Summary of Performance-Based Stock Award Activity and Related Information (Detail) (Stock awards, performance-based, USD $)	9 Months Ended
Sep. 30, 2012
Stock awards, performance-based
Number of Shares
Number of shares nonvested at beginning of period	556,985
Granted	1,062,632
Vested	(37,977)
Forfeited/Canceled	(539,020)
Number of shares nonvested at end of period	1,042,620
Weighted-Average Grant Date Fair Value
Weighted-Average Grant Date Fair Value nonvested at beginning of period	$ 3.89
Granted	$ 1.57
Vested	$ 5.82
Forfeited/Canceled	$ 3.10
Weighted-Average Grant Date Fair Value nonvested at end of period	$ 1.86

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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

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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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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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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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No definition available.

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