Investments in available-for-sale debt securities (Details 2) $ in Thousands	Sep. 30, 2022 USD ($)
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Fair Value
Fair value, Less than 12 months	$ 1,948	[1]
Fair value, 12 months or more	0	[1]
Fair value	1,948	[1]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss
Gross unrealized losses, Less than 12 months	(100)
Gross unrealized losses, 12 months or more	0
Gross unrealized losses	(100)
U.S. government
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Fair Value
Fair value, Less than 12 months	196	[1]
Fair value, 12 months or more	0	[1]
Fair value	196	[1]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss
Gross unrealized losses, Less than 12 months	(3)
Gross unrealized losses, 12 months or more	0
Gross unrealized losses	(3)
Corporate and other taxable bonds
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Fair Value
Fair value, Less than 12 months	1,186	[1]
Fair value, 12 months or more	0	[1]
Fair value	1,186	[1]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss
Gross unrealized losses, Less than 12 months	(28)
Gross unrealized losses, 12 months or more	0
Gross unrealized losses	(28)
Other
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Fair Value
Fair value, Less than 12 months	566	[1]
Fair value, 12 months or more	0	[1]
Fair value	566	[1]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss
Gross unrealized losses, Less than 12 months	(69)
Gross unrealized losses, 12 months or more	0
Gross unrealized losses	$ (69)

[1] The fair value of the Company's available-for-sale debt securities are determined based upon inputs, other than the quoted prices in active markets, that are observable either directly or indirectly and are classified as level 2 fair value measurements.