Inventories (Tables)

12 Months Ended

Dec. 31, 2014

Inventory Disclosure [Abstract]

Schedule of Inventories

	December 31,
(U.S. Dollars in thousands)	2014		2013
Raw materials	$	3,879	$	6,515
Work-in-process		4,830		6,606
Finished products		24,953		28,291
Field inventory		18,003		21,312
Consignment inventory		2,656		2,388
Deferred cost of sales		5,525		7,566
	$	59,846	$	72,678