Consolidated Statements of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Cash Flows [Abstract]
Net income from continuing operations	$ 48,400,000	$ 23,500,000
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	48,200,000	44,400,000
Accretion expense	200,000	100,000
Deferred tax benefit	23,700,000	(2,200,000)
Non-cash stock-based compensation	1,200,000	0
Derivative, Gain (loss) on Derivative, Net	1,300,000	0
Cash Paid On Derivative Not Recognized As Revenue	600,000	0
Amortization of debt issue costs	100,000	0
Amortization Of Premium On Notes	(400,000)	0
Distribution of earnings from equity investment	100,000	0
Income from equity investment	(4,200,000)	(1,000,000)
Changes in assets and liabilities:
Accounts receivable, accrued revenue and other	43,200,000	0
Natural gas and natural gas liquids, prepaid expenses and other	(7,700,000)	1,400,000
Accounts payable, accrued gas and crude oil purchases and other accrued liabilities	(35,000,000)	2,700,000
Net cash provided by operating activities	118,500,000	68,900,000
Cash flows from investing activities:
Additions to property and equipment	(97,800,000)	(99,900,000)
Acquisition of business	(50,300,000)	0
Distribution from limited liability company in excess of earnings	2,600,000	0
Net cash used in investing activities	(145,500,000)	(99,900,000)
Cash flows from financing activities:
Proceeds from borrowings	1,356,100,000	0
Payments on borrowings	(1,076,900,000)	0
Payments on capital lease obligations	(800,000)	0
Increase in drafts payable	(2,600,000)	0
Debt refinancing costs	(6,000,000)	0
Contributions by (distributions to) the partners	(22,100,000)	25,200,000
Contributions from noncontrolling Interests	500,000	0
Net cash provided by financing activities	248,200,000	25,200,000
Cash Provided by (Used in) Operating Activities, Discontinued Operations	5,000,000	4,700,000
Cash Provided by (Used in) Investing Activities, Discontinued Operations	(600,000)	(1,900,000)
Cash Provided by (Used in) Financing Activities, Discontinued Operations	(4,400,000)	(12,600,000)
Net Cash Provided by (Used in) Discontinued Operations	0	(9,800,000)
Net increase (decrease) in cash and cash equivalents	221,200,000	(15,600,000)
Cash and cash equivalents, beginning of period	0	15,600,000
Cash and cash equivalents, end of period	221,200,000	0
Cash paid for interest	$ 4,600,000	$ 0