Income Taxes - Unrecognized Tax Benefits for Permanent and Temporary Book/Tax Differences for Continuing Operations, Exclusive of Interest (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Balance at January 1	$ 987	$ 9,237	$ 7,517
Settlements for tax positions of prior years		(15,969)
Additions for tax positions of the current year	4,195	987	1,686
Additions for tax positions of prior years	181	7,837	62
Reductions for tax positions of prior years	(225)	(572)	(28)
Reductions for lapse of statute of limitations		(533)
Balance at December 31	$ 5,138	$ 987	$ 9,237