Statements of Capital Accounts - USD ($) shares in Millions, $ in Millions	Total	Total Retained Earnings	Total Restricted Retained Earnings	Unrestricted Retained Earnings	Accumulated Other Comprehensive Income/(Loss)	Common Class B - Putable Common Stock	Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Total Retained Earnings	Cumulative Effect, Period of Adoption, Adjustment [Member] Unrestricted Retained Earnings	Cumulative Effect, Period of Adoption, Adjustment [Member] Accumulated Other Comprehensive Income/(Loss)
Balance, Shares at Dec. 31, 2018						29
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of capital stock, shares						4
Repurchase of capital stock, shares						(3)
Balance, Shares at Mar. 31, 2019						30
Balance at Dec. 31, 2018	$ 6,530	$ 3,346	$ 647	$ 2,699	$ 235	$ 2,949
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss)	156	104	21	83	52
Issuance of capital stock, value	354					354
Repurchase of capital stock, value	(344)					(344)
Capital stock reclassified from/(to) mandatorily redeemable capital stock, net, value	0
Cash dividends on capital stock	(50)	(50)		(50)
Balance at Mar. 31, 2019	6,646	3,400	668	2,732	287	$ 2,959
Balance, Shares at Dec. 31, 2019						30
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of capital stock, shares						6
Repurchase of capital stock, shares						(4)
Net Shares Reclassified from/(to) Mandatorily Redeemable Capital Stock, Shares						0
Balance, Shares at Mar. 31, 2020						32
Balance at Dec. 31, 2019	6,741	3,467	713	2,754	274	$ 3,000
Balance (Accounting Standards Update 2016-13 [Member]) at Dec. 31, 2019										$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss)	(510)	(8)	0	(8)	(502)
Issuance of capital stock, value	607					607
Repurchase of capital stock, value	(373)					(373)
Capital stock reclassified from/(to) mandatorily redeemable capital stock, net, value	(3)					(3)
Cash dividends on capital stock	(52)	(52)		(52)
Balance at Mar. 31, 2020	$ 6,407	$ 3,404	$ 713	$ 2,691	$ (228)	$ 3,231
Adjustment for cumulative effect of accounting change | Accounting Standards Update 2016-13 [Member]							$ 3	$ 3	$ 3