Description of the business and recent developments: Allowance for credit losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Description of the business and recent developments:
Balance at Beginning of Period	$ 1,476	$ 1,457	$ 1,510	$ 1,921
Current-period Provision for Expected Credit Losses	1,059	1,187	2,005	3,199
Write offs Charged Against Allowance	(818)	(971)	(1,798)	(3,447)
Balance at End of Period	1,717	1,673	1,717	1,673
Bad debt recoveries	$ 400	$ 400	$ 1,000	$ 1,600