Changes in Unrecognized Income Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Line Items]
Unrecognized income tax benefits as of January 1	$ 13,488	$ 28,075	$ 20,974
Increases for tax positions
Increases for tax positions related to Prior years	0	389	14,685
Current year	1,356	913	1,447
Decreases for tax positions
Decreases for tax positions related to Prior years	(43)	(411)	(8,028)
Settlements with taxing authorities	(1,456)	(15,402)	0
Expiration of applicable statute of limitations	205	(76)	(1,003)
Unrecognized income tax benefits as of December 31	$ 13,550	$ 13,488	$ 28,075