Loans and Allowance for Credit Losses Non-Performing Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Non-accrual loans	$ 137,198	$ 125,098
Loans 90 days or more past due and still accruing	9,929	16,057
Total non-performing loans	147,127	141,155
OREO	4,178	6,831
Total non-performing assets	151,305	$ 147,986
Mortgage Loans in Process of Foreclosure, Amount	$ 8,100