Document And Entity Information	6 Months Ended
	Jun. 30, 2013
Document Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Entity Registrant Name	Southern Union Co
Entity Central Index Key	0000203248
Document Period End Date	Jun. 30, 2013
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	0