CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Interest-bearing deposits in banks and other financial institutions, collateral	$ 11,110	$ 0
Available-for-sale securities, amortized cost basis	2,097,114	1,909,483
Allowance for credit loss	8	136,625
Held-to-maturity securities, fair value	132,198	136,625
Allowance for credit losses	$ 232,192	$ 47,576
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	90,000,000	90,000,000
Common stock, issued (in shares)	57,533,236	57,435,658
Treasury stock, shares (in shares)	6,873,120	5,868,772