Earnings per Unit (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013
Basic weighted average units outstanding	55,419	55,484	55,453	55,464	55,470	55,446
Effect of dilutive units:
Unit options and restricted unit awards	325	152	0	0	253	84
Phantom units	80	186	0	0	144	261
Diluted weighted average units outstanding	55,824	55,822	55,453	55,464	55,867	55,791
Net income (loss) per limited partner unit - basic	$ 0.79	$ 0.85	$ (0.71)	$ (1.11)	$ 2.35	$ 1.24
Net income (loss) per limited partner unit - diluted	$ 0.79	$ 0.85	$ (0.71)	$ (1.11)	$ 2.33	$ 1.24