Fair Value (Fair Value Option) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Fair Value, Option, Quantitative Disclosures [Line Items]
Balance, beginning of the period	[1]	$ 4,370
Net gain/(loss) on advances and net (gain)/loss on consolidated obligation bonds from changes in fair value recognized in earnings		89	$ 39
Balance, end of the period	[1]	4,334
Advances
Fair Value, Option, Quantitative Disclosures [Line Items]
Balance, beginning of the period		4,370	5,133
New transactions elected for fair value option		7,070	0
Maturities and terminations		(7,197)	(125)
Net gain/(loss) on advances and net (gain)/loss on consolidated obligation bonds from changes in fair value recognized in earnings		91	46
Change in accrued interest		0	(1)
Balance, end of the period		4,334	5,053
Consolidated obligation bonds
Fair Value, Option, Quantitative Disclosures [Line Items]
Net gain/(loss) on advances and net (gain)/loss on consolidated obligation bonds from changes in fair value recognized in earnings		2	7
Balance, beginning of the period		337	2,019
New transactions elected for fair value option		0	0
Maturities and terminations		(85)	(830)
Change in accrued interest		0	(5)
Balance, end of the period		$ 254	$ 1,191

[1] At March 31, 2020, and December 31, 2019, none of these advances were 90 days or more past due or had been placed on nonaccrual status.