Segment Information (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area

	Year Ended December 31,
	2017		2016		2015
Net sales from external customers:
United States	$	3,348	$	4,100	$	3,246
Canada	1,938		1,809		2,746
Peru	508		—		—
Hong Kong1	174,926		263,482		245,737
China	7,282		9,086		4,425
Taiwan	5,591		6,213		5,965
South Korea	466		691		1,129
Russia, Kazakhstan and Ukraine2	913		858		1,139
Europe	2,278		1,234		382
Other foreign countries	313		255		91
Total net sales	$	197,563	$	287,728	$	264,860

Schedule of Segment Reporting Information, by Segment

	Year Ended December 31,
	2017			2016			2015
Net sales by product and service:
Product sales	$	187,591		$	269,731		$	253,041
Enrollment package revenue, freight and other	13,676			25,616			17,623
Less: sales returns	(3,704		)	(7,619		)	(5,804		)
Total net sales	$	197,563		$	287,728		$	264,860

Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country

	December 31,
	2017		2016
Long-lived assets:
United States	$	648	$	763
Hong Kong	78		140
China	112		199
Other foreign countries	311		286
Total long-lived assets	$	1,149	$	1,388