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- Definition

Employee Service Share Based Compensation Fair Values Of Each Nonvested Awards

+ References

No definition available.

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- Definition

Estimated Payout Percentage

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No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

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Benefit Plans (Fair Values Of Nonvested Performance Shares And Units) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Performance Shares [Member]
Defined Benefit Plan Disclosure [Line Items]
Nonvested awards (in shares/awards)	144,215	144,424	139,940	145,277
Performance Units [Member]
Defined Benefit Plan Disclosure [Line Items]
Nonvested awards (in shares/awards)	58,206	63,665	65,912	64,969
2015 Grant [Member] \| Performance Shares [Member]
Defined Benefit Plan Disclosure [Line Items]
Nonvested awards (in shares/awards)	45,403
Alliant Energy common stock closing price on December 31, 2015 (in dollars per share)	$ 62.45
Estimated payout percentage based on performance criteria	80.00%
Fair values of each nonvested award (in dollars per share)	$ 49.96
2015 Grant [Member] \| Performance Units [Member]
Defined Benefit Plan Disclosure [Line Items]
Nonvested awards (in shares/awards)	17,386
Alliant Energy common stock closing price on grant date (in dollars per share)	$ 65.09
Estimated payout percentage based on performance criteria	80.00%
Fair values of each nonvested award (in dollars per share)	$ 52.07
2014 Grant [Member] \| Performance Shares [Member]
Defined Benefit Plan Disclosure [Line Items]
Nonvested awards (in shares/awards)	49,719
Alliant Energy common stock closing price on December 31, 2015 (in dollars per share)	$ 62.45
Estimated payout percentage based on performance criteria	125.00%
Fair values of each nonvested award (in dollars per share)	$ 78.06
2014 Grant [Member] \| Performance Units [Member]
Defined Benefit Plan Disclosure [Line Items]
Nonvested awards (in shares/awards)	19,440
Alliant Energy common stock closing price on grant date (in dollars per share)	$ 53.77
Estimated payout percentage based on performance criteria	125.00%
Fair values of each nonvested award (in dollars per share)	$ 67.21
2013 Grant [Member] \| Performance Shares [Member]
Defined Benefit Plan Disclosure [Line Items]
Nonvested awards (in shares/awards)	49,093
Alliant Energy common stock closing price on December 31, 2015 (in dollars per share)	$ 62.45
Estimated payout percentage based on performance criteria	165.00%
Fair values of each nonvested award (in dollars per share)	$ 103.04
2013 Grant [Member] \| Performance Units [Member]
Defined Benefit Plan Disclosure [Line Items]
Nonvested awards (in shares/awards)	21,380
Alliant Energy common stock closing price on grant date (in dollars per share)	$ 47.58
Estimated payout percentage based on performance criteria	165.00%
Fair values of each nonvested award (in dollars per share)	$ 78.51