Stock-based Compensation

6 Months Ended

Jun. 30, 2021

Share-based Payment Arrangement [Abstract]

STOCK-BASED COMPENSATION

Stock Unit Awards

Restricted stock unit ("RSU") and performance stock unit ("PSU") awards activity is presented in the following tables.


	RSU Shares (in 000's)	PSU Shares (in 000's)	Total Shares (in 000's)	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (in years)
Unvested as of March 31, 2021	940.3	439.1	1,379.4	$	134.84	1.70
Granted	200.5	107.2	307.7	186.21
Vested	(10.7)	—	(10.7)	142.07
Forfeited	(12.0)	(1.1)	(13.1)	123.85
Unvested as of June 30, 2021	1,118.1	545.2	1,663.3	$	144.01	1.92

Unvested as of March 31, 2020	1,208.9	286.8	1,495.7	$	144.71	1.78
Granted	152.3	272.0	424.3	113.67
Vested	(10.2)	—	(10.2)	118.91
Forfeited	(7.8)	—	(7.8)	143.09
Unvested as of June 30, 2020	1,343.2	558.8	1,902.0	$	137.93	2.01


	RSU Shares (in 000's)	PSU Shares (in 000's)	Total Shares (in 000's)	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (in years)
Unvested as of December 31, 2020	1,096.2	531.5	1,627.7	$	137.42	1.69
Granted	257.1	107.2	364.3	179.95
Vested	(218.1)	(79.0)	(297.1)	150.45
Forfeited	(17.1)	(14.5)	(31.6)	138.47
Unvested as of June 30, 2021	1,118.1	545.2	1,663.3	$	144.01	1.92

Unvested as of December 31, 2019	1,532.3	286.8	1,819.1	$	141.51	2.39
Granted	162.0	272.0	434.0	118.66
Vested	(334.8)	—	(334.8)	136.36
Forfeited	(16.3)	—	(16.3)	140.22
Unvested as of June 30, 2020	1,343.2	558.8	1,902.0	$	137.93	2.01

As of June 30, 2021, we had $104.0 million of unamortized deferred compensation related to unvested RSUs and PSUs, which we anticipate recognizing over varying periods into 2026; $16.7 million relates to the awards issued in conjunction with the HFF acquisition.