Guarantee of Registered Securities - Narrative (Details)	Dec. 31, 2015
3.125% Senior Notes Percent Due 2016 [Member]
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	3.125%
5.00% Senior Notes due September 2020
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	5.00%
8.205% Junior Subordinated Deferrable Interest Debentures Percent Due 2027 [Member]
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	8.205%
6.25% Senior Notes due September 2040
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	6.25%
4.250% Notes Due 2042 [Member]
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	4.25%
4.45% Senior Notes due May 2043
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	4.45%
4.00% Senior Notes due November 2023
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	4.00%
2.875% Senior Notes due May 2026 (EUR 500M)
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	2.875%
3.50% Senior Notes due June 2024
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	3.50%
4.60% notes due May 2044 [Member]
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	4.60%
4.75% Senior Notes due 2045 | Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	4.75%
2.80% Senior Notes due 2021 | Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
Interest rate on debt ( in percentage)	2.80%