Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax liabilities:
Property-related	$ 9,315	$ 9,030
Pension	374	364
Investments in partnerships and joint ventures	1,925	442
Other	1,505	1,370
Total deferred tax liabilities	13,119	11,206
Deferred tax assets and valuation allowance:
Decommissioning reserves	313	306
Net operating loss carryforwards	350	482
Tax credit carryforwards	3,259	3,126
ARO and accrued asset removal costs	310	210
Regulatory liabilities	1,277	1,267
Other	751	720
Valuation allowance	(273)	(252)
Net deferred tax assets	5,987	5,859
Net deferred income taxes	7,132	5,347
Deferred tax assets and liabilities included in the consolidated balance sheets [Abstract]
Noncurrent other assets	235	417
Deferred income taxes - noncurrent liabilities	(7,367)	(5,764)	[1]
Net deferred income taxes	(7,132)	(5,347)
FPL[Member]
Deferred tax liabilities:
Property-related	6,113	6,045
Pension	357	342
Investments in partnerships and joint ventures	0	0
Other	791	584
Total deferred tax liabilities	7,261	6,971
Deferred tax assets and valuation allowance:
Decommissioning reserves	278	271
Net operating loss carryforwards	3	3
Tax credit carryforwards	0	0
ARO and accrued asset removal costs	237	146
Regulatory liabilities	1,283	1,273
Other	295	273
Valuation allowance	0	0
Net deferred tax assets	2,096	1,966
Net deferred income taxes	5,165	5,005
Deferred tax assets and liabilities included in the consolidated balance sheets [Abstract]
Noncurrent other assets	0	0
Deferred income taxes - noncurrent liabilities	(5,165)	(5,005)	[2]
Net deferred income taxes	$ (5,165)	$ (5,005)

[1] Amounts have been retrospectively adjusted as discussed in Note 14.

[2] Amounts have been retrospectively adjusted as discussed in Note 14.