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Age at which participants could elect to remain in the defined benefit plan as of August 31, 2008.

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Defined Benefit Plan, Total Recognized in Net Periodic Benefit Costs and Other Comprehensive Income, before Tax

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Carrying value as of the balance sheet date of obligations, excluding pension and other postretirement benefits, incurred through that date and payable for perquisites provided to employees pertaining to services received from them.

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 210

-Section S99

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-Subparagraph a

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-Name Regulation S-X (SX)

-Number 210

-Section 03

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The amount of employer securities or securities of parties related to the employer that are included in plan assets.

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Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

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-Publisher FASB

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Amount included in accumulated other comprehensive income (AOCI) related to gain (loss) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position.

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Amount included in accumulated other comprehensive income (AOCI) related to prior service cost (credit) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position.

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The number of employer shares or related party shares included in plan assets.

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Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

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Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

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

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Amount of discretionary contributions made by an employer to a defined contribution plan.

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Percentage employer matches of the employee's percentage contribution matched.

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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Value of the other investment not readily marketable determined by management based upon fair value methods, including pricing of similar securities and valuation techniques, that was used to record the investment for financial reporting purposes.

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Employee Retirement Benefits (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended					3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2008	Dec. 31, 2015	Mar. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Minimum participant age to elect				40 years
Employer discretionary contribution amount	$ 11	$ 10	$ 9
Requisite service period	3 years
Actual return on plan assets	11.70%	24.00%
Total recognized in net periodic benefit cost and other comprehensive income	(31)	63	(31)
Amortization of actuarial loss	5
Amortization of prior service cost	1
Pension plan assets at fair value	288	280	238
Cash dividends paid	288us-gaap_DividendsCommonStockCash	270us-gaap_DividendsCommonStockCash	263us-gaap_DividendsCommonStockCash
Domestic Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Allocation percentage of investments	81.00%
Domestic Equity Securities \| Information Technology Sector
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Allocation percentage of investments	19.00%
Domestic Equity Securities \| Financial Services Sector
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Allocation percentage of investments	23.00%
Domestic Equity Securities \| Healthcare Sector
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Allocation percentage of investments	14.00%
Domestic Equity Securities \| Industrial Sector
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Allocation percentage of investments	12.00%
Domestic Equity Securities \| All Remaining Sectors
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Allocation percentage of investments	10.00%
States, Municipalities and Political Subdivisions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Allocation percentage of investments	12.00%
Domestic Corporate Debt Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Allocation percentage of investments	7.00%
Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Pension plan assets at fair value	11	19
Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Matching contribution to defined contribution plan	6.00%
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Pension plan assets, shares	467,113	467,113
Pension plan assets, fair value	24	24
Shares sold during period		100,000
Pension plan assets, entity's shares sold, gain		5
Cash dividends paid	1	1
Pension Plan \| Benefit Obligations
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Percentage of increase decrease in discount rate	0.90%
Pension Plan \| Net Periodic Benefit Costs
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Percentage of increase decrease in discount rate	0.95%
Supplemental Employee Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Accrued employee benefit	13	9
Supplemental Employee Retirement Plan \| Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Expected contribution by employer during 2015					3
Supplemental Employee Retirement Plan \| Benefit Obligations
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Percentage of increase decrease in discount rate	0.75%
Supplemental Employee Retirement Plan \| Net Periodic Benefit Costs
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Percentage of increase decrease in discount rate	0.85%
Top Hat Savings Plan - Mutual Funds and Common Equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
CFC Top Hat Savings Plan	18	14
Subsequent Event \| Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block
Expected contribution by employer during 2015						$ 5