Stock Options - Summary of Activity in Stock Option Plan (Detail) (USD $)	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Outstanding at beginning of period	10,000	29,500
Shares, Granted
Shares, Exercised
Shares, Forfeited
Shares, Expired	(10,000)
Shares, Options outstanding, end of period		29,500
Shares, Options exercisable, end of period		29,500
Weighted Average Exercise Price Per Share, Outstanding at beginning of period	$ 35.00	$ 25.42
Weighted Average Exercise Price Per Share, Granted
Weighted Average Exercise Price Per Share, Exercised
Weighted Average Exercise Price Per Share, Forfeited
Weighted Average Exercise Price, Expired	$ (35.00)
Weighted Average Exercise Price Per Share, Options outstanding, end of period		$ 25.42
Weighted Average Exercise Price, Options exercisable, end of period		$ 25.42

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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

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iii)

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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 or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-Subparagraph (c)(1)(iv)(4)

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to 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)(iv)(3)

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

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No definition available.

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

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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No definition available.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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

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No definition available.

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Number of share options (or share units) exercised during the current period.

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-Name Regulation S-X (SX)

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