Junior Subordinated Debentures Issued To Capital Trusts (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Schedule Of Outstanding Junior Subordinated Debentures And The Related Trust Preferred Securities Issued [Line Items]
Net trading gains and losses included in non-cash credits	$ 1,300,000
Non-cash charges included in net trading gains and (losses)			5,800,000	15,800,000
Junior subordinated debentures issued to capital trusts	185,598,000		186,922,000
Maximum allowable period of interest deferment	five
VNB Capital Trust I [Member]
Schedule Of Outstanding Junior Subordinated Debentures And The Related Trust Preferred Securities Issued [Line Items]
Contractual principal balances			157,000,000
Face value			152,300,000
Principal face amounts redeemed of junior subordinated debentures	10,300,000
GCB Capital Trust III [Member]
Schedule Of Outstanding Junior Subordinated Debentures And The Related Trust Preferred Securities Issued [Line Items]
Contractual principal balances			24,700,000
Face value			24,000,000
Coupon rate of three-month LIBOR	1.40%
Junior Subordinated Debentures [Member] | VNB Capital Trust I [Member]
Schedule Of Outstanding Junior Subordinated Debentures And The Related Trust Preferred Securities Issued [Line Items]
Junior subordinated debentures issued to capital trusts	160,478,000	[1]	161,700,000
Contractual principal balances	157,024,000
Debt Instrument, Maturity Date	Dec. 15, 2031
Junior Subordinated Debentures [Member] | GCB Capital Trust III [Member]
Schedule Of Outstanding Junior Subordinated Debentures And The Related Trust Preferred Securities Issued [Line Items]
Junior subordinated debentures issued to capital trusts	25,120,000	[1]	25,200,000
Contractual principal balances	24,743,000
Debt Instrument, Maturity Date	Jul. 30, 2037
Trust Preferred Securities [Member] | VNB Capital Trust I [Member]
Schedule Of Outstanding Junior Subordinated Debentures And The Related Trust Preferred Securities Issued [Line Items]
Face value	152,313,000
Principal face amounts redeemed of junior subordinated debentures	10,000,000
Trust Preferred Securities [Member] | GCB Capital Trust III [Member]
Schedule Of Outstanding Junior Subordinated Debentures And The Related Trust Preferred Securities Issued [Line Items]
Face value	$ 24,000,000

[1] The carrying value for GCB Capital Trust III includes an unamortized purchase accounting premium of $377 thousand.