Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Deferred tax liabilities:
Property-related	$ 13,094	$ 12,204
Pension	454	455
Nuclear decommissioning trusts	253	219
Net unrealized gains on derivatives	581	528
Investments in partnerships and joint ventures	603	403
Other	1,272	1,196
Total deferred tax liabilities	16,257	15,005
Deferred tax assets and valuation allowance:
Decommissioning reserves	454	438
Postretirement benefits	145	141
Net operating loss carryforwards	427	604
Tax credit carryforwards	3,059	2,916
ARO and accrued asset removal costs	777	759
Other	1,024	836
Valuation allowance(a)	(269)	(223)
Net deferred tax assets	5,617	5,471
Net deferred income taxes	10,640	9,534
Deferred tax assets and liabilities included in the consolidated balance sheets [Abstract]
Noncurrent other assets	461	293
Deferred income taxes - noncurrent liabilities	(11,101)	(9,827)
Net deferred income taxes	(10,640)	(9,534)
FPL [Member]
Deferred tax liabilities:
Property-related	8,882	8,040
Pension	502	480
Nuclear decommissioning trusts	0	0
Net unrealized gains on derivatives	0	0
Investments in partnerships and joint ventures	0	0
Other	796	695
Total deferred tax liabilities	10,180	9,215
Deferred tax assets and valuation allowance:
Decommissioning reserves	401	386
Postretirement benefits	93	95
Net operating loss carryforwards	3	4
Tax credit carryforwards	0	0
ARO and accrued asset removal costs	699	697
Other	443	303
Valuation allowance(a)	0	0
Net deferred tax assets	1,639	1,485
Net deferred income taxes	8,541	7,730
Deferred tax assets and liabilities included in the consolidated balance sheets [Abstract]
Noncurrent other assets	0	0
Deferred income taxes - noncurrent liabilities	(8,541)	(7,730)
Net deferred income taxes	$ (8,541)	$ (7,730)