Balance Sheet Offsetting - Gross Presentation Effects of Offsetting and Net Presentation of Valley's Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Derivatives And Hedging Activities [Line Items]
Gross Amounts Recognized, Total	$ 544,730	$ 546,395
Gross Amounts Offset, Total
Net Amounts Presented, Total	544,730	546,395
Net Amount, Total	534
Repurchase agreements [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Recognized, Liabilities	520,000	520,000
Gross Amounts Offset, Liabilities
Net Amounts Presented, Liabilities	520,000	520,000
Interest rate caps and swaps, Liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Net Amount, Total	534
Gross Amounts Recognized, Liabilities	24,730	26,395
Gross Amounts Offset, Liabilities
Net Amounts Presented, Liabilities	24,730	26,395
Interest rate caps and swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Recognized, Assets	7,036	7,677
Gross Amounts Offset, Assets
Net Amounts Presented, Assets	7,036	7,677
Gross Amounts Not Offset, Assets	(6,508)	(7,002)
Financial Instruments [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Total	(528)	(675)
Financial Instruments [Member] | Repurchase agreements [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Liabilities
Financial Instruments [Member] | Interest rate caps and swaps, Liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Liabilities	(528)	(675)
Financial Instruments [Member] | Interest rate caps and swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Assets	(528)	(675)
Cash Collateral [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Total	(543,668)	(545,720)
Cash Collateral [Member] | Repurchase agreements [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Liabilities	(520,000)	(520,000)
Cash Collateral [Member] | Interest rate caps and swaps, Liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Liabilities	(23,668)	(25,720)
Cash Collateral [Member] | Interest rate caps and swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Assets