Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The components and classification of stock-based compensation expense were as follows (in thousands):

	Three Months Ended				Six Months Ended
	June 30, 2017		July 1, 2016		June 30, 2017		July 1, 2016
Stock options	$	283	$	585	$	993	$	1,194
Restricted stock and restricted stock units	2,998		1,542		6,957		3,768
Total stock-based compensation expense	$	3,281	$	2,127	$	7,950	$	4,962
Cost of sales	$	339	$	150	$	481	$	347
Selling, general and administrative expenses	2,733		1,528		4,892		3,183
Research, development and engineering costs, net	179		116		284		293
Other operating expenses, net	30		333		2,293		1,139
Total stock-based compensation expense	$	3,281	$	2,127	$	7,950	$	4,962

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

The weighted average fair value and assumptions used to value options granted are as follows:

	Six Months Ended
	June 30, 2017			July 1, 2016
Weighted average fair value	$	10.58		$	9.41
Risk-free interest rate	1.69		%	1.58		%
Expected volatility	37		%	26		%
Expected life (in years)	4.1			5.0
Expected dividend yield	—		%	—		%

Schedule of Share-based Compensation, Stock Options Activity

The following table summarizes the Company’s stock option activity:

	Number of Stock Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (In Years)	Aggregate Intrinsic Value (In Millions)
Outstanding at December 30, 2016	1,739,972		$	28.26
Granted	57,407		32.99
Exercised	(406,588	)	21.46
Forfeited or expired	(33,958	)	45.95
Outstanding at June 30, 2017	1,356,833		$	30.05	6.4	$	19.5
Exercisable at June 30, 2017	1,162,235		$	29.28	5.8	$	17.4

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

The following table summarizes time-vested restricted stock and RSU activity:

	Time-Vested Activity		Weighted Average Fair Value
Nonvested at December 30, 2016	39,394		$	45.51
Granted	264,111		32.45
Vested	(49,263	)	32.14
Forfeited	(11,658	)	38.19
Nonvested at June 30, 2017	242,584		$	34.34

The following table summarizes PSU activity:

	Performance- Vested Activity		Weighted Average Fair Value
Nonvested at December 30, 2016	356,586		$	31.87
Granted	378,219		30.74
Forfeited	(284,183	)	30.75
Nonvested at June 30, 2017	450,622		$	31.63