Schedule of Share-based Compensation, Stock Options, Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Shares
Outstanding at January 1	546	3,877	7,584
Exercised	(115)	(190)	(205)
Forfeited or expired	(166)	(3,141)	(3,502)
Outstanding at December 31	265	546	3,877
Exercisable at December 31	265	546	3,877
Weighted-Average Grant Price
Outstanding at January 1	$ 20.72	$ 45.00	$ 53.88
Exercised	$ 12.84	$ 11.88	$ 10.32
Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price	$ 36.42	$ 51.23	$ 66.25
Outstanding at December 31	$ 14.25	$ 20.72	$ 45.00
Exercisable at December 31	$ 14.25	$ 20.72	$ 45.00

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.

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)(iii)

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

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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.

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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

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

+ References

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

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