Schedule of Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012
Schedule of Unrecognized Tax Benefits [Line Items]
Unrecognized tax benefits-January 1,	$ 10,261	$ 10,011	$ 2,700
Increases related to tax positions in prior period	29	259
Decreases related to tax positions in prior period	(1,500)
Settlements/lapses	(6,090)	(9)
Unrecognized tax benefits-December 31	$ 2,700	$ 10,261	$ 2,700