Fair Value Measurements (Details 5) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Financial Assets:
Securities held-to-maturity	$ 2,119,542us-gaap_HeldToMaturitySecurities	$ 2,133,804us-gaap_HeldToMaturitySecurities
FHLB-NY stock	141,622us-gaap_FederalHomeLoanBankStock	140,754us-gaap_FederalHomeLoanBankStock
MSR, net	10,585us-gaap_ServicingAsset	11,401us-gaap_ServicingAsset
Level 2 fair value
Financial Assets:
Securities held-to-maturity	2,137,907	2,131,371
FHLB-NY stock	141,622	140,754
Financial Liabilities:
Deposits	9,439,513	9,534,918
Borrowings, net	4,337,180	4,395,604
Level 3 fair value
Financial Assets:
Loans held-for-sale, net	8,385	7,955
Loans Receivable, Fair Value Disclosure	11,862,011	11,967,608
MSR, net	10,589	11,406
Carrying value
Financial Assets:
Securities held-to-maturity	2,119,542	2,133,804
FHLB-NY stock	141,622	140,754
Loans held-for-sale, net	8,066	7,640
Loans Receivable, Fair Value Disclosure	11,711,367	11,845,848
MSR, net	10,585	11,401
Financial Liabilities:
Deposits	9,407,029	9,504,909
Borrowings, net	4,113,824	4,187,691
Estimate of Fair Value Measurement [Member]
Financial Assets:
Securities held-to-maturity	2,137,907	2,131,371
Loans held-for-sale, net	8,385	7,955
Loans Receivable, Fair Value Disclosure	11,862,011	11,967,608
MSR, net	10,589	11,406
Financial Liabilities:
Deposits	9,439,513	9,534,918
Borrowings, net	$ 4,337,180	$ 4,395,604

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Aggregate amount of servicing assets that are subsequently measured at fair value and servicing assets that are subsequently measured using the amortization method.

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