XML 78 R80.htm IDEA: XBRL DOCUMENT

Supplemental Oil and Gas Reserve Information (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Standardized Measure [Abstract]
Future cash inflows	$ 5,085,122	$ 4,701,004	$ 3,058,637
Future costs, production	(1,819,356)	(1,558,067)	(1,127,744)
Future costs, development	(651,292)	(510,709)	(308,420)
Future costs, income taxes	(673,686)	(757,253)	(455,980)
Future net cash flows	1,940,788	1,874,975	1,166,493
10% discount factor	(1,000,957)	(936,462)	(482,055)
Standardized measure of discounted net cash flows	$ 939,831	$ 938,513	$ 684,438

This is the amount that is derived from using a discount rate of ten percent a year to reflect the timing of the future net cash flows relating to proved oil and gas reserves.

+ References+ Details

- Definition

The estimated future income tax expenses that will be incurred based on the future income less future expenses derived from production and sale of proved oil and gas reserves in this geographic region.

+ References+ Details

- Definition

These amounts are the result of subtracting future development and production costs and future income tax expenses from future cash inflows for each geographic region where proved oil and gas reserves exist.

+ References+ Details