16. SHARE-BASED COMPENSATION

In accordance with ASC 718, compensation expense is recognized only for those shares expected to vest, based on the Company's historical experience and future expectations. The following table summarizes the effects of share-based compensation to options and awards granted under the Company's equity incentive plans for each of the periods presented:



	Year Ended December 31,
	2016			2015			2014
	(Dollars in thousands)
Salaries and employee benefits	$	3,094		$	4,181		$	6,101
Directors stock awards	97			78			37
Income tax benefit	(1,269		)	(1,694		)	(2,443		)
Net share-based compensation effect	$	1,922		$	2,565		$	3,695

The Company's share-based compensation arrangements are described below:

Equity Incentive Plans

We have adopted equity incentive plans for the purpose of granting options, restricted stock and other equity based awards for the Company's common stock to directors, officers and other key individuals. Option awards are generally granted with an exercise price equal to the market price of the Company's common stock at the date of grant; those option awards generally vest based on three or five years of continuous service and have 10-year contractual terms. Certain option and share awards provide for accelerated vesting if there is a change in control (as defined in the stock option plans below). We have historically issued new shares of common stock upon exercises of stock options and purchases of restricted awards.

In September 2004, we adopted and our shareholders approved the 2004 Stock Compensation Plan ("2004 Plan") making available 1,500,000 shares for grants to employees and directors. Upon adoption of the 2004 Plan, all unissued shares from the previous 1997 Plan were frozen and no new options were granted under the 1997 Plan. In May 2007, the 2004 Plan was amended to increase the number of shares available for grant by an additional 1,000,000 shares. In April 2011, the 2004 Plan was amended to increase the number of shares authorized from 1,402,589 to 4,944,831.

In April 2013, we adopted and our shareholders approved the 2013 Stock Compensation Plan ("2013 Plan") making available 2,200,000 shares for grants to employees and directors. Upon adoption of the 2013 Plan, all unissued shares from the 2004 Plan were frozen and no new grants will be granted under the 2004 Plan. Shares may continue to be settled under the 2004 Plan pursuant to previously outstanding awards. New shares are issued from the 2013 Plan.

At December 31, 2016, 2015 and 2014, a total of 1,671,752, 1,922,130 and 1,993,385 shares, respectively, were available for future grants under our 2013 Plan.

Stock Options

The fair value of each option award is estimated on the date of grant based on the following:

Valuation and amortization method—We estimate the fair value of stock options granted using the Black-Scholes option pricing formula and a single option award approach. We use historical data to estimate option exercise and employee termination activity within the valuation model; separate groups of employees that have similar historical exercise behavior are considered separately for valuation purposes. This fair value is then amortized on a straight-line basis over the requisite service periods of the awards, which is generally the vesting period.

Expected life—The expected life of options represents the period of time that options granted are expected to be outstanding.

Expected volatility—Expected volatilities are based on the historical volatility of the Company's common stock.

Risk-free interest rate—The risk-free interest rate for periods within the contractual life of the option is based on the Treasury yield curve in effect at the time of grant.

Expected dividend—The expected dividend assumption is based on our current expectations about our anticipated dividend policy.

The following is a summary of option activity for our stock option plans for the year ended December 31, 2016:



	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2016	239,417		$	22.01
Changes during the year:
Exercised	(65,472	)	14.36
Expired	—		—
Forfeited	(11,882	)	24.21
Outstanding at December 31, 2016	162,063		24.95		5.2	$	2,657

Exercisable at December 31, 2016	134,331		27.14		5.1	2,183

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying option awards and the quoted price of the Company's common stock for the options that were in-the-money at December 31, 2016. During the years ended December 31, 2016, 2015 and 2014, the aggregate intrinsic value of options exercised under our stock option plan was $0.8 million, $0.2 million and $31 thousand, respectively, determined as of the date of exercise.

As of December 31, 2016, the total compensation cost that was not yet recognized related to stock options granted to employees under our stock option plans was approximately $0.1 million, net of estimated forfeitures. This cost will be amortized on a straight-line basis over a weighted-average period of 0.3 years and will be adjusted for subsequent changes in estimated forfeitures. The total fair value of shares vested during the years ended December 31, 2016, 2015 and 2014 was $0.4 million, $0.4 million and $0.7 million, respectively.

No stock options were granted during 2016, 2015 and 2014.

Restricted Stock Awards and Units

Under the 1997, 2004 and 2013 Plans, we awarded restricted stock awards and units to our non-officer directors and certain senior management personnel. The awards typically vest over a three or five year period. Compensation expense is measured as the market price of the stock awards on the grant date, and is recognized over the specified vesting periods.

The table below presents the activity of restricted stock awards and units for the year ended December 31, 2016:



	Shares		Weighted Average Grant Date Fair Value
Unvested at January 1, 2016	463,917		$	17.41
Changes during the year:
Granted	296,078		23.65
Forfeited	(66,972	)	20.97
Vested	(255,326	)	15.83
Unvested at December 31, 2016	437,697		22.01

As of December 31, 2016, there was $7.0 million of total unrecognized compensation cost related to restricted stock awards and units that is expected to be recognized over a weighted-average period of 2.8 years.