Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 10, 2021	Jun. 30, 2020
Cover page. [Abstract]
Document type	10-K
Document annual report	true
Document period end date	Dec. 31, 2020
Current fiscal year end date	--12-31
Document transition report	false
Entity file number	000-50600
Entity registrant name	Blackbaud, Inc.
Entity incorporation, state or country code	DE
Entity tax identification number	11-2617163
Entity address, address line one	65 Fairchild Street
Entity address, city or town	Charleston
Entity address, state or province	SC
Entity address, postal zip code	29492
City area code	843
Local phone number	216-6200
Title of 12(b) security	Common Stock, $0.001 Par Value
Trading symbol	BLKB
Security exchange name	NASDAQ
Entity well-known seasoned issuer	Yes
Entity voluntary filers	No
Entity current reporting status	Yes
Entity interactive data current	Yes
Entity filer category	Large Accelerated Filer
Entity small business	false
Entity emerging growth company	false
ICFR auditor attestation flag	true
Entity shell company	false
Entity public float			$ 2,458,658,098
Entity common stock, shares outstanding		48,381,440
Documents incorporated by reference	Portions of the registrant's definitive Proxy Statement for the 2021 Annual Meeting of Stockholders currently scheduled to be held June 9, 2021 are incorporated by reference into Part III hereof. Such definitive Proxy Statement will be filed with the U.S. Securities and Exchange Commission no later than 120 days after the conclusion of the registrant's fiscal year ended December 31, 2020.
Amendment flag	false
Document fiscal year focus	2020
Document fiscal period focus	FY
Entity central index key	0001280058