The Cushing MLP & Infrastructure Total Return Fund (SRV) 424B2 17 May 24 Prospectus for primary offering Financial data

N-2

N-2 - USD ($)				3 Months Ended
		May 17, 2024	May 03, 2024	Feb. 29, 2024
Cover [Abstract]
Entity Central Index Key		0001400897
Amendment Flag		false
Document Type		424B2
Entity Registrant Name		NXG Cushing Midstream Energy Fund
Fee Table [Abstract]
Shareholder Transaction Expenses [Table Text Block]		Shareholder Transaction Expenses Sales load ( as a percentage of offering price 1.00% (1) Offering expenses borne by the Fund (as a percentage of offering price) 0.71% (2) Dividend Reinvestment Plan fees (per transaction sales fee) $ 15.00 (3)
Sales Load [Percent]	[1]	1%
Dividend Reinvestment and Cash Purchase Fees	[2]	$ 15
Other Transaction Expenses [Abstract]
Other Transaction Expenses [Percent]	[3]	0.71%
Annual Expenses [Table Text Block]		Annual Expenses Percentage of Net Assets (4) Management fees (5)(6) 1.52% Interest payments on borrowed funds (7) 1.46% Other expenses (8) 0.76% Total annual expenses 3.74% (1) Represents the estimated commission with respect to the Common Shares being sold under this Prospectus Supplement and the accompanying Prospectus. There is no guarantee that there will be any sales of Common Shares under this Prospectus Supplement and the accompanying Prospectus. Actual sales of Common Shares under this Prospectus Supplement and the accompanying Prospectus, if any, may be less than as set forth under “Capitalization” below. In addition, the price per Common Share of any such sale may be greater or less than the price set forth under “Capitalization” below, depending on market price of the Common Shares at the time of any such sale. (2) Assumes offering expenses of $50,000 and the sale of 175,000 Common Shares at a sales price per Common Share of $40.40, which represents the last reported sales price of the Common Shares on the NYSE on May 3, 2024. There is no guarantee that there will be any sales of Common Shares under this Prospectus Supplement and the accompanying Prospectus. Actual sales, if any, of the Common Shares under this Prospectus Supplement and the accompanying Prospectus may be at a price greater or less than $40.40 per Common Share, depending on the market price of the Common Shares at the time of any such sale. (3) There will be no brokerage charges with respect to Common Shares issued directly by the Fund. However, each participant will pay a pro rata share of brokerage commissions incurred in connection with open-market purchases. In addition, participants who request a sale of shares through the Plan Agent are subject to a $15.00 per transaction sales fee and pay a brokerage commission of $0.12 per share sold. The Fund’s transfer agent serves as Plan Agent. Fees paid by the Fund to the transfer agent are included in “Other expenses” below, which are ultimately borne by common shareholders. For additional information, see “Distribution Reinvestment Plan” in the accompanying Prospectus. (4) Based upon net assets attributable to common shares as of November 30, 2023. (5) The Fund pays the Investment Adviser an annual fee, payable monthly, in an amount equal to 1.25% of the Fund’s average weekly Managed Assets (net assets plus any assets attributable to Financial Leverage). The fee shown above is based upon outstanding Financial Leverage of 19% of the Fund’s Managed Assets (or 23% of the Fund’s net assets attributable to common shares). If Financial Leverage of more than 19% of the Fund’s Managed Assets (or 23% of the Fund’s net assets attributable to common shares) is used, the management fees, as a percentage of net assets attributable to common shares, would be higher than as shown above. (6) The Investment Adviser has contractually agreed to waive a portion of the management fee in an amount equal to 0.25% of the Fund's Managed Assets through February 1, 2025. The Fund’s annual expenses after giving effect to such management fee waiver are: Annual Expenses Percentage of Net Assets (4) Management fees (5) 1.52% Interest payments on borrowed funds (7) 1.46% Other expenses (8) 0.76% Total annual expenses (before fee waiver) 3.74% Fee Waiver (0.31)% Net annual expense (after fee waiver) 3.43% (7) Based upon the Fund’s outstanding borrowings as of November 30, 2023 of approximately $19.315 million and the interest rate as of November 30, 2023, of 6.46%. (8) “Other expenses” are estimated based upon those incurred during the fiscal year ended November 30, 2023. Other expenses do not include expense related to realized or unrealized investment gains or losses. See “Management of the Fund—Fund Expenses” in the accompanying Prospectus.
Management Fees [Percent]	[4],[5],[6]	1.52%
Interest Expenses on Borrowings [Percent]	[4],[7]	1.46%
Other Annual Expenses [Abstract]
Other Annual Expenses [Percent]	[4],[8]	0.76%
Total Annual Expenses [Percent]	[4]	3.74%
Expense Example [Table Text Block]		Example The following example illustrates the expenses that you would pay on a $1,000 investment in Common Shares, assuming (1) “Total annual expenses” of 3.74%, (2) the sales load of $10.00 and estimated offering expenses of $7.10, and (3) a 5% annual return*: 1 Year 3 Years 5 Years 10 Years Total Expenses Incurred $ 54 $ 130 $ 207 $ 409 * The example should not be considered a representation of future expenses or returns. Actual expenses may be higher or lower than those assumed. Moreover, the Fund’s actual rate of return may be higher or lower than the hypothetical 5% return shown in the example.
Expense Example, Year 01	[9]	$ 54
Expense Example, Years 1 to 3	[9]	130
Expense Example, Years 1 to 5	[9]	207
Expense Example, Years 1 to 10	[9]	$ 409
Purpose of Fee Table , Note [Text Block]		The following table contains information about the costs and expenses that Common Shareholders will bear directly or indirectly. The table is based on the capital structure of the Fund as of November 30, 2023 (except as noted below) after giving effect to the anticipated net proceeds of the Common Shares offered by this Prospectus Supplement and the accompanying Prospectus and assuming the Fund incurs the estimated offering expenses. If the Fund issues fewer than all of the Common Shares available for sale pursuant to the Distribution Agreement and the net proceeds to the Fund are less, all other things being equal, the total annual expenses shown would increase. The purpose of the table and the example below is to help you understand the fees and expenses that you, as a holder of Common Shares, would bear directly or indirectly.
Basis of Transaction Fees, Note [Text Block]		as a percentage of offering price
Other Transaction Fees, Note [Text Block]		There will be no brokerage charges with respect to Common Shares issued directly by the Fund. However, each participant will pay a pro rata share of brokerage commissions incurred in connection with open-market purchases. In addition, participants who request a sale of shares through the Plan Agent are subject to a $15.00 per transaction sales fee and pay a brokerage commission of $0.12 per share sold. The Fund’s transfer agent serves as Plan Agent. Fees paid by the Fund to the transfer agent are included in “Other expenses” below, which are ultimately borne by common shareholders. For additional information, see “Distribution Reinvestment Plan” in the accompanying Prospectus.
Other Expenses, Note [Text Block]		“Other expenses” are estimated based upon those incurred during the fiscal year ended November 30, 2023. Other expenses do not include expense related to realized or unrealized investment gains or losses. See “Management of the Fund—Fund Expenses” in the accompanying Prospectus.
General Description of Registrant [Abstract]
Share Price [Table Text Block]		Market Price Corresponding Net Asset Value Per Common Share Corresponding Premium/(Discount) as a Percentage of Net Asset Value Fiscal Quarter Ended High Low High Low High Low February 29, 2024 $37.86 $32.51 $37.71 $36.14 0.40% -10.04%
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Outstanding Securities [Table Text Block]		The following information regarding the Fund’s authorized shares is as of May 3, 2024: Title of Class Amount Authorized Amount Held by Fund Amount Outstanding Common Shares of Beneficial Interest Unlimited None 2,914,363
Common Shares [Member]
General Description of Registrant [Abstract]
Lowest Price or Bid				$ 32.51
Highest Price or Bid				37.86
Lowest Price or Bid, NAV				36.14
Highest Price or Bid, NAV				$ 37.71
Highest Price or Bid, Premium (Discount) to NAV [Percent]				0.40%
Lowest Price or Bid, Premium (Discount) to NAV [Percent]				(10.04%)
Share Price			$ 40.40
NAV Per Share			$ 40.49
Latest Premium (Discount) to NAV [Percent]			0.22%
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Outstanding Security, Title [Text Block]			Common Shares of Beneficial Interest
Outstanding Security, Held [Shares]			0
Outstanding Security, Not Held [Shares]			2,914,363
[1]Represents the estimated commission with respect to the Common Shares being sold under this Prospectus Supplement and the accompanying Prospectus. There is no guarantee that there will be any sales of Common Shares under this Prospectus Supplement and the accompanying Prospectus. Actual sales of Common Shares under this Prospectus Supplement and the accompanying Prospectus, if any, may be less than as set forth under “Capitalization” below. In addition, the price per Common Share of any such sale may be greater or less than the price set forth under “Capitalization” below, depending on market price of the Common Shares at the time of any such sale.[2] There will be no brokerage charges with respect to Common Shares issued directly by the Fund. However, each participant will pay a pro rata share of brokerage commissions incurred in connection with open-market purchases. In addition, participants who request a sale of shares through the Plan Agent are subject to a $15.00 per transaction sales fee and pay a brokerage commission of $0.12 per share sold. The Fund’s transfer agent serves as Plan Agent. Fees paid by the Fund to the transfer agent are included in “Other expenses” below, which are ultimately borne by common shareholders. For additional information, see “Distribution Reinvestment Plan” in the accompanying Prospectus. “Other expenses” are estimated based upon those incurred during the fiscal year ended November 30, 2023. Other expenses do not include expense related to realized or unrealized investment gains or losses. See “Management of the Fund—Fund Expenses” in the accompanying Prospectus.