Property and Equipment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Long Lived Assets Held-for-sale [Line Items]
Depreciation	$ 6,300	$ 6,700
Proceeds from sale of property and equipment	839	634
Loss on disposal of property plant and equipment	(512)	$ (372)
Impairment of long-lived assets held-for-use	$ 6,400