Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 3,270	$ 1,750	$ 407
Additions charged to Expense or Revenue	2,127	1,698	1,357
Deductions and write-offs	(555)	(178)	(14)
Balance at End of Year	4,842	3,270	1,750
Allowance for product returns
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	1,262	841	215
Additions charged to Expense or Revenue	8,319	3,257	2,215
Deductions and write-offs	(4,687)	(2,836)	(1,589)
Balance at End of Year	4,894	1,262	841
Allowance for obsolescence
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	397	527	322
Additions charged to Expense or Revenue	2,280	540	405
Deductions and write-offs	(1,849)	(670)	(200)
Balance at End of Year	$ 828	$ 397	$ 527