Segment Information - Schedule of Segment Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | |
Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Dec. 31, 2015 |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | $ 726.7 | $ 693.8 | $ 2,038.5 | $ 2,067.4 | |
Total interest charges | 43.9 | 46.1 | 133.6 | 140.4 | |
Net income (loss) from continuing operations | 69.4 | 64.9 | 148.6 | 190.2 | |
Income (loss) from discontinued operations, net | 0 | (11.7) | (0.1) | (67.2) | |
Net income | 69.4 | 53.2 | 148.5 | 123 | |
Total assets | 9,223.7 | | 9,223.7 | | $ 8,933.5 |
Tampa Electric Company [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 689.1 | 648.2 | 1,838.9 | 1,844.9 | |
Total interest charges | 26.1 | 27.8 | 79.8 | 82 | |
Net income | 100.6 | 88.3 | 239.6 | 226.4 | |
Total assets | 7,953.8 | | 7,953.8 | | 7,708.6 |
Tampa Electric Company [Member] | Intracompany Sales [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | 0 | 0 | 0 | 0 | |
Eliminations [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | (1.3) | (2.8) | (9.9) | (7) | |
Total interest charges | (0.2) | (0.3) | (0.7) | (1) | |
Net income (loss) from continuing operations | 0 | 0 | 0 | 0 | |
Income (loss) from discontinued operations, net | 0 | 0 | 0 | 0 | |
Net income | 0 | 0 | 0 | 0 | |
Total assets | (2,444.9) | | (2,444.9) | | (2,381.2) |
Eliminations [Member] | Tampa Electric Company [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | (0.5) | (2.1) | (7.5) | (4.8) | |
Total interest charges | 0 | 0 | (0.1) | 0 | |
Net income | 0 | 0 | 0 | 0 | |
Total assets | (452.6) | | (452.6) | | (431.3) |
Eliminations [Member] | Tampa Electric Company [Member] | Intracompany Sales [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | (0.5) | (2.1) | (7.5) | (4.8) | |
Revenues - External [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 726.7 | 693.8 | 2,038.5 | 2,067.4 | |
Revenues - External [Member] | Tampa Electric Company [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 689.1 | 648.2 | 1,838.9 | 1,844.9 | |
Revenues - External [Member] | Eliminations [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 0 | 0 | 0 | 0 | |
Revenues - External [Member] | Eliminations [Member] | Tampa Electric Company [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 0 | 0 | 0 | 0 | |
Sales to Affiliates [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | 0 | 0 | 0 | 0 | |
Sales to Affiliates [Member] | Eliminations [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | (1.3) | (2.8) | (9.9) | (7) | |
Tampa Electric [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 585.9 | 560.2 | 1,509.6 | 1,543.2 | |
Total interest charges | 22.4 | 24.1 | 68.8 | 71.2 | |
Net income (loss) from continuing operations | 94.1 | 82.1 | 212.9 | 198 | |
Income (loss) from discontinued operations, net | 0 | 0 | 0 | 0 | |
Net income | 94.1 | 82.1 | 212.9 | 198 | |
Total assets | 7,244.9 | | 7,244.9 | | 7,003.8 |
Tampa Electric [Member] | Operating Segments [Member] | Tampa Electric Company [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 585.9 | 560.2 | 1,509.6 | 1,543.2 | |
Total interest charges | 22.4 | 24.1 | 68.8 | 71.2 | |
Net income | 94.1 | 82.1 | 212.9 | 198 | |
Total assets | 7,244.9 | | 7,244.9 | | 7,003.8 |
Tampa Electric [Member] | Operating Segments [Member] | Tampa Electric Company [Member] | Intracompany Sales [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | 0 | 0.1 | 0.7 | 0.3 | |
Tampa Electric [Member] | Revenues - External [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 585.1 | 559.4 | 1,506.6 | 1,540.8 | |
Tampa Electric [Member] | Revenues - External [Member] | Operating Segments [Member] | Tampa Electric Company [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 585.9 | 560.1 | 1,508.9 | 1,542.9 | |
Tampa Electric [Member] | Sales to Affiliates [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | 0.8 | 0.8 | 3 | 2.4 | |
PGS [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 103.7 | 90.1 | 336.8 | 306.5 | |
Total interest charges | 3.7 | 3.7 | 11.1 | 10.8 | |
Net income (loss) from continuing operations | 6.5 | 6.2 | 26.7 | 28.4 | |
Income (loss) from discontinued operations, net | 0 | 0 | 0 | 0 | |
Net income | 6.5 | 6.2 | 26.7 | 28.4 | |
Total assets | 1,161.5 | | 1,161.5 | | 1,136.1 |
PGS [Member] | Operating Segments [Member] | Tampa Electric Company [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 103.7 | 90.1 | 336.8 | 306.5 | |
Total interest charges | 3.7 | 3.7 | 11.1 | 10.8 | |
Net income | 6.5 | 6.2 | 26.7 | 28.4 | |
Total assets | 1,161.5 | | 1,161.5 | | 1,136.1 |
PGS [Member] | Operating Segments [Member] | Tampa Electric Company [Member] | Intracompany Sales [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | 0.5 | 2 | 6.8 | 4.5 | |
PGS [Member] | Revenues - External [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 103.3 | 88.1 | 330 | 302 | |
PGS [Member] | Revenues - External [Member] | Operating Segments [Member] | Tampa Electric Company [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 103.2 | 88.1 | 330 | 302 | |
PGS [Member] | Sales to Affiliates [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | 0.4 | 2 | 6.8 | 4.5 | |
New Mexico Gas Co. [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 35.7 | 43.7 | 194 | 216.7 | |
Total interest charges | 2.8 | 3.2 | 9.1 | 9.8 | |
Net income (loss) from continuing operations | (19.8) | (2.8) | (4.8) | 11 | |
Income (loss) from discontinued operations, net | 0 | 0 | 0 | 0 | |
Net income | (19.8) | (2.8) | (4.8) | 11 | |
Total assets | 1,230.4 | | 1,230.4 | | 1,229.7 |
New Mexico Gas Co. [Member] | Revenues - External [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 35.7 | 43.7 | 194 | 216.7 | |
New Mexico Gas Co. [Member] | Sales to Affiliates [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | 0 | 0 | 0 | 0 | |
TECO Coal [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 0 | 0 | 0 | 0 | |
Total interest charges | 0 | 0 | 0 | 0 | |
Net income (loss) from continuing operations | 0 | 0 | 0 | 0 | |
Income (loss) from discontinued operations, net | 0 | (12.1) | 0 | (69.6) | |
Net income | 0 | (12.1) | 0 | (69.6) | |
Total assets | 0 | | 0 | | 0 |
TECO Coal [Member] | Revenues - External [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 0 | 0 | 0 | 0 | |
TECO Coal [Member] | Sales to Affiliates [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | 0 | 0 | 0 | 0 | |
Other [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 2.7 | 2.6 | 8 | 8 | |
Total interest charges | 15.2 | 15.4 | 45.3 | 49.6 | |
Net income (loss) from continuing operations | (11.4) | (20.6) | (86.2) | (47.2) | |
Income (loss) from discontinued operations, net | 0 | 0.4 | (0.1) | 2.4 | |
Net income | (11.4) | (20.2) | (86.3) | (44.8) | |
Total assets | 2,031.8 | | 2,031.8 | | $ 1,945.1 |
Other [Member] | Revenues - External [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Total revenues | 2.6 | 2.6 | 7.9 | 7.9 | |
Other [Member] | Sales to Affiliates [Member] | Operating Segments [Member] | | | | | |
Segment Reporting Information [Line Items] | | | | | |
Sales to affiliates/Intracompany sales | $ 0.1 | $ 0 | $ 0.1 | $ 0.1 | |