Income Taxes: Provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit)	$ 18,601	$ 13,860	$ 14,575
Current State and Local Tax Expense (Benefit)	745	(1,305)	2,145
Current Foreign Tax Expense (Benefit)	1,426	2,100	(70)
Current Income Tax Expense (Benefit)	20,772	14,655	16,650
Deferred Federal Income Tax Expense (Benefit)	4,524	(2,325)	164
Deferred State and Local Income Tax Expense (Benefit)	(960)	988	(996)
Deferred Foreign Income Tax Expense (Benefit)	378	139	(3,522)
Deferred Income Tax Expense (Benefit)	3,942	(1,198)	(4,354)
Income Tax Expense (Benefit)	24,714	13,457	12,296
Allowance for Doubtful Accounts [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	0	4	4
Inventory Valuation Reserve [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	284	(488)	341
Accruals other [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	(2,977)	(1,326)	(470)
State and Local Jurisdiction [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	502	(4)	552
Acquired future tax deductions [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	3,139	96	40
Depreciation and Amortization [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	1,080	(780)	(3,850)
Operating Income (Loss) [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	195	62	0
Tax credits [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	(635)	1,238	(971)
Valuation Allowance of Deferred Tax Assets [Member]
Income Tax Disclosure [Abstract]
Deferred Income Tax Expense (Benefit)	$ 2,354	$ 0	$ 0