Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 24, 2011	Jun. 25, 2011	Mar. 26, 2011	Dec. 29, 2012	Dec. 31, 2011	Dec. 25, 2010
Numerator:
Net income from continuing operations	$ 15,249	$ 19,756	$ 16,106	$ 15,294	$ 15,157	$ 15,016	$ 12,881	$ 13,148	$ 66,405	$ 56,202	$ 48,101
Net income (loss) from discontinued operations	51	586	3,636	284	1,487	(3,516)	(134)	(762)	4,557	(2,925)	(1,963)
Net income	$ 15,300	$ 20,342	$ 19,742	$ 15,578	$ 16,644	$ 11,500	$ 12,747	$ 12,386	$ 70,962	$ 53,277	$ 46,138
Denominator:
Weighted average basic shares outstanding									36,124	35,866	35,534
Effect of compensation awards									370	504	698
Weighted average diluted shares outstanding									36,494	36,370	36,232
Basic:
Net income from continuing operations									$ 1.84	$ 1.57	$ 1.35
Net income (loss) from discontinued operations									$ 0.12	$ (0.08)	$ (0.06)
Net income									$ 1.96	$ 1.49	$ 1.29
Diluted:
Net income from continuing operations									$ 1.82	$ 1.55	$ 1.33
Net income (loss) from discontinued operations									$ 0.12	$ (0.08)	$ (0.06)
Net income	$ 0.42	$ 0.56	$ 0.54	$ 0.43	$ 0.46	$ 0.32	$ 0.35	$ 0.34	$ 1.94	$ 1.47	$ 1.27