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The threshold value of the common units that were cancelled as a part of the corporate reorganization.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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Net number of non-option equity instruments granted to participants.

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Number of additional shares authorized for issuance under an established share-based compensation plan.

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Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of shares issued during the period upon the conversion of units. An example of a convertible unit is an umbrella partnership real estate investment trust unit (UPREIT unit).

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Equity-based Compensation (Details) - USD ($) $ / shares in Units, shares in Thousands				1 Months Ended			12 Months Ended			72 Months Ended
	May 17, 2011	May 16, 2011	May 11, 2011	Jan. 31, 2017	Jun. 30, 2015	May 31, 2011	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016
Compensation agreement
Tax shortfall related to equity-based compensation							$ 5,504,000	$ 18,603,000	$ 6,547,000
LTIP
Compensation agreement
Compensation expense recognized							40,100,000	75,100,000	74,500,000
Tax benefit							13,000,000	25,700,000	25,700,000
Tax shortfall related to equity-based compensation							$ 5,500,000	$ 18,600,000	$ 6,500,000
Other disclosures
Additional shares authorized					15,000
Approved and authorized awards (in shares)					39,500
Number of shares remaining available for grant							8,300			8,300
Minimum \| LTIP
Equity-based Compensation
Vesting period							3 years
Maximum \| LTIP
Equity-based Compensation
Vesting period							4 years
Service Vesting Restricted Stock Awards \| LTIP
Weighted-Average Grant-Date Fair Value for awards
Granted (in dollars per share)								$ 8.64
Outstanding unvested awards activity
Outstanding at the beginning of the period (in shares)				488			810	3,240	6,384
Granted (in shares)								660
Forfeited (in shares)								(2)	(122)
Vested (in shares)							(322)	(3,088)	(3,022)
Outstanding at the end of the period (in shares)							488	810	3,240	488
Weighted-Average Grant-Date Fair Value
Outstanding at beginning of the period (in dollars per share)				$ 8.83			$ 9.20	$ 16.95	$ 16.48
Granted (in dollars per share)								8.64
Forfeited (in dollars per share)								12.84	15.20
Vested (in dollars per share)							9.77	17.21	16.02
Outstanding at the end of the period (in dollars per share)							$ 8.83	$ 9.20	$ 16.95	$ 8.83
Market/Service Vesting Restricted Stock Awards \| LTIP
Outstanding unvested awards activity
Outstanding at the beginning of the period (in shares)							261	3,361	3,438
Forfeited (in shares)							(162)	(1,554)	(77)
Vested (in shares)							(99)	(1,546)
Outstanding at the end of the period (in shares)								261	3,361
Weighted-Average Grant-Date Fair Value
Outstanding at beginning of the period (in dollars per share)							$ 9.44	$ 13.00	$ 12.95
Forfeited (in dollars per share)							9.44	13.29	10.74
Vested (in dollars per share)							9.44	13.30
Outstanding at the end of the period (in dollars per share)								9.44	13.00
Market/Service Vesting Restricted Stock Awards \| Minimum \| LTIP
Weighted-Average Grant-Date Fair Value for awards
Granted (in dollars per share)							6.70
Weighted-Average Grant-Date Fair Value
Granted (in dollars per share)							6.70
Significant assumptions used to calculate fair values
Expected volatility (as a percent)										41.30%
Risk-free interest rate (as a percent)										0.50%
Market/Service Vesting Restricted Stock Awards \| Maximum \| LTIP
Weighted-Average Grant-Date Fair Value for awards
Granted (in dollars per share)							13.57
Weighted-Average Grant-Date Fair Value
Granted (in dollars per share)							$ 13.57
Significant assumptions used to calculate fair values
Expected volatility (as a percent)										56.70%
Risk-free interest rate (as a percent)										1.10%
Other disclosures
Vesting percentage of the awards granted							100.00%
Service Vesting Restricted Stock Units \| LTIP
Outstanding awards activity
Granted (in shares)				1,800
Weighted-Average Grant-Date Fair Value for awards
Granted (in dollars per share)							$ 4.05	$ 8.37	$ 10.80
Outstanding unvested awards activity
Outstanding at the beginning of the period (in shares)				4,160			3,592	3,367	2,238
Granted (in shares)							2,158	1,539	2,113
Forfeited (in shares)							(134)	(254)	(412)
Vested (in shares)							(1,456)	(1,060)	(572)
Outstanding at the end of the period (in shares)							4,160	3,592	3,367	4,160
Weighted-Average Grant-Date Fair Value
Outstanding at beginning of the period (in dollars per share)				$ 6.91			$ 9.79	$ 10.76	$ 10.74
Granted (in dollars per share)							4.05	8.37	10.80
Forfeited (in dollars per share)							8.87	10.14	10.90
Vested (in dollars per share)							9.61	10.71	10.74
Outstanding at the end of the period (in dollars per share)							6.91	9.79	10.76	$ 6.91
Market/Service Vesting Restricted Stock Units \| LTIP
Outstanding awards activity
Granted (in shares)				2,100
Weighted-Average Grant-Date Fair Value for awards
Granted (in dollars per share)							$ 4.88	$ 12.96	$ 15.71
Outstanding unvested awards activity
Outstanding at the beginning of the period (in shares)				7,194			6,578	3,246	1,858
Granted (in shares)							1,379	3,544	1,572
Forfeited (in shares)							(70)	(212)	(184)
Vested (in shares)							(693)
Outstanding at the end of the period (in shares)							7,194	6,578	3,246	7,194
Weighted-Average Grant-Date Fair Value
Outstanding at beginning of the period (in dollars per share)				$ 12.29			$ 14.24	$ 15.66	$ 15.59
Granted (in dollars per share)							4.88	12.96	15.71
Forfeited (in dollars per share)							14.49	14.48	15.48
Vested (in dollars per share)							15.81
Outstanding at the end of the period (in dollars per share)							12.29	$ 14.24	$ 15.66	$ 12.29
Market/Service Vesting Restricted Stock Units \| Minimum \| LTIP
Weighted-Average Grant-Date Fair Value for awards
Granted (in dollars per share)							4.83
Weighted-Average Grant-Date Fair Value
Granted (in dollars per share)							$ 4.83
Significant assumptions used to calculate fair values
Expected volatility (as a percent)							44.00%
Risk-free interest rate (as a percent)										0.50%
Market/Service Vesting Restricted Stock Units \| Maximum \| LTIP
Weighted-Average Grant-Date Fair Value for awards
Granted (in dollars per share)							$ 15.81
Weighted-Average Grant-Date Fair Value
Granted (in dollars per share)							$ 15.81
Significant assumptions used to calculate fair values
Expected volatility (as a percent)										54.00%
Risk-free interest rate (as a percent)										1.20%
Other disclosures
Vesting percentage of the awards granted							200.00%
Restricted Stock Awards and Restricted Stock Units
Weighted-Average Grant-Date Fair Value
Compensation expense not yet recognized							$ 31,600,000			$ 31,600,000
Weighted average period over which compensation expense is to be recognized							1 year 3 months 18 days
Restricted Stock Awards and Restricted Stock Units \| LTIP
Compensation agreement
Fair value of awards vested							$ 14,400,000	$ 52,200,000	$ 37,000,000
Profit units \| Kosmos Energy Holdings
Equity-based Compensation
Vesting period		4 years
Weighted-Average Grant-Date Fair Value for awards
Granted (in dollars per share)	$ 17.00
Weighted-Average Grant-Date Fair Value
Granted (in dollars per share)	$ 17.00
Other disclosures
Number of common shares into which the units were exchanged						31,700
Incremental compensation costs						$ 0
Threshold value of awards cancelled (in dollars per unit)						$ 90
Profit units \| Kosmos Energy Holdings \| Employees
Equity-based Compensation
Vesting rights on the second and fourth anniversary of issuance date (as a percent)		50.00%
Profit units \| Kosmos Energy Holdings \| Founding Management and Directors
Equity-based Compensation
Vesting rights as of the date of issuance (as a percent)		20.00%
Additional vesting rights on the anniversary date for each of the next four years (as a percent)		20.00%
Profit units \| Kosmos Energy Holdings \| Minimum
Equity-based Compensation
Threshold value to employees, management and directors (in dollars per units)		$ 0.85
Significant assumptions used to calculate fair values
Expected volatility (as a percent)		25.00%
Risk-free interest rate (as a percent)		1.30%
Expected life			1 year 2 months 12 days
Profit units \| Kosmos Energy Holdings \| Minimum \| Employees
Significant assumptions used to calculate fair values
Projected turnover rate (as a percent)			7.00%
Profit units \| Kosmos Energy Holdings \| Maximum
Equity-based Compensation
Threshold value to employees, management and directors (in dollars per units)		$ 90
Significant assumptions used to calculate fair values
Expected volatility (as a percent)		66.00%
Risk-free interest rate (as a percent)		5.10%
Expected life			8 years 1 month 6 days
Profit units \| Kosmos Energy Holdings \| Maximum \| Employees
Significant assumptions used to calculate fair values
Projected turnover rate (as a percent)			27.00%
Restricted stock awards
Equity-based Compensation
Exchanged (in shares)						10,000
Restricted stock awards \| LTIP
Equity-based Compensation
Exchanged (in shares)						10,000
Restricted stock units \| LTIP
Weighted-Average Grant-Date Fair Value
Compensation expense not yet recognized				$ 34,100,000
Weighted average period over which compensation expense is to be recognized				3 years
Restructuring Charges.. \| LTIP
Compensation agreement
Compensation expense recognized									$ 5,000,000