Inventory - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 693,499	$ 680,339
Work in process	254,684	233,746
Finished goods	1,141,556	1,016,731
Service parts	130,597	136,638
Total	$ 2,220,336	$ 2,067,454