Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

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

Summary of activity for Corporation's stock options

A summary of activity for the Corporation’s stock options as of and for the three months ended March 31, 2015 is presented below:

	Non-Vested Stock Options Outstanding						Stock Options Outstanding
	Number of Options		Weighted- Average Exercise Price Per Share		Weighted- Average Grant Date Fair Value Per Share		Number of Options		Weighted- Average Exercise Price Per Share
Outstanding at December 31, 2014	432,199		$	26.75	$	8.30	1,037,311		$	25.90
Granted	244,165		30.18		8.40		244,165		30.18
Exercised	—		—		—		(37,191	)	23.11
Vested	(150,224	)	25.57		7.80		—		—
Forfeited/expired	(3,049	)	27.42		8.59		(3,049	)	27.42
Outstanding at March 31, 2015	523,091		$	28.69	$	8.49	1,241,236		$	26.82
Exercisable/vested at March 31, 2015							718,145		$	25.46

Assumptions of Black-Scholes option pricing model

The fair value of the stock options granted during the three months ended March 31, 2015 was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions.

Expected dividend yield	3.50		%
Risk-free interest rate	1.78		%
Expected stock price volatility	39.1		%
Expected life of options – in years	7.0
Weighted average fair value of options granted	$	8.40

Summary of activity for restricted stock performance units

A summary of the activity for restricted stock units as of and for the three months ended March 31, 2015 is presented below:

	Number of Units		Weighted- Average Grant Date Fair Value  Per Unit
Outstanding at December 31, 2014	204,319		$	24.14
Granted	76,286		28.15
Converted into shares of common stock	(66,769	)	22.32
Forfeited/expired	(405	)	25.17
Outstanding at March 31, 2015	213,431		$	26.14