Employee Benefit and Stock Incentive Plans - RSU Activities (Details) - Restricted stock units	12 Months Ended
	Dec. 30, 2018 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning balance (in shares) | shares	63,200
Granted (in shares) | shares	43,800
Vested (in shares) | shares	(16,900)
Expired or forfeited (in shares) | shares	(4,200)
Outstanding, ending balance (in shares) | shares	85,900
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 37.45
Granted (in dollars per share) | $ / shares	76.57
Vested (in dollars per share) | $ / shares	36.74
Expired or forfeited (in dollars per share) | $ / shares	54.15
Outstanding, ending balance (in dollars per share) | $ / shares	$ 56.74