Stock Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Summary of Securities To Be Issued and Remaining Available For Future Issuance

The following table summarizes the number of securities to be issued and remaining available for future issuance under all of the Company’s stock incentive plans as of December 31, 2019:



	Number of securities to be issued upon vesting of RSUs and performance share awards	Weighted-average exercise price of vesting of RSUs and performance share awards		Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column 1)
2007 Long-Term Incentive Plan⁽¹⁾	1,624	$	0.01	—
2010 Long-Term Incentive Plan⁽²⁾	667,368	0.01		—
2019 Long-Term Incentive Plan⁽²⁾	17,086	0.01		3,550,881

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(1)	Includes RSUs.

(2)

Includes RSUs and performance shares.

Schedule of Share-based Compensation, Activity

The following table summarizes the aggregate intrinsic value of awards vested and exercised (in millions):



	Year Ended December 31,
	2019		2018		2017
Aggregate intrinsic value of awards vested and exercised:
RSUs	$	5.5	$	3.8	$	6.1
Performance shares	1.6		1.2		5.5

Assumptions Used for Fair Value

The fair values for RSUs and performance shares, which are based on the fair market value of the Company’s stock at date of grant, are included below:



	Year Ended December 31,
	2019		2018		2017
Weighted-average fair value per share of grants:
RSUs	$	29.67	$	23.66	$	38.37
Performance shares⁽¹⁾	$	29.90	$	23.78	N/A

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(1)

Of the 154,511 performance shares awarded in 2019, all were earned based upon 2019 performance criteria. Of the 193,006 performance shares awarded in 2018, 141,406 performance shares were earned based upon 2018 performance criteria.

The following table summarizes the activity for all RSUs and performance shares under all of the Long-Term Incentive Plans (“LTIPs”) for the year ended December 31, 2019:



		December 31, 2018			Activity during 2019												December 31, 2019
		Outstanding			Granted				Vested / Exercised				Canceled/Forfeited				Outstanding			Exercisable
Plans	Securities	Number	Price		Number		Price		Number		Price		Number		Price		Number	Price		Number	Price
2007 LTIP	RSUs	1,624	$	0.01	—		$	—	—		$	—	—		$	—	1,624	$	0.01	1,624	$	0.01
2010 LTIP	RSUs	453,896	0.01		223,308	⁽¹⁾	0.01		(203,243	)	0.01		(31,845	)	0.01		442,116	0.01		—	—
	Performance shares	142,011	0.01		144,352	⁽²⁾	0.01		(55,676	)	0.01		(5,435	)	0.01		225,252	0.01		—	—
2019 LTIP	RSUs	—	—		6,927	⁽¹⁾	0.01		—		0.01		—		—		6,927	0.01		—	—
	Performance shares	—	—		10,159	⁽²⁾	0.01		—		0.01		—		—		10,159	0.01		—	—
Total		597,531			384,746				(258,919	)			(37,280	)			686,078			1,624

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Note: Price is weighted-average price per share.


(1)	Consists of non-performance RSUs.

(2)

In 2019, the Company awarded a maximum of 154,511 performance shares that would be received if the highest level of performance was achieved. Subsequent to December 31, 2019, all performance shares were earned based upon 2019 performance criteria.

Schedule of Stock Options, Restricted Stock Units and Performance Shares Vested and Expected to Vest

The following table summarizes RSUs and performance shares that have vested and are expected to vest as of December 31, 2019:



		December 31, 2019
		Outstanding		Weighted-Average Remaining Contractual Term (years)		Aggregate Intrinsic Value⁽¹⁾ (dollars in thousands)
Plans	Securities	Vested	Expected to vest⁽²⁾	Vested	Expected to vest⁽²⁾	Vested		Expected to vest⁽²⁾
2007 LTIP	RSUs	1,624	—	—	—	$	44	$	—
2010 LTIP	RSUs	—	426,996	—	—	—		11,606
	Performance shares	—	222,999	—	—	—		6,061
2019 LTIP	RSUs	—	6,690	—	—	—		182
	Performance shares	—	10,057	—	—	—		273
Total		1,624	666,742			$	44	$	18,122

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(1)	Aggregate intrinsic value is calculated based upon the difference between the exercise price of RSUs and the Company’s closing common stock price on December 31, 2019 of $27.19, multiplied by the number of instruments that are vested or expected to vest. RSUs having grant prices greater than the closing stock price noted above are excluded from this calculation.


(2)	RSUs and performance shares that are expected to vest are net of estimated future forfeitures.