CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
CONSOLIDATED BALANCE SHEETS
Available-for-sale investment securities, amortized cost	$ 3,296,825	$ 3,549,599
Held-to-maturity investment securities, fair value	$ 3,697,261	$ 3,814,822
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	300,000,000	300,000,000
Common stock, issued (in shares)	141,327,860	140,963,918
Common stock outstanding (in shares)	127,608,037	127,363,327
Common stock repurchased (in shares)	13,719,823	13,600,591