Share-Based Compensation - Restricted Shares and Other (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 28, 2019 USD ($) item $ / shares shares	Dec. 29, 2018 USD ($) $ / shares shares	Dec. 30, 2017 USD ($) shares
2006 Incentive Plan
Additional disclosures
Shares available for grant	623,212
Options
Additional disclosures
Fair value of options vested | $	$ 0.7	$ 1.1	$ 1.5
Unrecognized compensation cost, net of expected forfeitures | $	$ 0.5
Weighted-average period over which cost is expected to be recognized	2 years 6 months
Forfeiture rate (as a percent)		0.40%	0.40%
Restricted stock
Additional disclosures
Number of vesting installments | item	4
Unrecognized compensation cost, net of expected forfeitures | $	$ 0.9
Weighted-average period over which cost is expected to be recognized	2 years 7 months 6 days
Forfeiture rate (as a percent)	0.90%
Restricted Stock and Stock Units, Number of Shares
Fair value of restricted shares vested | $	$ 0.5	$ 0.6	$ 0.6
Restricted stock | 2006 Incentive Plan
Restricted Stock and Stock Units, Number of Shares
Balance at the beginning of the period (in shares)	36,006
Granted (in shares)	11,772
Vested (in shares)	(16,255)
Balance at the end of the period (in shares)	31,523	36,006
Restricted Stock and Stock Units, Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 35.41
Granted (in dollars per share) | $ / shares	38.21
Vested (in dollars per share) | $ / shares	31.14
Balance at the end of the period (in dollars per share) | $ / shares	$ 38.66	$ 35.41
Time-Vesting RSUs
Additional disclosures
Number of vesting installments | item	4
Unrecognized compensation cost, net of expected forfeitures | $	$ 2.4
Weighted-average period over which cost is expected to be recognized	3 years 1 month 6 days
Forfeiture rate (as a percent)	0.90%
Restricted Stock and Stock Units, Number of Shares
Fair value of restricted shares vested | $	$ 1.3	$ 1.7	$ 2.0
Time-Vesting RSUs | 2006 Incentive Plan
Restricted Stock and Stock Units, Number of Shares
Balance at the beginning of the period (in shares)	79,759
Granted (in shares)	31,226
Vested (in shares)	(45,858)
Forfeited (in shares)	(489)
Balance at the end of the period (in shares)	64,638	79,759
Restricted Stock and Stock Units, Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 33.64
Granted (in dollars per share) | $ / shares	46.20
Vested (in dollars per share) | $ / shares	27.91
Forfeited (in dollars per share) | $ / shares	21.52
Balance at the end of the period (in dollars per share) | $ / shares	$ 43.87	$ 33.64
PRSU
Additional disclosures
Vesting period	2 years
PRSU | Vesting in the first year following performance period
Additional disclosures
Vesting percentage	75.00%
PRSU | Vesting on the fourth anniversary of date of grant
Additional disclosures
Vesting percentage	25.00%
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)	121,950
Granted (in shares)	29,234
Vested (in shares)	(65,976)
Forfeited (in shares)	(3,058)
Balance at the end of the period (in shares)	82,150	121,950
Restricted Stock and Stock Units, Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share) | $ / shares	$ 32.92
Granted (in dollars per share) | $ / shares	51.31
Vested (in dollars per share) | $ / shares	25.27
Forfeited (in dollars per share) | $ / shares	28.77
Balance at the end of the period (in dollars per share) | $ / shares	$ 45.88	$ 32.92
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
Offering period (in years)	0 years	0 years	0 years
Shares issued	0	0	0
Shares available for grant	211,777