Deposit Accounts - Aggregate Annual Maturities of Certificates of Deposit Accounts (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Amount
Within 3 months	$ 692,493
4 to 6 months	363,533
7 to 12 months	377,731
13 to 24 months	86,934
25 to 36 months	13,217
37 to 60 months	9,576
Over 60 months	83,358
Total certificates of deposit accounts	$ 1,626,842	$ 1,047,842
Weighted Average Interest Rate
Within 3 months	0.81%
4 to 6 months	1.12%
7 to 12 months	0.89%
13 to 24 months	0.82%
25 to 36 months	1.56%
37 to 60 months	1.24%
Over 60 months	0.35%
Total	0.88%	1.69%