11. EQUITY

Common Stock

The Company has paid quarterly dividends on its common stock since January 1999.

Treasury Stock

In September 2004, our Board of Directors approved a $5.0 million stock buyback plan (the “2004 Repurchase Plan”). Through September 19, 2016, the Company repurchased $4.1 million of our common stock, under the 2004 Repurchase Plan.

On September 19, 2016, the Company’s Board of Directors authorized the repurchase of up to $50.0 million of our common stock, from time to time, on the open market or in privately negotiated transactions (the “2016 Repurchase Plan”). The 2016 Repurchase Plan replaces the 2004 Repurchase Plan. As of December 31, 2017, the Company has $39.3 million available to be repurchased under the 2016 Repurchase Plan.

During the years ended December 31, 2017, 2016 and 2015, the Company repurchased the following shares under the 2004 Repurchase Plan and the 2016 Repurchase Plan


		Aggregate
	Shares	Cost		Average
Year ended December 31,	Repurchased	(in thousands)		Repurchase Price
2017	201,932	$	10,636	$	52.67
2016	32,407		2,195		64.72
2015	—		—		—

During the years ended December 31, 2017, 2016 and 2015, the Company repurchased the following shares from employees to satisfy tax withholding and stock options exercise obligations incurred in connection with the vesting of restricted stock awards and the exercise of stock options:


		Aggregate
	Shares	Cost		Average
Year ended December 31,	Repurchased	(in thousands)		Repurchase Price
2017	32,814	$	2,348	$	71.54
2016	38,279		2,775		72.50
2015	37,567		2,705		72.01

Stock‑Based Compensation

The Company has 2,000,000 shares reserved for the grant of stock options, restricted stock, restricted stock units, stock equivalents and awards of shares of common stock that are not subject to restrictions or forfeiture.

Stock Options

Stock options have a term of ten years and vest annually and ratably over a period of four years.

The following table summarizes stock option activity for the years ended December 31, 2017 and 2016:


	Year Ended December 31, 2017
				Weighted Average
		Weighted Avg.		Remaining
	Number of	Exercise		Contractual	Aggregate
	Options	Price		Term (Years)	Intrinsic Value
Outstanding at January 1, 2017	225,822	$	39.77
Granted	10,000		52.97
Exercised	(35,801)		32.29
Outstanding at December 31, 2017	200,021		41.76	3.6	$	2,780,253
Vested and expected to vest at December 31, 2017	200,021		41.76	3.6	$	2,780,253
Exercisable at December 31, 2017	187,521		40.77	3.6	$	2,757,353


	Year Ended December 31, 2016
				Weighted Average
				Remaining
	Number of	Weighted Avg.		Contractual	Aggregate
	Options	Exercise Price		Term (Years)	Intrinsic Value
Outstanding at January 1, 2016	268,875	$	38.64
Granted	—		—
Exercised	(43,053)		32.70
Outstanding at December 31, 2016	225,822		39.77	3.9	$	9,114,963
Vested and expected to vest at December 31, 2016	225,554		39.73	3.9	$	9,112,630
Exercisable at December 31, 2016	222,072		39.23	3.8	$	9,082,338

The unvested options as of December 31, 2017 represent $0.2 million in unamortized stock‑based compensation which will be recognized over a weighted average term of 3.0 years.

The following table summarizes information relating to options granted and exercised during the years ended December 31, 2017, 2016 and 2015 (in thousands, except fair value of options granted data):


	2017		2016		2015
Weighted-average fair value of options granted	$	13.77	$	—	$	30.70
Aggregate intrinsic value of options exercised		936		1,591		3,488
Cash proceeds received upon exercise of options		1,030		649		1,998
Excess tax benefits from share-based compensation		—		591		1,423

The aggregate intrinsic value represents the total pre‑tax intrinsic value (the difference between our closing common stock price on December 31st and the exercise price, multiplied by the number of the in‑the‑money stock options) that would have been received by the stock option holders had all stock options holders exercised their stock options on December 31st. The amount of aggregate intrinsic value will change based on the fair market value of the Company’s common stock.

The estimated fair value of the options granted during the years ended December 31, 2017 and 2015 were determined using a Black Scholes option pricing model, based on the following weighted average assumptions:


	2017		2016	2015

Risk-free interest rate	1.79	%	—	1.55	%
Expected dividend yield	1.28	%	—	1.76	%
Expected life	4.00	years	—	6.25	years
Expected volatility	34.01	%	—	51.85	%

The Company did not grant any options during the year ended December 31, 2016. The Company recognized $0.1 million, $0.1 million and $0.4 million, respectively, of stock compensation expense relating to the granted options during 2017, 2016, and 2015, respectively.

Restricted Stock

Restricted stock issued under the 2008 Equity Investment Plan vest ratably over four years.

The following table summarizes restricted stock activity during the year ended December 31, 2017:


		Weighted Avg.
	Shares	Fair Value
Unvested as of January 1, 2017	229,040	$	67.13
Granted	95,095		68.09
Forfeited	(12,074)		69.71
Vested and issued	(97,123)		64.01
Unvested as of December 31, 2017	214,938	$	68.62

The following table summarizes restricted stock activity during the year ended December 31, 2016:


		Weighted Avg.
	Shares	Fair Value
Unvested as of January 1, 2016	218,401	$	60.60
Granted	100,005		73.34
Forfeited	(1,125)		66.44
Vested and issued	(88,241)		58.01
Unvested as of December 31, 2016	229,040	$	67.13

In connection with the grant of restricted shares, the Company recognized $6.6 million, $6.2 million and $4.3 million of compensation expense within its income statements for the years ended December 31, 2017, 2016, and 2015, respectively. In addition, the Company recognized $0.3 million, $0.1 million, and $0.3 million of compensation expense within its income statement for the year ended December 31, 2017, 2016 and 2015, respectively, for shares of the Company’s subsidiaries granted to the management team of those subsidiaries.

The unvested shares as of December 31, 2017 represent $10.2 million in unamortized stock based compensation which will be recognized over a weighted average period of 2.4 years.