Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2011 Hydraulic fracturing services contract	Jun. 30, 2011 Natural gas gathering and services agreement
Commitments and Contingencies
Number of commitments		2
Contract term, maximum (in years)		10
Aggregate deficiency payments		$ 729.4
Commitment amount	180.0
Commitment term (in years)	two years
Maximum liability upon early termination	$ 24.0

Total financial obligation resulting from inability to meet long-term contractual delivery obligations.

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- Definition

Represents the maximum liability upon early termination of long term purchase commitment contract.

+ Details

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- Definition

Represents the number of long-term purchase commitments of the entity.

+ Details

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- Definition

The maximum term of the contract that is applicable to the existing commitments.

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- Definition

The minimum amount the entity agreed to spend under the long-term purchase commitment.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

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- Definition

Specifies the time period covered by the arrangement.

+ Details

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