Derivative Financial Instruments - Offsetting of Derivative Assets - Derivative Assets, Financial Assets, and Collateral Held by Counterparty (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Total
Net amounts of assets presented in the balance sheet	$ 530,852	$ 711,238
Net amount	530,852	711,238
JP Morgan
Total
Net amounts of assets presented in the balance sheet	56,606	17,149
Net amount	56,606	17,149
RJ O'Brien
Total
Net amounts of assets presented in the balance sheet	11,730	6,910
Net amount	11,730	6,910
Morgan Stanley Bank
Total
Net amounts of assets presented in the balance sheet	53,548	2,443
Net amount	53,548	2,443
Citibank, N.A.
Total
Net amounts of assets presented in the balance sheet	9,685	2,026
Net amount	9,685	2,026
Goldman Sachs
Total
Net amounts of assets presented in the balance sheet	4,203
Net amount	4,203
Wells Fargo Bank, N.A.
Total
Net amounts of assets presented in the balance sheet	18,524
Net amount	18,524
Bank of America, N.A.
Total
Net amounts of assets presented in the balance sheet	10,013
Net amount	10,013
Other
Total
Net amounts of assets presented in the balance sheet	3,620	2,749
Net amount	3,620	2,749
Interest rate lock commitments
Total
Net amounts of assets presented in the balance sheet	362,923	679,961
Net amount	$ 362,923	$ 679,961