Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 6,095	$ 30,343
Accounts receivable:
Trade, net of allowance for bad debt of $428 and $405, respectively	75,067	22,680
Accrued revenue and other	121,218	143,197
Fair value of derivative assets	4,336	2,867
Natural gas and natural gas liquids, prepaid expenses and other	15,110	9,965
Assets held for disposition	22,822	0
Total current assets	244,648	209,052
Property and equipment, net of accumulated depreciation of $473,433 and $406,773, respectively	1,395,812	1,242,890
Fair value of derivative assets	750	0
Intangible assets, net of accumulated amortization of $242,205 and $199,248, respectively	446,105	451,462
Goodwill	150,630	0
Investment in limited liability company	88,761	35,000
Other assets, net	27,168	24,212
Total assets	2,353,874	1,962,616
Current liabilities:
Accounts payable, drafts payable, and other	39,906	22,549
Accrued gas and crude oil purchases	99,526	106,233
Fair value of derivative liabilities	860	5,587
Other current liabilities	59,274	66,567
Accrued interest	15,326	24,918
Liabilities held for disposition	2,261	0
Total current liabilities	217,153	225,854
Long-term debt	970,331	798,409
Other long-term liabilities	31,922	23,919
Deferred tax liability	137,416	85,187
Fair value of derivative liabilities	12	0
Stockholders Equity	997,040	829,247
Total liabilities and stockholders' equity	$ 2,353,874	$ 1,962,616