Fair Value Measurement of Assets and Liabilities - Additional Information (Detail) (USD $)	12 Months Ended		6 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 VNB Capital Trust I [Member]	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Junior subordinated notes redeemed			$ 146,700,000
Fair value, unobservable inputs, quantitative information for assets measured on non-recurring basis, impaired loans non-current appraisal discount percentage	13.50%
Impaired collateral dependent loans, charge-offs	26,900,000	17,700,000
Collateral dependent impaired loans, recorded investment	41,800,000	76,900,000
Specific valuation allowance allocations	6,100,000	11,700,000
Reported net carrying amount of impaired loans	35,700,000	65,200,000
Valuation of loan servicing rights, prepayment rate				6.00%	26.00%
Valuation of loan servicing rights, discount rate	8.00%
Net recoveries of impairment charges	2,500,000	376,000
Foreclosed assets measured at fair value upon initial recognition	25,900,000	33,300,000
Allowance for loan losses, charge-offs	5,700,000	6,300,000
Loss due to re-measurement of repossessed assets	$ 3,100,000	$ 1,500,000