Merger Agreement with Sterling Bancorp (Details) - $ / shares	Mar. 06, 2017	Mar. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Authorized shares of Sterling Common Stock (in shares)		200,000,000	200,000,000
Sterling
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)	$ 0.01
Authorized shares of Sterling Common Stock (in shares)	190,000,000
Sterling | Sterling Merger Agreement
Business Acquisition [Line Items]
Authorized shares of Sterling Common Stock (in shares)	310,000,000
Sterling Merger Agreement
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)	$ 0.01
Common Stock | Sterling | Sterling Merger Agreement
Business Acquisition [Line Items]
Conversion ratio of preferred shares of acquiree to acquirer	0.875
6.50% Non-Cumulative Perpetual Preferred Stock, Series A
Business Acquisition [Line Items]
Non-Cumulative Perpetual Preferred Stock, dividend rate	6.50%
Non-Cumulative Perpetual Preferred Stock, par value (in dollars per share)	$ 1
Liquidation preference (in dollars per share)	$ 1,000
6.50% Non-Cumulative Perpetual Preferred Stock, Series A | Sterling
Business Acquisition [Line Items]
Non-Cumulative Perpetual Preferred Stock, dividend rate	6.50%
Non-Cumulative Perpetual Preferred Stock, par value (in dollars per share)	$ 0.01
Liquidation preference (in dollars per share)	$ 1,000
6.50% Non-Cumulative Perpetual Preferred Stock, Series A | Sterling | Sterling Merger Agreement
Business Acquisition [Line Items]
Conversion ratio of preferred shares of acquiree to acquirer	1