-Based Compensation

At December 31, 2017, we had four stock-based compensation plans: the Non-Employee Directors' Stock Retirement Plan ("Directors' Plan"), the 2004 Omnibus Long-Term Incentive Plan ("2004 Plan"), the 2009 Omnibus Equity and Performance Incentive Plan ("2009 Plan"), and the 2014 Performance & Incentive Plan ("2014 Plan"). Future grants can only be made under the 2014 Plan.

The 2009 Plan, and previously the 2004 Plan, provided for grants of incentive stock options or nonqualified stock options to officers, key employees, and non-employee members of the Board of Directors. In addition, the 2014 Plan, the 2009 Plan, and the 2004 Plan allow for grants of stock appreciation rights, restricted stock, restricted stock units ("RSUs"), performance shares, performance-based restricted stock units, and other stock awards.

The following table summarizes the compensation expense included in selling, general and administrative expenses in the Consolidated Statements of Earnings related to stock-based compensation plans:



	Years Ended December 31,
	2017		2016		2015
Service-Based RSUs	$	1,762	$	1,997	$	1,944
Performance-Based RSUs	2,350		665		1,235
Cash-settled awards	72		76		16
Total	$	4,184	$	2,738	$	3,195
Income tax benefit	1,573		1,029		1,201
Net	$	2,611	$	1,709	$	1,994

The fair value of all equity awards that vested during the periods ended December 31, 2017, 2016, and 2015 were $5,471, $4,959, and $2,803, respectively. We recorded a tax deduction related to equity awards that vested during the year ended December 31, 2017, in the amount of $1,927.

The following table summarizes the unrecognized compensation expense related to non-vested RSUs by type and the weighted-average period in which the expense is to be recognized:



	Unrecognized compensation expense at December 31, 2017		Weighted- average period
Service-Based RSUs	$	1,079	1.11 years
Performance-Based RSUs	2,313		1.62 years
Total	$	3,392	1.46 years

We recognize expense on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards.

The following table summarizes the status of these plans as of December 31, 2017:



	2014 Plan	2009 Plan	2004 Plan	Directors' Plan
Awards originally available to be granted	1,500,000	3,400,000	6,500,000	N/A

Performance stock options outstanding	295,000	—	—	—
Maximum potential RSU and cash settled awards outstanding	725,759	122,600	57,391	9,620
Maximum potential awards outstanding	1,020,759	122,600	57,391	9,620
RSUs and cash settled awards vested and released	176,221	—	—	—
Awards available to be granted	303,020	—	—	—

Stock Options

Stock options are exercisable in cumulative annual installments over a maximum 10-year period, commencing at least one year from the date of grant. Stock options are generally granted with an exercise price equal to the market price of our stock on the date of grant. The stock options generally vest over four years and have a 10-year contractual life. The awards generally contain provisions to either accelerate vesting or allow vesting to continue on schedule upon retirement if certain service and age requirements are met. The awards also provide for accelerated vesting if there is a change in control event.

We estimate the fair value of the stock option on the grant date using the Black-Scholes option-pricing model and assumptions for expected price volatility, option term, risk-free interest rate, and dividend yield. Expected price volatilities are based on historical volatilities of our common stock. The expected option term was derived from historical data of exercise behavior. The dividend yield was based on historical dividend payments. The risk-free rate for periods within the contractual life of the option was based on the U.S. Treasury yield curve in effect at the time of grant.

There were no outstanding stock options at December 31, 2017, or 2016 other than the performance-based stock options described below.

Performance-Based Stock Options

During 2015 and 2016, the Compensation committee of the Board of Directors (the "Committee") granted a total of 295,000 performance-based stock options (including forfeitures). The Performance-Based Option Awards have an exercise price of $18.37, a term of five years and generally will become exercisable (provided the optionee remains employed by the Company or an affiliate) upon our attainment of at least $600,000 in revenues during any of our four-fiscal-quarter trailing periods (as determined by the Committee) during the term. We have not recognized any expense on these Performance-Based Option Awards for the years ended December 31, 2017 and 2016, since the revenue target is not deemed likely to be attained based on our current forecast.

Service-Based Restricted Stock Units

Service-based RSUs entitle the holder to receive one share of common stock for each unit when the unit vests. RSUs are issued to officers, key employees and non-employee directors as compensation. Generally, the RSUs vest over a three-year period. RSUs granted to non-employee directors have historically vested one month after being granted, except beginning in 2016 they vest one year after being granted. Upon vesting, the non-employee directors elect to either receive the stock associated with the RSU immediately, or defer receipt of the stock to a future date. The fair value of the RSUs is equivalent to the trading value of our common stock on the grant date.

A summary of RSUs for all Plans is presented below:



	Units		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding at January 1, 2017	554,478		$	13.37
Granted	57,740		24.32
Released	(201,918	)	13.85
Forfeited	(10,953	)	17.11
Outstanding at December 31, 2017	399,347		$	14.60	24.58	$	10,283
Releasable at December 31, 2017	259,811		$	12.48	33.88	$	6,690



	Years Ended December 31,
	2017		2016		2015
Weighted-average grant date fair value	$	24.32	$	15.07	$	17.31
Intrinsic value of RSUs released	$	4,485	$	1,520	$	2,933

A summary of nonvested RSUs is presented below:



	RSUs		Weighted Average Grant Date Fair Value
Nonvested at January 1, 2017	251,245		$	15.81
Granted	57,740		$	24.32
Vested	(158,496	)	$	16.40
Forfeited	(10,953	)	$	17.11
Nonvested at December 31, 2017	139,536		$	18.56

Performance-Based Restricted Stock Units

We grant performance-based restricted stock unit awards ("PSUs") to certain executives and key employees. Units are usually awarded in the range from zero percent to 200% of a targeted number of shares. The award rate for the 2015-2017, 2016-2018, and 2017-2019 PSUs is dependent upon our achievement of sales growth targets, cash flow targets, and relative total shareholder return ("RTSR") using a matrix based on the percentile ranking of our stock price performance compared to a peer group over a three-year period. These awards are weighted 35% for achievement of the sales growth metric, 30% for achievement of the cash flow metric, and 35% for achievement of the RTSR metric. Other PSUs are granted from time to time based on other performance criteria.

A summary of PSUs for all Plans is presented below:



	Units		Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding at January 1, 2016	201,900		$	16.48
Granted	123,919		$	23.83
Released	(43,275	)	$	21.66
Forfeited	(26,524	)	$	22.56
Added by performance factor	15,285		$	21.66
Outstanding at December 31, 2017	271,305		$	18.77	1.62	$	6,986
Releasable at December 31, 2017	—		$	—	—	$	—

The following table summarizes each grant of performance awards outstanding at December 31, 2017:



Description	Grant Date	Vesting Year	Vesting Dependency	Target Units Outstanding	Maximum Number of Units to be Granted
2015-2017 Performance RSUs	February 5, 2015	2018	35% RTSR, 35% sales growth, 30% cash flow	62,000	124,000
2016-2018 Performance RSUs	February 16, 2016	2019	35% RTSR, 35% sales growth, 30% cash flow	92,840	185,680
2017-2019 Performance RSUs	February 9, 2017	2020	35% RTSR, 35% sales growth, 30% cash flow	71,796	143,592
2017-2019 Performance RSUs	February 9, 2017	2018- 2020	Operating Income	40,669	40,669
Single Crystal Performance RSUs	March 31, 2016	2019	Various	4,000	8,000
Total				271,305	501,941

Cash-Settled Restricted Stock Units

Cash-Settled RSUs entitle the holder to receive the cash equivalent of one share of common stock for each unit when the unit vests. These RSUs are issued to key employees residing in foreign locations as direct compensation. Generally, these RSUs vest over a three-year period. Cash-settled RSUs are classified as liabilities and are remeasured at each reporting date until settled. At December 31, 2017, and 2016, we had 14,082 and 12,074 cash-settled RSUs outstanding, respectively. At December 31, 2017, and 2016, liabilities of $241 and $170, respectively were included in Accrued expenses and other liabilities on our Consolidated Balance Sheets.