Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 790	$ 200	$ 202
Charged to costs and expenses	1,008	689	56
Charged to other accounts	341	0	0
Write-offs	(1,221)	(99)	(58)
Balance at end of year	$ 918	$ 790	$ 200