Employee Benefit Plans (Net Periodic Benefit Cost (Benefit)) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets, net of expenses	$ (10,412)	$ (11,434)	$ (11,008)
Interest Cost on projected benefit obligation	7,801	7,892	7,724
Net amortization and deferral	5,709	3,130	2,915
Net periodic cost (benefit)	$ 3,098	$ (412)	$ (369)