Regulatory and Capital Requirements - Schedule of Actual Capital Positions and Ratios under Banking Regulations (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Risk-based Capital Actual, Amount	$ 1,547,753	$ 1,403,836
Tier 1 Risk-based Capital Actual, Amount	1,318,466	1,141,526
Tier 1 Leverage Capital Actual, Amount	1,318,466	1,141,526
Risk-based Capital Actual, Ratio	11.40%	11.90%
Tier 1 Risk-based Capital Actual, Ratio	9.70%	9.70%
Tier 1 Leverage Capital Actual, Ratio	7.50%	7.30%
Risk-based Capital Minimum Capital Requirements, Amount	1,084,479	946,448
Tier 1 Risk-based Capital Minimum Capital Requirements, Amount	542,240	473,224
Tier 1 Leverage Capital Minimum Capital Requirements, Amount	707,082	628,256
Risk-based Capital Minimum Capital Requirements, Ratio	8.00%	8.00%
Tier 1 Risk-based Capital Minimum Capital Requirements, Ratio	4.00%	4.00%
Tier 1 Leverage Capital Minimum Capital Requirements, Ratio	4.00%	4.00%
Valley National Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Risk-based Capital Actual, Amount	1,481,184	1,376,695
Tier 1 Risk-based Capital Actual, Amount	1,376,897	1,239,510
Tier 1 Leverage Capital Actual, Amount	1,376,897	1,239,510
Risk-based Capital Actual, Ratio	10.90%	11.60%
Tier 1 Risk-based Capital Actual, Ratio	10.20%	10.50%
Tier 1 Leverage Capital Actual, Ratio	7.80%	7.90%
Risk-based Capital Minimum Capital Requirements, Amount	1,083,516	945,854
Tier 1 Risk-based Capital Minimum Capital Requirements, Amount	541,758	472,927
Tier 1 Leverage Capital Minimum Capital Requirements, Amount	706,992	627,333
Risk-based Capital Minimum Capital Requirements, Ratio	8.00%	8.00%
Tier 1 Risk-based Capital Minimum Capital Requirements, Ratio	4.00%	4.00%
Tier 1 Leverage Capital Minimum Capital Requirements, Ratio	4.00%	4.00%
Risk-based Capital To Be Well Capitalized Under Prompt Corrective Action Provision, Amount	1,354,395	1,182,317
Tier 1 Risk-based Capital To Be Well Capitalized Under Prompt Corrective Action Provision, Amount	813,637	709,390
Tier 1 Leverage Capital To Be Well Capitalized Under Prompt Corrective Action Provision, Amount	$ 883,740	$ 784,167
Risk-based capital to be well capitalized under prompt corrective action provision, ratio	10.00%	10.00%
Tier 1 Risk-based Capital To Be Well Capitalized Under Prompt Corrective Action Provision, Ratio	6.00%	6.00%
Tier 1 Leverage Capital To Be Well Capitalized Under Prompt Corrective Action Provision, Ratio	5.00%	5.00%