Short and Long-term Funding Remaining Contractual Maturity of Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Remaining Contractual Maturity of the Agreements
Repurchase agreements	$ 71,097	$ 91,941
Overnight and Continuous
Remaining Contractual Maturity of the Agreements
Repurchase agreements	71,097	91,941
Up to 30 days
Remaining Contractual Maturity of the Agreements
Repurchase agreements	0	0
30-90 days
Remaining Contractual Maturity of the Agreements
Repurchase agreements	0	0
Greater than 90 days
Remaining Contractual Maturity of the Agreements
Repurchase agreements	0	0
Agency mortgage-related securities
Remaining Contractual Maturity of the Agreements
Repurchase agreements	71,097	91,941
Agency mortgage-related securities | Overnight and Continuous
Remaining Contractual Maturity of the Agreements
Repurchase agreements	71,097	91,941
Agency mortgage-related securities | Up to 30 days
Remaining Contractual Maturity of the Agreements
Repurchase agreements	0	0
Agency mortgage-related securities | 30-90 days
Remaining Contractual Maturity of the Agreements
Repurchase agreements	0	0
Agency mortgage-related securities | Greater than 90 days
Remaining Contractual Maturity of the Agreements
Repurchase agreements	$ 0	$ 0