Reconciliation of Beginning and Ending Balances for Total Amounts of Gross Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Reconciliation of Unrecognized Tax Benefits [Line Items]
Gross unrecognized tax benefits, beginning balance	$ 12,536	$ 11,124
Gross increases in tax positions for prior years	404	3,383
Gross decreases in tax positions for prior years	(1,728)	(189)
Gross increases in tax positions for current year	38	367
Gross decreases in tax positions for current year	(15)
Settlements	(444)	(899)
Lapse of the statute of limitations	(1,182)	(1,250)
Gross unrecognized tax benefits, ending balance	$ 9,609	$ 12,536