Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities
Net loss	$ (112,635)	$ (36,740)	$ (1,279)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization	140,285	162,300	125,358
Impairments	72,576	0	0
Non-cash stock-based compensation	14,383	9,483	7,556
(Gain) loss on sale of property and other assets	(1,055)	(3,328)	264
Deferred tax (benefit) expense	(18,003)	(8,384)	(4,540)
Loss on derivatives recognized in net loss	2,304	1,006	7,776
Cash Settlements On Derivative Financial Instruments	633	4,514	7,015
Interest paid-in-kind	1,766	0	0
Amortization of debt issue costs	6,457	5,377	6,462
Amortization of discount on notes	1,897	1,897	1,897
Distributions of earnings from limited liability company	3,296	0	0
Equity in income of limited liability company	(46)	(3,250)	0
Changes in Assets and Liabilities
Accounts receivable, accrued revenue and other	(75,359)	(39,120)	44,121
Natural gas and natural gas liquids, prepaid expenses and other	(2,880)	(4,015)	(1,507)
Accounts payable, accrued gas and crude oil purchases and other accrued liabilities	55,486	19,744	(37,800)
Net cash provided by operating activities	87,839	100,456	141,293
Cash Flows from Investing Activities
Additions to property and equipment	(560,784)	(234,849)	(97,572)
Acquisitions of business	0	(214,957)	0
Proceeds from sale of property	19,420	11,773	478
Investment in limited liability company	(30,594)	(52,250)	(35,000)
Distribution from limited liability company in excess of earnings	14,172	0	0
Net cash provided by (used in) investing activities	(557,786)	(490,283)	(132,094)
Cash Flows from Financing Activities
Proceeds from borrowings	558,126	806,500	471,250
Payments on borrowings	(397,622)	(570,500)	(393,308)
Payments on capital lease obligations	(3,266)	(3,112)	(3,122)
Increase (decrease) in drafts payable	9,320	(1,912)	5,854
Debt refinancing costs	(3,508)	(7,155)	(3,954)
Distributions to non-controlling interest in the Partnership	(91,497)	(69,839)	(58,209)
Contribution from Noncontrolling Interests	4,819	0	0
Common dividends paid	(24,044)	(22,925)	(17,872)
Conversion of restricted units, net of units withheld for taxes	(1,928)	(1,030)	(1,798)
Conversion of restricted stock, net of shares withheld for taxes	(2,087)	(794)	(1,068)
Proceeds from exercise of share options	146	0	0
Proceeds from issuance of partnership units	419,498	232,791	0
Proceeds from exercise of partnerhip unit options	835	436	591
Net cash provided by (used in) financing activities	468,792	362,460	(1,636)
Net increase (decrease) in cash and cash equivalents	(1,155)	(27,367)	7,563
Cash and cash equivalents, beginning of period	2,976	30,343	22,780
Cash and cash equivalents, end of period	1,821	2,976	30,343
Cash paid for interest	89,438	81,237	71,950
Cash paid for income taxes	$ 8,628	$ 1,706	$ 1,104