Segment Information - Additional Information (Detail)	Dec. 31, 2012 Customer
Tampa Electric [Member]
Segment Reporting Information [Line Items]
Number of retail electric utility service customers in West Central Florida	687,000
Number of residential, commercial, industrial and power generation customers for natural gas purchase and distribution	345,000
Tampa Electric [Member] | TAMPA ELECTRIC CO [Member]
Segment Reporting Information [Line Items]
Number of retail electric utility service customers in West Central Florida	687,000
PGS [Member] | TAMPA ELECTRIC CO [Member]
Segment Reporting Information [Line Items]
Number of residential, commercial, industrial and power generation customers for natural gas purchase and distribution	345,000