Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Assets
Securities available-for-sale, amortized cost	$ 2,327,434,000	$ 1,959,773,000
Securities available-for-sale, allowance for credit Losses	0	0
Securities held to maturity, net of allowance for credit losses	0	0
Securities held to maturity, fair value	$ 515,296,000	$ 563,115,000
Shareholders' Equity
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, authorized (in shares)	250,000,000	250,000,000
Common stock, issued (in shares)	63,394,522	63,424,526
Common stock, outstanding (in shares)	63,394,522	63,424,526