v3.26.1
Shareholder Report
 12 Months Ended
Jun. 30, 2026
USD ($)
shares
Shareholder Report [Line Items]  
Document Type N-CSR
Amendment Flag false
Registrant Name The North Carolina Capital Management Trust
Entity Central Index Key 0000702149
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2026
North Carolina Capital Management Trust - Government Portfolio  
Shareholder Report [Line Items]  
Fund Name Government Portfolio
Class Name Government Portfolio
Trading Symbol NCCTX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains information about Government Portfolio for the period July 1, 2025 to June 30, 2026.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at fundresearch.fidelity.com/prospectus/sec. You can also request this information by contacting us at 1-800-222-3232.
Additional Information Phone Number 1-800-222-3232
Additional Information Website fundresearch.fidelity.com/prospectus/sec
Expenses [Text Block] What were your Fund costs for the last year?
(based on hypothetical $10,000 investment)
 
FUND COST (PREVIOUS YEAR)
 
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
 
Government Portfolio 
$ 14 
0.14%
  
Expenses Paid, Amount $ 14
Expense Ratio, Percent 0.14%
Net Assets $ 20,859,629,655
Holdings Count | shares 573
Advisory Fees Paid, Amount $ 45,135,495
Additional Fund Statistics [Text Block] Key Fund Statistics
(as of June 30, 2026)
 
KEY FACTS
 
  
  
Fund Size
$20,859,629,655
  
Number of Holdings
573
  
Total Advisory Fee
$45,135,495
  
Holdings [Text Block]   EFFECTIVE MATURITY DIVERSIFICATION (% of Fund's net assets)   Days   1-7 52.5   8-30 9.8   31-60 7.6   61-90 8.5   91-180 16.8   >180 5.4             U.S. Treasury Obligations 41.3 U.S. Government Agency - Debt 32.2 Repurchase Agreements 27.1 ASSET ALLOCATION (% of Fund's net assets)     U.S. Treasury Obligations - 41.3           U.S. Government Agency - Debt - 32.2       Repurchase Agreements - 27.1             Net Other Assets (Liabilities) - (0.6)%