Inventories (Tables)

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Schedule of Inventories

Inventories were as follows:

(U.S. Dollars, in thousands)	March 31, 2018		December 31, 2017
Raw materials	$	5,889	$	6,067
Work-in-process		13,666		12,487
Finished products		58,131		60,441
Deferred cost of sales		—		2,335
Inventories	$	77,686	$	81,330