v3.26.1
Shareholder Report
 6 Months Ended
Jun. 30, 2026
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name BNY Mellon Large Cap Securities Fund, Inc.
Entity Central Index Key 0000030146
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2026
C000000105 [Member]  
Shareholder Report [Line Items]  
Fund Name BNY Mellon Large Cap Securities Fund, Inc.
Class Name BNY Mellon Large Cap Securities Fund, Inc.
Trading Symbol DREVX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about BNY Mellon Large Cap Securities Fund, Inc. (the “Fund”) for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at bny.com/investments/literaturecenter. You can also request this information by calling 1-800-373-9387 (inside the U.S. only) or by sending an e-mail request to info@bny.com.
Additional Information Phone Number 1-800-373-9387
Additional Information Email info@bny.com
Additional Information Website bny.com/investments/literaturecenter
Expenses [Text Block]
What were the Fund’s costs for the last six months ?
(based on a hypothetical $10,000 investment)
Fund Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment
BNY Mellon Large Cap Securities Fund, Inc. $35 0.68%*
*
Annualized.
Expenses Paid, Amount $ 35
Expense Ratio, Percent 0.68% [1]
Net Assets $ 2,408,000,000
Holdings Count | Holding 51
Investment Company Portfolio Turnover 16.34%
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (AS OF 6/30/26 )

Fund Size (Millions)
Number of Holdings
Portfolio Turnover
$2,408 51 16.34%
Holdings [Text Block]
Portfolio Holdings (as of 6/30/26 )
Top Ten Holdings (Based on Net Assets) *
Graphical Representation - Top N Holdings Chart
* Excludes money market funds or other short-term securities held for the investment of cash and cash collateral for securities loaned, if any.
Sector Allocation (Based on Net Assets)
Graphical Representation - Allocation 1 Chart
Largest Holdings [Text Block]
Top Ten Holdings (Based on Net Assets) *
Graphical Representation - Top N Holdings Chart
* Excludes money market funds or other short-term securities held for the investment of cash and cash collateral for securities loaned, if any.
[1] Annualized.