Income Taxes - Reconciliation of Federal Statutory Rate to Provision (Benefit) for Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Reconciliation [Line Items]
Tax at statutory rate	35.00%	35.00%	35.00%
State taxes, net of federal benefit	7.00%	48.00%	4.00%
Affiliated stock loss		25.00%	(713.00%)
Contingency reserve		215.00%
Change in valuation allowance		(1343.00%)	681.00%
Other, net		1.00%	(2.00%)
Income tax expense (benefit)	42.00%	(1019.00%)	5.00%
Tax at statutory rate	$ 22,645	$ 4,547	$ 3,554
State taxes, net of federal benefit	4,793	6,222	442
Affiliated stock loss		3,283	(72,397)
Contingency reserve		27,911
Change in valuation allowance	(242)	(174,527)	69,109
Other, net	(166)	136	(195)
Income tax expense (benefit)	$ 27,030	$ (132,428)	$ 513

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

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The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to changes in the valuation allowance for deferred tax assets.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to all other items not otherwise listed in the existing taxonomy.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by the state and local income tax expense or benefit, net of the federal tax benefit (expense) thereon, recorded during the period.

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The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to changes in the valuation allowance for deferred tax assets in the period.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the year/accounting period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to all other items not otherwise listed in the existing taxonomy.

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Effective Income Tax Rate Reconciliation, Affiliated Stock Loss

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Effective Income Tax Rate Reconciliation, Contingency Reserve

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Effective Income Tax Reconciliation, Contingency Reserve

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Income Tax Reconciliation, Affiliated Stock Loss

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