Deposit Accounts - The aggregate annual maturities of certificates of deposit accounts (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amount
Within 3 months	$ 571,143
4 to 6 months	240,132
7 to 12 months	138,515
13 to 24 months	76,617
25 to 36 months	11,182
37 to 60 months	9,644
Over 60 months	609
Total certificates of deposit accounts	$ 1,047,842	$ 1,410,677
Weighted Average Interest Rate
Within 3 months (as a percent)	1.70%
4 to 6 months (as a percent)	1.87%
7 to 12 months (as a percent)	1.46%
13 to 24 months (as a percent)	1.49%
25 to 36 months (as a percent)	1.24%
37 to 60 months (as a percent)	1.71%
Over 60 months (as a percent)	2.08%
Total certificates of deposit accounts (as a percent)	1.69%	1.84%