Balance Sheet Offsetting - Gross Presentation Effects of Offsetting and Net Presentation of Valley's Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Derivatives And Hedging Activities [Line Items]
Gross Amounts Recognized, Total	$ 543,622	$ 540,439
Gross Amounts Offset, Total	0	0
Net Amounts Presented, Total	543,622	540,439
Net Amount, Total	0	0
Interest Rate Caps and Swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Recognized, Assets	14,924	14,805
Gross Amounts Offset, Assets	0	0
Net Amounts Presented, Assets	14,924	14,805
Gross Amounts Not Offset, Assets	8,877	6,521
Interest Rate Caps and Swaps, Liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Net Amount, Total	0	0
Gross Amounts Recognized, Liabilities	23,622	20,439
Gross Amounts Offset, Liabilities	0	0
Net Amounts Presented, Liabilities	23,622	20,439
Repurchase Agreements [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Recognized, Liabilities	520,000	520,000
Gross Amounts Offset, Liabilities	0	0
Net Amounts Presented, Liabilities	520,000	520,000
Net Amount, Liabilities	0	0
Financial Instruments [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Total	(6,047)	(8,284)
Financial Instruments [Member] | Interest Rate Caps and Swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Assets	(6,047)	(8,284)
Financial Instruments [Member] | Interest Rate Caps and Swaps, Liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Liabilities	(6,047)	(8,284)
Financial Instruments [Member] | Repurchase Agreements [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Liabilities
Cash Collateral [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Total	537,575	532,155
Cash Collateral [Member] | Interest Rate Caps and Swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Assets	0
Cash Collateral [Member] | Interest Rate Caps and Swaps, Liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Liabilities	(17,575)	(12,155)
Cash Collateral [Member] | Repurchase Agreements [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Liabilities	$ (520,000)	$ (520,000)