Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income	$ 173.5	$ 130.4	$ 197.7
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	350.2	341.9	329.5
Depreciation and amortization	349.0	315.3	291.8
Deferred income taxes and investment tax credits	117.5	89.4	110.1
Allowance for other funds used during construction	(17.4)	(10.5)	(6.3)
Non-cash stock compensation	13.1	12.7	13.5
Loss (gain) on disposals of business/assets, pretax	13.2	(0.2)	(1.6)
Deferred recovery clauses	26.4	(15.2)	(6.2)
Asset impairment	78.6	115.9	0.0
Receivables, less allowance for uncollectibles	36.0	(36.6)	(4.5)
Inventories	(22.6)	12.8	1.1
Prepayments and other current assets/deposits	(8.0)	2.8	(2.2)
Taxes accrued	(15.9)	1.1	1.4
Interest accrued	(3.6)	7.3	(1.3)
Accounts payable	(61.6)	23.4	35.9
Other	(69.8)	(10.4)	(8.5)
Cash flows from operating activities	609.6	664.8	658.6
Cash flows from investing activities
Capital expenditures	(739.7)	(703.8)	(526.1)
Purchase of NMGI, net of cash acquired	0.0	(751.5)	0.0
Net proceeds from sales of business/assets	0.0	0.2	4.3
Other investments	(0.3)	(7.9)	0.0
Cash flows used in investing activities	(740.0)	(1,463.0)	(521.8)
Cash flows from financing activities
Dividends paid	(211.7)	(199.2)	(191.2)
Proceeds from the sale of common stock	7.3	302.3	6.7
Proceeds from long-term debt issuance	499.7	563.6	0.0
Repayment of long-term debt/Purchase in lieu of redemption	(274.5)	(83.3)	(51.6)
Net change in short-term debt	108.0	55.0	84.0
Cash flows from/(used in) financing activities	128.8	638.4	(152.1)
Net increase (decrease) in cash and cash equivalents	(1.6)	(159.8)	(15.3)
Cash and cash equivalents at beginning of the year	25.4	185.2	200.5
Cash and cash equivalents at end of the year	23.8	25.4	185.2
Supplemental disclosure of cash flow information
Interest	179.6	161.3	161.0
Income taxes paid	14.5	2.9	1.8
Supplemental disclosure of non-cash activities
Debt assumed in NMGI acquisition	0.0	200.0	0.0
Change in accrued capital expenditures	8.0	13.3	4.7
Tampa Electric Company [Member]
Cash flows from operating activities
Net income	276.3	260.3	225.6
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	313.5	302.6	290.3
Deferred income taxes and investment tax credits	118.9	92.2	118.1
Allowance for other funds used during construction	(17.2)	(10.5)	(6.3)
Loss (gain) on disposals of business/assets, pretax	3.1	0.0	0.0
Deferred recovery clauses	26.5	(16.2)	(6.2)
Receivables, less allowance for uncollectibles	(3.0)	0.4	(13.8)
Inventories	(21.3)	13.1	(9.0)
Prepayments and other current assets/deposits	(4.0)	1.5	0.0
Taxes accrued	(17.2)	11.8	(34.3)
Interest accrued	(0.1)	0.6	(0.9)
Accounts payable	(26.8)	5.9	34.8
Other	(40.8)	(14.5)	(2.8)
Cash flows from operating activities	607.9	647.2	595.5
Cash flows from investing activities
Capital expenditures	(686.6)	(671.0)	(501.3)
Net proceeds from sale of assets	0.0	0.0	0.1
Cash flows used in investing activities	(686.6)	(671.0)	(501.2)
Cash flows from financing activities
Dividends paid	(268.4)	(262.6)	(222.1)
Proceeds from the sale of common stock	175.0	100.0	60.0
Proceeds from long-term debt issuance	251.1	296.3	0.0
Repayment of long-term debt/Purchase in lieu of redemption	(83.3)	(83.3)	(51.6)
Net change in short-term debt	3.0	(26.0)	84.0
Cash flows from/(used in) financing activities	77.4	24.4	(129.7)
Net increase (decrease) in cash and cash equivalents	(1.3)	0.6	(35.4)
Cash and cash equivalents at beginning of the year	10.4	9.8	45.2
Cash and cash equivalents at end of the year	9.1	10.4	9.8
Supplemental disclosure of cash flow information
Interest	106.2	102.5	102.4
Income taxes paid	63.7	52.6	56.4
Supplemental disclosure of non-cash activities
Change in accrued capital expenditures	$ 6.9	$ 14.3	$ 4.7