Income Taxes - Liability Associated with Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Gross unrecognized tax benefits at beginning of year	$ 2,712	$ 48,963	$ 52,837
Increases related to prior year tax positions	63		13
Decreases related to prior year tax positions	(84)	(286)	(2,323)
Increases related to current year tax positions		85	385
Decreases related to current year tax positions
Settlements with taxing authorities		(38,543)	(1,414)
Lapse of applicable statute of limitations	(2,116)	(7,507)	(535)
Gross unrecognized tax benefits at end of year	$ 575	$ 2,712	$ 48,963

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The gross amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date.

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-Name Accounting Standards Codification

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The gross amount of decreases in unrecognized tax benefits resulting from tax positions that have been or will be taken in the tax return for the current period, excluding amounts pertaining to examined tax returns.

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The gross amount of decreases in unrecognized tax benefits resulting from tax positions taken in prior period tax returns, excluding amounts pertaining to examined tax returns.

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The gross amount of decreases in unrecognized tax benefits resulting from settlements with taxing authorities.

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The gross amount of increases in unrecognized tax benefits resulting from tax positions that have been or will be taken in the tax return for the current period, excluding amounts pertaining to examined tax returns.

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The gross amount of decreases in unrecognized tax benefits resulting from lapses of the applicable statutes of limitations.

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