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- Definition

An entity may opt to disclose the lowest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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Share-based Compensation Arrangement by Share-based Payment Award, Number of Common Stock Trading Days Preceding the Vesting Date

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Current Market Price, Purchase Date

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Target Number of Common Shares Granted

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Share-based Compensation Arrangement by Share-based Payment Award, Performance Period

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Potential Annual Reduction in Vesting Based on Performance, Percentage

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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- Definition

Aggregate cash paid by the entity during the period to settle equity instruments granted under equity-based payment arrangements.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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No definition available.

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Stock-Based Compensation Plans - Additional Information (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) plan $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares
Amended and Restated 2004 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of active stock plans \| plan	1
Shares authorized under plans (in shares) \| shares	55,000,000
Shares available for grant under plans (in shares) \| shares	20,000,000
Compensation expense from award	$ 161	$ 205	$ 240
Recognized tax benefit from stock-based compensation arrangements	$ 61	$ 77	$ 91
Amended and Restated 2004 Stock Incentive Plan \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum contractual term (Years)	10 years
Award vesting period (in years)	3 years
Weighted-average fair value of options granted (in dollars per share) \| $ / shares	$ 15.11	$ 16.39	$ 13.42
Total intrinsic value of stock options exercised	$ 23	$ 24	$ 47
Unrecognized compensation expense related to unvested awards, options	$ 3
Weighted-average period of recognition of unrecognized compensation costs (Years)	1 year
Amended and Restated 2004 Stock Incentive Plan \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Unrecognized compensation expense related to unvested awards, awards other than options	$ 10
Weighted-average period of recognition of unrecognized compensation costs (Years)	1 year 2 months 12 days
Total fair value of awards vested	$ 28	$ 57	56
Weighted-average fair value of awards granted (in dollars per share) \| shares	0	0
Amended and Restated 2004 Stock Incentive Plan \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Unrecognized compensation expense related to unvested awards, awards other than options	$ 80
Weighted-average period of recognition of unrecognized compensation costs (Years)	1 year 11 months
Total fair value of awards vested	$ 27	$ 5	6
Weighted-average fair value of awards granted (in dollars per share) \| shares	1,316,000
Amended and Restated 2004 Stock Incentive Plan \| Performance Shares Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Unrecognized compensation expense related to unvested awards, awards other than options	$ 0
Weighted-average period of recognition of unrecognized compensation costs (Years)	1 month
Total fair value of awards vested	$ 30	33	16
Weighted-average fair value of awards granted (in dollars per share) \| shares	0
Amended and Restated 2004 Stock Incentive Plan \| Performance Shares Awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential annual reduction in vesting based on performance (percent)	50.00%
Amended and Restated 2004 Stock Incentive Plan \| Performance Shares Awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential annual reduction in vesting based on performance (percent)	100.00%
Amended and Restated 2004 Stock Incentive Plan \| Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Unrecognized compensation expense related to unvested awards, awards other than options	$ 28
Weighted-average period of recognition of unrecognized compensation costs (Years)	1 year
Total fair value of awards vested	$ 74	$ 20	10
Weighted-average fair value of awards granted (in dollars per share) \| shares	1,213,000
Performance period	3 years
Amended and Restated 2004 Stock Incentive Plan \| Performance Share Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target award opportunities	0.00%	0.00%
Amended and Restated 2004 Stock Incentive Plan \| Performance Share Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target award opportunities	150.00%	150.00%
Amended and Restated 2004 Stock Incentive Plan \| Cash-Settled Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested awards, awards other than options	$ 1
Weighted-average period of recognition of unrecognized compensation costs (Years)	1 month
Cash payments to settle awards	$ 70	$ 72	74
Amended and Restated 2004 Stock Incentive Plan \| Cash-Settled Units \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common stock trading days required under vesting condition	15 days
Amended and Restated 2004 Stock Incentive Plan \| Cash-Settled Units \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common stock trading days required under vesting condition	20 days
Associate Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under plans (in shares) \| shares	18,000,000
Shares available for grant under plans (in shares) \| shares	7,000,000
Compensation expense from award	$ 16	$ 13	$ 11
Minimum percentage of monthly base pay required for the purchase plan	1.00%
Maximum percentage of monthly base pay eligible for the purchase plan	15.00%
Percentage of current market price at which purchase plan shares are bought	85.00%
Dividend Reinvestment Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under plans (in shares) \| shares	8,000,000
Shares available for grant under plans (in shares) \| shares	7,000,000