Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2011	Feb. 23, 2012	Jun. 30, 2011
Document and Entity Information [Line Items]
Entity registrant name	PROGRESS ENERGY INC
Entity central index key	0001094093
Document type	10-K
Document period end date	Dec. 31, 2011
Amendment flag	false
Entity current reporting status	Yes
Entity voluntary filers	No
Current fiscal year end date	--12-31
Entity filer category	Large Accelerated Filer
Entity well known seasoned issuer	Yes
Entity common stock shares outstanding		295,219,128
Entity public float			$ 14,107,388,747
Document fiscal year focus	2011
Document fiscal period focus	FY
PEC
Document and Entity Information [Line Items]
Entity registrant name	Carolina Power & Light Co
Entity central index key	0000017797
Current fiscal year end date	--12-31
Entity filer category	Non-accelerated Filer
PEF
Document and Entity Information [Line Items]
Entity registrant name	Florida Power Corp
Entity central index key	0000037637
Current fiscal year end date	--12-31
Entity filer category	Non-accelerated Filer