v3.25.1
Cover
May 20, 2025
Document Information [Line Items]  
Document Type 8-K
Amendment Flag false
Document Period End Date May 20, 2025
Entity File Number 001-42258
Entity Registrant Name BLACK SPADE ACQUISITION II CO
Entity Central Index Key 0002025065
Entity Tax Identification Number 00-0000000
Entity Incorporation, State or Country Code E9
Entity Address, Address Line One Suite 2902
Entity Address, Address Line Two 29/F, The Centrium
Entity Address, Address Line Three 60 Wyndham Street
Entity Address, City or Town Central
Entity Address, Country HK
Entity Address, Postal Zip Code 00000
City Area Code 852
Local Phone Number 3955 1316
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company true
Elected Not To Use the Extended Transition Period false
Common Class A [Member]  
Document Information [Line Items]  
Title of 12(b) Security Class A ordinary shares, $0.0001 par value, included as part of the units
Trading Symbol BSII
Security Exchange Name NASDAQ
Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50, included as part of the units [Member]  
Document Information [Line Items]  
Title of 12(b) Security Redeemable warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50, included as part of the units
Trading Symbol BSIIW
Security Exchange Name NASDAQ
Units, each consisting of one Class A ordinary share and one-third of one redeemable warrant [Member]  
Document Information [Line Items]  
Title of 12(b) Security Units, each consisting of one Class A ordinary share and one-third of one redeemable warrant
Trading Symbol BSIIU
Security Exchange Name NASDAQ