Income Taxes Deferred income tax assets (liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets and liabilities [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	$ 12,686	$ 0
Non-current deferred tax asset	76,571	46,135
Deferred Tax Assets, Net	37,933	23,288
Non-current deferred tax asset, gross total [Member]
Deferred tax assets and liabilities [Line Items]
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Other	11,291	956
Deferred Tax Assets, Other	12,451	7,412
Noncurrent deferred tax asset - acquired future tax deductions	10,722	10,580
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	10,775	8,633
Deferred Tax Assets, Unrealized Currency Losses	3,108	3,425
Noncurrent deferred tax asset - tax credits state	14,470	11,220
Deferred Tax Assets, Inventory	5,674	10,658
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	830	636
Deferred Tax Assets, Valuation Allowance, Noncurrent	(5,436)	(7,385)
Noncurrent deferred tax liability [Member]
Deferred tax assets and liabilities [Line Items]
Noncurrent deferred tax liability - depreciation and amortization	35,387	21,005
Noncurrent deferred tax liability - state income taxes	2,639	1,640
Noncurrent deferred tax liability - foreign	612	202
Deferred Tax Liabilities, Net	$ 38,638	$ 22,847