Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred income tax assets:
Allowance for doubtful accounts	$ 225	$ 141
Property and equipment	0	145
ROU asset	3,122
Inventories	4,732	4,672
Stock-based compensation	785	562
Sales returns accrual	5,794	5,058
Acquisition costs, net of amortization	91	107
Intangible assets	6,434	4,087
Goodwill	786	926
Capital loss carry-over	0	191
Net operating loss carryforward	0	19
Federal and state credit carryforwards	497	2,070
Other liabilities, including foreign	3,341	1,894
Total gross deferred tax assets	26,992	20,920
Valuation allowance	(1,670)	(1,517)
Total deferred income tax assets	25,322	19,403
Property and equipment	(355)	0
Lease liability	(2,310)
Total deferred tax liabilities	(2,665)	0
Deferred income tax assets, net	22,657	19,403
HzO investment
Deferred income tax assets:
HzO investment	1,028	1,048
Valuation allowance	(1,028)	(1,048)
Celio investment
Deferred income tax assets:
HzO investment	157	0
Valuation allowance	$ (157)	$ (160)