Basis of Presentation (Narrative) (Details) - USD ($)	3 Months Ended
	Sep. 30, 2015	Mar. 31, 2014	Oct. 28, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Common stock, shares authorized	200,000,000			200,000,000
Deferred tax assets, net, increase resulting from state tax legislation	$ 4,200,000	$ 11,500,000
Income tax expense decrease resulting from state tax legislation	11,400,000	$ 11,500,000
Deferred tax asset valuation allowance	$ 7,200,000
New York Community Bancorp, Inc | Scenario, Forecast
Business Acquisition [Line Items]
Business Acquisition, Share Price			$ 0.01
Business Acquisition, Equity Interest Issued or Issuable for Each Share			$ 0.50
Common stock, shares authorized			1.00
Business Combination, Contingent Consideration, Early Contract Termination Fee			$ 69,500,000
Minimum | New York Community Bancorp, Inc | Scenario, Forecast
Business Acquisition [Line Items]
Common stock, shares authorized			600
Maximum | New York Community Bancorp, Inc | Scenario, Forecast
Business Acquisition [Line Items]
Common stock, shares authorized			900