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)	$ (8,174)	$ (8,226)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	30,815	24,284
Accretion of asset retirement obligations	1,732	1,322
Recognition of unit-based awards	1,026	420
General and administrative expense contributed by affiliates		8,612
Unrealized gains on derivative contracts	24,289	32,792
Other items	1,400	395
Changes in operating assets and liabilities:
Accounts receivable and other assets	(14,997)	4,094
Accounts payable and other liabilities	(2,169)	5,094
Net cash provided by operating activities	33,922	68,787
Cash flows from investing activities:
Additions to oil and gas properties	(18,507)	(33,211)
Acquistions	2,277	(11,500)
Net cash used in investing activities	(16,230)	(44,711)
Cash flows from financing activities:
Proceeds from issuance of units	80
Distributions to unitholders	(32,284)	(20,545)
Distributions to the Predecessor		(11,124)
Proceeds from bank borrowings		11,500
Deferred financing costs	(1,848)
Other	104	(21)
Net cash provided by (used in) financing activities	(33,948)	(20,190)
Increase (decrease) in cash and cash equivalents	(16,256)	3,886
Cash and cash equivalents at beginning of period	31,836	17,433
Cash and cash equivalents at end of period	$ 15,580	$ 21,319