Share-Based Compensation Plans: (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

The vesting periods and grant date fair values for restricted stock and restricted stock units issued, including the EarthLink replacement awards issued in 2017, were as follows for the years ended December 31:



(Number of shares in thousands)	2019		2018		2017
Service-based restricted stock and restricted units:
Vest variably over remaining service period, up to three-years	—		—		571.7
Vest ratably over a three-year service period	—		—		490.3
Vest one year from date of grant, service based - granted to non-employee directors	—		109.6		41.4
Vest immediately on date of grant, service based - granted to non-employee directors	—		41.1		—
Vest three years from date of grant, service based	—		—		6.8
Total granted	—		150.7		1,110.2
Grant date fair value (Dollars in millions)	$	—	$	1.1	$	33.3

Schedule of Share-based Compensation, Restricted Stock Units Award Activity

estricted stock and restricted unit activity for the year ended December 31, 2019 was as follows:



	Service-Based				Performance-Based
	(Thousands) Underlying Number of Shares		Weighted Average Fair Value Per Share		(Thousands) Underlying Number of Shares		Weighted Average Fair Value Per Share
Non-vested at December 31, 2018	522.1		$	23.34	325.4		$	28.35
Granted	—		$	—	698.5		$	3.40
Vested	(143.5	)	$	32.57	(160.8	)	$	28.91
Forfeited	(19.0	)	$	34.83	(740.1	)	$	4.77
Non-vested at December 31, 2019	359.6		$	19.05	123.0		$	27.80

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

A summary of share-based compensation expense was as follows for the years ended December 31:



(Millions)	2019		2018		2017
Restricted stock, restricted units and stock options	$	2.7	$	11.3	$	32.5
Employee savings plan (See Note 11)	—		—		22.9
Share-based compensation expense	$	2.7	$	11.3	$	55.4