SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for Doubtful Accounts [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning	[1]	$ 769	$ 546	$ 637
Provision	[1]	620	414	522
Write-offs and recoveries, net	[1]	(31)	(191)	(613)
Balance Ending	[1]	$ 1,358	$ 769	$ 546

[1] The provision is included in sales and marketing expenses.