Summary of stock option activity (Detail) - $ / shares	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Options Outstanding
Outstanding at beginning of period			44,797	100,437	100,437
Granted			0		0
Exercised	0	0	0	0	0
Forfeited			0		0
Expired			(44,797)		(55,640)
Outstanding at end of period	0		0		44,797
Share Based Compensation Arrangement By Share Based Payment Award Options Additional Disclosures Abstract
Outstanding at beginning of period			$ 272	$ 253.64	$ 253.64
Granted			0		0
Exercised			0		0
Forfeited			0		0
Share Based Compensation Arrangement By Share Based Payment Award Options Expirations In Period Weighted Average Exercise Price			272		238.85
Outstanding at end of period	$ 0		$ 0		$ 272

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- Definition

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

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-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

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- Definition

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

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- Definition

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

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

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

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- Definition

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

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

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