CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 35,553	$ 30,244
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	5,767	5,438
Allowance for doubtful accounts	(14)	4
Amortization of deferred financing costs	238	238
Loss on disposition of fixed assets		7
Share-based compensation-Affiliates	1,186	1,124
Share-based compensation	93	122
Change in assets and liabilities:
Accounts receivable	(4,601)	3,637
Inventories	(3,275)	1,462
Prepaid expenses and other current assets	(229)	(414)
Other long-term assets	(82)	(82)
Accounts payable	(3,497)	3,274
Deferred revenue	27,639	7,004
Accrued expenses and other current liabilities	(1,229)	1,944
Other long-term liabilities	(64)	(188)
Net cash provided by operating activities	57,485	53,814
Cash flows from investing activities:
Capital expenditures	(18,063)	(22,274)
Net cash used in investing activities	(18,063)	(22,274)
Cash flows from financing activities:
Distributions to common unitholders-affiliates	(9,776)	(29,941)
Cash distribution to common unitholders-non-affiliates	(4,252)	(13,001)
Net cash used in financing activities	(14,028)	(42,942)
Net increase (decrease) in cash and cash equivalents	25,394	(11,402)
Cash and cash equivalents, beginning of period	127,848	236,975
Cash and cash equivalents, end of period	153,242	225,573
Supplemental disclosures:
Cash paid for income taxes	6
Cash paid for interest, net of capitalized interest of $422 and $545 in 2013 and 2012, respectively	1,064	1,300
Non-cash investing and financing activities:
Accrual of construction in progress additions	$ (8,495)	$ (2,970)