Significant Accounting Policies Major Components of Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Raw materials and purchased components	$ 220,301	$ 194,108
Service parts, garments and accessories	320,237	307,684
Finished goods	428,894	329,288
Less: reserves	(46,507)	(47,119)
Inventories	$ 922,925	$ 783,961