Income taxes: Income tax expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current:
Federal		$ 32
State	$ (3,116)	(2,908)	$ (2,647)
Foreign	(1,833)	(947)	(370)
Deferred:
Federal	(17,959)	(1,867)	(10,899)
State	(2,348)	1,241	(1,285)
Foreign	2,021	353	47
Total income tax expense	$ (23,235)	$ (4,096)	$ (15,154)