Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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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Fair value amount of debt instrument that was repurchased.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Debt (Narrative) (Details) - USD ($)					1 Months Ended				3 Months Ended	12 Months Ended
Debt (Narrative) (Details) - USD ($)	Nov. 24, 2015	Sep. 30, 2014	May. 31, 2014	Mar. 28, 2014	Sep. 30, 2015	Oct. 31, 2014	May. 31, 2014	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2015
Debt Instrument [Line Items]
Repayments of long-term debt										$ 61,000,000	$ 331,000,000	$ 260,000,000
Cost for early redemption										$ 0	137,000,000	$ 24,000,000
3.75% Senior Debt Obligations Due 2026
Debt Instrument [Line Items]
Debt instrument, amount					$ 600,000,000
Interest rate					3.75%					3.75%
Debt instrument, term					10 years 6 months
2.35% Senior Debt Obligations Due 2020
Debt Instrument [Line Items]
Debt instrument, amount													$ 500,000,000
Interest rate										2.35%			2.35%
2.35% Senior Debt Obligations Due 2019
Debt Instrument [Line Items]
Debt instrument, amount		$ 300,000,000
Interest rate		2.35%								2.35%
Debt instrument, term		5 years
2.55% Senior Debt Obligations Due 2018
Debt Instrument [Line Items]
Interest rate										2.55%
Other Debt Facilities
Debt Instrument [Line Items]
Revolving credit facility, amount outstanding									$ 600,000	$ 400,000	600,000
Debt instrument, unused borrowing capacity									260,000,000	$ 229,000,000	$ 260,000,000
4.80% Senior Debt Obligations Due 2021
Debt Instrument [Line Items]
Interest rate										4.80%
Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, term				5 years
Line of credit facility, current borrowing capacity	$ 1,200,000,000.0
Amended Revolving Credit Facility November 24, 2015
Debt Instrument [Line Items]
Revolving credit facility, borrowing capacity	$ 1,500,000,000.0
Amended Revolving Credit Facility March 28, 2014
Debt Instrument [Line Items]
Debt instrument, term	5 years
Revolving credit facility, borrowing capacity										$ 1,200,000,000.0
Revolving credit facility, amount outstanding										$ 0
5.75% Senior Debt Obligations Due 2015
Debt Instrument [Line Items]
Interest rate										5.75%
5.375% Senior Debt Obligations Due 2014
Debt Instrument [Line Items]
Interest rate			5.375%				5.375%			5.375%
2.30% Senior Debt Obligations Due 2017
Debt Instrument [Line Items]
Interest rate										2.30%
Three-Year Delayed Draw Term Loan Facility
Debt Instrument [Line Items]
Debt instrument, term								3 years
Revolving credit facility, borrowing capacity								$ 50,000,000
4.05% Senior Debt Obligations Due 2023
Debt Instrument [Line Items]
Interest rate										4.05%
3.50% Senior Debt Obligations Due 2025
Debt Instrument [Line Items]
Debt instrument, amount		$ 500,000,000
Interest rate		3.50%								3.50%
Debt instrument, term		10 years 6 months
3.50% Senior Debt Obligations Due 2024
Debt Instrument [Line Items]
Debt instrument, amount			$ 600,000,000				$ 600,000,000
Interest rate			3.50%				3.50%			3.50%
Debt instrument, term			10 years
9.25% Senior Debt Obligations Due 2019
Debt Instrument [Line Items]
Interest rate						9.25%
Partial redemption of notes						$ 400,000,000
Senior Debt Obligations Due 2015 and Senior Debt Obligations Due 2019
Debt Instrument [Line Items]
Partial redemption of notes						630,000,000
Repayments of long-term debt						$ 765,000,000
Cost for early redemption									$ 137,000,000
5.375% Senior Debt Obligations Due 2014
Debt Instrument [Line Items]
Repayments of long-term debt							$ 320,000,000
5.75% Senior Debt Obligations Due 2015
Debt Instrument [Line Items]
Interest rate						5.75%
Partial redemption of notes						$ 230,000,000
Line of Credit \| Uncommitted Bank Credit Line
Debt Instrument [Line Items]
Revolving credit facility, borrowing capacity					$ 150,000,000
Short-term Debt										$ 0