Unaudited Condensed Consolidated Statement of Partners' Equity (USD $) In Thousands, unless otherwise specified	Total	Limited Partners [Member]	General Partner [Member]	Special L.P. Interests [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Translation Adjustment [Member]	Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Beginning balance, value at Dec. 31, 2012	$ 154,451	$ 177,660	$ 1	$ 5,290		$ (2,751)	$ (25,749)
Beginning balance, units at Dec. 31, 2012		55,618
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Limited partnership unit options exercised		3
Issuance of limited partnership units as compensation		93
Net income	128,688	128,687	1
Partnership distribution declared ($1.88 per limited partnership unit)		(104,458)
Expense recognized for limited partnership unit options		680
Limited partnership unit options exercised		43
Tax effect of units involved in option exercises and treasury unit transactions		(148)
Issuance of limited partnership units as compensation		3,964
Weighted average limited partner units outstanding	55,472
Current period activity, net of tax ($1,125) at Sep. 29, 2013	7,803						7,803
Ending balance, value at Sep. 29, 2013	192,217	206,428	2	5,290	(19,503)	(1,557)	(17,946)
Current period activity, net of tax ($689) at Sep. 29, 2013	$ 1,194					$ 1,194
Ending balance, units at Sep. 29, 2013		55,714