Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 27, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-35547
Entity Incorporation, State or Country Code	DE
Trading Symbol	MDRX
Entity Registrant Name	ALLSCRIPTS HEALTHCARE SOLUTIONS, INC.
Entity Tax Identification Number	36-4392754
Entity Central Index Key	0001124804
Entity Address, Address Line One	222 Merchandise Mart Plaza
Entity Address, Address Line Two	Suite 2024
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60654
City Area Code	800
Local Phone Number	334-8534
Title of 12(b) Security	Common Stock, par value $0.01 per share
Security Exchange Name	NASDAQ
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		162,700,920
Entity Public Float			$ 1,893,913,552
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement related to its 2020 annual meeting of stockholders (the “2020 Proxy Statement”) are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. The 2020 Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates