Stock Compensation Plans (Tables)

6 Months Ended

Jun. 30, 2019

Share-based Payment Arrangement [Abstract]

Summary of stock compensation expense and related net tax benefit

The following table presents a summary of the total compensation costs and the related net tax benefits associated with the Company’s various share-based compensation plans for the three and six months ended June 30, 2019 and 2018:

($ in thousands)	Three Months Ended June 30,				Six Months Ended June 30,
	2019		2018		2019		2018
Stock compensation costs	$	8,081	$	7,057	$	15,525	$	13,215
Related net tax benefits for stock compensation plans	$	1	$	97	$	4,708	$	4,875

Summary of activity for time-based and performance-based restricted stock units

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 six months ended June 30, 2019. The number of outstanding performance-based RSUs stated below assumes the associated performance targets will be met at the target level:

	Six Months Ended June 30, 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	490,809		52.60		134,600		54.64
Vested	(355,029	)	31.58		(159,407	)	29.18
Forfeited	(39,930	)	56.90		—		—
Outstanding, at end of period	1,217,241		$	57.32	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 six months ended June 30, 2019:

	Six Months Ended June 30, 2019
	Shares
Outstanding, at beginning of period	—
Granted	12,145
Vested	—
Forfeited	—
Outstanding, at end of period	12,145