Income Taxes (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Income Tax Contingency [Line Items]
Total gross deferred tax assets	$ 115,735,000	$ 93,558,000
Deferred tax assets:
Allowances for losses	48,243,000	54,511,000
Compensation and benefits (principally pension and other postretirement benefit plans)	45,849,000	21,955,000
Mortgage loans (principally deferred loan origination costs)	981,000	7,524,000
Net unrealized loss on securities available-for-sale	0	4,010,000
State and local net operating loss carryforwards	16,122,000	0
Other deductible temporary differences	4,540,000	5,558,000
Less valuation allowance	(7,220,000)	0
Deferred tax assets, net of valuation allowance	108,515,000	93,558,000
Deferred tax liabilities:
Premises and equipment	(3,102,000)	(3,882,000)
Net unrealized gain on securities available-for-sale	(1,035,000)	0
MSR	(910,000)	(69,000)
Total gross deferred tax liabilities	(5,047,000)	(3,951,000)
Net deferred tax assets (included in other assets)	103,468,000	89,607,000
New York State Division of Taxation and Finance
Income Tax Contingency [Line Items]
Income Tax Expense Decrease Resulting from State Tax Legislation	15,700,000
State and local taxes, net of federal tax effect	15,700,000
Operating Loss Carryforwards	199,200,000
New York City
Income Tax Contingency [Line Items]
Operating Loss Carryforwards	85,300,000
Total gross deferred tax assets	$ 7,200,000