Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net income	$ 568	$ 1,808
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	65,085	61,326
Gain on sale of property	(504)	(80)
Deferred tax benefit	(1,871)	(2,009)
Non-cash stock-based compensation	5,113	4,115
Non-cash portion of derivatives (gain) loss	(5,975)	828
Amortization of debt issue costs	1,321	4,065
Amortization of discount on notes	948	948
Equity in loss of limited liability company	0	236
Changes in assets and liabilities:
Accounts receivable, accrued revenue and other	24,991	(10,657)
Natural gas and natural gas liquids, prepaid expenses and other	(8,971)	(5,378)
Accounts payable, accrued gas purchases and other accrued liabilities	(29,300)	8,640
Net cash provided by operating activities	51,405	63,842
Cash flows from investing activities:
Additions to property and equipment	(90,046)	(49,643)
Proceeds from sale of property	632	107
Investment in limited liability company	(52,250)	(35,000)
Net cash used in investing activities	(141,664)	(84,536)
Cash flows from financing activities:
Proceeds from borrowings	548,500	277,250
Payments on borrowings	(335,500)	(232,308)
Increase in restricted cash	(245,100)
Payments on capital lease obligations	(1,536)	(1,510)
Increase (decrease) in drafts payable	(5,985)	3,165
Debt refinancing costs	(4,962)	(3,792)
Conversion of restricted stock, net of shares withheld for taxes	(627)	(1,019)
Distributions to non-controlling partners in the Partnership	(32,583)	(27,320)
Common dividends	(11,221)	(8,192)
Issuance of common units by the Partnership	158,014
Conversion of restricted units, net of units withheld for taxes	(980)	(1,740)
Proceeds from exercise of Partnership unit options	95	392
Net cash provided by financing activities	68,113	4,926
Net decrease in cash and cash equivalents	(22,146)	(15,768)
Cash and cash equivalents, beginning of period	30,343	22,780
Cash and cash equivalents, end of period	8,197	7,012
Cash paid for interest	36,252	35,936
Cash paid for income taxes	$ 784	$ 752