Share-Based Compensation - Restricted Shares and Other (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Jan. 01, 2022 USD ($) installment $ / shares shares	Jan. 02, 2021 USD ($) $ / shares shares	Dec. 28, 2019 USD ($) shares
2006 Incentive Plan
Additional disclosures
Shares available for grant	339,796
Options
Additional disclosures
Fair value of options vested | $	$ 0.2	$ 0.2	$ 0.7
Unrecognized compensation cost, net of expected forfeitures | $	$ 0.1
Weighted-average period over which cost is expected to be recognized	10 months 24 days
Restricted stock
Additional disclosures
Number of vesting installments | installment	4
Unrecognized compensation cost, net of expected forfeitures | $	$ 1.3
Weighted-average period over which cost is expected to be recognized	3 years
Forfeiture rate (as a percent)	0.90%
Restricted Stock and Stock Units, Number of Shares
Fair value of restricted shares vested | $	$ 0.5	$ 0.5	0.5
Restricted stock | 2006 Incentive Plan
Restricted Stock and Stock Units, Number of Shares
Balance at the beginning of the period (in shares)	33,540
Granted (in shares)	10,491
Vested (in shares)	(13,248)
Forfeited (in shares)	0
Balance at the end of the period (in shares)	30,783	33,540
Restricted Stock and Stock Units, Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 38.73
Granted (in dollars per share) | $ / shares	85.78
Vested (in dollars per share) | $ / shares	39.16
Forfeited (in dollars per share) | $ / shares	0
Balance at the end of the period (in dollars per share) | $ / shares	$ 54.58	$ 38.73
Time-Vesting RSUs
Additional disclosures
Unrecognized compensation cost, net of expected forfeitures | $	$ 3.4
Weighted-average period over which cost is expected to be recognized	2 years 10 months 24 days
Forfeiture rate (as a percent)	0.90%
Restricted Stock and Stock Units, Number of Shares
Fair value of restricted shares vested | $	$ 1.3	$ 1.0	$ 1.3
Time-Vesting RSUs | Minimum
Additional disclosures
Number of vesting installments | installment	4
Time-Vesting RSUs | Maximum
Additional disclosures
Number of vesting installments | installment	5
Time-Vesting RSUs | 2006 Incentive Plan
Restricted Stock and Stock Units, Number of Shares
Balance at the beginning of the period (in shares)	84,989
Granted (in shares)	26,563
Vested (in shares)	(29,171)
Forfeited (in shares)	0
Balance at the end of the period (in shares)	82,381	84,989
Restricted Stock and Stock Units, Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 45.93
Granted (in dollars per share) | $ / shares	61.90
Vested (in dollars per share) | $ / shares	44.79
Forfeited (in dollars per share) | $ / shares	0
Balance at the end of the period (in dollars per share) | $ / shares	$ 51.48	$ 45.93
PRSU
Additional disclosures
Vesting period (in years)	2 years
PRSU | Vesting on the fourth anniversary of date of grant
Additional disclosures
Vesting percentage	25.00%
PRSU | Vesting in the first year following performance period
Additional disclosures
Vesting percentage	75.00%
PRSU | Minimum
Additional disclosures
PRSUs performance measure (as a percent)	50.00%
PRSU | Maximum
Additional disclosures
PRSUs performance measure (as a percent)	125.00%
PRSU | 2006 Incentive Plan
Restricted Stock and Stock Units, Number of Shares
Balance at the beginning of the period (in shares)	90,580
Granted (in shares)	25,924
Vested (in shares)	(22,823)
Forfeited (in shares)	(300)
Balance at the end of the period (in shares)	93,381	90,580
Restricted Stock and Stock Units, Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 50.06
Granted (in dollars per share) | $ / shares	68.71
Vested (in dollars per share) | $ / shares	44.72
Forfeited (in dollars per share) | $ / shares	47.45
Balance at the end of the period (in dollars per share) | $ / shares	$ 56.55	$ 50.06
Additional disclosures
Achievement percentage (as a percent)	125.00%
1998 Employee Stock Purchase Plan (ESPP)
Additional disclosures
Number of shares authorized	243,000
Purchase price as a percentage of fair market value (as a percent)	85.00%
Offering period under the plan (in years)	1 year
Shares issued	0	0	0
Shares available for grant	211,777