Employee Benefit Plans - Weighted-average Assumptions (Detail)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Pension Plan, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate used for Net Periodic Pension Cost	5.00%	4.00%
Discount Rate used for Disclosure	4.00%	5.00%
Expected return on plan assets	7.50%	8.00%
Rate of compensation increase	0.00%	0.00%
Rate of compensation increase for net periodic pension cost	0.00%	0.00%
Expected future interest crediting rate	3.00%	3.00%
Other Postretirement Benefit Plan, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate used for Net Periodic Pension Cost	5.00%	4.00%
Discount Rate used for Disclosure	4.00%	5.00%
Rate of compensation increase	0.00%	0.00%
Rate of compensation increase for net periodic pension cost	0.00%	0.00%

Defined benefit plan assumptions used calculating benefit obligation discount rate for disclosure.

No definition available.

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- Definition

Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Cash Balance Interest Crediting Rate

+ References

No definition available.

+ Details

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- Definition

Expected rate of compensation increases (for pay-related plans).

+ 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 (k)(2)

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

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- Definition

The interest rate used to adjust for the time value of money.

+ 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 (k)(1)

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

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- Definition

An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Glossary Expected Long-Term Rate of Return on Plan Assets

-URI http://asc.fasb.org/extlink&oid=6512013

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (k)(3)

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

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- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

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