Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Investment securities held-to-maturity, fair value	$ 275,608	$ 332,573
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	400,000,000	400,000,000
Common Stock, shares issued	51,585,248	51,813,011
Common Stock, shares outstanding	26,802,964	26,386,583
Treasury stock, shares	24,535,807	24,927,157