Statements of Consolidated Balance Sheets - USD ($) $ in Millions		Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment
Plant		$ 29,816.1	$ 27,551.3
Accumulated depreciation and amortization		(8,104.1)	(7,708.7)
Net Property, Plant and Equipment	[1]	21,712.0	19,842.6
Investments and Other Assets
Unconsolidated affiliates		5.2	1.6
Available-for-sale debt securities (amortized cost of $178.2 and $166.7, allowance for credit losses of $0.9 and $0.9, respectively)		161.9	151.6
Other investments		76.4	71.0
Total Investments and Other Assets		243.5	224.2
Current Assets
Cash and cash equivalents		56.0	40.8
Restricted Cash		50.6	34.6
Accounts receivable		585.1	1,065.8
Allowance for credit losses		(15.5)	(23.9)
Accounts receivable, net		569.6	1,041.9
Gas inventory		297.8	531.7
Materials and supplies, at average cost		183.7	151.4
Electric production fuel, at average cost		60.0	68.8
Exchange gas receivable		37.8	128.1
Regulatory assets		217.8	233.2
Prepayments and other		162.6	210.0
Total Current Assets	[1]	1,815.4	2,584.3
Other Assets
Regulatory assets		2,277.5	2,347.6
Goodwill		1,485.9	1,485.9
Deferred charges and other		293.9	252.0
Total Other Assets		4,057.3	4,085.5
Total Assets		27,828.2	26,736.6
Stockholders' Equity
Common stock - $0.01 par value, 600,000,000 shares authorized; 413,324,607 and 412,142,602 shares outstanding, respectively		$ 4.2	$ 4.2
Preferred Stock, Shares Outstanding		902,500	1,302,500
Preferred stock - $0.01 par value, 20,000,000 shares authorized; 902,500 and 1,302,500 shares outstanding, respectively		$ 1,152.6	$ 1,546.5
Treasury stock		(99.9)	(99.9)
Additional paid-in capital		7,393.0	7,375.3
Retained deficit		(1,200.6)	(1,213.6)
Accumulated other comprehensive loss		(36.9)	(37.1)
Total NiSource Stockholders’ Equity		7,212.4	7,575.4
Noncontrolling interest in consolidated subsidiaries		556.9	326.4
Total Equity		7,769.3	7,901.8
Long-term debt, excluding amounts due within one year		11,011.3	9,523.6
Total Capitalization		18,780.6	17,425.4
Current Liabilities
Current portion of long-term debt		26.8	30.0
Short-term borrowings		2,219.9	1,761.9
Accounts payable		648.2	899.5
Dividends payable - common stock		103.8	0.0
Dividends payable - preferred stock		8.1	0.0
Customer deposits and credits		286.6	324.7
Taxes accrued		176.1	246.2
Interest accrued		150.4	138.4
Exchange gas payable		44.1	147.6
Regulatory liabilities		320.2	236.8
Asset Retirement Obligation		57.1	35.5
Accrued compensation and employee benefits		183.3	167.5
Obligations to renewable generation asset developer		0.0	347.2
Other accruals		170.8	325.2
Total Current Liabilities	[2]	4,395.4	4,660.5
Other Liabilities
Deferred income taxes		2,011.4	1,854.5
Accrued liability for postretirement and postemployment benefits		236.0	245.5
Regulatory liabilities		1,643.5	1,775.8
Asset retirement obligations		469.8	478.1
Other noncurrent liabilities		291.5	296.8
Total Other Liabilities	[2]	4,652.2	4,650.7
Total Capitalization and Liabilities		27,828.2	26,736.6
Joint Ventures
Property, Plant and Equipment
Net Property, Plant and Equipment		1,338.6
Current Assets
Total Current Assets		65.5	25.7
Current Liabilities
Total Current Liabilities		41.0	128.2
Other Liabilities
Total Other Liabilities		$ 55.0	$ 30.6

[1] Includes $1,338.6 million and $978.5 million at September 30, 2023 and December 31, 2022, respectively, of net property, plant and equipment assets and $65.5 million and $25.7 million at September 30, 2023 and December 31, 2022, respectively, of current assets of consolidated VIEs that may be used only to settle obligations of the consolidated VIEs. Refer to Note 11, "Variable Interest Entities," for additional information.

[2] Includes $41.0 million and $128.2 million at September 30, 2023 and December 31, 2022, respectively, of current liabilities and $55.0 million and $30.6 million at September 30, 2023 and December 31, 2022, respectively, of other liabilities of consolidated VIEs that creditors do not have recourse to our general credit. Refer to Note 11, "Variable Interest Entities," for additional information.