Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Valuation Allowance [Line Items]
Deferred tax assets	$ 153,987,000	$ 25,635,000
Federal net operating loss carryforward	124,000,000
State net operating loss carryforwards	27,000,000
Valuation allowance	19,492,000	19,063,000
Deferred tax assets classified as a current income tax receivable	31,200,000
Liabilities for unrecognized tax benefits	0	0	0
Interest and penalty charges	$ 0	$ 0	$ 2,100,000
Federal
Valuation Allowance [Line Items]
Operating loss carryforward Expiration Date	2031
State and Local Jurisdiction \| Minimum
Valuation Allowance [Line Items]
Operating loss carryforward Expiration Date	2024
State and Local Jurisdiction \| Maximum
Valuation Allowance [Line Items]
Operating loss carryforward Expiration Date	2031

The current portion of the aggregate tax effects as of the balance sheet date of all future tax deductions arising from temporary differences between tax basis and generally accepted accounting principles basis recognition of assets, liabilities, revenues and expenses, which can only be deducted for tax purposes when permitted under enacted tax laws; after deducting the allocated valuation allowance, if any, to reduce such amount to net realizable value. Deferred tax liabilities and assets are classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, are classified according to the expected reversal date of the temporary difference. An unrecognized tax benefit that is directly related to a position taken in a tax year that results in a net operating loss carryforward is presented as a reduction of the related deferred tax asset.

+ References+ Details

The tax effect as of the balance sheet date of the amount of excess of tax deductions over gross income in a year which cannot be used on the tax return of the country of domicile in the current year but can be carried forward to reduce taxable income or income taxes payable in a future year, for which there must be sufficient tax-basis income to utilize a portion or all of the carryforward amount to realize the deferred tax asset.

+ References+ Details

- Definition

The tax effect as of the balance sheet date of the amount of excess of tax deductions over gross income in a year which cannot be used on the tax return of a state or local jurisdiction in the current year but can be carried forward to reduce taxable income or income taxes payable in a future year, for which there must be sufficient tax-basis income to utilize a portion or all of the carryforward amount to realize the deferred tax asset.

+ References+ Details

- Definition

The sum of the portions of deferred tax assets as of the balance sheet date for which, based on the weight of available evidence, it is more likely than not will not be realized through future reductions of tax-based income.

+ References+ Details