Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Statement of Financial Position [Abstract]
Securities, Available-for-sale, Amortized Cost	$ 4,961,438	$ 4,177,179	$ 3,950,510
Loans held-for-sale, fair value	$ 61,511	$ 79,585	$ 39,659
Common stock, par value	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000	200,000,000
Common stock, shares issued	142,285,611	142,161,834	142,314,930
Treasury stock, shares	938,004	938,591	928,417