Borrowings (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitment and Contingencies
Total borrowings, net	$ 4,187,691,000	$ 4,137,161,000
Weighted average rate (as a percent)	2.26%us-gaap_DebtWeightedAverageInterestRate	2.41%us-gaap_DebtWeightedAverageInterestRate
Reverse repurchase agreements
Commitment and Contingencies
Reverse repurchase agreements	1,100,000,000	1,100,000,000	1,100,000,000
Weighted average rate, long-term debt	3.62%	3.87%	4.32%
FHLB advances \| FHLB-NY
Commitment and Contingencies
FHLB-NY advances	2,384,000,000	2,454,000,000	2,897,000,000
Weighted average rate, long-term debt	1.72%	1.79%	2.07%
Other borrowings, net
Commitment and Contingencies
Other borrowings, net	248,691,000	248,161,000
Weighted average rate, long-term debt	5.00%	5.00%
Federal funds purchased
Commitment and Contingencies
Federal Funds Purchased	455,000,000	335,000,000
Weighted average rate, short-term debt	0.31%	0.28%
Federal Reserve Bank of New York
Commitment and Contingencies
FRB discount window	350,000,000
Securities pledged as collateral	102,100,000
Federal Reserve Bank of New York \| Commercial real estate mortgage loans
Commitment and Contingencies
Loans pledged as collateral	$ 601,200,000

Securities Pledged as Collateral, Amortized Cost

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Represents the aggregate of total long-term debt, including current maturities and short-term debt.

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Weighted average interest rate of debt outstanding.

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Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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Weighted average interest rate of long-term debt outstanding.

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Including both current and noncurrent portions, carrying amount as of the balance sheet date of other forms of debt not elsewhere specified in the taxonomy with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Weighted average interest rate of short-term debt outstanding.

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