Note 2 - Investments - Realized Gains and Losses Related to the Sale of Securities (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Gross gains	$ 20,612	$ 3,951	$ 64,907	$ 3,951
Gross losses	(26,537)	(18,479)	(289,785)	(18,479)
Net security losses	$ (5,925)	$ (14,528)	$ (224,878)	$ (14,528)

The gross gain realized from the sale, exchange, redemption, or retirement of securities, not separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

No definition available.

Name:	usac_GainOnSaleOfSecuritiesGross
Namespace Prefix:	usac_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration