EMPLOYEE BENEFIT PLANS

Retirement Plans

The Company has a 401(k) retirement plan that covers substantially all employees. The Company has also historically had a discretionary profit sharing and employee stock ownership plan (“ESOP”) covering substantially all employees. Effective December 31, 2016, the ESOP was merged into the Company’s 401(k) retirement plan. This merger allows participants to fully diversify their ESOP account balance and have reporting access to all retirement account balances in one place. Contribution expense to the plans totaled $10,769,000, $6,343,000 and $5,488,000 in 2018, 2017 and 2016, respectively.

The Company also provides deferred compensation agreements with certain active and retired officers. The agreements provide monthly payments of retirement compensation for either stated periods or for the life of the participant. The charges to income for the plans were $2,309,000 for 2018, $1,596,000 for 2017 and $1,056,000 for 2016. Such charges reflect the straight-line accrual over the employment period of the present value of benefits due each participant, as of their full eligibility date, using an appropriate discount factor.

Employee Stock Purchase Plan

The Company established an Employee Stock Purchase Plan in 2015 which generally allows participants to make contributions of up to $25,000 per year, for the purpose of acquiring the Company’s stock. At the end of each plan year, full shares of the Company’s stock are purchased for each employee based on that employee’s contributions. The Company has issued both general and special stock offerings under the plan. Substantially all employees are eligible for the general stock offering, under which full shares of the Company’s stock are purchased for an amount equal to 95% of their fair market value at the end of the plan year, or, if lower, 95% of their fair market value at the beginning of the plan year.

The special stock offering is available to substantially all non-highly compensated employees with at least six months of service, and these employees may allocate up to $10,000 to this offering. Under the special stock offering, full shares of the Company’s stock are purchased for an amount equal to 85% of their fair market value at the end of the plan year, or, if lower, 85% of their fair market value at the beginning of the plan year.

Stock-Based Compensation Plans

The Company’s Board of Directors has adopted various stock-based compensation plans. The plans provide for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock units and performance stock units. Pursuant to the plans, shares are reserved for future issuance by the Company upon exercise of stock options or awarding of bonus shares granted to directors, officers and other key employees.

Stock-based compensation expense for all stock-based compensation awards granted after January 1, 2006, is based on the grant date fair value. For all awards except stock option awards, the grant date fair value is the market value per share as of the grant date. For stock option awards, the fair value is estimated at the date of grant using the Black-Scholes option-pricing model. This model requires the input of highly subjective assumptions, changes to which can materially affect the fair value estimate. Additionally, there may be other factors that would otherwise have a significant effect on the value of employee stock options granted but are not considered by the model. Accordingly, while management believes that the Black-Scholes option-pricing model provides a reasonable estimate of fair value, the model does not necessarily provide the best single measure of fair value for the Company’s employee stock options.

The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model that uses various assumptions. Expected volatility is based on historical volatility of the Company’s stock and other factors. The Company uses historical data to estimate option exercise and employee termination within the valuation model. The expected term of options granted is derived from the output of the option valuation model and represents the period of time that options granted are expected to be outstanding. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. Forfeitures are estimated at the time of grant, and are based partially on historical experience.

Share and per share information regarding Stock-Based Compensation Plans has been adjusted to reflect the effects of the Company’s two-for-one stock split which became effective on February 8, 2018. The table below summarizes the transactions under the Company’s active stock compensation plans at December 31, 2018, 2017 and 2016, and changes during the years then ended:



	Stock Options Outstanding				Stock Awards Outstanding				Stock Units Outstanding
	Number of Shares (000)		Weighted Average Exercise Price		Number of Shares (000)		Weighted Average Exercise Price		Number of Shares (000)		Weighted Average Exercise Price

Balance, December 31, 2015	970		$	20.31	342		$	17.83	158		$	21.33
Granted	116		23.51		272		23.46		286		23.48
Stock options exercised	(127	)	15.14		—		—		—		—
Stock awards/units vested	—		—		(318	)	20.96		(25	)	22.77
Forfeited/expired	(13	)	17.53		(18	)	21.85		(13	)	23.04

Balance, December 31, 2016	946		21.43		278		20.48		406		22.70
Granted	—		—		—		—		906		28.86
Stock options exercised	(122	)	17.66		—		—		—		—
Stock awards/units vested	—		—		(91	)	19.40		(449	)	27.13
Forfeited/expired	(12	)	22.67		(25	)	21.91		(35	)	25.76

Balance, December 31, 2017	812		21.98		162		20.85		828		26.13
Granted	—		—		—		—		429		29.16
Stock options exercised	(112	)	19.22		—		—		—		—
Stock awards/units vested	—		—		(80	)	20.41		(311	)	25.56
Forfeited/expired	(5	)	21.73		(10	)	20.12		(129	)	27.95

Balance, December 31, 2018	695		$	22.42	72		$	21.45	817		$	27.65

Exercisable, December 31, 2018	662		$	22.37

The following table summarizes information about stock options under the plans outstanding at December 31, 2018:



					Options Outstanding			Options Exercisable
Range of Exercise Prices					Number of Shares (000)	Weighted Average Remaining Contractual Life (Years)	Weighted Average Exercise Price	Number of Shares (000)	Weighted Average Exercise Price
$	9.46	—	$	9.46	1	3.04	$9.46	1	$9.46
10.65		—	10.65		4	4.07	10.65	4	10.65
10.76		—	10.76		2	1.05	10.76	2	10.76
20.29		—	20.29		71	6.00	20.29	71	20.29
20.36		—	20.36		3	5.88	20.36	2	20.36
22.20		—	22.20		74	6.23	22.20	74	22.20
22.75		—	22.75		436	6.61	22.75	436	22.75
23.51		—	23.51		97	7.05	23.51	65	23.51
24.07		—	24.07		7	6.71	24.07	7	24.07

$	9.46	—	$	24.07	695	6.53	$22.42	662	$22.37

The table below summarizes the Company’s restricted performance stock unit activity for the years ended December 31, 2018, 2017 and 2016:



(In thousands)	Performance Stock Units
Non-vested, December 31, 2015	118
Granted	70
Vested (earned)	—
Forfeited	(7	)

Non-vested, December 31, 2016	181
Granted	57
Vested (earned)	(57	)
Forfeited	(4	)

Non-vested, December 31, 2017	177
Granted	72
Vested (earned)	(55	)
Forfeited	(17	)

Non-vested, December 31, 2018	177

Stock-based compensation expense was $11,227,000 in 2018, $11,763,000 in 2017 and $5,451,000 in 2016. Stock-based compensation expense is recognized ratably over the requisite service period for all stock-based awards. There was no unrecognized stock-based compensation expense related to stock options at December 31, 2018. Unrecognized stock-based compensation expense related to non-vested stock awards and stock units was $14,714,000 at December 31, 2018. At such date, the weighted-average period over which this unrecognized expense is expected to be recognized was 1.7 years.

The intrinsic value of stock options outstanding and stock options exercisable at December 31, 2018 was $1,187,000 and $1,165,000. Aggregate intrinsic value represents the difference between the Company’s closing stock price on the last trading day of the period, which was $24.13 at December 31, 2018, and the exercise price multiplied by the number of options outstanding. There were 111,728 stock options exercised in 2018 with an intrinsic value of $561,000. There were 122,012 stock options exercised in 2017 with an intrinsic value of $1,329,000. There were 127,424 stock options exercised in 2016 with an intrinsic value of $2,031,000.

The fair value of the Company’s employee stock options granted is estimated on the date of grant using the Black-Scholes option-pricing model. This model requires the input of highly subjective assumptions, changes to which can materially affect the fair value estimate. There were no stock options granted during the years ended December 31, 2018 and 2017. The weighted-average fair value of stock options granted during the year ended December 31, 2016 was $5.82 per share. The Company estimated expected market price volatility and expected term of the options based on historical data and other factors. The weighted-average assumptions used to determine the fair value of options granted for the years ended December 31, 2016 is detailed in the table below:



	2016
Expected dividend yield	1.96	%
Expected stock price volatility	27.34	%
Risk-free interest rate	2.01	%
Expected life of options (in years)	7