Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 55,440	$ 122,474
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	57,478	49,610
Accretion of asset retirement obligations	3,490	2,697
Recognition of unit-based awards	3,185	768
General and administrative expense contributed by affiliates		18,019
Unrealized gains on derivative contracts	(19,807)	(76,880)
Other items	2,999	2,371
Changes in operating assets and liabilities:
Accounts receivable and other assets	(14,108)	(3,566)
Accounts payable and other liabilities	4,542	2,341
Net cash provided by operating activities	93,219	117,834
Cash flows from investing activities:
Additions to oil and gas properties	(39,028)	(76,721)
Acquistions	(2,210)	(225,118)
Net cash used in investing activities	(41,238)	(301,839)
Cash flows from financing activities:
Proceeds from issuance of units	80	162,195
Management incentive fee to the General Partner	(748)	(1,730)
Distributions to unitholders	(70,752)	(45,351)
Distributions to the Predecessor		(18,884)
Proceeds from bank borrowings	15,000	96,500
Repayments on bank borrowings	(5,000)
Deferred financing costs	(1,826)	(3,608)
Other	(905)	(21)
Net cash provided by (used in) financing activities	(64,151)	189,101
Increase (decrease) in cash	(12,170)	5,096
Cash at beginning of period	31,836	17,433
Cash at end of period	$ 19,666	$ 22,529