Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 44,124	$ 2,976
Accounts receivable:
Trade, net of allowance for bad debt of $890 and $535, respectively	66,571	63,690
Accrued revenue and other	133,303	155,828
Fair value of derivative assets	3,288	3,234
Natural gas and natural gas liquids inventory, prepaid expenses and other	23,298	11,866
Assets held for disposition	0	22,599
Total current assets	270,584	260,193
Property and equipment, net of accumulated depreciation of $550,075 and $504,442, respectively	1,721,486	1,472,161
Fair value of derivative assets	112	0
Intangible assets, net of accumulated amortization of $286,061 and $263,305, respectively	402,248	425,005
Goodwill	153,802	152,627
Investment in limited liability company	99,354	90,500
Other assets, net	28,651	25,989
Total assets	2,676,237	2,426,475
Current liabilities:
Accounts payable, drafts payable and other	26,481	32,265
Accrued gas and crude oil purchases	129,902	140,344
Fair value of derivative liabilities	673	1,310
Other current liabilities	91,501	71,916
Accrued Interest	27,089	26,712
Liabilities held for disposition	0	3,572
Total current liabilities	275,646	276,119
Long-term debt	992,665	1,036,305
Other long-term liabilities	28,732	30,256
Deferred tax liability	127,460	133,555
Commitments and contingencies
Stockholders' Equity	1,251,734	950,240
Total liabilities and stockholders' equity	$ 2,676,237	$ 2,426,475