Financing (Senior Notes) (Narrative) (Details) $ in Millions		3 Months Ended
Mar. 08, 2016 USD ($) d Rate	Mar. 31, 2016 USD ($) d Rate
Financing
Unsecured senior notes description		The Company has issued a cumulative $1.9 billion aggregate principal amount of unsecured senior notes, which are due between January 2021 and March 2026 with UMB as trustee. Interest on the senior notes, ranging from 3.550% to 4.875%, is payable semi-annually and is computed on the basis of a 360-day year.
Aggregate principle of unsecured senior notes \| $		$ 1,900
Maturity date range, minimum		Jan. 14, 2021
Maturity date range, maximum		Mar. 08, 2026
Interest rate of notes, minimum		3.55%
Interest rate of notes, maximum		4.875%
Number of days in annual interest calculation period \| d		360
Debt instrument covenant description		Each of the senior notes is subject to certain customary covenants, with which the Company complied as of March 31, 2016.
$500 million, 3.550% Senior Notes due 2026 [Member]
Financing
Issuance date of senior notes	Mar. 08, 2016
Face amount of senior notes \| $	$ 500
Interest rate of senior notes	3.55%
Percentage of face value of debt instrument	99.832%
Number of days in annual interest calculation period \| d	360

The percent of face value at which the debt instrument was offered to the public.

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The number of days in a year used to calculate interest.

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States whether the entity was in compliance with the debt covenants throughout the reporting period, and describes facts and circumstances of any compliance failure.

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Identification of the lender and information about a contractual promise to repay a short-term or long-term obligation, which includes borrowings under lines of credit, notes payable, commercial paper, bonds payable, debentures, and other contractual obligations for payment. This may include rationale for entering into the arrangement, significant terms of the arrangement, which may include amount, repayment terms, priority, collateral required, debt covenants, borrowing capacity, call features, participation rights, conversion provisions, sinking-fund requirements, voting rights, basis for conversion if convertible and remarketing provisions. The description may be provided for individual debt instruments, rational groupings of debt instruments, or by debt in total.

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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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Maximum contractual interest rate for funds borrowed, under the debt agreement.

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Minimum contractual interest rate for funds borrowed, under the debt agreement.

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Date the debt instrument was issued, in CCYY-MM-DD format.

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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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Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

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Earliest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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