Fair Value Measurements - Schedule of Carrying Values of Assets Measured at Estimated Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value of Financial Instruments
Total securities available-for-sale	$ 265,899	$ 280,045
GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	227,292	240,793
Non-GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	1,136	1,443
GSE pass-through certificates
Fair Value of Financial Instruments
Total securities available-for-sale	8,576	8,930
Obligations of GSEs
Fair Value of Financial Instruments
Total securities available-for-sale	28,893	28,875
Fannie Mae stock
Fair Value of Financial Instruments
Total securities available-for-sale	2	4
Recurring
Fair Value of Financial Instruments
Total securities available-for-sale	265,899	280,045
Recurring | GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	227,292	240,793
Recurring | Non-GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	1,136	1,443
Recurring | GSE pass-through certificates
Fair Value of Financial Instruments
Total securities available-for-sale	8,576	8,930
Recurring | Obligations of GSEs
Fair Value of Financial Instruments
Total securities available-for-sale	28,893	28,875
Recurring | Fannie Mae stock
Fair Value of Financial Instruments
Total securities available-for-sale	2	4
Recurring | Level 1
Fair Value of Financial Instruments
Total securities available-for-sale	2	4
Recurring | Level 1 | GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	0	0
Recurring | Level 1 | Non-GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	0	0
Recurring | Level 1 | GSE pass-through certificates
Fair Value of Financial Instruments
Total securities available-for-sale	0	0
Recurring | Level 1 | Obligations of GSEs
Fair Value of Financial Instruments
Total securities available-for-sale	0	0
Recurring | Level 1 | Fannie Mae stock
Fair Value of Financial Instruments
Total securities available-for-sale	2	4
Recurring | Level 2
Fair Value of Financial Instruments
Total securities available-for-sale	265,897	280,041
Recurring | Level 2 | GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	227,292	240,793
Recurring | Level 2 | Non-GSE issuance REMICs and CMOs
Fair Value of Financial Instruments
Total securities available-for-sale	1,136	1,443
Recurring | Level 2 | GSE pass-through certificates
Fair Value of Financial Instruments
Total securities available-for-sale	8,576	8,930
Recurring | Level 2 | Obligations of GSEs
Fair Value of Financial Instruments
Total securities available-for-sale	28,893	28,875
Recurring | Level 2 | Fannie Mae stock
Fair Value of Financial Instruments
Total securities available-for-sale	$ 0	$ 0