Statements of Consolidated Comprehensive Income - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net (Loss) Income		$ (27.7)	$ 78.2	$ 247.6	$ 344.4
Net unrealized (loss) gain on available-for-sale securities	[1]	(1.2)	0.5	(0.3)	0.8
Net unrealized gain on cash flow hedges	[2]	0.7	0.7	1.6	1.3
Unrecognized pension and OPEB (cost) benefit	[3]	2.7	(0.1)	2.9	0.1
Total other comprehensive income		2.2	1.1	4.2	2.2
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		(25.5)	79.3	251.8	346.6
Less: Net income attributable to noncontrolling interest		8.7	0.0	15.6	0.0
Comprehensive (Loss) Income attributable to NiSource		$ (34.2)	$ 79.3	$ 236.2	$ 346.6

[1] Net unrealized (loss) gain on available-for-sale securities, net of $0.7 million tax benefit and $0.2 million tax expense in the second quarter of 2015 and 2014, respectively, and $0.2 million tax benefit and $0.4 million tax expense for the first six months of 2015 and 2014, respectively.

[2] Net unrealized gains on derivatives qualifying as cash flow hedges, net of $0.5 million and $0.4 million tax expense in the second quarter of 2015 and 2014, respectively, and $0.9 million and $0.8 million tax expense for the first six months of 2015 and 2014, respectively.

[3] Unrecognized pension and OPEB benefit (cost), net of $2.3 million tax expense and $0.7 million tax benefit in the second quarter of 2015 and 2014, respectively, and $2.2 million and $0.7 million tax expense for the first six months of 2015 and 2014, respectively.