CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011		Sep. 30, 2010
Revenue:
Firm storage	$ 82.7	$ 86.4	[1]	$ 80.5	[1]
Transportation	28.4	14.0	[1]	12.1	[1]
Hub services	14.9	6.5	[1]	1.6	[1]
Related party firm storage (Note 8)	11.8	4.0	[1]	0.5	[1]
Salt	52.0	52.3	[1]	52.2	[1]
Revenues	189.8	163.2	[1]	146.9	[1]
Costs and expenses:
Storage related	5.9	9.0	[1]	5.2	[1]
Transportation related	5.2	6.8	[1]	6.8	[1]
Salt related	30.3	30.6	[1]	30.0	[1]
Operating and administrative	30.4	19.4	[1]	19.2	[1]
Depreciation and amortization	50.5	43.9	[1]	42.4	[1]
Loss on disposal of assets	0	0	[1]	0.9	[1]
Costs and Expenses, Total	122.3	109.7	[1]	104.5	[1]
Operating income	67.5	53.5	[1]	42.4	[1]
Other income	0	0	[1]	0.8	[1]
Interest expense, net	1.8	0	[1]	0	[1]
Net income	65.7	53.5	[1]	43.2	[1]
Net income attributable to non-controlling partners	0	0	[1]	(0.8)	[1]
Net income attributable to partners	65.7	53.5	[1]	42.4	[1]
Less: net income prior to initial public offering of Inergy Midstream, L.P.	12.9
Less: net income earned by US Salt, LLC prior to acquisition (Note 10)	7.8
Net income available to partners	45.0
Partners' interest information:
Non-managing general partner interest in net income	1.9
Total limited partners' interest in net income	$ 43.1
Net income per limited partner unit:
Basic	$ 0.58
Diluted	$ 0.58
Weighted-average limited partners' units (in thousands)
Basic	74,768
Diluted	74,768

[1] Retrospectively adjusted as described in Note 1.