Share-based compensation (Tables)

9 Months Ended

Sep. 30, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Components of Share-Based Compensation Expense

Components of share-based compensation expense are as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
(U.S. Dollars, in thousands)	2020		2019		2020		2019
Cost of sales	$	149	$	169	$	535	$	536
Sales and marketing		668		583		2,897		1,885
General and administrative		2,770		4,760		7,939		13,888
Research and development		254		332		1,028		1,069
Total	$	3,841	$	5,844	$	12,399	$	17,378

	Three Months Ended September 30,				Nine Months Ended September 30,
(U.S. Dollars, in thousands)	2020		2019		2020		2019
Stock options	$	786	$	599	$	1,840	$	3,637
Time-based restricted stock awards and units		1,632		3,805		6,804		8,462
Market-based restricted stock units		1,049		1,092		2,529		4,015
Stock purchase plan		374		348		1,226		1,264
Total	$	3,841	$	5,844	$	12,399	$	17,378