Transactions With Shareholders (Details) - USD ($) $ in Millions		Jun. 30, 2019	Dec. 31, 2018
Minimum
Definition of related party, minimum percent		10.00%
Definition of shareholder concentration, percentage		10.00%
Regulatory Capital Stock Outstanding	[1]	$ 7,335	$ 7,597
Federal Home Loan Bank, Advances, Par Value		100,982	108,414
Bank of America [Member]
Minimum
Regulatory Capital Stock Outstanding		$ 770	$ 855
Percent of Total Regulatory Capital Stock Outstanding		14.81%	15.58%
Federal Home Loan Bank, Advances, Par Value		$ 17,759	$ 19,759
Percent of Total Par Value Advances		17.59%	18.23%
Interest-bearing Deposits		$ 0	$ 0
Percent of Total Interest-bearing Deposits		0.01%	0.01%
Navy Federal Credit Union [Member]
Minimum
Regulatory Capital Stock Outstanding			$ 570
Percent of Total Regulatory Capital Stock Outstanding			10.39%
Federal Home Loan Bank, Advances, Par Value			$ 13,058
Percent of Total Par Value Advances			12.04%
Interest-bearing Deposits			$ 0
Percent of Total Interest-bearing Deposits			0.04%

[1] Total regulatory capital does not include accumulated other comprehensive income, but does include mandatorily redeemable capital stock.