Earnings Per Share (CPE Inc. Only) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Numerator for calculation of diluted earnings per share:
Net income			$ 20,104	$ 60,296
Denominator for basic income per share - weighted-average shares outstanding	60,629	60,015	60,619	60,011
Denominator for diluted earnings per share (in shares)	61,165	60,870	61,123	60,826
Diluted earnings per share (in dollars per share)	$ 0.08	$ 0.55	$ 0.33	$ 0.99
CPE Inc
Numerator for calculation of diluted earnings per share:
Net income	$ 4,709	$ 33,678	$ 20,104	$ 60,296
Denominator for basic income per share - weighted-average shares outstanding	60,629	60,015	60,619	60,011
Dilutive effect of stock equivalents (in shares)	536	855	504	815
Denominator for diluted earnings per share (in shares)	61,165	60,870	61,123	60,826
Diluted earnings per share (in dollars per share)	$ 0.08	$ 0.55	$ 0.33	$ 0.99
CPE Inc \| Restricted stock and units
Anti-dilutive securities excluded from diluted earnings per share calculation
Number of anti-dilutive securities excluded		6	36	110
CPE Inc \| Options outstanding
Anti-dilutive securities excluded from diluted earnings per share calculation
Number of anti-dilutive securities excluded	68		98
CPE Inc \| Employee stock purchase plan
Anti-dilutive securities excluded from diluted earnings per share calculation
Number of anti-dilutive securities excluded		7	56	3

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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- Definition

The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

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