Note 14 - Concentration of Credit Risk and Significant Customers (Details Textual)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Customer Concentration Risk [Member] \| Revenue from Contract with Customer Benchmark [Member]
Number of Major Customers	0	0

Represents the number of major customers accounting for 10% or more of the specified concentration risk benchmark, which includes, but not limited to, sales revenue, accounts receivable, etc.

No definition available.

Name:	usio_NumberOfMajorCustomers
Namespace Prefix:	usio_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration