Share-based compensation (Tables)

6 Months Ended

Jun. 30, 2021

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 June 30,				Six Months Ended June 30,
(U.S. Dollars, in thousands)	2021		2020		2021		2020
Cost of sales	$	209	$	205	$	387	$	386
Sales and marketing		957		1,533		1,674		2,229
General and administrative		2,607		2,639		5,136		5,169
Research and development		134		322		431		774
Total	$	3,907	$	4,699	$	7,628	$	8,558

	Three Months Ended June 30,				Six Months Ended June 30,
(U.S. Dollars, in thousands)	2021		2020		2021		2020
Stock options	$	398	$	750	$	1,059	$	1,054
Time-based restricted stock awards and units		2,019		2,751		3,746		5,172
Market-based restricted stock units		1,053		810		1,950		1,480
Stock purchase plan		437		388		873		852
Total	$	3,907	$	4,699	$	7,628	$	8,558