v3.26.3
Fair Value Measurements - Financial Instruments (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Sep. 30, 2025
Dec. 31, 2024
Financial assets:        
Cash and cash equivalents $ 266,002 $ 209,057 $ 299,193 $ 205,869
Total available for sale debt securities 3,284,350 3,164,756    
Investment securities held to maturity, fair value 241,620 275,218    
FHLBNY stock 128,937 115,687    
Equity securities 19,706 19,875    
Loans, net of allowance for credit losses 19,986,233 19,334,004    
Derivative assets 150,359 105,260    
Financial liabilities:        
Certificates of deposit 3,224,905 3,287,276    
Total deposits 19,806,835 19,278,683    
Borrowings 2,390,788 2,111,955    
Subordinated debentures 429,464 406,582    
Derivative liabilities 150,503 106,445    
Quoted Prices in Active Markets for Identical Assets (Level 1)        
Financial assets:        
Cash and cash equivalents 266,002 211,484    
Total available for sale debt securities 185,342 266,744    
Investment securities held to maturity, fair value 0 0    
FHLBNY stock 128,937 115,687    
Equity securities 19,706 19,875    
Loans, net of allowance for credit losses 0 0    
Derivative assets 0 0    
Financial liabilities:        
Deposits other than certificates of deposits 16,581,930 15,991,407    
Certificates of deposit 0 0    
Total deposits 16,581,930 15,991,407    
Borrowings 0 0    
Subordinated debentures 0 0    
Derivative liabilities 0 0    
Significant Other Observable  Inputs (Level 2)        
Financial assets:        
Cash and cash equivalents 0 0    
Total available for sale debt securities 3,099,008 2,898,012    
Investment securities held to maturity, fair value 241,620 275,218    
FHLBNY stock 0 0    
Equity securities 0 0    
Loans, net of allowance for credit losses 0 0    
Derivative assets 160,809 105,734    
Financial liabilities:        
Deposits other than certificates of deposits 0 0    
Certificates of deposit 3,223,491 3,288,485    
Total deposits 3,223,491 3,288,485    
Borrowings 2,384,895 2,116,467    
Subordinated debentures 438,934 433,450    
Derivative liabilities 150,316 108,102    
Significant Unobservable Inputs (Level 3)        
Financial assets:        
Cash and cash equivalents 0 0    
Total available for sale debt securities 0 0    
Investment securities held to maturity, fair value 0 0    
FHLBNY stock 0 0    
Equity securities 0 0    
Loans, net of allowance for credit losses 19,723,548 19,421,891    
Derivative assets 0 0    
Financial liabilities:        
Deposits other than certificates of deposits 0 0    
Certificates of deposit 0 0    
Total deposits 0 0    
Borrowings 0 0    
Subordinated debentures 0 0    
Derivative liabilities 0 0    
U.S. Treasury obligations        
Financial assets:        
Total available for sale debt securities 185,342 266,744    
U.S. Treasury obligations | Quoted Prices in Active Markets for Identical Assets (Level 1)        
Financial assets:        
Total available for sale debt securities 185,342 266,744    
U.S. Treasury obligations | Significant Other Observable  Inputs (Level 2)        
Financial assets:        
Total available for sale debt securities 0 0    
U.S. Treasury obligations | Significant Unobservable Inputs (Level 3)        
Financial assets:        
Total available for sale debt securities 0 0    
Government-agency obligations        
Financial assets:        
Total available for sale debt securities 27,206 33,539    
Investment securities held to maturity, fair value   3,378    
Government-agency obligations | Quoted Prices in Active Markets for Identical Assets (Level 1)        
Financial assets:        
Total available for sale debt securities 0 0    
Investment securities held to maturity, fair value 0 0    
Government-agency obligations | Significant Other Observable  Inputs (Level 2)        
Financial assets:        
Total available for sale debt securities 27,206 33,539    
Investment securities held to maturity, fair value 0 3,378    
Government-agency obligations | Significant Unobservable Inputs (Level 3)        
Financial assets:        
Total available for sale debt securities 0 0    
Investment securities held to maturity, fair value 0 0    
Mortgage-backed securities        
Financial assets:        
Total available for sale debt securities 2,818,445 2,612,347    
Mortgage-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)        
Financial assets:        
Total available for sale debt securities 0 0    
Mortgage-backed securities | Significant Other Observable  Inputs (Level 2)        
Financial assets:        
Total available for sale debt securities 2,818,445 2,612,347    
Mortgage-backed securities | Significant Unobservable Inputs (Level 3)        
Financial assets:        
Total available for sale debt securities 0 0    
Asset-backed securities        
Financial assets:        
Total available for sale debt securities 34,476 41,761    
Asset-backed securities | Quoted Prices in Active Markets for Identical Assets (Level 1)        
Financial assets:        
Total available for sale debt securities 0 0    
Asset-backed securities | Significant Other Observable  Inputs (Level 2)        
Financial assets:        
Total available for sale debt securities 34,476 41,761    
Asset-backed securities | Significant Unobservable Inputs (Level 3)        
Financial assets:        
Total available for sale debt securities 0 0    
State and municipal obligations        
Financial assets:        
Total available for sale debt securities 103,903 112,999    
Investment securities held to maturity, fair value 241,620 269,711    
State and municipal obligations | Quoted Prices in Active Markets for Identical Assets (Level 1)        
Financial assets:        
Total available for sale debt securities 0 0    
Investment securities held to maturity, fair value 0 0    
State and municipal obligations | Significant Other Observable  Inputs (Level 2)        
Financial assets:        
Total available for sale debt securities 103,903 112,999    
Investment securities held to maturity, fair value 241,620 269,711    
State and municipal obligations | Significant Unobservable Inputs (Level 3)        
Financial assets:        
Total available for sale debt securities 0 0    
Investment securities held to maturity, fair value 0 0    
Corporate obligations        
Financial assets:        
Total available for sale debt securities 114,978 97,366    
Investment securities held to maturity, fair value   2,129    
Corporate obligations | Quoted Prices in Active Markets for Identical Assets (Level 1)        
Financial assets:        
Total available for sale debt securities 0 0    
Investment securities held to maturity, fair value 0 0    
Corporate obligations | Significant Other Observable  Inputs (Level 2)        
Financial assets:        
Total available for sale debt securities 114,978 97,366    
Investment securities held to maturity, fair value 0 2,129    
Corporate obligations | Significant Unobservable Inputs (Level 3)        
Financial assets:        
Total available for sale debt securities 0 0    
Investment securities held to maturity, fair value 0 0    
Carrying value        
Financial assets:        
Cash and cash equivalents 266,002 211,484    
Total available for sale debt securities 3,284,350 3,164,756    
Investment securities held to maturity, fair value 257,084 282,127    
FHLBNY stock 128,937 115,687    
Equity securities 19,706 19,875    
Loans, net of allowance for credit losses 19,986,233 19,334,004    
Derivative assets 160,809 105,734    
Financial liabilities:        
Deposits other than certificates of deposits 16,581,930 15,991,407    
Certificates of deposit 3,224,905 3,287,276    
Total deposits 19,806,835 19,278,683    
Borrowings 2,390,788 2,111,955    
Subordinated debentures 429,464 406,582    
Derivative liabilities 150,316 108,102    
Carrying value | U.S. Treasury obligations        
Financial assets:        
Total available for sale debt securities 185,342 266,744    
Carrying value | Government-agency obligations        
Financial assets:        
Total available for sale debt securities 27,206 33,539    
Investment securities held to maturity, fair value 0 3,400    
Carrying value | Mortgage-backed securities        
Financial assets:        
Total available for sale debt securities 2,818,445 2,612,347    
Carrying value | Asset-backed securities        
Financial assets:        
Total available for sale debt securities 34,476 41,761    
Carrying value | State and municipal obligations        
Financial assets:        
Total available for sale debt securities 103,903 112,999    
Investment securities held to maturity, fair value 257,084 276,585    
Carrying value | Corporate obligations        
Financial assets:        
Total available for sale debt securities 114,978 97,366    
Investment securities held to maturity, fair value 0 2,142    
Fair value        
Financial assets:        
Cash and cash equivalents 266,002 211,484    
Total available for sale debt securities 3,284,350 3,164,756    
Investment securities held to maturity, fair value 241,620 275,218    
FHLBNY stock 128,937 115,687    
Equity securities 19,706 19,875    
Loans, net of allowance for credit losses 19,723,548 19,421,891    
Derivative assets 160,809 105,734    
Financial liabilities:        
Deposits other than certificates of deposits 16,581,930 15,991,407    
Certificates of deposit 3,223,491 3,288,485    
Total deposits 19,805,421 19,279,892    
Borrowings 2,384,895 2,116,467    
Subordinated debentures 438,934 433,450    
Derivative liabilities 150,316 108,102    
Fair value | U.S. Treasury obligations        
Financial assets:        
Total available for sale debt securities 185,342 266,744    
Fair value | Government-agency obligations        
Financial assets:        
Total available for sale debt securities 27,206 33,539    
Investment securities held to maturity, fair value 0 3,378    
Fair value | Mortgage-backed securities        
Financial assets:        
Total available for sale debt securities 2,818,445 2,612,347    
Fair value | Asset-backed securities        
Financial assets:        
Total available for sale debt securities 34,476 41,761    
Fair value | State and municipal obligations        
Financial assets:        
Total available for sale debt securities 103,903 112,999    
Investment securities held to maturity, fair value 241,620 269,711    
Fair value | Corporate obligations        
Financial assets:        
Total available for sale debt securities 114,978 97,366    
Investment securities held to maturity, fair value $ 0 $ 2,129