Cover Page - USD ($)	11 Months Ended
	Dec. 31, 2019	Mar. 19, 2020
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	Haymaker Acquisition Corp. II
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001771908
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Shell Company	true
Entity Filer Category	Non-accelerated Filer
Entity Address, State or Province	NY
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Public Float	$ 402,000,000
Common Units [Member]
Document Information [Line Items]
Trading Symbol	HYACU
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock
Common Class A [Member]
Document Information [Line Items]
Trading Symbol	HYAC
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock
Entity Common Stock, Shares Outstanding		40,000,000
Warrant [Member]
Document Information [Line Items]
Trading Symbol	HYACW
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		10,000,000