Schedule Of Share Based Compensation Arrangement [Line Items]

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- Definition

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option 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)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

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

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

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- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option 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)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ 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 (g)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ 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 (g)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ 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 (e)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Share-Based Compensation - Summary of Stock Options Outstanding and Exercisable (Detail) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Share Based Compensation Arrangement [Line Items]
Number (shares)	3.4	3.7	3.9	3.9
Weighted- Average Remaining Contractual Life	4 years 2 months
Weighted- Average Exercise Price (usd per share)	$ 21.44	$ 21.29	$ 22.01	$ 22.25
Number (shares)	2.6
Weighted- Average Exercise Price (usd per share)	$ 21.67
$10.01 - $20.00
Schedule Of Share Based Compensation Arrangement [Line Items]
Exercise price range, lower range limit	10.01
Exercise price range, upper range limit	$ 20.00
Number (shares)	1.7
Weighted- Average Remaining Contractual Life	5 years
Weighted- Average Exercise Price (usd per share)	$ 16.53
Number (shares)	1.5
Weighted- Average Exercise Price (usd per share)	$ 16.53
$20.01 - $30.00
Schedule Of Share Based Compensation Arrangement [Line Items]
Exercise price range, lower range limit	20.01
Exercise price range, upper range limit	$ 30.00
Number (shares)	1.4
Weighted- Average Remaining Contractual Life	4 years 1 month 1 day
Weighted- Average Exercise Price (usd per share)	$ 25.01
Number (shares)	0.8
Weighted- Average Exercise Price (usd per share)	$ 26.89
Greater than $30.00
Schedule Of Share Based Compensation Arrangement [Line Items]
Exercise price range, lower range limit	$ 30.01
Number (shares)	0.3
Weighted- Average Remaining Contractual Life	4 months 31 days
Weighted- Average Exercise Price (usd per share)	$ 33.48
Number (shares)	0.3
Weighted- Average Exercise Price (usd per share)	$ 33.48