Capital Mandatorily Redeemable Capital Stock (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Mandatorily Redeemable Capital Stock [Roll Forward]
Balance at beginning of year	$ 31,868	$ 35,923	$ 32,687
Capital stock subject to mandatory redemption reclassified from capital	0	309	8,670
Redemption/repurchase of mandatorily redeemable capital stock	(26,062)	(4,364)	(5,434)
Balance at end of year	$ 5,806	$ 31,868	$ 35,923
Number of stockholders holding mandatorily redeemable capital stock	9	10	9