Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 506	$ 208	$ 0
Additions based on tax positions of the current year	197	152	69
Additions based on tax positions of prior year	79	146	139
Decreases related to settlements of prior year tax positions	(101)	0	0
Ending balance	$ 681	$ 506	$ 208