Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017		Sep. 30, 2017
Inventory Disclosure [Abstract]
Raw material		$ 82,397		$ 78,732
Work in process		42,304		51,545
Finished goods		163,956		165,271
Total	$ 295,548	$ 288,657	[1]	$ 295,548

[1] December 31, 2017 balances were derived from audited consolidated financial statements.