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.

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=96867065&loc=d3e5070-113901

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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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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=96867065&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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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No definition available.

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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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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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
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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
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SHARE-BASED COMPENSATION - Stock Options Outstanding and Exercisable (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	$ 22.13
Range of Exercise Prices Per Share - Upper Range	$ 87.71
Options Outstanding - Stock Option Shares	3,652	6,340	7,918	9,307
Options Outstanding - Weighted-Average Remaining Term (Yrs)	5 years 4 months 24 days
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 56.05	$ 52.56	$ 50.94	$ 48.84
Options Exercisable - Stock Option Shares	2,104	4,493	6,085
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 50.67
$22.13 - $48.56
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	22.13
Range of Exercise Prices Per Share - Upper Range	$ 48.56
Options Outstanding - Stock Option Shares	823
Options Outstanding - Weighted-Average Remaining Term (Yrs)	2 years 6 months
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 38.56
Options Exercisable - Stock Option Shares	823
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 38.56
$49.50 - $57.93
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	49.50
Range of Exercise Prices Per Share - Upper Range	$ 57.93
Options Outstanding - Stock Option Shares	1,034
Options Outstanding - Weighted-Average Remaining Term (Yrs)	5 years 6 months
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 55.64
Options Exercisable - Stock Option Shares	608
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 54.04
$58.08 - $61.81
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	58.08
Range of Exercise Prices Per Share - Upper Range	$ 61.81
Options Outstanding - Stock Option Shares	748
Options Outstanding - Weighted-Average Remaining Term (Yrs)	5 years 6 months
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 61.29
Options Exercisable - Stock Option Shares	234
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 61.22
$61.95 - $71.04
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	61.95
Range of Exercise Prices Per Share - Upper Range	$ 71.04
Options Outstanding - Stock Option Shares	944
Options Outstanding - Weighted-Average Remaining Term (Yrs)	7 years 4 months 24 days
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 65.69
Options Exercisable - Stock Option Shares	439
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 63.06
$71.84 - $87.71
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices Per Share - Lower Range	71.84
Range of Exercise Prices Per Share - Upper Range	$ 87.71
Options Outstanding - Stock Option Shares	103
Options Outstanding - Weighted-Average Remaining Term (Yrs)	9 years
Options Outstanding - Weighted-Average Exercise Price Per Share	$ 73.53
Options Exercisable - Stock Option Shares	0
Options Exercisable - Weighted-Average Exercise Price Per Share	$ 0.00