Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Statement of Financial Position [Abstract]
Securities, Available-for-sale, Amortized Cost	$ 5,981,374	$ 4,177,179	$ 4,238,624
Loans held-for-sale, fair value	$ 46,081	$ 79,585	$ 94,666
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	142,467,687	142,161,834	142,121,595
Treasury stock, shares	937,803	938,591	934,859