Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 30, 2018
Statement Of Financial Position [Abstract]
Securities held to maturity, estimated fair value	$ 584,678	$ 579,499
Loans receivable, unamortized yield adjustments	$ (52,025)	$ (66,567)
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	800,000,000	800,000,000
Common stock, shares issued	89,125,655	99,626,400
Common stock, shares outstanding	89,125,655	99,626,400
Employee Stock Ownership Plan (ESOP), Number of Suspense Shares	3,160,987	3,361,684