Unrecognized Tax Benefits Excluding Interest Correlative Effects and Indirect Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Unrecognized Tax Benefits
Unrecognized tax benefits at beginning of year	$ 9,288	$ 11,011	$ 16,722
Gross increases - tax positions in prior years	19,434	1,217	19,619
Gross decreases - tax positions in prior years	(13,876)	(1,510)	(3,258)
Gross increases - tax positions in current year	1,555	6,274	6,462
Gross decreases - tax positions in current year		(4,625)	(5,135)
Settlements with taxing authorities	(1,021)	(3,079)	(12,573)
Lapse of statute of limitations			(10,826)
Unrecognized tax benefits at end of year	$ 15,380	$ 9,288	$ 11,011

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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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