Summary of Significant Accounting Policies - Schedule of Changes in Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts Receivable
Balance at beginning of year	$ 477	$ 811	$ 531
Provision and reserve adjustments	2	(152)	305
Write-offs less recoveries	(54)	(182)	(25)
Balance at end of year	$ 425	$ 477	$ 811