Stockholders' Equity and Stock-Based Compensation (Tables)

12 Months Ended

Dec. 26, 2015

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share repurchases

Shares repurchased and retired for the indicated periods of the applicable repurchase programs with the associated cost of repurchase and amount available for repurchase at the end of the respective periods are as follows (in thousands, except number of shares and weighted average price per share):

	Fiscal Year 2015		Fiscal Year 2014		Fiscal Year 2013
Number of shares of common stock repurchased		111,050		362,633		332,771
Weighted average price per share	$	15.49	$	14.74	$	15.03
Total cost of repurchase	$	1,721	$	5,344	$	5,000
Amount available for repurchase at end of period	$	4,397	$	6,118	$	11,462

Option plans

The Nanometrics option plans are as follows:

Plan Name	Participants	Shares Authorized
2005 Equity Incentive Plan	Employees, consultants and directors		7,292,594
2002 Non-statutory Stock Option Plan	Employees and consultants		1,200,000
2000 Employee Stock Option Plan	Employees and consultants		2,450,000
2000 Director Stock Option Plan	Non-employee directors		250,000
Accent Optical Technologies, Inc. Stock Incentive Plan	Employees and consultants		205,003

Stock options and employee stock purchase plan assumptions

The weighted-average fair value calculations are based on the following average assumptions:

	Fiscal Year 2015			Fiscal Year 2014			Fiscal Year 2013
Stock Options:
Expected life		—		4.6 years			4.5 years
Volatility		—			54.9	%		69.9	%
Risk free interest rate		—			1.54	%		1.05	%
Dividends		—			—			—
Employee Stock Purchase Plan:
Expected life	0.5 years			0.5 years			0.5 years
Volatility		36.9	%		31.2	%		26.8	%
Risk free interest rate		0.12	%		0.54	%		0.11	%
Dividends		—			—			—

Stock option plans activity

A summary of activity of stock options in 2015 is as follows:

	Number of Shares Outstanding (Options)			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in Thousands)
Options
Outstanding at December 27, 2014		1,382,993		$	13.92		3.41	$	4,108
Exercised		(229,510	)	$	9.65
Granted		—		$	—		-	$	—
Cancelled		(94,012	)	$	16.67
Outstanding at December 26, 2015		1,059,471		$	14.61		2.47	$	1,920
Exercisable at December 26, 2015		926,415		$	14.36		2.15	$	1,879

Ranges of outstanding and exercisable options

The following table summarizes ranges of outstanding and exercisable options as of December 26, 2015.

	Options Outstanding						Options Exercisable
Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Number Exercisable		Weighted Average Exercise Price
$2.38-$10.46		134,762		0.90	$	7.84		134,762	$	7.8400
$10.83-$11.17		14,156		1.30	$	10.93		14,156	$	1.9279
$11.37-$11.37		114,166		1.89	$	11.37		114,166	$	11.3700
$12.98-$14.8		111,259		2.62	$	13.67		94,579	$	13.6200
$14.88-$15.65		111,967		3.84	$	15.44		78,894	$	15.4300
$15.74-$15.98		161,850		1.81	$	15.91		143,100	$	15.9200
$16.00-$16.50		41,804		4.76	$	16.43		23,190	$	16.4200
$16.70-$16.7		186,434		1.86	$	16.70		186,434	$	16.7000
$16.89-$18.51		123,773		4.22	$	17.82		80,931	$	17.8300
$18.79-$19.84		59,300		2.98	$	19.12		56,203	$	19.1300
$2.38-$19.84		1,059,471		2.47	$	14.61		926,415	$	14.3600

Summary of activity for RSUs

A summary of activity for RSUs is as follows:

Summary of activity for RSUs	Number of RSUs			Weighted Average Fair Value
Outstanding RSUs as of December 27, 2014		563,337		$	17.90
Granted		506,459		$	15.62
Released		(237,520	)	$	16.59
Cancelled		(119,033	)	$	16.59
Outstanding RSUs as of December 26, 2015		713,243		$	15.99

PSUs valuation assumptions

The assumptions for the valuation of PSUs are summarized as follows:

	2015 Award
Number of PSUs granted and outstanding as of December 26, 2015		40,000
Grant Date Fair Value Per Share	$	18.35
Weighted-average assumptions/inputs:
Expected Divident		—
Range of risk-free interest rates	0.25%-1.1%
Range of expected volatilities for peer group	23%-65%

Stock-based compensation expense for all share-based payment awards

Stock-based compensation expense for all share-based payment awards made to the Company’s employees and directors pursuant to the employee stock option and employee stock purchase plans by function were as follows (in thousands):

	Fiscal Year 2015		Fiscal Year 2014		Fiscal Year 2013
Cost of products	$	274	$	268	$	207
Cost of service		309		287		278
Research and development		1,036		1,245		1,478
Selling		1,881		1,642		1,894
General and administrative		2,748		3,243		2,919
Restructuring		—		67		898
Total stock-based compensation expense related to employee    stock options and employee stock purchases	$	6,248	$	6,752	$	7,674

Stock Options and Restricted Stock Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock option plans activity including options and RSUs

A summary of activity under the Company’s stock option plans including options and RSUs during fiscal year 2015, 2014 and 2013 and shares available for grant as of the respective period end dates, is as follows:

	Fiscal Year 2015			Fiscal Year 2014			Fiscal Year 2013
Shares available for grant at beginning of fiscal year		2,464,082			2,937,001			1,093,565
Increase in authorized shares		—			—			2,600,000
Options - granted		—			(74,300	)		(430,800	)
Options - cancelled		94,012			191,061			150,459
Options - expired plan shares		(1,800	)		(17,491	)		(53,607	)
RSUs – granted		(860,980	)		(805,120	)		(664,902	)
RSUs – cancelled		202,356			167,404			133,418
RSUs - shares issued to satisfy tax    withholding obligations		120,919			65,527			108,868
PSUs – granted		(68,000	)		—			—
Shares available for grant at end of fiscal year		1,950,589			2,464,082			2,937,001