Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Reconciliation Of Provision Of Income Taxes [Line Items]
Balance, Unrecognized tax benefits	$ 4,994	$ 3,912	$ 3,601
Additions based on tax provisions related to the current year	1,870	524	549
Additions based on tax provisions related to the prior year	716	1,010
Deductions based on settlement/expiration of prior year tax positions	(503)	(452)	(680)
Balance, Unrecognized tax benefits	$ 7,077	$ 4,994	$ 3,912