Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Investment securities held-to-maturity, fair value	$ 219,607	$ 230,926
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	51,487,907	51,498,016
Common Stock, shares outstanding	30,958,581	30,769,063
Treasury stock, shares	20,421,540	20,582,459