Stockholders' Equity (Details) - USD ($)				12 Months Ended
	Oct. 28, 2015	Jan. 07, 2014	Mar. 19, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 18, 2007
Class of Stock [Line Items]
Par value (in dollars per share)				$ 1.00	$ 1.00
Issuance of preferred stock, series C						$ 129,796,000
Dividend reinvestment and stock purchase plan, shares of authorized and unissued reserved for the plan				1,500,000
Maximum optional cash purchases amount per month of additional shares of common stock through the dividend reinvestment and stock purchase plan		$ 10,000
Sale of treasury stock (in shares)				482,460
Proceeds from sales of treasury stock				$ 6,168,000	$ 8,121,000	$ 0
Stock repurchase program approved (in shares)							10,000,000
Percentage of common stock outstanding							10.00%
The remaining number of shares authorized to be purchased				7,675,593
Maximum dividend per share without consent of NYCB				$ 0.04
Astoria Bank
Class of Stock [Line Items]
Minimum notice period required for declaring dividend				30 days
Dividend paid by Astoria Bank				$ 63,400,000
Depositary share
Class of Stock [Line Items]
Shares issued (in shares)			5,400,000
Liquidation preference (in dollars per share)			$ 25
Redemption price (in dollars per share)			$ 25
Series C Preferred Stock
Class of Stock [Line Items]
Shares issued (in shares)			135,000
Depository shares representing percentage in non cumulative perpetual preferred stock, Series C			2.50%
Dividend rate	6.50%		6.50%	6.50%
Par value (in dollars per share)	$ 1.00		$ 1.00
Liquidation preference (in dollars per share)	$ 1,000		$ 1,000	$ 1,000
Issuance of preferred stock, series C			$ 129,800,000
Redemption price (in dollars per share)			$ 1,000