Inventories (Summary of Activity within the Reserve for Excess, Obsolete, and Slow Moving Inventory) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Inventory [Roll Forward]
Beginning balance	$ 7,428	$ 5,575	$ 5,570
Excess, obsolete and slow moving inventory expense	(239)	1,539	731
Scrapped inventory and other adjustments	(3,388)	314	(726)
Ending balance	$ 3,801	$ 7,428	$ 5,575