 Months Ended
Dec. 31, 2014 item	Dec. 31, 2013 item
Qualified Domestic Pension Plan [Member] \| Equity securities [Member]
Defined benefit plan disclosure
Minimum investment in class of securities (as a percentage)	55.00%
Maximum investment in class of securities (as a percentage)	65.00%
Qualified Domestic Pension Plan [Member] \| Fixed income securities [Member]
Defined benefit plan disclosure
Minimum investment in class of securities (as a percentage)	20.00%
Maximum investment in class of securities (as a percentage)	40.00%
Qualified Domestic Pension Plan [Member] \| Private equity funds [Member]
Defined benefit plan disclosure
Number of private equity funds included in pension plan assets	2	2
Number of private equity funds included in pension plan assets focused on financial companies	1
Qualified Domestic Pension Plan [Member] \| Long-term growth [Member]
Defined benefit plan disclosure
Minimum investment in class of securities (as a percentage)	85.00%
Maximum investment in class of securities (as a percentage)	90.00%
Qualified Domestic Pension Plan [Member] \| Near-term benefit payments [Member]
Defined benefit plan disclosure
Minimum investment in class of securities (as a percentage)	10.00%
Maximum investment in class of securities (as a percentage)	15.00%
Postretirement Benefit Plans [Member] \| Fixed income securities [Member]
Defined benefit plan disclosure
Minimum investment in class of securities (as a percentage)	25.00%
Maximum investment in class of securities (as a percentage)	75.00%
Postretirement Benefit Plans [Member] \| Long-term growth [Member]
Defined benefit plan disclosure
Minimum investment in class of securities (as a percentage)	35.00%
Maximum investment in class of securities (as a percentage)	65.00%
Postretirement Benefit Plans [Member] \| Near-term benefit payments [Member]
Defined benefit plan disclosure
Minimum investment in class of securities (as a percentage)	35.00%
Maximum investment in class of securities (as a percentage)	60.00%

The number of investments in private equity funds.

No definition available.

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- Definition

The number of private equity funds focused on financial companies.

+ References

No definition available.

+ Details

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- Details

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- Definition

Target allocation maximum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(i)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)(i)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2446-114920

+ Details

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- Definition

Target allocation minimum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ References

+ Details

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- Details

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