Stock-Based Compensation

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation

Stock-Based Compensation

Stock Options

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, 2020 (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, 2019	10,784	$	7.38	6.52	$	71,745
Granted	1,086	9.96
Exercised	(1,009)	5.88
Cancelled	(162)	9.00
Outstanding at March 31, 2020	10,699	$	7.75	6.80	$	33,024
Options vested and exercisable at March 31, 2020	6,922	$	6.52	5.80	$	26,557

Restricted Stock Units

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, 2020 (shares in thousands):

	Number of Awards	Weighted Average Grant Date Fair Value
Unvested balance at December 31, 2019	3,943	$	11.42
Granted	1,747	10.30
Issued	(663)	10.88
Cancelled / forfeited	(184)	10.17
Unvested balance at March 31, 2020	4,843	$	11.14

Additionally, RSU awards were granted during the three months ended March 31, 2020, which are excluded from the table above as the number of shares will not be calculated until May 2020. The approximate fair value of the awards, $12.1 million, is recorded in accrued expenses and other liabilities in the consolidated balance sheet.

Employee Stock Purchase Plan

Under the Company's 2015 Employee Stock Purchase Plan ("ESPP"), eligible employees are offered shares bi-annually through a 24-month offering period that encompasses four six-month purchase periods. Each purchase period begins on the first trading day on or after May 15 and November 15 of each year. Employees may purchase a limited number of shares of the Company’s common stock via regular payroll deductions at a discount of 15% of the lower of the fair market value of the Company’s common stock on the first trading date of each offering period or on the exercise date. Employees may deduct up to 15% of payroll, with a cap of $25,000 of fair market value of shares in any calendar year and 10,000 shares per employee per purchase period.

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,
	2020		2019
Cost of customer agreements and incentives	$	1,946	$	632
Cost of solar energy systems and product sales	673		167
Sales and marketing	3,478		1,128
Research and development	1,075		336
General and administration	11,773		3,520
Total	$	18,945	$	5,783