Equity-Based Compensation Plans

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

Equity Plans

On March 31, 2015, we adopted the 2015 Equity Incentive Plan (the 2015 Plan). On January 1, 2020, an additional 6,794 shares of our Class A common stock were reserved for issuance under the automatic increase provisions of the 2015 Plan, and as of December 31, 2020, 27,340 shares were available for issuance as future awards under the plan.

On March 31, 2015, we adopted the 2015 Employee Stock Purchase Plan (the ESPP). On January 1, 2020, an additional 1,000 shares of our Class A common stock were reserved for issuance under the automatic increase provisions of the ESPP, and as of December 31, 2020, 4,081 shares were available for issuance under the plan.

Equity Plan Activity

The following table summarizes stock option activity:


	Number of Shares of Class A Common Stock (#)	Weighted- Average Grant- Date Fair Value ($)	Weighted- Average Exercise Price ($)	Weighted- Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value ($)








Outstanding at December 31, 2017	13,460		18.63
Granted	1,208	22.19	61.49
Exercised	(4,779)		14.08		246.4
Forfeited	(362)		34.05
Outstanding at December 31, 2018	9,527		25.77
Granted	1,401	24.91	71.74
Exercised	(3,976)		17.78		213.8
Forfeited	(648)		54.43
Outstanding at December 31, 2019	6,304		38.08
Granted	154	22.33	68.05
Exercised	(2,613)		29.71		121.0
Forfeited	(417)		62.82
Outstanding at December 31, 2020	3,428		42.79	6.0	137.6
Vested at December 31, 2020	2,458		33.90	5.2	120.6

The following table summarizes stock award activity:


						Number of Shares of Class A Common Stock (#)
Outstanding at December 31, 2017(1)						4,199
Granted						3,152
Vested						(1,545)
Forfeited						(450)
Outstanding at December 31, 2018(1)						5,356
Granted						3,057
Vested						(2,187)
Forfeited						(986)
Outstanding at December 31, 2019(1)						5,240
Granted						4,157
Vested						(2,368)
Forfeited						(896)
Outstanding at December 31, 2020						6,133

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(1) Includes financial-based PSUs for which performance targets have not yet been established, and which are not yet considered granted for accounting purposes. The balance of outstanding awards is comprised of the following:


	Number of Shares of Class A Common Stock (#)	Weighted Average Fair Value Per Share ($)





RSUs	3,952	53.77
Financial-based PSUs granted for accounting purposes	505	63.18
Financial-based PSUs not yet granted for accounting purposes	899	N/A
Outstanding at December 31, 2018	5,356

RSUs	4,247	65.12
Financial-based PSUs granted for accounting purposes	401	73.28
Financial-based PSUs not yet granted for accounting purposes	592	N/A
Outstanding at December 31, 2019	5,240

RSUs	5,356	70.54
TSR-based RSUs	349	106.14
Financial-based PSUs granted for accounting purposes	223	66.97
Financial-based PSUs not yet granted for accounting purposes	205	N/A
Outstanding at December 31, 2020	6,133

At December 31, 2020, total unrecognized compensation expense related to non-vested options and awards was $17.0 million and $284.2 million, respectively, with expected remaining weighted-average recognition periods of approximately 2.1 years and 2.5 years, respectively. Such amounts exclude PSUs not yet considered granted for accounting purposes.

2019 Error Correction

During 2019, we reversed $15.6 million of equity-based compensation expense as we determined that we had previously recognized such expense related to certain PSUs prior to the establishment of a grant date for accounting purposes. We determined the amounts related to the prior periods were immaterial considering both quantitative and qualitative factors.