Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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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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Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective fair value hedge that is amortized upon discontinuation of the fair value hedge.

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Gain (loss) related to the termination of a contract between the parties. The termination may be due to many causes including early termination of a lease by a lessee, a breach of contract by one party, or a failure to perform.

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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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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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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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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 ($)	3 Months Ended
Debt (Narrative) (Details) - USD ($)	Mar. 31, 2016	Apr. 30, 2016	Dec. 31, 2015
Debt
Short-term Debt	$ 0		$ 0
Losses recorded to AOCI			21,600,000
Treasury rate lock agreements
Debt
Losses recorded to AOCI	66,100,000
Interest rate swap agreements \| Designated as hedging instruments
Debt
Gains recorded as reduction of debt	31,600,000		33,100,000
Gain on settlement of contract	0
Commercial Paper
Debt
Short-term Debt	0		0
Maximum borrowing capacity	1,750,000,000.000
Commercial Paper \| Subsequent Event
Debt
Maximum borrowing capacity		$ 2,000,000,000.000
Revolving Credit Facility
Debt
Long-term line of credit	0		$ 0
Level 2
Debt
Senior notes, fair value	$ 14,939,000,000