Derivative Financial Instruments - Offsetting of Derivative Assets - Derivative Assets, Financial Assets, and Collateral Held by Counterparty (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Total
Net amounts of assets presented in the balance sheet	$ 371,269	$ 711,238
Net amount	371,269	711,238
JP Morgan
Total
Net amounts of assets presented in the balance sheet	11,325	17,149
Net amount	11,325	17,149
RJ O'Brien
Total
Net amounts of assets presented in the balance sheet	4,961	6,910
Net amount	4,961	6,910
Morgan Stanley Bank
Total
Net amounts of assets presented in the balance sheet		2,443
Net amount		2,443
Citibank, N.A.
Total
Net amounts of assets presented in the balance sheet		2,026
Net amount		2,026
Barclays
Total
Net amounts of assets presented in the balance sheet	3,166
Net amount	3,166
Bank of America, N.A.
Total
Net amounts of assets presented in the balance sheet	5,972
Net amount	5,972
Other
Total
Net amounts of assets presented in the balance sheet	1,717	2,749
Net amount	1,717	2,749
Interest rate lock commitments
Total
Net amounts of assets presented in the balance sheet	344,128	679,961
Net amount	$ 344,128	$ 679,961