Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Jan. 31, 2016	Jun. 30, 2015
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2015
Entity Registrant Name	SemGroup Corporation
Entity Central Index Key	0001489136
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 3,466,750,226
Entity Current Reporting Status	No
Entity Voluntary Filers	No
Class A [Member]
Entity Common Stock, Shares Outstanding		43,932,174
Class B
Entity Common Stock, Shares Outstanding		0