Inventories (Components) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Raw materials	$ 55,930		$ 43,438
Work in process	2,867		2,279
Finished goods	5,920		3,017
Inventory, gross	64,717		48,734
Less: Allowance for excess and obsolete inventories	(1,642)	$ (1,442)	(1,382)	$ (1,065)	$ (894)	$ (757)
Total, net	$ 63,075		$ 47,352