Condensed Statements of Changes in Shareholders’ Equity (Parenthetical)	3 Months Ended
Mar. 31, 2019 shares
Statement of Stockholders' Equity [Abstract]
Sale of units, net of underwriting discounts and offering expenses	5,750,000
Sale of Private Units	270,000

Sale of units, net of underwriting discounts and offering expenses.

No definition available.

Name:	hhhhu_SaleOfUnitsNetOfUnderwritingDiscountsAndOfferingExpenses
Namespace Prefix:	hhhhu_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration