XML 95 R60.htm IDEA: XBRL DOCUMENT v3.8.0.1
Fair Value Measurements (Reconciliation of Change in Fair Value of Derivatives, Significant Unobservable Inputs) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Realized and unrealized gains (losses):      
Realized and unrealized gains (losses) reflected in operating revenues $ 379 $ 397 $ 462
Unrealized gains (losses) reflected in operating revenues, for derivatives still held at the reporting date 281 283 289
Derivative Financial Instruments, Net [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Fair value of derivatives based on significant unobservable inputs beginning balance 578 538 622
Realized and unrealized gains (losses):      
Realized and unrealized gains (losses) included in earnings 376 333 451
Realized and unrealized gains (losses) included in other comprehensive income (loss) (18) 8 11
Realized and unrealized gains (losses) included in regulatory assets and liabilities 0 1 3
Purchases 126 261 180
Settlements (317) (390) (473)
Issuances (197) (195) (202)
Transfers in(c) 17 19 (13)
Transfers out(c) 1 3 (41)
Fair value of derivatives based on significant unobservable inputs ending balance 566 578 538
The amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to derivatives still held at the reporting date(d) 277 219 277
FPL[Member] | Derivative Financial Instruments, Net [Member]      
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]      
Fair value of derivatives based on significant unobservable inputs beginning balance 1 0 5
Realized and unrealized gains (losses):      
Realized and unrealized gains (losses) included in earnings 0 0 0
Realized and unrealized gains (losses) included in other comprehensive income (loss) 0 0 0
Realized and unrealized gains (losses) included in regulatory assets and liabilities 0 1 3
Purchases 0 0 0
Settlements (1) 0 (8)
Issuances 0 0 0
Transfers in(c) 0 0 0
Transfers out(c) 0 0 0
Fair value of derivatives based on significant unobservable inputs ending balance 0 1 0
The amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to derivatives still held at the reporting date(d) $ 0 $ 0 $ 0