Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Income Taxes
Income tax expense (benefit)	$ 129	$ 79	$ (21)	$ 374
Unrecognized tax benefits	10,568		10,568		$ 9,218
Unrecognized tax benefits, if recognized, would impact effective tax rate	410		410		540
Anticipated decrease of liability for uncertain tax positions due to expiration of certain statutes of limitation in foreign jurisdictions	147		147
Interest on uncertain tax position expense	17	$ 20	116	$ 59
Liability related to interest and penalties for uncertain tax positions	$ 292		$ 292		$ 375