Income taxes: Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of the Federal statutory income taxes to the amounts reported in the financial statements
Federal income tax expense at statutory rates	$ (14,999)	$ (2,166)	$ (11,061)
State income tax, net of federal benefit	(4,123)	(1,091)	(2,973)
Impact of foreign operations	715	(365)	(505)
Non-deductible expenses	(1,365)	(411)	(491)
Tax effect of TCJA from foreign earnings	(389)	(66)	(28)
Other		32	(32)
Change in valuation allowance	(3,074)	(29)	(64)
Total income tax expense	$ (23,235)	$ (4,096)	$ (15,154)