Annual Rate at Which Stock Repurchase Right Lapses

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- Definition

Liability Related To Common Stock Subject To Repurchase

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- Definition

Monthly Rate At Which Stock Repurchase Right Lapses

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- Definition

Percentage Of Voting Stock

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No definition available.

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- Definition

Repurchase Price Per Share

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No definition available.

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Award Term

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- Definition

Stock Option Grants Exercise Price Minimum Percentage On Fair Market Value

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

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-Section S99

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-Subparagraph (SAB TOPIC 14.F)

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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-Name Accounting Standards Codification

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-SubTopic 10

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- Definition

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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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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-Publisher FASB

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-Topic 718

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- Definition

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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- Definition

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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-Name Accounting Standards Codification

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-Subparagraph (d)(2)

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- Definition

Net number of share options (or share units) granted during the period.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

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- Definition

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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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

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- Definition

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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- Definition

Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Stock-Based Compensation - Additional Information (Detail) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Term of stock options granted			10 years
Vesting period of stock options			4 years
Number of common stock shares reserved for issuance under the 2003 Equity Incentive Plan	334,070		4,753,323
Aggregate intrinsic value of options exercised			$ 451,000	$ 290,000	$ 284,000
Total estimated grant date fair value of options vested			3,000,000	1,800,000	1,600,000
Unamortized share based compensation expected to be recognized over the remaining vesting period			5,400,000
Unamortized share based compensation period for recognition			2 years 8 months 12 days
Weighted-average per share fair value of employee options granted			$ 4.70	$ 5.90	$ 5.90
Share based compensation, options weighted average exercise price	$ 13.98		$ 7.38	$ 8.35	$ 9.00
Share based compensation expense	1,923,000	1,411,000	2,809,000	2,353,000	1,934,000
Unvested common shares, outstanding			1,125	2,484
Unvested common shares, repurchase price			$ 8.45	$ 7.85
Percentage of repurchase rights that lapse after one year			25.00%
Percentage of repurchase rights that lapse monthly for 36 months after the first year			2.08%
Liability for shares issued with repurchase rights			10,000	20,000
Incentive Stock Options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Exercise price of stock options granted as a minimum percentage of fair value of common stock			100.00%
Nonstatutory Stock Options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Exercise price of stock options granted as a minimum percentage of fair value of common stock			85.00%
10% or more
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Exercise price of stock options granted as a minimum percentage of fair value of common stock			110.00%
Percentage of voting stock			10.00%
Nonemployee Stock Options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period of stock options			4 years
Share based compensation, options granted			6,380	0	33,750
Share based compensation, options weighted average exercise price			$ 7.00		$ 9.00
Share based compensation expense			$ 144,000	$ 65,000	$ 172,000