Summary of Significant Accounting Policies - Impairment of long lived assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Loss on write down of property, equipment and other	$ 4,409	$ 0	$ 0	$ 4,409