CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Securities—trading, amortized cost basis	$ 28,663	$ 30,154
Securities—available-for-sale, amortized cost basis	1,338,863	806,336
Securities—held-to-maturity, fair value	$ 268,663	$ 270,528
SHAREHOLDERS’ EQUITY
Preferred stock, share par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares outstanding	0	0
Voting Common Stock [Member]
SHAREHOLDERS’ EQUITY
Common stock, share par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	33,154,755	33,108,599
Common stock, shares outstanding	33,154,755	33,108,599
Nonvoting Common Stock [Member]
SHAREHOLDERS’ EQUITY
Common stock, share par value	$ 0.01	$ 0.01
Common stock, shares authorized	5,000,000	5,000,000
Common stock, shares issued	100,029	84,788
Common stock, shares outstanding	100,029	84,788
Loans [Member] | Recurring [Member]
ASSETS
Loans Held-for-sale, Fair Value Disclosure	$ 64,399	$ 9,600