Balance Sheet Offsetting - Gross Presentation Effects of Offsetting and Net Presentation of Valley's Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Derivatives And Hedging Activities [Line Items]
Gross Amounts Recognized, Total	$ 537,714	$ 546,395
Gross Amounts Offset, Total
Net Amounts Presented, Total	537,714	546,395
Net Amount, Total	2,579
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	2,579
Gross Amounts Recognized, Liabilities	17,714	26,395
Gross Amounts Offset, Liabilities
Net Amounts Presented, Liabilities	17,714	26,395
Interest rate caps and swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Recognized, Assets	5,036	7,677
Gross Amounts Offset, Assets
Net Amounts Presented, Assets	5,036	7,677
Gross Amounts Not Offset, Assets	4,011	7,002
Financial Instruments [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Total	(1,025)	(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	(1,025)	(675)
Financial Instruments [Member] | Interest rate caps and swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Assets	(1,025)	(675)
Cash Collateral [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Total	(534,110)	(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	(14,110)	(25,720)
Cash Collateral [Member] | Interest rate caps and swaps, Assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amounts Not Offset, Assets