Common Stock and Stock-Based Compensation (Tables)

3 Months Ended

Mar. 27, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Options under Employee Equity Incentive Plan and Stock Option Plan for Non-Employee Directors

Information related to stock options under the Restated Employee Equity Incentive Plan and the Stock Option Plan for Non-Employee Directors is summarized as follows:

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term in Years		Aggregate Intrinsic Value (in thousands)
Outstanding at December 26, 2020		241,847		$	228.58
Granted		18,998			1,028.71
Forfeited		-			-
Expired		-			-
Exercised		(31,020	)		195.05
Outstanding at March 27, 2021		229,825		$	229.25		3.30	$	120,540
Exercisable at March 27, 2021		81,710		$	214.22		3.30	$	197,820
Vested and expected to vest at March 27, 2021		210,570		$	294.96		3.30	$	182,149

Weighted Average Assumptions used to Estimate Fair Value of Stock Options

Weighted average assumptions used to estimate fair values of stock options on the date of grants are as follows:

	2021
Expected Volatility		36.1	%
Risk-free interest rate		1.4	%
Expected Dividends		0.0	%
Exercise factor	2.5 times
Discount for post-vesting restrictions		0.0	%

Summary of Vesting Activities of Shares Issued Under Investment Share Program and Restricted Stock Awards

The following table summarizes vesting activities of shares issued under the investment share program and restricted stock awards:

	Number of Shares			Weighted Average Fair Value
Non-vested at December 26, 2020		114,316		$	263.47
Granted		17,632			880.81
Vested		(22,885	)		221.81
Forfeited		(196	)		150.24
Non-vested at March 27, 2021		108,867		$	373.08

Stock-Based Compensation Expense Included in Operating Expenses

The following table provides information regarding stock-based compensation expense included in operating expenses in the accompanying consolidated statements of comprehensive income:

	Thirteen weeks ended
	March 27, 2021		March 28, 2020
	(in thousands)
Amounts included in advertising, promotional and selling expenses	$	1,672	$	705
Amounts included in general and administrative expenses		3,285		1,861
Total stock-based compensation expense	$	4,957	$	2,566