Long-Term Debt (Partnership's Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Long-Term Debt Disclosure [Abstract]
Senior notes	$ 1,355,147	$ 856,061
Revolving loans	332,000	285,000
Total	1,687,147	1,141,061
Less: current portion	0	0
Long-term debt, net	1,687,147	1,141,061
Total credit facility limit	900,000	900,000
Revolving loans	(332,000)	(285,000)
Letters of credit	(19,000)	(16,015)
Total available	$ 549,000	$ 598,985