GOODWILL

Goodwill represents the excess of the cost of an acquisition over the fair value of the identifiable net assets acquired. The following table shows changes to our goodwill balances by segment during the years ended December 31, 2018 and 2017:



	Wisconsin				Illinois				Other States				Non-Utility Energy Infrastructure					Total
(in millions)	2018		2017		2018		2017		2018		2017		2018			2017		2018			2017
Goodwill balance as of January 1	$	2,104.3	$	2,104.3	$	758.7	$	758.7	$	183.2	$	183.2	$	7.3		$	—	$	3,053.5		$	3,046.2
Acquisition of Bluewater ⁽¹⁾	—		—		—		—		—		—		—			7.3		—			7.3
Adjustment to Bluewater purchase price allocation ⁽¹⁾	—		—		—		—		—		—		(0.7		)	—		(0.7		)	—
Goodwill balance as of December 31 ⁽²⁾	$	2,104.3	$	2,104.3	$	758.7	$	758.7	$	183.2	$	183.2	$	6.6		$	7.3	$	3,052.8		$	3,053.5


⁽¹⁾	See Note 2, Acquisitions, for more information on the acquisition of Bluewater.


⁽²⁾	We had no accumulated impairment losses related to our goodwill as of December 31, 2018.

In the third quarter of 2018, annual impairment tests were completed at all of our reporting units that carried a goodwill balance as of July 1, 2018. No impairments resulted from these tests.