Advances from the Federal Home Loan Bank (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Federal Home Loan Bank, Advances, Rolling Maturity
Due within one year	$ 20,000	$ 107,200
Due over 1 year to 2 years	57,000	20,000
Due over 2 years to 3 years	30,000	15,000
Due over 3 years to 4 years	19,000
Due over 4 years to 5 years	30,000
Total	$ 156,000	$ 142,200
Weighted Average Rate
Due within one year (as a percent)	2.16%	2.39%
Due over 1 year to 2 years (as a percent)	2.50%	2.16%
Due over 2 years to 3 years (as a percent)	2.37%	2.32%
Due over 3 years to 4 years (as a percent)	2.16%
Due over 4 years to 5 years (as a percent)	1.87%
Total (as a percent)	2.27%	2.35%
FHLB Des Moines
Federal Home Loan Bank advances
Available additional unused FHLB advances	$ 727,500	$ 769,300
Territorial Savings Bank | FHLB Des Moines
Federal Home Loan Bank advances
Percentage of total assets used to determine maximum line of credit	45.00%