Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011
Income Taxes [Line Items]
Unrecognized tax benefits at beginning of year	$ 1,445
Gross increases - tax positions in prior period
Gross decreases - tax positions in prior period
Gross increases - current period tax positions
Gross decreases - current period tax positions
Settlements
Lapse of statute of limitations	(1,445)
Unrecognized tax benefits at end of year

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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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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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