Schedule of Continuous Unrealized Loss Position for 12 Months or Longer (Details) $ in Thousands	Jan. 31, 2022 USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Unrealized Losses, Securities in a continuous unrealized loss position for 12 months or longer	$ 160
Fair Value, Securities in a continuous unrealized loss position for 12 months or longer	3,056
US Treasury Bill Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Unrealized Losses, Securities in a continuous unrealized loss position for 12 months or longer	57
Fair Value, Securities in a continuous unrealized loss position for 12 months or longer	1,603
Corporate Bond Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Unrealized Losses, Securities in a continuous unrealized loss position for 12 months or longer	103
Fair Value, Securities in a continuous unrealized loss position for 12 months or longer	$ 1,453