XML 88 R90.htm IDEA: XBRL DOCUMENT

Supplemental Oil and Natural Gas Disclosures (Unaudited) (Costs Incurred in Oil and Natural Gas Activities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property acquisitions.
Proved	$ 491,041	$ 86,465	$ 3,373,450
Unevaluated	115,270	17,858	1,297,695
Exploration	12,019	31,483	8,728
Development	1,111,314	1,144,243	658,758
Total costs incurred	$ 1,729,644	$ 1,280,049	$ 5,338,631

- Definition

Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have proved reserves.

+ References+ Details

- Definition

Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have unproved reserves.

+ References+ Details

- Definition

Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

+ References+ Details

- Definition

Exploration costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

+ References+ Details