Fair Value Measurements - Book Value and Estimated Fair Value of Bank's Significant Financial Instruments Not Recorded at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Financial Assets:
Securities held-to-maturity	$ 485,124	$ 495,082
Financial Liabilities:
Securities sold under agreements to repurchase with retail customers	62,341	68,304
Book Value [Member]
Financial Assets:
Cash and due from banks	43,817	33,958
Securities held-to-maturity	478,389	495,599
Federal Home Loan Bank of New York stock	20,246	14,518
Loans receivable and mortgage loans held for sale	1,633,114	1,542,245
Financial Liabilities:
Deposits other than time deposits	1,490,791	1,528,820
Time deposits	214,719	217,943
Securities sold under agreements to repurchase with retail customers	62,341	68,304
Federal Home Loan Bank advances and other borrowings	332,500	202,500
Level 1 Inputs [Member]
Financial Assets:
Cash and due from banks	43,817	33,958
Financial Liabilities:
Securities sold under agreements to repurchase with retail customers	62,341	68,304
Level 2 Inputs [Member]
Financial Assets:
Securities held-to-maturity	484,524	493,432
Financial Liabilities:
Deposits other than time deposits	1,490,791	1,528,820
Time deposits	216,988	220,409
Federal Home Loan Bank advances and other borrowings	332,380	201,393
Level 3 Inputs [Member]
Financial Assets:
Securities held-to-maturity	600	1,650
Federal Home Loan Bank of New York stock	20,246	14,518
Loans receivable and mortgage loans held for sale	$ 1,652,659	$ 1,561,208