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 (loss)	$ (5,104)	$ 2,769
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	33,745	32,196
(Gain) loss on sale of property and other assets	11	(98)
Deferred tax benefit	(1,781)	(738)
Non-cash stock-based compensation	5,106	2,564
Non-cash portion of derivatives (gain) loss	(643)	1,143
Distribution of earnings from limited liability company	3,328	0
Amortization of debt issue costs	1,533	1,247
Amortization of discount on notes	474	474
Changes in assets and liabilities:
Accounts receivable, accrued revenue and other	12,975	34,949
Natural gas and natural gas liquids, prepaid expenses and other	(2,511)	(5,817)
Accounts payable, accrued gas and crude oil purchases and accrued liabilities	(36,640)	(57,642)
Net cash provided by operating activities	10,493	11,047
Cash flows from investing activities:
Additions to property and equipment	(121,284)	(36,269)
Acquisition	0	0
Proceeds from sale of property	18,005	121
Investment in limited liability company	(12,980)	(4,860)
Distribution from limited liability company in excess of earnings	1,185	0
Net cash used in investing activities	(115,074)	(41,008)
Cash flows from financing activities:
Proceeds from borrowings	77,500	169,000
Payments on borrowings	(114,500)	(115,000)
Payments on capital lease obligations	(801)	(762)
Decrease in drafts payable	(1,156)	(2,651)
Debt refinancing costs	(2,506)	(1,240)
Conversion of restricted stock for common, net of shares withheld for taxes	(1,196)	(734)
Distributions to non-controlling partners in the Partnership	(20,652)	(16,037)
Contributions from non-controlling partners	408	0
Common dividends	(5,846)	(5,366)
Issuance of common units by the Partnership	185,528	0
Conversion of restricted units, net of units withheld for taxes	(1,259)	(980)
Proceeds from exercise of Partnership unit options	371	178
Net cash provided by financing activities	115,891	26,408
Net decrease in cash and cash equivalents	11,310	(3,553)
Cash and cash equivalents, beginning of period	2,976	30,343
Cash and cash equivalents, end of period	14,286	26,790
Cash paid for interest	33,730	34,183
Cash paid for income taxes	$ 70	$ 0