Stockholders' Equity and Stock Plans (Tables)

12 Months Ended

Dec. 31, 2019

Schedule of Share-based Compensation, Stock Options, Activity

A summary of stock option activity for the years ended December 31, 2019 and 2018 is presented in the following table. The intrinsic value of options outstanding and exercisable is calculated as the number of in-the-money options times the difference between the market price of our stock and the exercise prices of the in-the-money options as of each year-end period presented.



	Number of Shares		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)		Weighted Average Grant-Date Fair Value		Weighted Average Remaining Contractual Term (in years)
Options outstanding at December 31, 2017	517,936		$	20.42	$	7,075			5.34
Granted	74,096		33.97				$	7.17
Cancelled, expired or forfeited	(9,140	)	28.25
Exercised	(157,192	)	13.93		3,462
Options outstanding at December 31, 2018	425,700		25.01		6,910				5.85
Exercisable (vested) at December 31, 2018	311,050		22.57		5,809				4.94
Options outstanding at December 31, 2018	425,700		25.01		6,910				5.85
Granted	53,370		44.01				9.37
Cancelled, expired or forfeited	(13,580	)	38.88
Exercised	(48,108	)	16.11		1,247
Options outstanding at December 31, 2019	417,382		28.01		7,112				5.50
Exercisable (vested) at December 31, 2019	333,870		25.34		6,581				4.76

Schedule of Unrecognized Compensation Cost, Nonvested Awards

The following table summarizes non-vested restricted stock awards and changes during the years ended December 31, 2019 and 2018.



	Number of Shares		Weighted Average Grant-Date Fair Value
Non-vested awards at December 31, 2017	91,216		$	28.16
Granted	37,040		33.58
Vested	(28,812	)	26.06
Cancelled or forfeited	(12,056	)	27.32
Non-vested awards at December 31, 2018	87,388		31.26
Granted	29,110		44.45
Vested	(28,099	)	27.88
Cancelled or forfeited	(18,333	)	32.34
Non-vested awards at December 31, 2019	70,066		37.81

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range

A summary of the options outstanding and exercisable by price range as of December 31, 2019 is presented in the following table:



	Stock Options Outstanding as of December 31, 2019			Stock Options Exercisable as of December 31, 2019
Range of Exercise Prices	Stock Options Outstanding	Remaining Contractual Life (in years)	Weighted Average Exercise Price	Stock Options Exercisable	Weighted Average Exercise Price
$10.01 - $20.00	84,618	1.8	18.63	84,618	18.63
$20.01 - $30.00	166,454	4.8	23.88	166,454	23.88
$30.01 - $40.00	114,976	7.7	33.89	69,384	33.88
$40.01 - $50.00	51,334	8.9	43.71	13,414	41.61
	417,382			333,870

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

We determine the fair value of stock options at the grant date using the Black-Scholes pricing model that takes into account the stock price at the grant date, exercise price, and the following assumptions (weighted-average shown).



	Years ended December 31,
	2019		2018
Risk-free interest rate	2.51	%	2.60	%
Expected dividend yield on common stock	1.75	%	1.76	%
Expected life in years	5.8		5.9
Expected price volatility	22.71	%	22.47	%

Summary of Cash Dividends Paid to Common Shareholders

Presented below is a summary of cash dividends paid in 2019 and 2018 to common shareholders, recorded as a reduction from retained earnings. On January 24, 2020, the Board of Directors declared a $0.22 per share cash dividend, paid February 14, 2020 to the shareholders of record at the close of business on February 7, 2020.



	Years ended December 31,
(in thousands except per share data)	2019		2018
Cash dividends to common stockholders	$	10,958	$	8,860
Cash dividends per common share	$	0.80	$	0.64