Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended
Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing stock price	$ 10.27
Cash received from employee stock option exercises	$ 0	$ 0
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stocks granted	1,573,500
Fair value of restricted stock awards vested	400,000	4,300,000
Unrecognized compensation cost	17,300,000
Unrecognized compensation cost, estimated weighted average amortization period	2.2
Restricted stock \| Senior Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stocks granted	1,377,000
Restricted stock \| Senior Management \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense on awards	17,400,000
Restricted stock \| Senior Management \| Awards subject to performance criteria
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stocks granted	1,007,750
Restricted stocks granted, financial performance measurement year	2014
Restricted stock \| Senior Management \| Awards subject to service criteria
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stocks granted	369,250
Restricted stock \| Chief Executive Officer \| Phantom Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stocks granted	100,000
Liability related to earned portion of potential cash payment	$ 25,000

Share Based Compensation Arrangement by Share Based Payment Award, Financial Performance Measurement Period

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- Definition

Share Based Compensation Arrangement by Share Based Payment Award, Options, Closing Stock Price

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- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

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- Definition

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

+ References

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-Publisher FASB

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- Definition

The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

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- Definition

The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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- Definition

Equity-based compensation cost during the period with respect to the award, which will be recognized in income (as well as the total recognized tax benefit) or capitalized as part of the cost of an asset.

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- Definition

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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- Definition

The total fair value of equity-based awards 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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