Employee Benefit Plans (Weighted-Average Assumptions Used to Determine Benefit Obligations) (Detail)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations, Discount rate	4.20%	5.05%	5.55%
Net periodic benefit cost, Discount rate	5.05%	5.55%	5.95%
Net periodic benefit cost, Expected return on plan assets	7.75%	8.25%	8.75%