Shares issued under the 2017 Employee Stock Purchase Plan during the three months ended March 31, 2020 and 2019, totaled 31,794 and 32,174, respectively.


	Number of Shares	Weighted Average Exercise Price ($)		Weighted Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value of In-the-Money Options ($)
Outstanding as of December 31, 2019	4,006,816	$	18.18
Exercised	(23,223)	17.21
Forfeited	(57,744)	19.08
Expired	(6,090)	18.44
Outstanding as of March 31, 2020	3,919,759	$	18.17	3.13	$	23,427,581
Exercisable as of March 31, 2020	3,772,523	$	18.10	3.18	$	22,816,683

The total intrinsic value of stock options exercised during the three months ended March 31, 2020 and 2019, was $0.3 million and $5.3 million, respectively. There were no stock options granted during the three months ended March 31, 2020 or 2019.

A summary of nonvested long-term incentive program performance share awards (“LTIP performance shares”) is as follows:


	Number of Shares at Expected Attainment	Weighted Average Grant Date Fair Value
Nonvested as of December 31, 2019	669,469	$	20.12
Vested	(668,240)	20.12
Forfeited	(5,368)	20.12
Change in attainment	4,139	20.12
Nonvested as of March 31, 2020	—	$	—

During the three months ended March 31, 2020, a total of 668,240 LTIPs vested. The Company withheld 165,237 of those shares to pay the employees’ portion of the minimum payroll withholding taxes.


	Number of Shares	Weighted Average Grant Date Fair Value
Nonvested as of December 31, 2019	92,842	$	20.13
Vested	(88,913)	20.12
Forfeited	(3,929)	20.35
Nonvested as of March 31, 2020	—	$	—

During the three months ended March 31, 2020, a total of 88,913 RSAs vested. The Company withheld 28,233 of those shares to pay the employees’ portion of the minimum payroll withholding taxes.


	Number of Shares	Weighted Average Grant Date Fair Value
Nonvested as of December 31, 2019	1,062,291	$	35.77
Granted	677,195	30.01
Vested	(199,413)	24.37
Forfeited	(59,733)	38.95
Change in payout rate	(14,259)	24.37
Nonvested as of March 31, 2020	1,466,081	$	34.64

During the three months ended March 31, 2020, a total of 199,413 TSRs awards granted in fiscal 2017 vested and achieved a payout rate of 93% based on the Company's total shareholder return as compared to a group of peer companies over a three-year performance period. The Company withheld 53,033 of those shares to pay the employees’ portion of the minimum payroll withholding taxes.

The fair value of TSRs granted during the three months ended March 31, 2020 and 2019, were estimated on the date of grant using the Monte Carlo simulation model, acceptable under ASC 718, using the following weighted average assumptions:


	Three Months Ended March 31,
	2020		2019
Expected life (years)	2.8		2.8
Risk-free interest rate	0.5	%	2.5	%
Expected volatility	31.4	%	29.3	%
Expected dividend yield	—		—


	Number of Shares	Weighted Average Grant Date Fair Value
Nonvested as of December 31, 2019	1,009,404	$	29.96
Granted	726,012	25.43
Vested	(327,491)	28.40
Forfeited	(74,771)	30.02
Nonvested as of March 31, 2020	1,333,154	$	27.87

During the three months ended March 31, 2020, a total of 327,491 RSUs vested. The Company withheld 103,839 of those shares to pay the employees’ portion of the minimum payroll withholding taxes.

As of March 31, 2020, there were unrecognized compensation costs of $33.7 million related to nonvested RSUs, $31.5 million related to nonvested TSRs, and less than $0.1 million related to nonvested stock options, which the Company expects to recognize over weighted average periods of 2.4 years, 2.5 years, and 0.9 years, respectively.