Number of Employee SARs and Director SARs Granted, Associated Weighted Average Base Values, And Weighted Average Grant-Date Fair Values (Detail) - Stock Appreciation Rights - $ / shares	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	300,000
Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	300,000	300,000	700,000
Weighted average exercise price (per unit)	$ 83	$ 53	$ 39
Weighted average grant-date fair value (per RSU)	$ 26	$ 17	$ 13
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	2,773	3,277	5,903
Weighted average exercise price (per unit)	$ 80	$ 59	$ 44
Weighted average grant-date fair value (per RSU)	$ 29	$ 22	$ 15

The weighted average exercise price at grant for share-based awards issued during the period on other than stock option plans (for example, phantom stock plan, stock appreciation rights plan, performance target plan).

No definition available.

+ Details

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ 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.

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