Long-Term Debt (Parenthetical) (Detail)	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
6.6% Senior Notes, Due 2018
Debt Instrument [Line Items]
Maturity date	2018
Interest rate on notes	6.60%
Interest rate	6.81%
7% Debentures, Due 2025
Debt Instrument [Line Items]
Maturity date	2025
Interest rate on notes	7.00%
Interest rate	7.12%
6.25% Senior Notes, Due 2037
Debt Instrument [Line Items]
Maturity date	2037
Interest rate on notes	6.25%
Interest rate	6.45%
4.25% Senior Notes, Due 2024
Debt Instrument [Line Items]
Maturity date	2024
Interest rate on notes	4.25%
Interest rate	4.25%
Floating Rate Notes, Due 2017
Debt Instrument [Line Items]
Maturity date	2017	2017
Interest rate	1.71%	1.33%
Term Loan Facility, Due 2018
Debt Instrument [Line Items]
Maturity date	2018	2018
Interest rate	1.86%	1.67%

Debt instrument maturity date year.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

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- Definition

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

+ References

+ Details

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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.

+ References

No definition available.

+ Details

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