Number Of Trading Days Consider For Average Closing Price

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Percentage Of Performance Share Awards Based On Shareholder Return

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Rights Received For Each Performance Share Unit1

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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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Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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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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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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 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 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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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.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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Equity-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Oct. 19, 2017 shares	May 22, 2017	Sep. 30, 2017 shares	Dec. 31, 2017 USD ($) day $ / shares shares	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)				16,050,000
Stock-based compensation expense \| $				$ 26,534	$ 24,103	$ 25,272
Associated tax benefit \| $				$ 6,300	8,300	8,700
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Stock-based compensation expense \| $				$ 19,500	20,000	21,400
Fair value of awards vested \| $				$ 22,000	$ 6,900	$ 9,500
PSUs that vested in period (shares)				1,676,735
Weighted average grant date fair value of awards granted (in dollars per share) \| $ / shares				$ 15.03	$ 5.63	$ 14.28
Unrecognized expense \| $				$ 23,200
Unrecognized expense recognition period				1 year 10 months 24 days
Restricted unit awards granted (shares)				1,639,560
Performance share unit awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense \| $				$ 6,700	$ 4,200	$ 3,900
Fair value of awards vested \| $					$ 1,000	$ 800
PSUs that vested in period (shares)				0
Weighted average grant date fair value of awards granted (in dollars per share) \| $ / shares				$ 16.89	$ 3.00	$ 11.20
Unrecognized expense \| $				$ 7,600
Unrecognized expense recognition period				2 years 7 months 6 days
Right to received shares of common stock				1
Grant date fair value amortization term					4 years	4 years
Number of trading days \| day				30
Restricted unit awards granted (shares)				509,800
Performance share unit awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSU granted percentage of earnings				0.00%
Grant date fair value amortization term				2 years
Performance share unit awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSU granted percentage of earnings				200.00%
Grant date fair value amortization term				4 years
Restricted unit awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense \| $				$ 100
PSUs that vested in period (shares)				0
Weighted average grant date fair value of awards granted (in dollars per share) \| $ / shares				$ 17.00
Unrecognized expense \| $				$ 100
Unrecognized expense recognition period				8 months 12 days
Restricted unit awards granted (shares)				11,766
Phantom units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSUs that vested in period (shares)				0
Weighted average grant date fair value of awards granted (in dollars per share) \| $ / shares				$ 16.40
Restricted unit awards granted (shares)				101,500
OMP [Member] \| Restricted unit awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted unit awards granted (shares)			11,766
Vesting period		10 years
Long Term Incentive Plan (LTIP) \| OMP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)				1,842,500
Long Term Incentive Plan (LTIP) \| OMP [Member] \| Restricted unit awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			1 year
Long Term Incentive Plan (LTIP) \| Oasis Midstream Partners, LP [Member] \| Phantom units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense recognition period				2 years 9 months 18 days
Restricted unit awards granted (shares)	101,500
Vesting period	3 years
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options \| $				$ 1,600