Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

The following table summarizes the activity for all stock options under all of the Company’s equity incentive plans for the three months ended March 31, 2019 (shares and aggregate intrinsic value in thousands):



	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Aggregate Intrinsic Value
Outstanding at December 31, 2018	13,590		$	6.07	6.63	$	66,462
Granted	1,064		14.57
Exercised	(1,139	)	3.86
Cancelled	(17	)	10.30
Outstanding at March 31, 2019	13,498		$	6.92	6.71	$	97,127

Options vested and exercisable at March 31, 2019	8,154		$	6.21	5.67	$	64,261

Summary of activity for all restricted stock units (RSUs)

The following table summarizes the activity for all restricted stock units (“RSUs”) under all of the Company’s equity incentive plans for the three months ended March 31, 2019 (shares in thousands):



	Number of Awards		Weighted Average Grant Date Fair Value
Unvested balance at December 31, 2018	4,182		$	7.05
Granted	1,524		14.42
Issued	(451	)	6.75
Cancelled / forfeited	(295	)	7.20
Unvested balance at March 31, 2019	4,960		$	9.33

Summary of stock-based compensation expense

The Company recognized stock-based compensation expense, including ESPP expenses, in the consolidated statements of operations as follows (in thousands):



	Three Months Ended March 31,
	2019		2018
Cost of customer agreements and incentives	$	632	$	611
Cost of solar energy systems and product sales	167		170
Sales and marketing	1,128		4,150
Research and development	336		295
General and administration	3,520		5,468
Total	$	5,783	$	10,694