Acquisitions (Tables)

6 Months Ended

Jun. 30, 2013

Business Combinations [Abstract]

Allocation of Recorded Value of Net Assets Acquired in Transaction

The following represents the allocation of the recorded value of net assets acquired in the transaction.

	(in millions)
Proved oil and gas properties.	$	39.2
Unevaluated oil and gas properties.		1.6
Asset retirement obligations.		(14.4	)
Total fair value of net assets.	$	26.4