Stock Compensation Plans

Pursuant to the Company’s 2016 Stock Incentive Plan, as amended, the Company may issue stocks, stock options, restricted stock awards, restricted stock units (“RSUs”), stock appreciation rights, stock purchase warrants, phantom stock and dividend equivalents to eligible employees, consultants, other service providers, and non-employee directors of the Company and its subsidiaries. There were no outstanding stock awards other than RSUs as of both March 31, 2019 and December 31, 2018.

The following table presents a summary of the total share-based compensation expense and the related net tax benefits associated with the Company’s various employee share-based compensation plans for the three months ended March 31, 2019 and 2018:




($ in thousands)	Three Months Ended March 31,
($ in thousands)	2019		2018
Stock compensation costs	$	7,444	$	6,158
Related net tax benefits for stock compensation plans	$	4,707	$	4,778

RSUs — RSUs are granted under the Company’s long-term incentive plan at no cost to the recipient. RSUs vest ratably over three years or cliff vest after three or five years of continued employment from the date of the grant. RSUs are authorized to settle predominantly in shares of the Company’s common stock. Certain RSUs will be settled in cash that subject these RSUs to variable accounting whereby compensation expense is adjusted to fair value based on changes in the Company’s stock price up to the settlement date. RSUs entitle the recipient to receive cash dividend equivalents to any dividends paid on the underlying common stock during the period the RSUs are outstanding. RSU dividends are accrued during the vesting period and are paid at the time of vesting. While a portion of RSUs are time-vesting awards, others vest subject to the attainment of specified performance goals referred to as “Performance-based RSUs.” All RSUs are subject to forfeiture until vested.

Performance-based RSUs are granted at the target amount of awards. Based on the Company’s attainment of specified performance goals and consideration of market conditions, the number of shares that vest can be adjusted to a minimum of zero and to a maximum of 200% of the target. The amount of performance-based RSUs that are eligible to vest is determined at the end of each performance period and is then added together to determine the total number of performance shares that are eligible to vest. Performance-based RSUs cliff vest three years from the date of each grant.

Compensation costs for the time-based awards that will be settled in shares of the Company’s common stock are based on the quoted market price of the Company’s common stock at the grant date. Compensation costs for certain time-based awards that will be settled in cash are adjusted to fair value based on changes in the share price of the Company’s common stock up to the settlement date. Compensation costs associated with performance-based RSUs are based on grant date fair value which considers both market and performance conditions, and is subject to subsequent adjustments based on the changes in the Company’s projected outcome of the performance criteria. Compensation costs of both time-based awards and performance-based awards are recognized on a straight-line basis from the grant date until the vesting date of each grant.

The following table presents a summary of the activities and pricing information for the Company’s time-based and performance-based RSUs that will be settled in shares for the three months ended March 31, 2019. The number of outstanding performance-based RSUs stated below assumes the associated performance targets will be met at the target level:




	Three Months Ended March 31, 2019
	Time-Based RSUs				Performance-Based RSUs
	Shares		Weighted-Average Grant Date Fair Value		Shares		Weighted-Average Grant Date Fair Value
Outstanding, at beginning of period	1,121,391		$	51.22	411,290		$	49.93
Granted	475,833		52.75		134,600		54.64
Vested	(350,755	)	31.38		(159,407	)	29.18
Forfeited	(10,168	)	56.23		—		—
Outstanding, at end of period	1,236,301		$	57.40	386,483		$	60.13

The following table presents a summary of the activities for the Company’s time-based RSUs that will be settled in cash for the three months ended March 31, 2019:




		Three Months Ended March 31, 2019
		Shares
Outstanding, at beginning of period		—
Granted		12,145
Vested		—
Forfeited		—
Outstanding, at end of period		12,145

As of March 31, 2019, there were $34.0 million and $22.0 million of total unrecognized compensation costs related to unvested time-based and performance-based RSUs, respectively. These costs are expected to be recognized over a weighted-average period of 2.26 years and 2.38 years, respectively.