Equity-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2018

Share Based Compensation [Abstract]

Details of Equity-Based Compensation Expense and Related Income Tax Benefit

The following table details equity-based compensation expense and the related income tax benefit:

	Three Months Ended September 30,				Nine Months Ended September 30,
(Dollars in thousands)	2018		2017		2018		2017
Employee equity-based compensation expense:
Performance shares	$	1,074	$	905	$	3,084	$	2,678
Restricted stock units		536		283		1,470		858
Accelerated share-based termination benefits in connection with the merger		3		—		1,767		—
Total employee equity-based compensation expense	$	1,613	$	1,188	$	6,321	$	3,536
Deferred compensation stock equivalent units expense	$	16	$	166	$	197	$	488
Total tax benefit recognized for share-based expense	$	74	$	95	$	258	$	284

Fair Value of Performance Share Awards

The following table presents the key inputs used in the Monte Carlo simulation to calculate the fair value of the performance share awards in 2018 and 2017:

	Nine Months Ended September 30,
	2018			2017
Stock price as of valuation date	$	54.00		$	43.60
Risk-free rate		2.46	%		1.61	%
Expected volatility		23.74	%		24.22	%
Expected dividends		2.96	%		3.44	%
Expected term (years)		3.00			3.00
Fair value	$	75.37		$	53.85

Summary of Outstanding Performance Share Awards

The following table summarizes outstanding performance share awards as of September 30, 2018 and changes during the nine months ended September 30, 2018:

(Dollars in thousands, except grant date fair value)	Shares			Weighted-Avg. Grant Date Fair Value		Aggregate Intrinsic Value
Unvested shares outstanding at December 31, 2017		200,631		$	39.19
Granted		67,747		$	75.37
Forfeited		(5,082	)	$	47.90
Unvested shares outstanding at September 30, 2018		263,296		$	48.33	$	10,782

Summary of Outstanding RSU Awards

The following table summarizes outstanding RSU awards as of September 30, 2018 and changes during the nine months ended September 30, 2018:

(Dollars in thousands, except grant date fair value)	Shares			Weighted-Avg. Grant Date Fair Value		Aggregate Intrinsic Value
Unvested shares outstanding at December 31, 2017		67,871		$	32.87
Granted		43,693		$	51.54
Vested		(1,000	)	$	42.92
Forfeited		(3,694	)	$	45.36
Unvested shares outstanding at September 30, 2018		106,870		$	39.98	$	4,376