Deposits - Summary of Deposits Including Accrued Interest Payable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Amount
Non-interest-bearing accounts	$ 2,133,195	$ 1,377,396
Interest-bearing checking accounts	3,646,866	2,539,428
Money market deposit accounts	783,521	578,147
Savings accounts	1,491,251	898,174
Time deposits	1,372,783	935,632
Total deposits	$ 9,427,616	$ 6,328,777
Weighted Average Cost
Non-interest-bearing accounts	0.00%	0.00%
Interest-bearing checking accounts	0.49%	0.68%
Money market deposit accounts	0.19%	0.68%
Savings accounts	0.05%	0.13%
Time deposits	1.51%	1.82%
Total deposits	0.43%	0.62%