v3.26.1
N-2
6 Months Ended
May 31, 2026
Cover [Abstract]  
Entity Central Index Key 0001400897
Amendment Flag false
Entity Inv Company Type N-2
Document Type N-CSRS
Entity Registrant Name NXG Cushing Midstream Energy Fund
Capital Stock, Long-Term Debt, and Other Securities [Abstract]  
Document Period End Date May 31, 2026