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, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits [Line Items]
Gross unrecognized tax benefits, beginning balance	$ 9,609	$ 12,536
Gross increases in tax positions for prior years	1,681	404
Gross decreases in tax positions for prior years	292	1,728
Gross increases in tax positions for current year	412	38
Gross decreases in tax positions for current year	6	15
Settlements	90	444
Lapse of the statute of limitations	7,226	1,182
Gross unrecognized tax benefits, ending balance	$ 4,088	$ 9,609