Stock-Based Compensation - Weighted Average Exercise Price and Remaining Term Information about Significant Option Groups Outstanding (Detail) (USD $)	12 Months Ended
Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	302,729
Weighted Average Remaining Term	3 years 3 months 18 days
Weighted Average Exercise Price	$ 18.18
Aggregate Intrinsic Value	$ 0
Vested Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	302,729
Weighted Average Exercise Price	$ 18.18
Less than $10.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Upper Range	$ 10.00
Number Outstanding	300
Weighted Average Remaining Term	5 years 6 months
Weighted Average Exercise Price	$ 8.90
Aggregate Intrinsic Value	0
Less than $10.00 [Member] \| Vested Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	300
Weighted Average Exercise Price	$ 8.90
$10.00 - $19.99 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range	$ 10.00
Exercise Price Upper Range	$ 19.99
Number Outstanding	170,170
Weighted Average Remaining Term	4 years 4 months 24 days
Weighted Average Exercise Price	$ 11.85
Aggregate Intrinsic Value	0
$10.00 - $19.99 [Member] \| Vested Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	170,170
Weighted Average Exercise Price	$ 11.85
$20.00 - $29.99 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range	$ 20.00
Exercise Price Upper Range	$ 29.99
Number Outstanding	107,959
Weighted Average Remaining Term	2 years 1 month 6 days
Weighted Average Exercise Price	$ 23.24
Aggregate Intrinsic Value	0
$20.00 - $29.99 [Member] \| Vested Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	107,959
Weighted Average Exercise Price	$ 23.24
$30.00 - $39.99 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range	$ 30.00
Exercise Price Upper Range	$ 39.99
Number Outstanding	17,800
Weighted Average Remaining Term	1 year 1 month 6 days
Weighted Average Exercise Price	$ 36.70
Aggregate Intrinsic Value	0
$30.00 - $39.99 [Member] \| Vested Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	17,800
Weighted Average Exercise Price	$ 36.70
$40.00 - $49.99 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range	$ 40.00
Exercise Price Upper Range	$ 49.99
Number Outstanding	4,500
Weighted Average Remaining Term	8 months 12 days
Weighted Average Exercise Price	$ 47.89
Aggregate Intrinsic Value	0
$40.00 - $49.99 [Member] \| Vested Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	4,500
Weighted Average Exercise Price	$ 47.89
$50.00 - $59.99 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Lower Range	$ 50.00
Exercise Price Upper Range	$ 59.99
Number Outstanding	2,000
Weighted Average Remaining Term	8 months 12 days
Weighted Average Exercise Price	$ 53.85
Aggregate Intrinsic Value	$ 0
$50.00 - $59.99 [Member] \| Vested Options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	2,000
Weighted Average Exercise Price	$ 53.85

Share based compensation shares authorized under stock option plans exercise price range aggregate Intrinsic value.

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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 number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ 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)-(ii)

-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 could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

+ 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)-(ii)

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

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- Definition

Weighted average remaining contractual term of outstanding stock options, 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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- 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

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