Capital Narratives (Details) - USD ($)	2 Months Ended	12 Months Ended			17 Months Ended
	Aug. 10, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Jan. 16, 2019
Dividends on mandatorily redeemable capital stock		$ 974,000	$ 1,923,000	$ 1,558,000
Minimum repurchase of excess capital stock	$ 100,000				$ 100,000
Excess capital stock		$ 79,700,000	$ 88,700,000		$ 88,700,000
Excess capital stock to total capital stock outstanding, percent		4.30%	3.50%		3.50%
Excess capital stock to total assets, percent		0.10%
Certain member assets eligible to secure advances [Member]
Class B stock purchase requirement		0.20%
Overnight advances [Member]
Class B stock purchase requirement		3.00%
All other advances greater than overnight [Member]
Class B stock purchase requirement		4.00%
Outstanding letters of credit [Member]
Class B stock purchase requirement		0.25%
Certain member assets rligible to secure advances prior to January 16, 2019 [Member]
Class B stock purchase requirement						0.35%
Common Class B [Member]
Common Stock, Class B, putable par value per share		$ 100	$ 100		$ 100
Minimum [Member]
Repurchase of excess capital stock held by shareholders, excess stock exceeds, amount	$ 10,000,000.0				$ 10,000,000.0
Repurchase of excess capital stock held by shareholders, excess stock exceeds, percentage	25.00%		10.00%		10.00%