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Stock-Based Compensation - Additional Information (Detail) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013 2013 Stock Incentive Plan [Member]	Oct. 31, 2013 2013 Stock Incentive Plan [Member]	Sep. 30, 2014 Stock Option Plan 2000 [Member]	Feb. 28, 2003 Equity Incentive Plan 2003 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, Number of shares authorized				1,960,168	150,297	4,336,731
Stock reserved for future issuance				1,960,168
Percentage of Common stock share outstanding			4.00%
Weighted-average grant-date fair value of options granted	$ 14.75
Intrinsic value of options exercised	$ 8,200,000
Cash received for options exercised	486,000	851,000
Fair value of shares vested	2,000,000
Unrecognized compensation expense related to non-vested stock-options, net of related forfeiture estimates	$ 9,100,000
Unrecognized compensation expense recognition period	4 years

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Common Stock Capital Shares Minimum Increase In Shares Reserved For Future Issuance

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Percentage of shares of company's common stock outstanding for increase in shares reserved for issuance under stock plan.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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-Glossary Financing Activities

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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