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	5,750,000
Sale of private units	270,000

Total number of units sold, net of underwriting discounts.

No definition available.

Name:	HHHHU_SaleOfUnitsNetOfUnderwritingDiscountsShares
Namespace Prefix:	HHHHU_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration