Stock-Based Incentive Plan (Tables)

3 Months Ended

Mar. 31, 2017

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

Status of Options Granted Under Long-Term Incentive Plan

The following is a summary of the Corporation's stock option activity and related information for the three months ended March 31, 2017:

(Dollars in thousands, except per share data)	Shares Under Option		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value at March 31, 2017
Outstanding at December 31, 2016	504,908		$	19.06
Granted	191,297		28.15
Expired	(65,500	)	22.98
Forfeited	—		—
Exercised	(47,704	)	18.04
Outstanding at March 31, 2017	583,001		21.66		7.9	$	2,898
Exercisable at March 31,2017	210,691		17.96		6.0	1,672

Summary of Nonvested Stock Options

The following is a summary of nonvested stock options at March 31, 2017 including changes during the three months then ended:

(Dollars in thousands, except per share data)	Nonvested Stock Options		Weighted Average Grant Date Fair Value
Nonvested stock options at December 31, 2016	308,940		$	6.15
Granted	191,297		6.72
Vested	(127,927	)	6.08
Forfeited	—		—
Nonvested stock options at March 31, 2017	372,310		6.46

Aggregated Assumptions Used to Estimate Fair Value of Options Granted

The following aggregated assumptions were used to estimate the fair value of options granted during the three months ended March 31, 2017 and 2016:

	Three months ended March 31,
	2017			2016
	Actual			Range			Weighted Average
Expected option life in years	6.9			7.9	-	8.2	7.9
Risk free interest rate	2.30		%	1.81%	-	1.89%	1.89		%
Expected dividend yield	2.84		%	4.07%	-	4.19%	4.07		%
Expected volatility	29.75		%	46.13%	-	46.22%	46.13		%
Fair value of options	$	6.72		$5.98	-	$6.27	$	6.26

Summary of Nonvested Restricted Stock Awards

The following is a summary of nonvested restricted stock awards at March 31, 2017 including changes during the three months then ended:

(Dollars in thousands, except per share data)	Nonvested Share Awards		Weighted Average Grant Date Fair Value
Nonvested share awards at December 31, 2016	285,158		$	19.74
Granted	58,448		28.15
Vested	(47,164	)	18.32
Forfeited	(13,125	)	18.78
Nonvested share awards at March 31, 2017	283,317		21.76

Certain Information Regarding Restricted Stock

The fair value of restricted stock is equivalent to the fair value on the date of grant and is amortized over the vesting period. Certain information regarding restricted stock is summarized below for the periods indicated:

	Three months ended March 31,
(Dollars in thousands, except per share data)	2017		2016
Shares granted	58,448		58,580
Weighted average grant date fair value	$	28.15	$	19.68
Intrinsic value of awards vested	$	1,333	$	971

Schedule of Unrecognized Compensation Cost, Nonvested Awards

The total unrecognized compensation expense and the weighted average period over which unrecognized compensation expense is expected to be recognized related to nonvested stock options and nonvested restricted stock awards at March 31, 2017 is presented below:

(Dollars in thousands)	Unrecognized Compensation Cost		Weighted-Average Period Remaining (Years)
Stock options	$	2,082	2.4
Restricted stock awards	4,189		1.9
	$	6,271	2.1

Compensation Expense Related to Stock Incentive Plans Recognized

The following table presents information related to the Corporation’s compensation expense related to stock incentive plans recognized for the periods indicated:

	Three months ended March 31,
(Dollars in thousands)	2017		2016
Stock-based compensation expense:
Stock options	$	221	$	151
Restricted stock awards	610		300
Employee stock purchase plan	15		16
Total	$	846	$	467
Tax benefit on nonqualified stock option expense, restricted stock awards and disqualifying dispositions of incentive stock options	$	507	$	151