Supplemental Cash Flow Information (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013
Supplemental Cash Flow Information [Abstract]
Cash paid during the period for interest	$ 25,834		$ 22,647
Change in accrued capital expenditures	(496)		11,565
Amortization of increasing rate distributions	8,018	[1]	7,697	[1]
Recognition of deferred Class B unit obligations	$ 141,777

[1] Amortization of increasing rate distributions is offset in the preferred unitholders’ capital account by a non-cash distribution