Derivative Instruments (Tables)

3 Months Ended

Mar. 31, 2019

Derivative Instruments [Line Items]

Notional Amounts Of Derivative Instruments

As of March 31, 2019, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):

	FTRs		Natural Gas		Coal		Diesel Fuel
	MWhs	Years	Dths	Years	Tons	Years	Gallons	Years
Alliant Energy	3,903	2019	158,337	2019-2026	10,042	2019-2021	2,268	2019
IPL	2,378	2019	68,345	2019-2026	4,429	2019-2021	—	—
WPL	1,525	2019	89,992	2019-2026	5,613	2019-2021	2,268	2019

Fair Value Of Financial Instruments

Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions):

	Alliant Energy				IPL				WPL
	March 31, 2019		December 31, 2018		March 31, 2019		December 31, 2018		March 31, 2019		December 31, 2018
Current derivative assets		$15.8		$24.6		$9.0		$16.1		$6.8		$8.5
Non-current derivative assets	5.9		3.7		2.9		1.6		3.0		2.1
Current derivative liabilities	3.6		5.6		2.1		3.1		1.5		2.5
Non-current derivative liabilities	12.1		17.7		5.0		8.1		7.1		9.6

IPL [Member]

Derivative Instruments [Line Items]

Notional Amounts Of Derivative Instruments

As of March 31, 2019, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):

	FTRs		Natural Gas		Coal		Diesel Fuel
	MWhs	Years	Dths	Years	Tons	Years	Gallons	Years
Alliant Energy	3,903	2019	158,337	2019-2026	10,042	2019-2021	2,268	2019
IPL	2,378	2019	68,345	2019-2026	4,429	2019-2021	—	—
WPL	1,525	2019	89,992	2019-2026	5,613	2019-2021	2,268	2019

Fair Value Of Financial Instruments

Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions):

	Alliant Energy				IPL				WPL
	March 31, 2019		December 31, 2018		March 31, 2019		December 31, 2018		March 31, 2019		December 31, 2018
Current derivative assets		$15.8		$24.6		$9.0		$16.1		$6.8		$8.5
Non-current derivative assets	5.9		3.7		2.9		1.6		3.0		2.1
Current derivative liabilities	3.6		5.6		2.1		3.1		1.5		2.5
Non-current derivative liabilities	12.1		17.7		5.0		8.1		7.1		9.6

WPL [Member]

Derivative Instruments [Line Items]

Notional Amounts Of Derivative Instruments

As of March 31, 2019, gross notional amounts and settlement/delivery years related to outstanding swap contracts, option contracts, physical forward contracts and FTRs that were accounted for as commodity derivative instruments were as follows (units in thousands):

	FTRs		Natural Gas		Coal		Diesel Fuel
	MWhs	Years	Dths	Years	Tons	Years	Gallons	Years
Alliant Energy	3,903	2019	158,337	2019-2026	10,042	2019-2021	2,268	2019
IPL	2,378	2019	68,345	2019-2026	4,429	2019-2021	—	—
WPL	1,525	2019	89,992	2019-2026	5,613	2019-2021	2,268	2019

Fair Value Of Financial Instruments

Derivative instruments are recorded at fair value each reporting date on the balance sheets as assets or liabilities as follows (in millions):

	Alliant Energy				IPL				WPL
	March 31, 2019		December 31, 2018		March 31, 2019		December 31, 2018		March 31, 2019		December 31, 2018
Current derivative assets		$15.8		$24.6		$9.0		$16.1		$6.8		$8.5
Non-current derivative assets	5.9		3.7		2.9		1.6		3.0		2.1
Current derivative liabilities	3.6		5.6		2.1		3.1		1.5		2.5
Non-current derivative liabilities	12.1		17.7		5.0		8.1		7.1		9.6