Income (Loss) Per Share (Details) - $ / shares	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Weighted Average Number of Shares Outstanding, Basic	49,557,748	50,554,234	50,080,234	50,462,990
Weighted Average Number Diluted Shares Outstanding Adjustment	0	45,740	0	221,735
Weighted Average Number of Shares Outstanding, Diluted	49,557,748	50,599,974	50,080,234	50,684,725
Earnings Per Share, Basic	$ (0.67)	$ 3.13	$ (1.87)	$ 2.62
Earnings Per Share, Diluted	$ (0.67)	$ 3.13	$ (1.87)	$ 2.61
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3,518,070	6,029,156	3,549,770	4,618,618
Maximum [Member]
Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount	$ 6.75	$ 6.75	$ 6.75	$ 6.75

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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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic net Income or Loss per outstanding limited partnership unit in the future and that were not included in the computation of diluted net income per limited partnership unit, because to do so would increase net income per unit amounts or decrease loss per unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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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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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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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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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.

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