v3.25.1

Cover	Jun. 02, 2025
Document Information [Line Items]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Jun. 02, 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	true
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
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
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

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The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

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ISO 3166-1 alpha-2 country code.

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Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

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The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Trading symbol of an instrument as listed on an exchange.

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Black Spade Acquisition II Co 8-K