The table below sets forth the line items where share-based compensation expense was recorded:

	Three Months Ended
	March 31,
	2019		2018
Cost of goods sold	$	125	$	90
Selling, general and administrative		3,637		5,454
Research and development		715		736
Total share-based compensation expense	$	4,477	$	6,280

	Three Months Ended
	March 31,
	2019		2018
Stock options	$	-	$	191
Share grants		4,477		6,089
Total share-based compensation expense	$	4,477	$	6,280

Stock Options. Approximately $6.7 million in cash proceeds was received from stock option exercises during the three months ended March 31, 2019.

As of March 31, 2019, we had no unrecognized share-based compensation expense related to unvested stock options.

Share Grants. Restricted stock awards and restricted stock units generally vest in equal annual installments over a four-year period. We also have share grants that are performance-based and time-based that vest upon achievement of certain performance criteria over time.

As of March 31, 2019, total unrecognized share-based compensation expense related to share grants was approximately $40.1 million, before income taxes, and is expected to be recognized over a weighted average period of approximately 2.1 years.