Summary of Significant Accounting Policies - Trade Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowance for doubtful accounts, beginning balance	$ 1,390	$ 1,120	$ 1,815
Charged to revenues, costs and expenses	1,412	1,073	167
Amounts charged off, net	(1,192)	(803)	(862)
Allowance for doubtful accounts, ending balance	$ 1,610	$ 1,390	$ 1,120