Share-based compensation

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Share-based compensation

13. Share-based compensation

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

During the three months ended June 30, 2021 and 2020, the Company issued 194,745 and 152,885 shares, respectively, of common stock related to stock purchase plan issuances, stock option exercises, and the vesting of restricted stock awards and units. During the six months ended June 30, 2021 and 2020, the Company issued 245,255 and 186,444 shares, respectively, of common stock related to stock purchase plan issuances, stock option exercises, and the vesting of restricted stock awards and units