Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2016

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, 2016 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, 2015	479,755		$	28.75	$	8.49	1,054,739		$	25.38
Granted	441,167		32.81		6.15		441,167		32.81
Exercised	—		—		—		(70,885	)	20.69
Vested	(118,273	)	28.30		8.40		—		—
Forfeited/expired	(8,783	)	32.21		6.66		(8,783	)	32.21
Outstanding at March 31, 2016	793,866		$	31.03	$	7.22	1,416,238		$	27.89
Exercisable/vested at March 31, 2016							622,372		$	23.88

Assumptions of Black-Scholes option pricing model

The fair value of the stock options granted during the three months ended March 31, 2016 was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions.

Expected dividend yield	3.30		%
Risk-free interest rate	1.39		%
Expected stock price volatility	27.9		%
Expected life of options – in years	6.5
Weighted average fair value of options granted	$	6.15

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, 2016 is presented below:

	Number of Units		Weighted- Average Grant Date Fair Value  Per Unit
Outstanding at December 31, 2015	207,989		$	26.41
Granted	98,425		30.40
Converted into shares of common stock	(42,812	)	22.47
Forfeited/expired	(1,116	)	30.29
Outstanding at March 31, 2016	262,486		$	28.53