Unaudited Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Statement of Financial Position [Abstract]    
Investment securities held to maturity, fair value $ 0 $ 87,561
Premises and equipment, accumulated depreciation and amortization 78,343 76,763
Identified intangible assets, accumulated amortization $ 37,817 $ 37,481
Common stock, par value (in dollars per share) $ 0.01 $ 0.01
Common stock, shares authorized 200,000,000 200,000,000
Common stock, shares issued 85,177,172 85,177,172
Treasury stock, shares 5,862,811 5,003,127
Unallocated common stock held by ESOP, shares 72,441 79,548