Consolidated Statements of Financial Condition (Parenthetical) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Securities held-to-maturity, net estimated fair value	$ 869,167,000	$ 832,815,000
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, liquidation preference	$ 1,000,000	$ 1,000,000
Preferred stock, shares authorized (shares)	5,000,000	5,000,000
Preferred stock, shares issued (shares)	0	0
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (shares)	150,000,000	150,000,000
Common stock, shares issued (shares)	51,900,222	51,900,222
Common stock, shares outstanding (shares)	51,131,804	47,951,168
Treasury stock, shares (shares)	768,418	459,251